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Qian Y, Tong Z, Cai B, Zhu W, Si M. Cleaning effects of decontamination methods on clinically failed TiUnite implants and their impacts on surface roughness and chemistry: An in vitro pilot study. Int J Oral Implantol (Berl) 2022; 15:149-165. [PMID: 35546724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
PURPOSE To evaluate the in vitro cleaning effects of different decontamination methods and their impacts on surface characteristics using clinically failed TiUnite implants (Nobel Biocare, Kloten, Switzerland). MATERIALS AND METHODS Thirty clinically failed TiUnite implants were treated using different decontamination methods. Group 1 (control group) received physiological saline irrigation; Group 2 underwent erythritol powder air polishing (AIRFLOW Master Piezon, EMS Dental, Nyon, Switzerland); Group 3 was treated with erythritol powder air polishing with ethylenediaminetetraacetic acid brushing (FileRite PRC, Pulpdent, Watertown, MA, USA); Group 4 received ultrasonic scaling with polyetheretherketone tips (EMS Dental); Group 5 underwent ultrasonic scaling with polyetheretherketone tips with ethylenediaminetetraacetic acid; and Group 6 was treated with a combination of ultrasonic scaling with polyetheretherketone tips, erythritol powder air polishing and ethylenediaminetetraacetic acid. Surface cleaning effects, quantified by relative contaminated area reduction and visual analogue scale score, as well as surface roughness and chemistry, were assessed after decontamination. The cleaning effects of each decontamination method were also compared between TiUnite and SLA (sandblasted, large-grit acid-etched; Straumann, Basel, Switzerland) implants. RESULTS Group 6 showed the highest relative contaminated area reduction (stereoscopic microscopy 83.92%, scanning electron microscopy 96.40%), visual analogue scale score (2.83) and reduction in surface roughness (thread bottom -0.78 μm, tip -1.35 μm), as well as an almost maximal decrease in the proportion of carbon (thread bottom -12.33%, tip -8.77%) and increase in that of titanium (thread bottom 13.71%, tip 10.73%). Polyetheretherketone remnants were observed in Groups 4 and 5 but appeared to be reduced in Group 6. When comparing the outcomes with those for SLA implants, no significant differences were found. CONCLUSION Within the limitations of the present study, the combination of ultrasonic scaling with polyetheretherketone tips, erythritol powder air polishing and ethylenediaminetetraacetic brushing achieved reasonable cleaning effects. The original surface modification did not seem to have any impact on the decontamination results for any of the methods examined.
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Qin X, Feng N, Kang Z, Hu D. Construction of wood-based cellulose micro-framework composite form-stable multifunctional materials with thermal and electrical response via incorporating erythritol-urea (thiourea)-carbon nanotubes. Int J Biol Macromol 2021; 184:538-550. [PMID: 34175336 DOI: 10.1016/j.ijbiomac.2021.06.150] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/15/2021] [Accepted: 06/22/2021] [Indexed: 01/11/2023]
Abstract
In this study, two kinds of form-stable multifunctional materials with thermal and electrical response (FPCMs: DP-E7U3-CNT, DP-E7T3-CNT) are composed of wood-based honeycomb-like celluloses micro-framework (DP), carbon nanotubes (CNT), erythritol-urea (E7U3) or erythritol-thiourea (E7T3). In FPCMs, DP acts as a skeleton structure to seal E7U3 and E7T3 and provide more pathways for heat conduction. The CNT acts as an extended surface to further improve thermal conductivity. FE-SEM showed that the honeycomb-like pore structure of DP was completely filled with E7U3, E7T3 and CNT. FTIR and XRD analysis show that there is only a combination of physical interactions between the components of FPCMs. DSC curves and thermal conductivity analysis results show that DP-E7U3-1.5CNT and DP-E7T3-1.5CNT with the mass fraction of carbon nanotubes (1.5 wt%) have the highest latent heat values (230.3 J/g, 272.2 J/g) and thermal conductivity (0.9832 W/(m·K), 0.9363 W/(m·K)). Both DP-E7U3-1.5CNT and DP-E7T3-1.5CNT exhibit high latent heat retention and thermal stability after 100 heating-cooling cycles. In addition, DP-E7U3-1.5CNT and DP-E7T3-1.5CNT show excellent performance in light-heat energy conversion-storage, actual latent heat storage and release, thermal and electrical response performance, which make it has great potential to be multifunctional materials with thermal storage sand electrical response.
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Affiliation(s)
- Xiang Qin
- State Key Laboratory of Featured Metal Resources and Advanced Materials, Guangxi University, Nanning 530004, China; Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, Guangxi University, Nanning 530004, China; School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
| | - Nianrong Feng
- State Key Laboratory of Featured Metal Resources and Advanced Materials, Guangxi University, Nanning 530004, China; Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, Guangxi University, Nanning 530004, China; School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
| | - Zhe Kang
- State Key Laboratory of Featured Metal Resources and Advanced Materials, Guangxi University, Nanning 530004, China; Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, Guangxi University, Nanning 530004, China; School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
| | - Dongying Hu
- State Key Laboratory of Featured Metal Resources and Advanced Materials, Guangxi University, Nanning 530004, China; Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, Guangxi University, Nanning 530004, China; School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.
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Wang S, Wang H, Lv J, Deng Z, Cheng H. Highly Efficient Erythritol Recovery from Waste Erythritol Mother Liquor by a Yeast-Mediated Biorefinery Process. J Agric Food Chem 2017; 65:11020-11028. [PMID: 29220176 DOI: 10.1021/acs.jafc.7b04112] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Erythritol, a natural sugar alcohol, is produced industrially by fermentation and crystallization, but this process leaves a large amount of waste erythritol mother liquor (WEML) which contains more than 200 g/L erythritol as well as other polyol byproducts. These impurities make it very difficult to crystallize more erythritol. In our study, an efficient process for the recovery of erythritol from the WEML is described. The polyol impurities were first identified by high-performance liquid chromatography and gas chromatography-mass spectrometry, and a yeast strain Candida maltosa CGMCC 7323 was then isolated to metabolize those impurities to purify erythritol. Our results demonstrated that the process could remarkably improve the purity of erythritol and thus make the subsequent crystallization easier. This newly developed strategy is expected to have advantages in WEML treatment and provide helpful information with regard to green cell factories and zero-waste processing.
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Affiliation(s)
- Siqi Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University , Shanghai 200240, China
| | - Hengwei Wang
- Innovation and Application Institute (IAI), Zhejiang Ocean University , Zhoushan 316022, China
| | - Jiyang Lv
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University , Shanghai 200240, China
| | - Zixin Deng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University , Shanghai 200240, China
| | - Hairong Cheng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University , Shanghai 200240, China
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Duong TH, Huynh BLC, Chavasiri W, Chollet-Krugler M, Nguyen VK, Nguyen THT, Hansen PE, Le Pogam P, Thüs H, Boustie J, Nguyen KPP. New erythritol derivatives from the fertile form of Roccella montagnei. Phytochemistry 2017; 137:156-164. [PMID: 28222890 DOI: 10.1016/j.phytochem.2017.02.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 02/03/2017] [Accepted: 02/08/2017] [Indexed: 06/06/2023]
Abstract
Chemical investigation of the methanol extract of the fertile form of Roccella montagnei collected in Vietnam afforded twelve secondary metabolites, including five new montagnetol derivatives, orsellinylmontagnetols A-D and a furanyl derivative together with seven known compounds. Their chemical structures were elucidated by analysis of 1D and 2D NMR and high resolution mass spectroscopic data. The relative stereochemistry of two chiral centers (C-2 and C-3) of orsellinylmontagnetols A and B was elucidated by comparison of their coupling constants and the specific rotation with those reported in the literature while the absolute stereochemistry was determined by the application of a modified Mosher method for the hydroxy group at C-3. The absolute configuration (2R,3S) of the butanetetraol moiety of these compounds is in accordance with that of erythrin, a recognized chemotaxonomic marker of the genus Roccella. Five of these compounds were evaluated for their cytotoxic activities against four cancer cell lines. Only orsellinylmontagnetol A exerted a moderate activity against MCF-7 cell line with an IC50 value of 68.39 ± 3.46 μM.
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Affiliation(s)
- Thuc Huy Duong
- Department of Chemistry, Ho Chi Minh City University of Pedagogy, 280 An Duong Vuong Street, District 5, Ho Chi Minh City 748342, Viet Nam
| | - Bui Linh Chi Huynh
- Department of Organic Chemistry, University of Science, National University - Ho Chi Minh City, 227 Nguyen Van Cu Str., Dist. 5, Ho Chi Minh City 748355, Viet Nam
| | - Warinthorn Chavasiri
- Natural Products Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Rd., Patumwan, Bangkok 10330, Thailand
| | - Marylene Chollet-Krugler
- Institute of Chemistry of Rennes, ISCR, UMR CNRS 6226, University of Rennes 1, 2 Av. du Pr. Léon Bernard, Rennes Cedex 35043, France
| | - Van Kieu Nguyen
- Natural Products Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Rd., Patumwan, Bangkok 10330, Thailand
| | - Thi Hoai Thu Nguyen
- Department of Basic Science, Ho Chi Minh City University of Medicine and Pharmacy, 217 Hong Bang Street, Dist. 5, Ho Chi Minh City 749051, Viet Nam
| | - Poul Erik Hansen
- Department of Science and Environment, Roskilde University, P.O. Box 260, DK-4000 Roskilde, Denmark
| | - Pierre Le Pogam
- Institute of Chemistry of Rennes, ISCR, UMR CNRS 6226, University of Rennes 1, 2 Av. du Pr. Léon Bernard, Rennes Cedex 35043, France; Institute of Electronics and Telecommunications of Rennes (IETR), UMR CNRS 6164, University of Rennes 1, 263 Av. du Général Leclerc, Rennes Cedex 35042, France
| | - Holger Thüs
- Life Science Department, The Natural History Museum, Cromwell Road, SW7 5BD London, England, UK
| | - Joël Boustie
- Institute of Chemistry of Rennes, ISCR, UMR CNRS 6226, University of Rennes 1, 2 Av. du Pr. Léon Bernard, Rennes Cedex 35043, France.
| | - Kim Phi Phung Nguyen
- Department of Organic Chemistry, University of Science, National University - Ho Chi Minh City, 227 Nguyen Van Cu Str., Dist. 5, Ho Chi Minh City 748355, Viet Nam.
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Sandbrink L, Beckerle K, Meiners I, Liffmann R, Rahimi K, Okuda J, Palkovits R. Supported Molybdenum Catalysts for the Deoxydehydration of 1,4-Anhydroerythritol into 2,5-Dihydrofuran. ChemSusChem 2017; 10:1375-1379. [PMID: 28165202 DOI: 10.1002/cssc.201700010] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 02/03/2017] [Indexed: 05/23/2023]
Abstract
Efficient deoxygenation strategies are crucial for the valorization of renewable feedstocks. Deoxydehydration (DODH) enables the direct transformation of two adjacent hydroxyl groups into a double bond. Supported molybdenum-based catalysts were utilized for the first time in DODH. MoOx /TiO2 showed superior catalytic activity compared to common molybdenum salts. The catalyst efficiently converted 1,4-anhydroerythritol into 2,5-dihydrofuran in the presence of 3-octanol as reducing agent, showing high reproducibility and stability.
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Affiliation(s)
- Lennart Sandbrink
- Institut für Technische und Makromolekulare Chemie (ITMC), RWTH Aachen University, Aachen, 52074, Germany
| | - Klaus Beckerle
- Institut für Anorganische Chemie, RWTH Aachen University, Aachen, 52074, Germany
| | - Isabell Meiners
- Institut für Technische und Makromolekulare Chemie (ITMC), RWTH Aachen University, Aachen, 52074, Germany
| | - Rebecca Liffmann
- Institut für Anorganische Chemie, RWTH Aachen University, Aachen, 52074, Germany
| | - Khosrow Rahimi
- DWI-Leibniz-Institute for Interactive Materials, Aachen, 52074, Germany
| | - Jun Okuda
- Institut für Anorganische Chemie, RWTH Aachen University, Aachen, 52074, Germany
| | - Regina Palkovits
- Institut für Technische und Makromolekulare Chemie (ITMC), RWTH Aachen University, Aachen, 52074, Germany
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Flury S, Peutzfeldt A, Schmidlin PR, Lussi A. Exposed Dentin: Influence of Cleaning Procedures and Simulated Pulpal Pressure on Bond Strength of a Universal Adhesive System. PLoS One 2017; 12:e0169680. [PMID: 28081572 PMCID: PMC5233420 DOI: 10.1371/journal.pone.0169680] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 12/20/2016] [Indexed: 12/11/2022] Open
Abstract
Purpose To compare various pre-treatments serving as cleaning procedures of dentin on the bond strength of resin composite promoted by a universal adhesive system applied either in the absence or presence of simulated pulpal pressure. Materials and Methods Prior to application of the adhesive system (Scotchbond Universal) and resin composite (Filtek Z250), ground dentin surfaces were given one of five pre-treatments either without or with simulated pulpal pressure: 1) no pre-treatment, adhesive system in “self-etch” mode, 2) phosphoric acid etching, adhesive system in “total-etch” mode, 3) polishing with pumice on prophylaxis cup, 4) air abrasion with AIR-FLOW PLUS powder, 5) air abrasion with AIR-FLOW PERIO powder; n = 20/group of pre-treatment. After storage (37°C, 100% humidity, 24 h), micro shear bond strength was measured and data analyzed with parametric ANOVA including Bonferroni-Holm correction for multiple testing followed by Student’s t tests (significance level: α = 0.05). Results The ANOVA found type of pre-treatment and simulated pulpal pressure to have no significant effect on dentin bond strength. The explorative post-hoc tests showed a negative effect of simulated pulpal pressure for phosphoric acid etching (adhesive system in “total-etch” mode; p = 0.020), but not for the other four pre-treatments (all p = 1.000). Conclusion Air abrasion with powders containing either erythritol and chlorhexidine (AIR-FLOW PLUS) or glycine (AIR-FLOW PERIO) yielded dentin bond strengths similar to no pre-treatment, phosphoric acid etching, or polishing with pumice. Simulated pulpal pressure reduced the bond strength only when the self-etch adhesive system was used in total-etch mode.
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Affiliation(s)
- Simon Flury
- Department of Preventive, Restorative, and Pediatric Dentistry, School of Dental Medicine, University of Bern, Bern, Switzerland
- * E-mail:
| | - Anne Peutzfeldt
- Department of Preventive, Restorative, and Pediatric Dentistry, School of Dental Medicine, University of Bern, Bern, Switzerland
| | - Patrick R. Schmidlin
- Department of Preventive, Restorative, and Pediatric Dentistry, School of Dental Medicine, University of Bern, Bern, Switzerland
- Division of Periodontology and Peri-Implant Diseases, Clinic of Preventive Dentistry, Periodontology, and Cariology, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Adrian Lussi
- Department of Preventive, Restorative, and Pediatric Dentistry, School of Dental Medicine, University of Bern, Bern, Switzerland
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Arai T, Tamura M, Nakagawa Y, Tomishige K. Synthesis of 2-Butanol by Selective Hydrogenolysis of 1,4-Anhydroerythritol over Molybdenum Oxide-Modified Rhodium-Supported Silica. ChemSusChem 2016; 9:1680-8. [PMID: 27226396 DOI: 10.1002/cssc.201600295] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 04/27/2016] [Indexed: 05/23/2023]
Abstract
Rh-MoOx /SiO2 (Mo/Rh=0.13) is an effective catalyst for the hydrogenolysis of 1,4-anhydroerythritol (1,4-AHERY) and provides 2-BuOH in high yield of 51 %. This is the first report of the production of 2-BuOH from 1,4-AHERY by hydrogenolysis. 1,4-AHERY was more suitable as a starting material than erythritol because the 2-BuOH yield from erythritol was low (34 %). Based on the kinetics and comparison of reactivities of the related compounds using Rh-MoOx /SiO2 and Rh/SiO2 catalysts, the modification of Rh/SiO2 with MoOx leads to the high activity and high selectivity to 2-BuOH because of the generation of reactive hydride species and the strong adsorption of 1,4-AHERY on MoOx species. The reaction proceeds by main two routes, (I) the combination of single C-O hydrogenolysis with the desorption of intermediates, a usual route in hydrogenolysis, and (II) multiple C-O hydrogenolysis without the desorption of intermediates from the active site, and the reaction mechanism for Route (II) is proposed.
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Affiliation(s)
- Takahiro Arai
- Department of Applied Chemistry, School of Engineering, Tohoku University, 6-6-07, Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan
| | - Masazumi Tamura
- Department of Applied Chemistry, School of Engineering, Tohoku University, 6-6-07, Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan
- Research Center for Rare Metal and Green Innovation, Tohoku University, 468-1, Aoba, Aramaki, Aoba-ku, Sendai, 980-0845, Japan
| | - Yoshinao Nakagawa
- Department of Applied Chemistry, School of Engineering, Tohoku University, 6-6-07, Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan
- Research Center for Rare Metal and Green Innovation, Tohoku University, 468-1, Aoba, Aramaki, Aoba-ku, Sendai, 980-0845, Japan
| | - Keiichi Tomishige
- Department of Applied Chemistry, School of Engineering, Tohoku University, 6-6-07, Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan.
- Research Center for Rare Metal and Green Innovation, Tohoku University, 468-1, Aoba, Aramaki, Aoba-ku, Sendai, 980-0845, Japan.
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Huang Y, Wang Z, Zha S, Wang Y, Jiang W, Liao Y, Song Z, Qi Z, Yin Y. De Novo Transcriptome and Expression Profile Analysis to Reveal Genes and Pathways Potentially Involved in Cantharidin Biosynthesis in the Blister Beetle Mylabris cichorii. PLoS One 2016; 11:e0146953. [PMID: 26752526 PMCID: PMC4709229 DOI: 10.1371/journal.pone.0146953] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 12/27/2015] [Indexed: 12/04/2022] Open
Abstract
The dried body of Mylabris cichorii is well-known Chinese traditional medicine. The sesquiterpenoid cantharidin, which is secreted mostly by adult male beetles, has recently been used as an anti-cancer drug. However, little is known about the mechanisms of cantharidin biosynthesis. Furthermore, there is currently no genomic or transcriptomic information for M. cichorii. In this study, we performed de novo assembly transcriptome of M. cichorii using the Illumina Hiseq2000. A single run produced 9.19 Gb of clean nucleotides comprising 29,247 sequences, including 23,739 annotated sequences (about 81%). We also constructed two expression profile libraries (20–25 day-old adult males and 20–25 day-old adult females) and discovered 2,465 significantly differentially-expressed genes. Putative genes and pathways involved in the biosynthesis of cantharidin were then characterized. We also found that cantharidin biosynthesis in M. cichorii might only occur via the mevalonate (MVA) pathway, not via the methylerythritol 4-phosphate/deoxyxylulose 5-phosphate (MEP/DOXP) pathway or a mixture of these. Besides, we considered that cantharidin biosynthesis might be related to the juvenile hormone (JH) biosynthesis or degradation. The results of transcriptome and expression profiling analysis provide a comprehensive sequence resource for M. cichorii that could facilitate the in-depth study of candidate genes and pathways involved in cantharidin biosynthesis, and may thus help to improve our understanding of the mechanisms of cantharidin biosynthesis in blister beetles.
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Affiliation(s)
- Yi Huang
- Key Laboratory of Genetic Function and Regulation, School of Life Science, Chongqing University, Chongqing 400030, China
| | - Zhongkang Wang
- Key Laboratory of Genetic Function and Regulation, School of Life Science, Chongqing University, Chongqing 400030, China
| | - Shenfang Zha
- Key Laboratory of Genetic Function and Regulation, School of Life Science, Chongqing University, Chongqing 400030, China
| | - Yu Wang
- Key Laboratory of Genetic Function and Regulation, School of Life Science, Chongqing University, Chongqing 400030, China
- Panzhihua University, Panzhihua 617000, China
| | - Wei Jiang
- Key Laboratory of Genetic Function and Regulation, School of Life Science, Chongqing University, Chongqing 400030, China
| | - Yufeng Liao
- Clinical Medicine college of Tianjin Medical University, Tianjin 300270, China
| | - Zhangyong Song
- Key Laboratory of Genetic Function and Regulation, School of Life Science, Chongqing University, Chongqing 400030, China
| | - Zhaoran Qi
- Key Laboratory of Genetic Function and Regulation, School of Life Science, Chongqing University, Chongqing 400030, China
| | - Youping Yin
- Key Laboratory of Genetic Function and Regulation, School of Life Science, Chongqing University, Chongqing 400030, China
- * E-mail:
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González-Cabanelas D, Wright LP, Paetz C, Onkokesung N, Gershenzon J, Rodríguez-Concepción M, Phillips MA. The diversion of 2-C-methyl-D-erythritol-2,4-cyclodiphosphate from the 2-C-methyl-D-erythritol 4-phosphate pathway to hemiterpene glycosides mediates stress responses in Arabidopsis thaliana. Plant J 2015; 82:122-37. [PMID: 25704332 DOI: 10.1111/tpj.12798] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 01/26/2015] [Accepted: 02/10/2015] [Indexed: 05/28/2023]
Abstract
2-C-Methyl-D-erythritol-2,4-cyclodiphosphate (MEcDP) is an intermediate of the plastid-localized 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway which supplies isoprenoid precursors for photosynthetic pigments, redox co-factor side chains, plant volatiles, and phytohormones. The Arabidopsis hds-3 mutant, defective in the 1-hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate synthase step of the MEP pathway, accumulates its substrate MEcDP as well as the free tetraol 2-C-methyl-D-erythritol (ME) and glucosylated ME metabolites, a metabolic diversion also occurring in wild type plants. MEcDP dephosphorylation to the free tetraol precedes glucosylation, a process which likely takes place in the cytosol. Other MEP pathway intermediates were not affected in hds-3. Isotopic labeling, dark treatment, and inhibitor studies indicate that a second pool of MEcDP metabolically isolated from the main pathway is the source of a signal which activates salicylic acid induced defense responses before its conversion to hemiterpene glycosides. The hds-3 mutant also showed enhanced resistance to the phloem-feeding aphid Brevicoryne brassicae due to its constitutively activated defense response. However, this MEcDP-mediated defense response is developmentally dependent and is repressed in emerging seedlings. MEcDP and ME exogenously applied to adult leaves mimics many of the gene induction effects seen in the hds-3 mutant. In conclusion, we have identified a metabolic shunt from the central MEP pathway that diverts MEcDP to hemiterpene glycosides via ME, a process linked to balancing plant responses to biotic stress.
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Affiliation(s)
- Diego González-Cabanelas
- Plant Metabolism and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus de la Universitat Autònoma de Barcelona, 08193, Bellaterra (Barcelona), Spain
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Yang SQ, Deng J, Wu QQ, Li H, Gao WY. A specific process to purify 2-methyl-D-erythritol-4-phosphate enzymatically converted from D-glyceraldehyde-3-phosphate and pyruvate. Nat Prod Commun 2015; 10:339-340. [PMID: 25920278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023] Open
Abstract
A one-pot enzymatic cascade was established to synthesize MEP, one of the key intermediates in the MEP terpenoid biosynthetic pathway. D-GAP and sodium pyruvate were converted to MEP in a reaction catalyzed by DXP synthase and DXP reductoisomerase (DXR) in the presence of the coenzymes ThPP, NADPH, and Mg2+. The product was then isolated by using a specific two-step purification process and MEP was obtained in a yield of nearly 60% and high purity. Importantly, MEP prepared by this way was totally free from contamination by minor amounts of DXP that was not completely convertible by DXR.
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Krasutsky S, Urbansky M, Davis CE, Lherbet C, Coates RM, Poulter CD. Synthesis of methylerythritol phosphate analogues and their evaluation as alternate substrates for IspDF and IspE from Agrobacterium tumefaciens. J Org Chem 2014; 79:9170-8. [PMID: 25184438 PMCID: PMC4184463 DOI: 10.1021/jo501529k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Indexed: 11/29/2022]
Abstract
The methylerythritol phosphate biosynthetic pathway, found in most Bacteria, some parasitic protists, and plant chloroplasts, converts D-glyceraldehyde phosphate and pyruvate to isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), where it intersects with the mevalonate pathway found in some Bacteria, Archaea, and Eukarya, including the cytosol of plants. D-3-Methylerythritol-4-phosphate (MEP), the first pathway-specific intermediate in the pathway, is converted to IPP and DMAPP by the consecutive action of the IspD-H proteins. We synthesized five D-MEP analogues-D-erythritol-4-phosphate (EP), D-3-methylthrietol-4-phosphate (MTP), D-3-ethylerythritol-4-phosphate (EEP), D-1-amino-3-methylerythritol-4-phosphate (NMEP), and D-3-methylerythritol-4-thiolophosphate (MESP)-and studied their ability to function as alternative substrates for the reactions catalyzed by the IspDF fusion and IspE proteins from Agrobacterium tumefaciens, which covert MEP to the corresponding eight-membered cyclic diphosphate. All of the analogues, except MTP, and their products were substrates for the three consecutive enzymes.
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Affiliation(s)
- Sergiy
G. Krasutsky
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Marek Urbansky
- Department
of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
| | - Chad E. Davis
- Department
of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
| | - Christian Lherbet
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Robert M. Coates
- Department
of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
| | - C. Dale Poulter
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
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12
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Haymond A, Johny C, Dowdy T, Schweibenz B, Villarroel K, Young R, Mantooth CJ, Patel T, Bases J, Jose GS, Jackson ER, Dowd CS, Couch RD. Kinetic characterization and allosteric inhibition of the Yersinia pestis 1-deoxy-D-xylulose 5-phosphate reductoisomerase (MEP synthase). PLoS One 2014; 9:e106243. [PMID: 25171339 PMCID: PMC4149570 DOI: 10.1371/journal.pone.0106243] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 07/29/2014] [Indexed: 11/19/2022] Open
Abstract
The methylerythritol phosphate (MEP) pathway found in many bacteria governs the synthesis of isoprenoids, which are crucial lipid precursors for vital cell components such as ubiquinone. Because mammals synthesize isoprenoids via an alternate pathway, the bacterial MEP pathway is an attractive target for novel antibiotic development, necessitated by emerging antibiotic resistance as well as biodefense concerns. The first committed step in the MEP pathway is the reduction and isomerization of 1-deoxy-D-xylulose-5-phosphate (DXP) to methylerythritol phosphate (MEP), catalyzed by MEP synthase. To facilitate drug development, we cloned, expressed, purified, and characterized MEP synthase from Yersinia pestis. Enzyme assays indicate apparent kinetic constants of KMDXP = 252 µM and KMNADPH = 13 µM, IC50 values for fosmidomycin and FR900098 of 710 nM and 231 nM respectively, and Ki values for fosmidomycin and FR900098 of 251 nM and 101 nM respectively. To ascertain if the Y. pestis MEP synthase was amenable to a high-throughput screening campaign, the Z-factor was determined (0.9) then the purified enzyme was screened against a pilot scale library containing rationally designed fosmidomycin analogs and natural product extracts. Several hit molecules were obtained, most notably a natural product allosteric affector of MEP synthase and a rationally designed bisubstrate derivative of FR900098 (able to associate with both the NADPH and DXP binding sites in MEP synthase). It is particularly noteworthy that allosteric regulation of MEP synthase has not been described previously. Thus, our discovery implicates an alternative site (and new chemical space) for rational drug development.
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Affiliation(s)
- Amanda Haymond
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Chinchu Johny
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Tyrone Dowdy
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Brandon Schweibenz
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Karen Villarroel
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Richard Young
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Clark J. Mantooth
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Trishal Patel
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Jessica Bases
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Geraldine San Jose
- Department of Chemistry, George Washington University, Washington DC, United States of America
| | - Emily R. Jackson
- Department of Chemistry, George Washington University, Washington DC, United States of America
| | - Cynthia S. Dowd
- Department of Chemistry, George Washington University, Washington DC, United States of America
| | - Robin D. Couch
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
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Ramos KRM, Valdehuesa KNG, Liu H, Nisola GM, Lee WK, Chung WJ. Combining De Ley-Doudoroff and methylerythritol phosphate pathways for enhanced isoprene biosynthesis from D-galactose. Bioprocess Biosyst Eng 2014; 37:2505-13. [PMID: 24928200 DOI: 10.1007/s00449-014-1228-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 05/25/2014] [Indexed: 01/17/2023]
Abstract
An engineered Escherichia coli strain was developed for enhanced isoprene production using D-galactose as substrate. Isoprene is a valuable compound that can be biosynthetically produced from pyruvate and glyceraldehyde-3-phosphate (G3P) through the methylerythritol phosphate pathway (MEP). The Leloir and De Ley-Doudoroff (DD) pathways are known existing routes in E. coli that can supply the MEP precursors from D-galactose. The DD pathway was selected as it is capable of supplying equimolar amounts of pyruvate and G3P simultaneously. To exclusively direct D-galactose toward the DD pathway, an E. coli ΔgalK strain with blocked Leloir pathway was used as the host. To obtain a fully functional DD pathway, a dehydrogenase encoding gene (gld) was recruited from Pseudomonas syringae to catalyze D-galactose conversion to D-galactonate. Overexpressions of endogenous genes known as MEP bottlenecks, and a heterologous gene, were conducted to enhance and enable isoprene production, respectively. Growth test confirmed a functional DD pathway concomitant with equimolar generation of pyruvate and G3P, in contrast to the wild-type strain where G3P was limiting. Finally, the engineered strain with combined DD-MEP pathway exhibited the highest isoprene production. This suggests that the equimolar pyruvate and G3P pools resulted in a more efficient carbon flux toward isoprene production. This strategy provides a new platform for developing improved isoprenoid producing strains through the combined DD-MEP pathway.
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Affiliation(s)
- Kristine Rose M Ramos
- Department of Energy and Biotechnology (DEB), Energy and Environment Fusion Technology Center (E2FTC), Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin-si, Gyeonggi-do, 449-728, Republic of Korea
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14
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Wölwer-Rieck U, May B, Lankes C, Wüst M. Methylerythritol and mevalonate pathway contributions to biosynthesis of mono-, sesqui-, and diterpenes in glandular trichomes and leaves of Stevia rebaudiana Bertoni. J Agric Food Chem 2014; 62:2428-35. [PMID: 24579920 DOI: 10.1021/jf500270s] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The biosynthesis of the diterpenoid steviol glycosides rebaudioside A and stevioside in nonrooted cuttings of Stevia rebaudiana was investigated by feeding experiments using the labeled key precursors [5,5-(2)H2]-mevalonic acid lactone (d2-MVL) and [5,5-(2)H2]-1-deoxy-d-xylulose (d2-DOX). Labeled glycosides were extracted from the leaves and stems and were directly analyzed by LC-(-ESI)-MS/MS and by GC-MS after hydrolysis and derivatization of the resulting isosteviol to the corresponding TMS-ester. Additionally, the incorporation of the proffered d2-MVL and d2-DOX into volatile monoterpenes, sesquiterpenes, and diterpenes in glandular trichomes on leaves and stems was investigated by headspace-solid phase microextraction-GC-MS (HS-SPME-GC-MS). Incorporation of the labeled precursors indicated that diterpenes in leaves and monoterpenes and diterpenes in glandular trichomes are predominately biosynthesized via the methylerythritol phosphate (MEP) pathway, whereas both the MEP and mevalonate (MVA) pathways contribute to the biosynthesis of sesquiterpenes at equal rates in glandular trichomes. These findings give evidence for a transport of MEP pathway derived farnesyl diphosphate precursors from plastids to the cytosol. Contrarily, the transport of MVA pathway derived geranyl diphosphate and geranylgeranyl diphosphate precursors from the cytosol to the plastid is limited.
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Affiliation(s)
- Ursula Wölwer-Rieck
- Institute of Nutrition and Food Sciences, Chair of Bioanalytics/Food Chemistry, Rheinische Friedrich-Wilhelms-Universität Bonn , Endenicher Allee 11-13, 53115 Bonn, Germany
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15
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Li Z, Sharkey TD. Metabolic profiling of the methylerythritol phosphate pathway reveals the source of post-illumination isoprene burst from leaves. Plant Cell Environ 2013; 36:429-37. [PMID: 22831282 DOI: 10.1111/j.1365-3040.2012.02584.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The methylerythritol phosphate (MEP) pathway in plants produces the prenyl precursors for all plastidic isoprenoids, including carotenoids and quinones. The MEP pathway is also responsible for synthesis of approximately 600 Tg of isoprene per year, the largest non-methane hydrocarbon flux into the atmosphere. There have been few studies of the regulation of the MEP pathway in plants under physiological conditions. In this study, we combined gas exchange techniques and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS) and measured the profile of MEP pathway metabolites under different conditions. We report that in the MEP pathway, metabolites immediately preceding steps requiring reducing power were in high concentration. Inhibition of the MEP pathway by fosmidomycin caused deoxyxylulose phosphate accumulation in leaves as expected. Evidence is presented that accumulation of MEP pathway intermediates, primarily methylerythritol cyclodiphosphate, is responsible for the post-illumination isoprene burst phenomenon. Pools of intermediate metabolites stayed at approximately the same level 10 min after light was turned off, but declined eventually under prolonged darkness. In contrast, a strong inhibition of the second-to-last step of the MEP pathway caused suppression of isoprene emission in pure N(2). Our study suggests that reducing equivalents may be a key regulator of the MEP pathway and therefore isoprene emission from leaves.
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Affiliation(s)
- Ziru Li
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
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16
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Gupta P, Agarwal AV, Akhtar N, Sangwan RS, Singh SP, Trivedi PK. Cloning and characterization of 2-C-methyl-D-erythritol-4-phosphate pathway genes for isoprenoid biosynthesis from Indian ginseng, Withania somnifera. Protoplasma 2013; 250:285-95. [PMID: 22526204 DOI: 10.1007/s00709-012-0410-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 03/29/2012] [Indexed: 05/16/2023]
Abstract
Withania somnifera (L.) is one of the most valuable medicinal plants used in Ayurvedic and other indigenous medicines. Pharmaceutical activities of this herb are associated with presence of secondary metabolites known as withanolides, a class of phytosteroids synthesized via mevalonate (MVA) and 2-C-methyl-D-erythritol-4-phosphate pathways. Though the plant has been well characterized in terms of phytochemical profiles as well as pharmaceutical activities, not much is known about the genes responsible for biosynthesis of these compounds. In this study, we have characterized two genes encoding 1-deoxy-D-xylulose-5-phosphate synthase (DXS; EC 2.2.1.7) and 1-deoxy-D-xylulose-5-phosphate reductase (DXR; EC 1.1.1.267) enzymes involved in the biosynthesis of isoprenoids. The full-length cDNAs of W. somnifera DXS (WsDXS) and DXR (WsDXR) of 2,154 and 1,428 bps encode polypeptides of 717 and 475 amino acids residues, respectively. The expression analysis suggests that WsDXS and WsDXR are differentially expressed in different tissues (with maximal expression in flower and young leaf), chemotypes of Withania, and in response to salicylic acid, methyl jasmonate, as well as in mechanical injury. Analysis of genomic organization of WsDXS shows close similarity with tomato DXS in terms of exon-intron arrangements. This is the first report on characterization of isoprenoid biosynthesis pathway genes from Withania.
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Affiliation(s)
- Parul Gupta
- National Botanical Research Institute, Council of Scientific and Industrial Research, Rana Pratap Marg, Lucknow 226001, India
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17
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Zhou K, Zou R, Stephanopoulos G, Too HP. Metabolite profiling identified methylerythritol cyclodiphosphate efflux as a limiting step in microbial isoprenoid production. PLoS One 2012; 7:e47513. [PMID: 23133596 PMCID: PMC3487848 DOI: 10.1371/journal.pone.0047513] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 09/12/2012] [Indexed: 11/18/2022] Open
Abstract
Isoprenoids are natural products that are all derived from isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). These precursors are synthesized either by the mevalonate (MVA) pathway or the 1-Deoxy-D-Xylulose 5-Phosphate (DXP) pathway. Metabolic engineering of microbes has enabled overproduction of various isoprenoid products from the DXP pathway including lycopene, artemisinic acid, taxadiene and levopimaradiene. To date, there is no method to accurately measure all the DXP metabolic intermediates simultaneously so as to enable the identification of potential flux limiting steps. In this study, a solid phase extraction coupled with ultra performance liquid chromatography mass spectrometry (SPE UPLC-MS) method was developed. This method was used to measure the DXP intermediates in genetically engineered E. coli. Unexpectedly, methylerythritol cyclodiphosphate (MEC) was found to efflux when certain enzymes of the pathway were over-expressed, demonstrating the existence of a novel competing pathway branch in the DXP metabolism. Guided by these findings, ispG was overexpressed and was found to effectively reduce the efflux of MEC inside the cells, resulting in a significant increase in downstream isoprenoid production. This study demonstrated the necessity to quantify metabolites enabling the identification of a hitherto unrecognized pathway and provided useful insights into rational design in metabolic engineering.
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Affiliation(s)
- Kang Zhou
- Chemical and Pharmaceutical Engineering, Singapore-MIT Alliance, Singapore
| | - Ruiyang Zou
- Chemical and Pharmaceutical Engineering, Singapore-MIT Alliance, Singapore
| | - Gregory Stephanopoulos
- Chemical and Pharmaceutical Engineering, Singapore-MIT Alliance, Singapore
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Heng-Phon Too
- Chemical and Pharmaceutical Engineering, Singapore-MIT Alliance, Singapore
- Department of Biochemistry, National University of Singapore, Singapore
- * E-mail:
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18
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Amada Y, Watanabe H, Hirai Y, Kajikawa Y, Nakagawa Y, Tomishige K. Production of biobutanediols by the hydrogenolysis of erythritol. ChemSusChem 2012; 5:1991-9. [PMID: 22865539 DOI: 10.1002/cssc.201200121] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Revised: 04/05/2012] [Indexed: 05/08/2023]
Abstract
The hydrogenolysis of erythritol using an Ir-ReO(x)/SiO(2) catalyst was performed for the production of butanediols, which are widely used as a raw material of polymers. The activity and selectivity to butanediols on Ir-ReO(x)/SiO(2) was much higher than that on conventional hydrogenolysis catalysts. The maximum selectivity to 1,4- and 1,3-butanediols reached 33 and 12 % at 74 % conversion, respectively. The erythritol conversion and selectivity to butanediols was almost maintained during four repeating tests if small amounts of acid were added to the reaction and the catalyst was calcined again. The reaction kinetics, reactivity trends, and characterization results indicate a direct hydrogenolysis mechanism in which the hydride species on the Ir metal surface attacks the alkoxide species on the 3D ReO(x) clusters. Based on the production of erythritol by the fermentation of glucose and glycerol, erythritol hydrogenolysis may be a promising pathway for the production of biobutanediols.
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Affiliation(s)
- Yasushi Amada
- Department of Applied Chemistry, School of Engineering, Tohoku University, 6-6-07, Aoba, Aramaki, Sendai 980-8579, Japan
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19
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Abstract
INTRODUCTION Dental caries is a diet-associated disease which continues to be a serious health problem in most industrialized and developing countries. Strategies to maximize caries prevention should automatically consider the use of sugar substitutes. It is important that public health authorities are made cognizant of the availability of new polyol-type sugar substitutes. REVIEW SUMMARY Clinical studies have shown that xylitol, a natural, physiologic sugar alcohol of the pentitol type, can be used as a safe and effective caries-limiting sweetener. Habitual use of xylitol-containing food and oral hygiene adjuvants has been shown to reduce the growth of dental plaque, to interfere with the growth of caries-associated bacteria, to decrease the incidence of dental caries, and to be associated with remineralization of caries lesions. Numerous public regulatory bodies have endorsed the use of xylitol as a caries-limiting agent. Other sugar alcohols that have been successfully used as sugar substitutes include D-glucitol (sorbitol), which, however, owing to its hexitol nature, normally has no strong effect on the mass and adhesiveness of bacterial plaque and on the growth of mutans streptococci. A tetritol-type alditol, erythritol, has shown potential as a non-cariogenic sugar substitute. Combinations of xylitol and erythritol may reduce the incidence of caries more effectively than either alditol alone. CONCLUSIONS Partial sugar substitution with polyols is an important dietary tool in the prevention of dental caries that should be used to enhance existing fluoride-based caries prevention programmes. The most effective method of conveying this information to the public is through a proper health claim for these alditols in food labelling. The present review summarizes clinical and biochemical aspects of the above three dietary polyols and emphasizes the role of sugar substitution as a potential health-promoting strategy.
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Affiliation(s)
- Kauko K Mäkinen
- Institute of Dentistry, University of Turku, Lemminkäisenkatu 2, Turku, Finland.
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Kessler SH, Smith JD, Che DL, Worsnop DR, Wilson KR, Kroll JH. Chemical sinks of organic aerosol: kinetics and products of the heterogeneous oxidation of erythritol and levoglucosan. Environ Sci Technol 2010; 44:7005-7010. [PMID: 20707414 DOI: 10.1021/es101465m] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The heterogeneous oxidation of pure erythritol (C(4)H(10)O(4)) and levoglucosan (C(6)H(10)O(5)) particles was studied in order to evaluate the effects of atmospheric aging on the mass and chemical composition of atmospheric organic aerosol. In contrast to what is generally observed for the heterogeneous oxidation of reduced organics, substantial volatilization is observed in both systems. However, the ratio of the decrease in particle mass to the decrease in the concentration of the parent species is about three times higher for erythritol than for levoglucosan, indicating that details of chemical structure (such as carbon number, cyclic moieties, and oxygen-containing functional groups) play a governing role in the importance of volatilization reactions. The kinetics of the reaction indicate that while both compounds react at approximately the same rate, reactions of their oxidation products appear to be slowed substantially. Estimates of volatilities of organic species based on elemental composition measurements suggest that the heterogeneous oxidation of oxygenated organics may be an important loss mechanism of organic aerosol.
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Affiliation(s)
- Sean H Kessler
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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21
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Eoh H, Narayanasamy P, Brown AC, Parish T, Brennan PJ, Crick DC. Expression and characterization of soluble 4-diphosphocytidyl-2-C-methyl-D-erythritol kinase from bacterial pathogens. ACTA ACUST UNITED AC 2010; 16:1230-9. [PMID: 20064433 DOI: 10.1016/j.chembiol.2009.10.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Revised: 10/09/2009] [Accepted: 10/21/2009] [Indexed: 11/17/2022]
Abstract
Many bacterial pathogens utilize the 2-C-methyl-D-erythritol 4-phosphate pathway for biosynthesizing isoprenoid precursors, a pathway that is vital for bacterial survival and absent from human cells, providing a potential source of drug targets. However, the characterization of 4-diphosphocytidyl-2-C-methyl-D-erythritol (CDP-ME) kinase (IspE) has been hindered due to a lack of enantiopure CDP-ME and difficulty in obtaining pure IspE. Here, enantiopure CDP-ME was chemically synthesized and recombinant IspE from bacterial pathogens were purified and characterized. Although gene disruption was not possible in Mycobacterium tuberculosis, IspE is essential in Mycobacterium smegmatis. The biochemical and kinetic characteristics of IspE provide the basis for development of a high throughput screen and structural characterization.
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Affiliation(s)
- Hyungjin Eoh
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
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Narayanasamy P, Eoh H, Brennan PJ, Crick DC. Synthesis of 4-diphosphocytidyl-2-C-methyl-D-erythritol 2-phosphate and kinetic studies of Mycobacterium tuberculosis IspF. Chem Biol 2010; 17:117-22. [PMID: 20189102 PMCID: PMC2837070 DOI: 10.1016/j.chembiol.2010.01.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Revised: 01/22/2010] [Accepted: 01/29/2010] [Indexed: 10/19/2022]
Abstract
Many pathogenic bacteria utilize the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway for the biosynthesis of isopentenyl diphosphate and dimethylallyl diphosphate, two major building blocks of isoprenoid compounds. The fifth enzyme in the MEP pathway, 2-C-methyl-D-erythritol 2,4-cyclodiphosphate (ME-CPP) synthase (IspF), catalyzes the conversion of 4-diphosphocytidyl-2-C-methyl-D-erythritol 2-phosphate (CDP-ME2P) to ME-CPP with a corresponding release of cytidine 5-monophosphate (CMP). Because there is no ortholog of IspF in human cells, IspF is of interest as a potential drug target. However, study of IspF has been hindered by a lack of enantiopure CDP-ME2P. Herein, we report the first, to our knowledge, synthesis of enantiomerically pure CDP-ME2P from commercially available D-arabinose. Cloned, expressed, and purified M. tuberculosis IspF was able to utilize the synthetic CDP-ME2P as a substrate, a result confirmed by mass spectrometry. A convenient, sensitive, in vitro IspF assay was developed by coupling the CMP released during production of ME-CPP to mononucleotide kinase, which can be used for high throughput screening.
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Affiliation(s)
| | | | - Patrick J. Brennan
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences. Colorado State University, 1682 Campus Delivery, Fort Collins CO 80523-1682, USA
| | - Dean C. Crick
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences. Colorado State University, 1682 Campus Delivery, Fort Collins CO 80523-1682, USA
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Ershov IV, Mazikin KV, Ostrovskiĭ DN. [Screening of potential antibiotics, inhibitors of the nonmevalonate pathway of isoprenoid biosynthesis--2-C-methyl-D-erythritol-2,4-cyclodiphosphate derivatives]. Antibiot Khimioter 2010; 55:3-7. [PMID: 21033467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The recently discovered nonmevalonate pathway of isoprenoid biosynthesis is a prospective target in screening of new antibiotics. Because of the absence of the pathway in the animal cells, the specific inhibitors of the pathway will be a new class of antibiotics against many pathogens (which cause, e.g., malaria, tuberculosis, etc), combining high efficiency and low toxicity. Several derivatives of 2-C-methyl-D-erythritol-2,4-cyclodiphosphate (MEC) were synthesized. 4-Phospho-methyl-D-erythritol-1,2-cyclophosphate, benzyl ether and benzyliden derivative of MEC inhibited the 14C-MEC incorporation into isoprenoids of chromoplasts from red pepper with IC50 of 1.7-5 MM. Some inhibition (about 10%) was also observed with the use of dimethyl ether and isopropyliden derivative of MEC.
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Kim YB, Kim SM, Kang MK, Kuzuyama T, Lee JK, Park SC, Shin SC, Kim SU. Regulation of resin acid synthesis in Pinus densiflora by differential transcription of genes encoding multiple 1-deoxy-D-xylulose 5-phosphate synthase and 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase genes. Tree Physiol 2009; 29:737-749. [PMID: 19203978 DOI: 10.1093/treephys/tpp002] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Pinus densiflora Siebold et Zucc. is the major green canopy species in the mountainous area of Korea. To assess the response of resin acid biosynthetic genes to mechanical and chemical stimuli, we cloned cDNAs of genes encoding enzymes involved in the 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway (1-deoxy-d-xylulose 5-phosphate synthase (PdDXS), 1-deoxy-d-xylulose 5-phosphate reductoisomerase (PdDXR) and 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase (PdHDR)) by the rapid amplification of cDNA ends (RACE) technique. In addition, we cloned the gene encoding abietadiene synthase (PdABS) as a marker for the site of pine resin biosynthesis. PdHDR and PdDXS occurred as two gene families. In the phylogenetic trees, PdDXSs, PdDXR and PdHDRs each formed a separate clade from their respective angiosperm homologs. PdDXS2, PdHDR2 and PdDXR were most actively transcribed in stem wood, whereas PdABS was specifically transcribed. The abundance of PdDXS2 transcripts in wood in the resting state was generally 50-fold higher than the abundance of PdDXS1 transcripts, and PdHDR2 transcripts were more abundant by an order of magnitude in wood than in other tissues, with the ratio of PdHDR2 to PdHDR1 transcripts in wood being about 1. Application of 1 mM methyl jasmonate (MeJA) selectively enhanced the transcript levels of PdDXS2 and PdHDR2 in wood. The ratios of PdDXS2 to PdDXS1 and PdHDR2 to PdHDR1 reached 900 and 20, respectively, on the second day after MeJA treatment, whereas the transcript level of PdABS increased twofold by 3 days after MeJA treatment. Wounding of the stem differentially enhanced the transcript ratios of PdDXS2 to PdDXS1 and PdHDR2 to PdHDR1 to 300 and 70, respectively. The increase in the transcript levels of the MEP pathway genes in response to wounding was accompanied by two orders of magnitude increase in PdABS transcripts. These observations indicated that resin acid biosynthesis activity, represented by PdABS transcription, was correlated with the selective transcriptions of PdDXS2 and PdHDR2. Introduction of PdDXS2, PdHDR1 and PdHDR2 rescued their respective knockout Escherichia coli mutants, confirming that at least these three genes were functionally active. Intracellular targeting of the green fluorescent protein fused to the N-terminal 100 amino acid residues of these genes in the Arabidopsis transient expression system showed that the proteins were all targeted to the chloroplasts. Our results suggest that the MEP pathway regulates resin biosynthesis in the wood of P. densiflora by differential transcription of the multiple PdDXS and PdHDR genes.
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Affiliation(s)
- Yeon-Bok Kim
- Program in Applied Life Chemistry, Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea
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Xie Z, Kapteyn J, Gang DR. A systems biology investigation of the MEP/terpenoid and shikimate/phenylpropanoid pathways points to multiple levels of metabolic control in sweet basil glandular trichomes. Plant J 2008; 54:349-61. [PMID: 18248593 DOI: 10.1111/j.1365-313x.2008.03429.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The glandular trichome is an excellent model system for investigating plant metabolic processes and their regulation within a single cell type. We utilized a proteomics-based approach with isolated trichomes of four different sweet basil (Ocimum basilicum L.) lines possessing very different metabolite profiles to clarify the regulation of metabolism in this single cell type. Significant differences in the distribution and accumulation of the 881 highly abundant and non-redundant protein entries demonstrated that although the proteomes of the glandular trichomes of the four basil lines shared many similarities they were also each quite distinct. Correspondence between proteomic, expressed sequence tag, and metabolic profiling data demonstrated that differential gene expression at major metabolic branch points appears to be responsible for controlling the overall production of phenylpropanoid versus terpenoid constituents in the glandular trichomes of the different basil lines. In contrast, post-transcriptional and post-translational regulation of some enzymes appears to contribute significantly to the chemical diversity observed within compound classes for the different basil lines. Differential phosphorylation of enzymes in the 2-C-methyl-d-erythritol 4-phosphate (MEP)/terpenoid and shikimate/phenylpropanoid pathways appears to play an important role in regulating metabolism in this single cell type. Additionally, precursors for different classes of terpenoids, including mono- and sesquiterpenoids, appear to be almost exclusively supplied by the MEP pathway, and not the mevalonate pathway, in basil glandular trichomes.
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Affiliation(s)
- Zhengzhi Xie
- Department of Plant Sciences and BIO5 Institute, University of Arizona, Tucson, AZ 85721, USA
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26
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Yang L, Sun H, Weng S, Zhao K, Zhang L, Zhao G, Wang Y, Xu Y, Lu X, Zhang C, Wu J, Jia'er C. Terahertz absorption spectra of some saccharides and their metal complexes. Spectrochim Acta A Mol Biomol Spectrosc 2008; 69:160-6. [PMID: 17466571 DOI: 10.1016/j.saa.2007.03.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2006] [Accepted: 03/15/2007] [Indexed: 05/15/2023]
Abstract
In this work, THz absorption spectra of some saccharides and their metal complexes were measured. The main purpose of this work is to investigate the M-O vibrations, intermolecular and intramolecular hydrogen bonds and other vibrations in the FIR region using powerful spectroscopic techniques adopting the metal-sugar complexes prepared in our laboratory. The M-O vibrations in the FIR spectra of metal-sugar complexes indicate the formation of metal complexes. The THz spectrum of glucose below 100cm(-1) was measured at first to confirm the THz experimental method. Characteristic absorption bands in the spectra of various samples are observed. THz spectra of saccharides below 100cm(-1) often have several absorption bands, and different saccharides have various absorption peaks in the THz region, which may be used to distinguish different saccharides. The differences in the number of bands observed are related to different structures of the samples, and these absorption bands are related to the collective motion of molecules. But the THz spectra of their metal complexes are different from the ligands, and no band appears in the region below 50cm(-1) at the present experimental condition, which indicates that THz spectroscopy may also be helpful to identify the formation of metal-sugar complexes, and the changes after complexation in the THz spectra below 100cm(-1) may be related to different metal ions. The metal-sugar complexes with similar crystal structures resemble mid-IR spectra, but their THz spectra may have some differences.
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Affiliation(s)
- Limin Yang
- Institute of Heavy Ion Physics, Peking University, Beijing 100871, China.
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Munos JW, Pu X, Liu HW. Synthesis and analysis of a fluorinated product analogue as an inhibitor for 1-deoxy-D-xylulose 5-phosphate reductoisomerase. Bioorg Med Chem Lett 2007; 18:3090-4. [PMID: 18078746 DOI: 10.1016/j.bmcl.2007.11.062] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2007] [Revised: 11/12/2007] [Accepted: 11/15/2007] [Indexed: 11/19/2022]
Abstract
1-deoxy-D-xylulose 5-phosphate (DXP) reductoisomerase (DXR) is an NADPH-dependent enzyme catalyzing the rearrangement and reduction of DXP to methyl-D-erythritol 4-phosphate (MEP). Two mechanisms for this enzymatic reaction have been proposed, involving either an alpha-ketol rearrangement or a retroaldol/aldol rearrangement. In this study, a fluorinated product analogue, FCH(2)-MEP, was synthesized as a possible mechanism-based inactivator for DXR if the retroaldol/aldol mechanism is operative. FCH(2)-MEP was found to be a weak competitive inhibitor, and thus was unable to discriminate between the mechanisms. This result is due to the inability of the targeted enzyme, DXR, to oxidize FCH(2)-MEP to the aldehyde intermediate that is common to both mechanisms. While FCH(2)-MEP failed to act as a mechanism-based inactivator, the insight gained from this study will assist in the future design of inhibitors of DXR.
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Affiliation(s)
- Jeffrey W Munos
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas, Austin, TX 78712, USA
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Takada K, Bermingham A, O'Keefe BR, Wamiru A, Beutler JA, Le Grice SFJ, Lloyd J, Gustafson KR, McMahon JB. An HIV RNase H inhibitory 1,3,4,5-tetragalloylapiitol from the African plant Hylodendron gabunensis. J Nat Prod 2007; 70:1647-1649. [PMID: 17935297 DOI: 10.1021/np0702279] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A new compound, 1,3,4,5-tetragalloylapiitol ( 1), was isolated from the aqueous extract of the plant Hylodendron gabunensis and was found to be a potent inhibitor of RNase H enzymatic activity. The structure of 1 was elucidated by NMR analyses to be an apiitol ( 2) sugar moiety substituted with four gallic acid residues. Optical rotation measurements of the free sugar following basic hydrolysis indicated that the 3 S absolute configuration was the same as that of d-apiitol. Compound 1 inhibited HIV-1, HIV-2, and human RNase H with IC 50 values of 0.24, 0.13, and 1.5 microM, respectively, but it did not show inhibition of E. coli RNase H at 10 microM.
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Affiliation(s)
- Kentaro Takada
- Molecular Targets Development Program, Center for Cancer Research, National Cancer Institute, Building 1052, Room 121, Frederick, Maryland 21702-1201, USA
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Gonnissen Y, Remon JP, Vervaet C. Development of directly compressible powders via co-spray drying. Eur J Pharm Biopharm 2007; 67:220-6. [PMID: 17317123 DOI: 10.1016/j.ejpb.2006.12.021] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Revised: 12/21/2006] [Accepted: 12/22/2006] [Indexed: 11/26/2022]
Abstract
Continuous production of directly compressible powders was achieved by coprocessing acetaminophen and carbohydrates via spray drying. Binary and ternary powder mixtures containing drug substance and carbohydrates were prepared by co-spray drying and evaluated on spray drying processibility, powder hygroscopicity, flowability, and compactability. The influence of process parameters during spray drying on the compaction behaviour of drug/excipient mixtures was investigated via Heckel analysis. Erythritol, lactose, maltodextrin, and mannitol were efficient in co-spray drying with acetaminophen. However, lactose mixtures showed poor flowability. Spray dried mixtures containing mannitol and erythritol were characterised as non-hygroscopic, highly dense, and good flowing powders. Mannitol increased tablet tensile strength in contrast with the poor compactability of erythritol. Maltodextrin was selected for further experiments because it provided excellent tablet tensile strength. The use of erythritol, maltodextrin and mannitol in binary drug/excipient mixtures resulted in high process yields. Compacts of erythritol, mannitol, and maltodextrin were characterised by higher tablet tensile strength at higher spray drying temperatures due to the increased particle fragmentation of erythritol and mannitol mixtures and to the increased plastic deformation of maltodextrin formulations. A combination of erythritol, maltodextrin, and mannitol was selected for further formulation and process optimisation of co-spray dried powders for direct compression.
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Affiliation(s)
- Y Gonnissen
- Laboratory of Pharmaceutical Technology, Ghent University, Ghent, Belgium
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Usha R, Ramasami T. Stability of collagen with polyols against guanidine denaturation. Colloids Surf B Biointerfaces 2007; 61:39-42. [PMID: 17720461 DOI: 10.1016/j.colsurfb.2007.07.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2007] [Revised: 07/04/2007] [Accepted: 07/08/2007] [Indexed: 11/28/2022]
Abstract
The effect of polyol osmolytes such as erythritol, xylitol and sorbitol on the protection of collagen against guanidine hydrochloride (GdmCl) was studied using circular dichroism and fluorescence spectroscopy. Collagen was denatured by various concentrations of GdmCl in the presence of polyols. The absorbance was high for GdmCl treated collagen than native and polyols treated analogue. Fluorescence emission properties were studied at the excitation wavelength of 235 nm. The emission wavelength is red shifted from 308 to 370 nm for GdmCl treated collagen with polyols. Increasing the concentration of GdmCl did not affect the peak position. CD studies proved that the aggregation of collagen in the presence of lower concentrations of GdmCl. At higher concentrations of GdmCl due to the loss of secondary structure no clear CD spectra were observed. This shows that the unfolding of collagen is closely related to GdmCl concentrations. The ability of the polyols to protect collagen against guanidine denaturation decreased in order from erythritol to xylitol to sorbitol. The presence of OH group in the solvent structure is important for stabilization of collagen due to the formation of additional stabilizing hydrogen bonds.
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Affiliation(s)
- R Usha
- Biophysics Laboratory, Central Leather Research Institute, Adyar, Chennai, India.
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Abstract
Optically active 2-C-trifluoromethylerythritols, analogues of 2-C-methylerythritol, which is a key intermediate in the biosynthesis of isoprenoid with a mevalonate-independent route, were conveniently synthesized from 1,1,1-trifluoro-2,3-epoxypropane.
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Affiliation(s)
- Hua Wang
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Science, 354 Fenglin Road, Shanghai 200032, China
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32
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Mastovská K, Lehotay SJ, Anastassiades M. Combination of analyte protectants to overcome matrix effects in routine GC analysis of pesticide residues in food matrixes. Anal Chem 2007; 77:8129-37. [PMID: 16351165 DOI: 10.1021/ac0515576] [Citation(s) in RCA: 159] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Analyte protectants were previously defined as compounds that strongly interact with active sites in the gas chromatographic (GC) system, thus decreasing degradation, adsorption, or both of coinjected analytes. In this study, we evaluated various combinations of promising analyte protectants for the volatility range of GC-amenable pesticides using GC/quadrupole mass spectrometry (MS) and 1-microL hot splitless injection for sample introduction. A mixture of ethylglycerol, gulonolactone, and sorbitol (at 10, 1, and 1 mg/mL, respectively, in the injected samples) was found to be the most effective in minimizing losses of susceptible analytes and significantly improving their peak shapes (due to reduction of peak tailing). When added to final sample extracts and matrix-free calibration standards alike, these analyte protectants induced a similar response enhancement in both instances, resulting in effective equalization of the matrix-induced response enhancement effect even after a large number of fruit and vegetable extract injections. As compared to matrix-matched standardization, the analyte protectant approach offers a more convenient solution to the problems associated with calibration in routine GC/MS analysis of pesticide residues and possibly other susceptible analyte types in diverse samples. Moreover, the use of analyte protectants also substantially reduced another adverse matrix-related effect caused by gradual build-up of nonvolatile matrix components in the GC system, thus improving ruggedness and, consequently, reducing need for frequent maintenance.
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Affiliation(s)
- Katerina Mastovská
- Agricultural Research Service, Eastern Regional Research Center, U.S. Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA
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Grauvogel C, Petersen J. Isoprenoid biosynthesis authenticates the classification of the green alga Mesostigma viride as an ancient streptophyte. Gene 2007; 396:125-33. [PMID: 17433859 DOI: 10.1016/j.gene.2007.02.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2007] [Revised: 02/23/2007] [Accepted: 02/27/2007] [Indexed: 10/23/2022]
Abstract
Land plants harbor two essential and completely different metabolic pathways for isoprenoid synthesis. The cytosolic mevalonate pathway (MVA) is shared with heterotrophic eukaryotes, whereas the plastidial 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway has a cyanobacterial origin and was recruited after primary endosymbiosis. Terrestrial plants and green algae have a common evolutionary ancestry, but biochemical as well as genome analyses indicate that the cytosolic MVA pathway is generally absent from Chlorophyta. We investigated the distribution of genes for both pathways in the green alga Mesostigma viride, a key species at the basis of streptophycean (charophycean green algae, land plant) evolution. Ten of altogether twelve generally weakly expressed genes for isoprenoid biosynthesis, including three for the cytosolic MVA pathway, were amplified using a reverse transcription PCR approach with individually designed degenerate primers. Two full length cDNA clones for the first enzyme of the MVA pathway (HMGS) were additionally established from the charophycean green alga Chara vulgaris by library screening. The presence of the MVA pathway in these advanced green algae indicates a universal distribution among Streptophyta, and our phylogenetic HMGS analyses substantiate the recent classification of Mesostigma basal to charophytes and land plants. We identified each of the five cytosolic MVA genes/cDNAs in the genome of the rhodophyte Galdieria sulphuraria and, furthermore, amplified four of them from the glaucophyte Cyanophora paradoxa. Our data indicate that the MVA pathway is a characteristic trait of Plantae in general and propose that it was specifically lost in a common ancestor of Chlorophyta.
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Affiliation(s)
- Carina Grauvogel
- Institut für Genetik, Technische Universität Braunschweig, Spielmannstrasse 7, D-38106 Braunschweig, Germany
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Ershov IV. [2-C-Methylerythritol phosphate pathway of isoprenoid biosynthesis as a target in identifying of new antibiotics, herbicides, and immunomodulators (Review) ]. Prikl Biokhim Mikrobiol 2007; 43:133-57. [PMID: 17476799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Specific inhibitors of 2-C-methylerythritol phosphate pathway (MEP-pathway), including compounds obtained based on its metabolites, may compose a new class of antibiotics combining high efficiency and low toxicity. MEP-pathway of isoprenoid biosynthesis is a promising target in identifying new herbicides, immunomodulators, and other physiologically active compounds.
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Goncharenko AV, Ershov IV, Salina EG, Wiesner J, Vostroknutova GN, Sandanov AA, Kapel'iants AS, Ostrovskiĭ DN. [The role of 2-C-methylerythritol-2,4-cyclopyrophosphate in the resuscitation of the "nonculturable" forms of Mycobacterium smegmatis]. Mikrobiologiia 2007; 76:172-8. [PMID: 17583212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
2-C-Methyl-D-erythritol-2,4-cyclopyrophosphate (MEC), an intermediate of the biosynthesis of isoprenoid compounds in bacteria, was found to be capable of exerting a resuscitating effect on resting Mycobacterium smegmatis cells. The introduction of an additional copy of the ispE gene encoding cytidyl-methylerythritol kinase, an enzyme involved in MEC synthesis in M. smegmatis, resulted in the emergence of a capacity for spontaneous reactivation of "nonculturable" M. smegmatis cells, which is not characteristic of the wild-type cells of this species. The involvement of MEC in the transition from the "nonculturable" state to the state of active growth is indicative of a previously unknown function of MEC, assumed to consist in regulation of the bacterial genome activity.
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Adeuya A, Price N. Rapid characterization of polyalcohols by silylation and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Rapid Commun Mass Spectrom 2007; 21:3977-3981. [PMID: 17994528 DOI: 10.1002/rcm.3302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry method for rapidly enumerating hydroxyl groups in analytes is described, and applied to some common polyalcohols (erythritol, mannitol and xylitol). Polyalcohols were derivatized with trimethylsilylimidazole (TMSI) either separately or as mixtures, and were analyzed, without chromatographic separation or purification. The mass spectra revealed consecutive peaks that are separated by 72 m/z units as a consequence of displacement of one hydroxyl hydrogen atom by one TMS group. The number of observed peaks was used to confirm the number of hydroxyl groups in each analyte.
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Affiliation(s)
- Anthony Adeuya
- U.S. Department of Agriculture, Agricultural Research Service-NCAUR, Bioproducts and Biocatalysis Research Unit, 1815 North University Street, Peoria, IL 61604, USA.
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Abstract
The first enantioselective synthesis of C(3) fluoro-MEP is herein reported. The synthetic pathway developed takes advantage of a selective hydrofluorination of a 2,3-epoxy-1-alcohol to introduce the required tertiary fluoride unit.
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Kim SM, Kuzuyama T, Chang YJ, Kwon HJ, Kim SU. Cloning and functional characterization of 2-C-methyl-D-erythritol 4-phosphate cytidyltransferase (GbMECT) gene from Ginkgo biloba. Phytochemistry 2006; 67:1435-41. [PMID: 16828818 DOI: 10.1016/j.phytochem.2006.05.034] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2006] [Revised: 04/27/2006] [Accepted: 05/24/2006] [Indexed: 05/10/2023]
Abstract
2-C-methyl-D-erythritol 4-phosphate cytidyltransferase (MECT), the third enzyme of the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway, catalyzes formation of 4-(cytidine 5'-diphospho)-2-C-methyl-D-erythritol from MEP. GbMECT, presumably involved in ginkgolide biosynthesis, was cloned and characterized from Ginkgo biloba embryonic roots. The protein containing the N-terminal chloroplast transit peptide consisted of 327 amino acid residues. Complementation of GbMECT with Escherichia coli NMW33, ygbP (EcMECT) knock-out mutant, rescued the mutant, confirming the function of the protein. Transcription levels of GbMECT remained generally constant in embryonic roots and leaves for 1 month. Full 88 N-terminal residues were necessary to deliver the protein into the chloroplast as shown by protein-targeting analysis with GFP as a reporter protein in Arabidopsis thaliana protoplasts.
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Affiliation(s)
- Sang-Min Kim
- Program in Applied Life Chemistry, School of Agricultural Biotechnology, Seoul National University, Sinlim-dong, Gwanak-gu, Seoul 151-921, Republic of Korea; Plant Metabolism Research Center, Kyung Hee University, Yongin 449-701, Republic of Korea
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Lopes Jesus AJ, Tomé LIN, Eusébio MES, Redinha JS. Determination of the Enthalpy of Solute−Solvent Interaction from the Enthalpy of Solution: Aqueous Solutions of Erythritol and l-Threitol. J Phys Chem B 2006; 110:9280-5. [PMID: 16671745 DOI: 10.1021/jp0561221] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this work the enthalpy of the solute-solvent interaction of erythritol and L-threitol in aqueous solution was determined from the values obtained for the enthalpy of solvation. The values for this property were calculated from those determined for the enthalpies of solution and sublimation. To determine the values of the enthalpy of solute-solvent interaction, the solvation process is considered as taking place in three steps: opening a cavity in the solvent to hold the solute molecule, changing the solute conformation when it passes from the gas phase into solution, and interaction between the solute and the solvent molecules. The cavity enthalpy was calculated by the scaled particle theory and the conformational enthalpy change was estimated from the value of this function in the gas phase and in solution. Both terms were determined by DFT calculations. The solvent effect on the solute conformation in solution was estimated using the CPCM solvation model. The importance of the cavity and conformational terms in the interpretation of the enthalpy of solvation is noted. While the cavity term has been used by some authors, the conformational term is considered for the first time. The structural features in aqueous solution of erythritol and L-threitol are discussed.
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Affiliation(s)
- A J Lopes Jesus
- Department of Chemistry, University of Coimbra, 3004-535, Coimbra, Portugal
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Traini D, Young PM, Jones M, Edge S, Price R. Comparative study of erythritol and lactose monohydrate as carriers for inhalation: atomic force microscopy and in vitro correlation. Eur J Pharm Sci 2005; 27:243-51. [PMID: 16330191 DOI: 10.1016/j.ejps.2005.10.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2005] [Revised: 10/04/2005] [Accepted: 10/11/2005] [Indexed: 11/29/2022]
Abstract
The adhesion of micronised salbutamol sulphate to two carrier excipients, lactose monohydrate and erythritol, was investigated using the atomic force microscope (AFM) colloid probe technique and correlated with their respective physico-mechanical properties and aerosolisation performance. The particle size, morphology and moisture sorption properties of the carriers were similar thereby allowing direct comparison of functionality. AFM force measurements (n = 1024 force curves) were obtained between salbutamol sulphate drug probes (n = 4) and the excipients, as 63-90 microm sieve fractions and atomically smooth crystals. In general, significant differences in drug adhesion to lactose monohydrate and erythritol were observed (ANOVA, p<0.05), with erythritol exhibiting relatively greater adhesiveness. A linear relationship between drug probe adhesion to lactose monohydrate and drug probe adhesion to erythritol was established with salbutamol sulphate-lactose monohydrate adhesion being 60-70% of that of the erythritol system. In vitro analysis suggested good correlation with the adhesion measurements. The aerosolisation of salbutamol sulphate from erythritol carrier particles was significantly less (ANOVA, p<0.05) than from lactose monohydrate, with a fine particle dose (<6.4 microm) of 41.9 +/- 7.4 microg and 24.9 +/- 3.1 microg for the lactose monohydrate and erythritol carriers, respectively (n = 3).
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Affiliation(s)
- Daniela Traini
- Advanced Drug Delivery Group, Faculty of Pharmacy (A15), University of Sydney, NSW 2006, Australia
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Yang L, Xu Y, Wang Y, Zhang S, Weng S, Zhao K, Wu J. Interactions between metal ions and carbohydrates. The coordination behavior of neutral erythritol to lanthanum and erbium ions. Carbohydr Res 2005; 340:2773-81. [PMID: 16289000 DOI: 10.1016/j.carres.2005.10.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2005] [Accepted: 09/30/2005] [Indexed: 11/21/2022]
Abstract
Lanthanide ions and erythritol form metal-alditol complexes with various structures. Lanthanum nitrate and erbium chloride coordinate to erythritol to give new coordination structures. The lanthanum nitrate-erythritol complex (LaEN), 2La(NO3)3.C4H10O(4).8H2O, La3+ exhibits the coordination number of 11 (namely 11 polar atoms bound to one lanthanum) and is 11-coordinated to two hydroxyl groups from one erythritol molecule, six oxygen atoms from three nitrate ions and three water molecules. One erythritol molecule is coordinated to two La3+ ions and links the two metal ions together. The ratio of M:L is 2:1. The erbium chloride-erythritol complex (ErE), ErCl2.C4H9O(4).2C2H5OH was obtained from ErCl3 and erythritol in aqueous ethanol solution and the structure shows that deprotonation reaction occurs in the reaction process. The Er3+ cation is 8-coordinated with three hydroxyl groups of one erythritol molecule, two hydroxyl groups from another erythritol molecule, two ethanol molecules, and one chloride ion. Erythritol provides its three hydroxyl groups to one erbium cation and two hydroxyl groups to another erbium cation, that is, one hydroxyl group is coordinated to two metal ions and therefore loses its hydrogen atom and becomes a oxygen bridge. Another chloride ion is hydrogen bonded in the structure. The results indicate the complexity of metal-sugar coordination.
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Affiliation(s)
- Limin Yang
- The State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
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Abstract
The mechanism of the reaction catalyzed by 2-C-methyl-d-erythritol 4-phosphate (MEP) synthase from Escherichia coli has been studied by steady-state and single-turnover kinetic experiments for the 1-deoxy-d-xylulose 5-phosphoric acid (DXP) analogues, 1,1,1-trifluoro-1-deoxy-d-xylulose 5-phosphoric acid (CF(3)-DXP), 1,1-difluoro-1-deoxy-d-xylulose 5-phosphoric acid (CF(2)-DXP), 1-fluoro-1-deoxy-d-xylulose 5-phosphoric acid (CF-DXP), and 1,2-dideoxy-d-hexulose 6-phosphate (Et-DXP). CF(3)-DXP, CF(2)-DXP, and Et-DXP were poor inhibitors, most likely because of the increase in steric bulk at C1 of DXP. The three analogues were also poor substrates for the enzyme. In contrast, CF-DXP was a good substrate (k(cat)(CF)(-)(DXP) = 37 +/- 2 s(-)(1), K(m)(CF)(-)(DXP) = 227 +/- 25 microM) for MEP synthase when compared to DXP (k(cat)(DXP) = 29 +/- 1 s(-)(1), K(m)(DXP) = 45 +/- 4 microM). A primary deuterium isotope effect was observed under single-turnover conditions when CF-DXP was incubated with 4S-[(2)H]NADPH ((H)k/(D)k = 1.34 +/-0.01), whereas no isotope effect was observed upon incubation with DXP and 4S-[(2)H]NADPH ((H)k/(D)k = 1.02 +/- 0.02). The reaction did not exhibit burst kinetics for either substrate, indicating that product release is not rate-limiting. These studies suggest that positive charge does not develop at C2 of DXP during catalysis. In addition, the isotope effect with CF-DXP and 4S-[(2)H]NADPH but not DXP indicates that the rearrangement step, which precedes hydride transfer, is rate-limiting for DXP but becomes partially rate-limiting for CF-DXP. Thus, rearrangement appears to be enhanced by substitution of a hydrogen atom in the methyl group of DXP by fluorine. These observations are consistent with a retro-aldol/aldol mechanism for the rearrangement during conversion of DXP to MEP.
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Affiliation(s)
- David T Fox
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, USA
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Li Q, Ricardo A, Benner SA, Winefordner JD, Powell DH. Desorption/Ionization on Porous Silicon Mass Spectrometry Studies on Pentose−Borate Complexes. Anal Chem 2005; 77:4503-8. [PMID: 16013866 DOI: 10.1021/ac050258d] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Desorption/ionization on porous silicon mass spectrometry (DIOS-MS) was used to investigate the binding affinities between aldopentose isomers and boron. Boron has been recognized for its importance in pentose synthesis and stabilization in prebiotic conditions. Boron may also account for the fact that ribose, among other aldopentoses, is the favored building block in RNA synthesis. This research started with the detection of aldopentoses in the positive mode through cationization and the aldopentose-borate complexes in the negative mode. Then two competition schemes, one using a pentose structure analogue and the other using 13C-labeled ribose, were designed to compare the relative binding affinities of four aldopentoses (xylose, lyxose, arabinose, and ribose) to boron. Both approaches determined the binding preference to be ribose > lyxose > arabinose > xylose. This work illustrates the potential of DIOS-MS in the analyses of nonvolatile, small molecules in delicate chemical equilibria. Without externally introduced matrices, background signals are not a limiting factor. Furthermore, the possible dramatic change of pH associated with the matrix introduction, which may disturb the equilibria of interest, is avoided.
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Affiliation(s)
- Qian Li
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, USA
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Saakov VS. Pools of 14C-malic acid as a substrate for pyruvate production for the DOXP/MEP pathway of biosynthesis of carotenoids in chloroplasts. DOKL BIOCHEM BIOPHYS 2005; 400:7-13. [PMID: 15846973 DOI: 10.1007/s10628-005-0020-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- V S Saakov
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St Petersburg, 194223 Russia
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Chapman TM, Davies IG, Gu B, Block TM, Scopes DIC, Hay PA, Courtney SM, McNeill LA, Schofield CJ, Davis BG. Glyco- and peptidomimetics from three-component Joullié-Ugi coupling show selective antiviral activity. J Am Chem Soc 2005; 127:506-7. [PMID: 15643858 DOI: 10.1021/ja043924l] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Chlorination-elimination chemistry coupled with three-component Joullié-Ugi reaction and facile deprotection allowed efficient access to an array of polyhydroxylated pyrrolidines through parallel synthesis that may be considered to be a library of imino (aza) sugars (glycomimetics) and/or dihydroxyprolyl peptides (peptidomimetics). The utility of generating such a library was illustrated by screening against 15 different targets that revealed potent and selective inhibition of the Gaucher's disease glycosyltransferase enzyme glucosylceramide synthase and of primary pathogen model for human hepatitis C virus (HCV) and bovine diarrhoeal virus (BVDV). An observed selectivity for this HCV model over hepatitis B virus and remarkably low toxicity suggest a novel mode of action.
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Affiliation(s)
- Timothy M Chapman
- Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford UK, OX1 3TA
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Jesus AJL, Tomé LIN, Rosado MTS, Leitão MLP, Redinha JS. Conformational study of erythritol and threitol in the gas state by density functional theory calculations. Carbohydr Res 2005; 340:283-91. [PMID: 15639248 DOI: 10.1016/j.carres.2004.11.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2004] [Revised: 11/26/2004] [Accepted: 11/27/2004] [Indexed: 10/26/2022]
Abstract
Density functional theory calculations using the B3LYP functional and the 6-311++G(d,p) basis set were carried out on the isolated molecules of erythritol and L-threitol. For the meso isomer, a relatively large number of conformers have to be considered to describe the gas state structure. The lowest energy conformer is characterized by the establishment of a strong intramolecular H-bond between the two terminal hydroxyl groups, giving rise to a seven-membered ring and two additional weaker H-bonds between vicinal OH groups. In the case of L-threitol, two conformers are predominant in the gas state, and both are stabilized by the formation of a cyclic system of four intramolecular hydrogen bonds involving all OH groups. The conformational stability in both diastereomers is discussed in terms of the electronic energy and of the Gibbs energy. The weighted mean enthalpy of both diastereomers in the gas state at 298.15 K was obtained from the thermodynamic data and Boltzmann populations of the low-energy conformers.
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Hampel D, Mosandl A, Wüst M. Biosynthesis of mono- and sesquiterpenes in carrot roots and leaves (Daucus carota L.): metabolic cross talk of cytosolic mevalonate and plastidial methylerythritol phosphate pathways. Phytochemistry 2005; 66:305-311. [PMID: 15680987 DOI: 10.1016/j.phytochem.2004.12.010] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2004] [Revised: 12/07/2004] [Indexed: 05/24/2023]
Abstract
The biosynthesis of the monoterpenes terpinolene and myrcene and the sesquiterpene beta-caryophyllene in roots and leaves of two carrot varieties (Daucus carota L. cultivars Bolero and Kazan) were investigated by in vivo feeding experiments with [5,5-2H2]-mevalonic acid lactone (d2-MVL) and [5,5-2H2]-1-deoxy-D-xylulose (d2-DOX). The volatiles of the tissues were extracted by stir bar sorptive extraction and analyzed using thermal desorption-multidimensional gas chromatography-mass spectrometry. The experiments demonstrate independent de novo-biosynthesis of terpenoids in carrot roots and in carrot leaves. In both plant tissues monoterpenes are biosynthesized exclusively via the 1-deoxy-D-xylulose/2-C-methyl-D-erythritol-4-phosphate (DOXP/MEP) pathway, whereas sesquiterpenes are generated by the classical mevalonic acid pathway as well as by the DOXP/MEP route. A more detailed investigation of carrot root tissues revealed that the biosynthesis of terpenes is mainly localized in the phloem. Nevertheless, in xylem a de novo-biosynthesis of terpenes was detectable as well, even in the absence of oil ducts in this tissue.
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Affiliation(s)
- Daniela Hampel
- Institut für Lebensmittelchemie, Johann Wolfgang Goethe-Universität, Marie-Curie-Strasse 9, D-60439 Frankfurt/Main, Germany
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Watkins MA, Winger BE, Shea RC, Kenttämaa HI. Ion−Molecule Reactions for the Characterization of Polyols and Polyol Mixtures by ESI/FT-ICR Mass Spectrometry. Anal Chem 2005; 77:1385-92. [PMID: 15732922 DOI: 10.1021/ac049031t] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A mass spectrometric method is described for the identification and counting of hydroxyl groups in an analyte. Analytes introduced into a FT-ICR mass spectrometer and ionized by positive mode ESI were allowed to react with the neutral reagent diethylmethoxyborane. This results in derivatization of the hydroxyl groups of the analytes by replacement of a proton with a diethylborenium ion. Protonated polyols react by consecutive derivatization reactions, wherein all, or nearly all, of the hydroxyls are derivatized. The polyol derivatization products are separated by 68 mass units in the mass spectrum. This 68 Da mass shift, along with 30 Da mass shifts arising from intramolecular derivatization of the primary derivatization products, makes it easy to count the number of functional groups present in the analyte. The utility of this method for the analysis of polyols as single-component solutions, as mixtures, or in HPLC effluent (LC-MS analysis) is demonstrated.
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Affiliation(s)
- Michael A Watkins
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, and Eli Lilly and Company, Indianapolis, Indiana 46285, USA
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Endo K, Amikawa S, Matsumoto A, Sahashi N, Onoue S. Erythritol-based dry powder of glucagon for pulmonary administration. Int J Pharm 2005; 290:63-71. [PMID: 15664131 DOI: 10.1016/j.ijpharm.2004.11.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2004] [Revised: 11/18/2004] [Accepted: 11/21/2004] [Indexed: 11/15/2022]
Abstract
Glucagon, a key regulatory element of glycogen metabolism, is known to be effective in the clinical treatment of hypoglycemia and the maintenance of normal circulating glucose levels in patients with total pancreatectomy, however the clinical use of this gut hormone has been restricted to parenteral administration. In this investigation, we prepared dry powder dosage forms of glucagon, which were formulated by mixing micronized glucagon particles and excipients with larger carrier particles. To achieve alveolar deposition for subsequent systemic absorption, a dry powder inhalant (DPI) of glucagon was size-reduced to a mass median diameter between 1 and 6 microm, as measured by laser diffraction analysis. The use of erythritol as both excipient and carrier in DPI of glucagon resulted in high and reproducible flowability and dispersibility of the powder mixtures, and therefore it provided a low dosing of the active substances. Distinct transpulmonary absorption of glucagon was confirmed after intratracheal administration of the glucagon dry powder to anesthetized rats, as evidenced by the increase in the blood glucagon and blood sugar levels. These results suggested the usefulness of an erythritol-based powder form of glucagon for systemic administration.
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Affiliation(s)
- Kosuke Endo
- Pharmaceutical Division, Ito Life Sciences Inc., 1-2-1 Kubogaoka, Moriya, Ibaraki 302-0104, Japan
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Klewicki R, Klewicka E. Antagonistic activity of lactic acid bacteria as probiotics against selected bacteria of the Enterobaceriacae family in the presence of polyols and their galactosyl derivatives. Biotechnol Lett 2004; 26:317-20. [PMID: 15055768 DOI: 10.1023/b:bile.0000015450.59100.60] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Probiotic lactic acid bacteria were grown on erythritol, xylitol, sorbitol or lactitol and produced various derivatives: gal-erythritol, gal-xylitol, and gal-sorbitol as prebiotics. Galactosyl derivatives of erythritol, xylitol and sorbitol were metabolised by Lactobacillus spp. This resulted in their antagonistic activity against the test microflora. No activity was observed in the presence of xylitol and erythritol. Gal-sorbitol obtained by enzymatic transglycosylation from lactose had the same abilities of inducing the antagonistic activity of lactic acid bacteria that lactitol had.
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Affiliation(s)
- Robert Klewicki
- Institute of Chemical Technology of Food, Technical University of Lodz, 4/10 Stefanowskiego Street, 90-924 Lodz, Poland.
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