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Bertelmann C, Mock M, Schmid A, Bühler B. Efficiency aspects of regioselective testosterone hydroxylation with highly active CYP450-based whole-cell biocatalysts. Microb Biotechnol 2024; 17:e14378. [PMID: 38018939 PMCID: PMC10832557 DOI: 10.1111/1751-7915.14378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 11/12/2023] [Indexed: 11/30/2023] Open
Abstract
Steroid hydroxylations belong to the industrially most relevant reactions catalysed by cytochrome P450 monooxygenases (CYP450s) due to the pharmacological relevance of hydroxylated derivatives. The implementation of respective bioprocesses at an industrial scale still suffers from several limitations commonly found in CYP450 catalysis, that is low turnover rates, enzyme instability, inhibition and toxicity related to the substrate(s) and/or product(s). Recently, we achieved a new level of steroid hydroxylation rates by introducing highly active testosterone-hydroxylating CYP450 BM3 variants together with the hydrophobic outer membrane protein AlkL into Escherichia coli-based whole-cell biocatalysts. However, the activity tended to decrease, which possibly impedes overall productivities and final product titres. In this study, a considerable instability was confirmed and subject to a systematic investigation regarding possible causes. In-depth evaluation of whole-cell biocatalyst kinetics and stability revealed a limitation in substrate availability due to poor testosterone solubility as well as inhibition by the main product 15β-hydroxytestosterone. Instability of CYP450 BM3 variants was disclosed as another critical factor, which is of general significance for CYP450-based biocatalysis. Presented results reveal biocatalyst, reaction and process engineering strategies auguring well for industrial implementation of the developed steroid hydroxylation platform.
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Affiliation(s)
| | - Magdalena Mock
- Department of Solar MaterialsLeipzigGermany
- Present address:
Department of Mechanical Engineering and Material SciencesGeorg Agricola University of Applied SciencesBochumGermany
| | | | - Bruno Bühler
- Department of Solar MaterialsLeipzigGermany
- Department of Microbial BiotechnologyHelmholtz Centre for Environmental Research GmbH–UFZLeipzigGermany
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Benucci I, Mazzocchi C, Lombardelli C, Del Franco F, Cerreti M, Esti M. Inclusion of curcumin in b-cyclodextrin: a promising prospective as food ingredient. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2022; 39:1942-1952. [PMID: 36255357 DOI: 10.1080/19440049.2022.2135764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In the present work, the inclusion complexes between curcumin (CC) and β-cyclodextrin (β-CD) were obtained through co-precipitation at different times of magnetic stirring and simple mixing. The stoichiometric ratio between CC and β-CD was ascertained to be 1:2. The samples prepared by co-precipitation (24 h magnetic stirring and 24 h cold static precipitation) and by simple mixing, showed the best performance in terms of powder recovery (72 and 97%, respectively), encapsulation efficiency (72 and 95%, respectively) and tinting power, while no significant differences were revealed in terms of loading capacity (about 14%). Using either inclusion method, the complexation of CC into β-CD make the colorant 20-fold more water soluble than pure CC. The pigment stability was also enhanced under different storage conditions (high temperature and light exposure), either when applied in liquid or gel state. However, after 30 days under natural light exposure, an appreciable colour change from yellow to orange was revealed to an extent probably perceptible by an inexperienced observer.
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Affiliation(s)
- Ilaria Benucci
- Department of Agriculture and Forestry Science (DAFNE), Tuscia University, Viterbo, Italy
| | - Caterina Mazzocchi
- Department of Agriculture and Forestry Science (DAFNE), Tuscia University, Viterbo, Italy
| | - Claudio Lombardelli
- Department of Agriculture and Forestry Science (DAFNE), Tuscia University, Viterbo, Italy
| | - Felicia Del Franco
- Department of Agriculture and Forestry Science (DAFNE), Tuscia University, Viterbo, Italy
| | - Martina Cerreti
- Department of Agriculture and Forestry Science (DAFNE), Tuscia University, Viterbo, Italy
| | - Marco Esti
- Department of Agriculture and Forestry Science (DAFNE), Tuscia University, Viterbo, Italy
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Royal Jelly Components Encapsulation in a Controlled Release System—Skin Functionality and Biochemical Activity for Skin Applications. Pharmaceuticals (Basel) 2022; 15:ph15080907. [PMID: 35893731 PMCID: PMC9332036 DOI: 10.3390/ph15080907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/15/2022] [Accepted: 07/19/2022] [Indexed: 02/06/2023] Open
Abstract
Royal jelly is a yellowish-white substance with a gel texture that is secreted from the hypopharyngeal and mandibular glands of young worker bees. It consists mainly of water (50–56%), proteins (18%), carbohydrates (15%), lipids (3–6%), minerals (1.5%), and vitamins, and has many beneficial properties such as antimicrobial, anti-inflammatory, anticancer, antioxidant, antidiabetic, immunomodulatory, and anti-aging. Royal jelly has been used since ancient times in traditional medicine, cosmetics and as a functional food due to its high nutritional value. The main bioactive substances are royalactin, and 10-hydroxy-2-decenoic acid (10-HDA). Other important bioactive molecules with antioxidant and photoprotective skin activity are polyphenols. However, they present difficulties in extraction and in use as they are unstable physicochemically, and a higher temperature causes color change and component degradation. In the present study, a new encapsulation and delivery system consisting of liposomes and cyclodextrins incorporating royal jelly has been developed. The new delivery system aims to the elimination of the stability disadvantages of royal jelly’s sensitive component 10-HDA, but also to the controlled release of its ingredients and, more particularly, 10-HDA, for an enhanced bioactivity in cosmeceutical applications.
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Suresh A, Narayan R, Nayak UY. Recent advances in the development of asenapine formulations. Expert Opin Drug Deliv 2020; 17:1377-1393. [PMID: 32633149 DOI: 10.1080/17425247.2020.1792439] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Asenapine maleate (AM) is an atypical antipsychotic agent, that has been widely prescribed for the management of schizoaffective disorders. However, the bioavailability of AM is extremely poor due to the extensive first-pass metabolism. With the advancement in pharmaceutical technologies, significant strides have been made to create novel formulations to address the bioavailability problem of AM. AREAS COVERED This review article provides an insight into all the formulation approaches undertaken by researchers to increase the bioavailability of AM encompassing the works utilizing ultrasound mediated transdermal delivery, nose to brain delivery, intestinal lymphatic system targeting, in situ implants, etc. All the patents associated with AM formulation have also been discussed and summarized. EXPERT OPINION Numerous studies have been carried out on AM formulations over the recent years, many of these studies have shown significant improvement in bioavailability. We have also mentioned the unexplored domains which can be exploited for further enhancing the bioavailability of AM. Nonetheless, most of these studies are still limited to the research laboratory level and face multiple hurdles before making into the market. Attaining controllability and reproducibility for the production of novel formulations is needed to enable its transition from bench to bedside.
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Affiliation(s)
- Akhil Suresh
- Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education , Manipal, India
| | - Reema Narayan
- Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education , Manipal, India
| | - Usha Y Nayak
- Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education , Manipal, India
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Altin A, Vimalanandan A, Sarfraz A, Rohwerder M, Erbe A. Pretreatment with a β-Cyclodextrin-Corrosion Inhibitor Complex Stops an Initiated Corrosion Process on Zinc. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:70-77. [PMID: 30525645 DOI: 10.1021/acs.langmuir.8b03441] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Metal pretreatment is typically the first step in a reliable corrosion protection system. This work explores the incorporation of complexes between the cyclic oligosaccharide β-cyclodextrin (β-CD) and the molecular organic corrosion inhibitor 2-mercaptobenzothiazole (MBT) into an oxide-based pretreatment layer on metallic zinc. The layers were produced by a precorrosion step in the presence of β-CD. The resulting films have a morphology dominated by spherical particles. X-ray photoelectron spectroscopy investigations of the surfaces show the sulfur atoms of MBT to be partially oxidized but mostly intact. Samples pretreated with such a layer were subsequently coated with a model polymer coating, and the delamination of this model coating from an artificial defect was monitored by a scanning Kelvin probe (SKP). The SKP results show a slow down of delamination after several hours of the ongoing corrosion process for surfaces pretreated with the complexes. Finally, an increase in the electrode potential in the defect was observed, with a subsequent complete stop in delamination and repassivation of the defect after ≈10 h. This repassivation is attributed to the release of MBT after the initiation of the corrosion process. Most likely, the increase of pH, combined with the availability of aqueous solution, facilitates the MBT release after the initiation of a corrosion process. Consequently, complexes formed from β-CD and corrosion inhibitors can be effectively incorporated into inorganic pretreatments, and the inhibitor component can be released upon start of the corrosion process.
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Affiliation(s)
- Abdulrahman Altin
- Max-Planck-Institut für Eisenforschung GmbH , Max-Planck-Str. 1 , 40237 Düsseldorf , Germany
| | | | - Adnan Sarfraz
- Max-Planck-Institut für Eisenforschung GmbH , Max-Planck-Str. 1 , 40237 Düsseldorf , Germany
| | - Michael Rohwerder
- Max-Planck-Institut für Eisenforschung GmbH , Max-Planck-Str. 1 , 40237 Düsseldorf , Germany
| | - Andreas Erbe
- Max-Planck-Institut für Eisenforschung GmbH , Max-Planck-Str. 1 , 40237 Düsseldorf , Germany
- Department of Materials Science and Engineering , NTNU, Norwegian University of Science and Technology , 7491 Trondheim , Norway
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Characterization of Inclusion Complexes between Miconazole and Different Cyclodextrin Derivatives. ACTA MEDICA MARISIENSIS 2018. [DOI: 10.2478/amma-2018-0012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Objective: Miconazole, an imidazole antifungal derivative, is a very hydrophobic compound, a major drawback in obtaining topical pharmaceutical formulations with optimal bioavailability. Cyclodextrins (CDs) may increase local drug delivery by enhancing the drug release and/or permeation. The aim of the study is the characterization of inclusion complexes between miconazole and different CD derivatives.
Methods: Several CD derivatives were tested in the experiments. The binary systems between miconazole and different CDs were prepared in 1:1 molar ratios by physical-mixture and kneading methods. Differential scanning calorimetry (DSC) and Fourier transformed-infrared spectroscopy (FT-IR) methods were used to characterize solid state interactions between miconazole and CDs in their binary systems.
Results: The FT-IR analysis suggests the formation of a new solid phase, indicating a molecular interaction between the components. The DSC analysis sustains the hypothesis of formation of partial inclusion complexes between miconazole nitrate and CD.
Conclusion: The thermic behaviour of the complexes depends both on the preparation method and the composition of the products.
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Ho TM, Tuyen T, Howes T, Bhandari BR. Method of Measurement of CO2 Adsorbed into α-Cyclodextrin by Infra-Red CO2 Probe. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2016. [DOI: 10.1080/10942912.2015.1084005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Thao M. Ho
- School of Agriculture and Food Sciences, The University of Queensland, Brisbane, Australia
| | - Truong Tuyen
- School of Agriculture and Food Sciences, The University of Queensland, Brisbane, Australia
| | - Tony Howes
- School of Chemical Engineering, The University of Queensland, St. Lucia, Australia
| | - Bhesh R. Bhandari
- School of Agriculture and Food Sciences, The University of Queensland, Brisbane, Australia
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Xu D, Wang L, Gourevich D, Kabha E, Arditti F, Athamna M, Cochran S, Melzer A, Gnaim JM. Synthesis and Inclusion Study of a Novel γ-Cyclodextrin Derivative as a Potential Thermo-Sensitive Carrier for Doxorubicin. Chem Pharm Bull (Tokyo) 2014; 62:627-35. [DOI: 10.1248/cpb.c13-00950] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Doudou Xu
- Institute for Medical Science and Technology (IMSaT), College of Medicine, Dentistry and Nursing, University of Dundee
| | - Lijun Wang
- Institute for Medical Science and Technology (IMSaT), College of Medicine, Dentistry and Nursing, University of Dundee
| | - Dana Gourevich
- Institute for Medical Science and Technology (IMSaT), College of Medicine, Dentistry and Nursing, University of Dundee
| | | | | | | | - Sandy Cochran
- Institute for Medical Science and Technology (IMSaT), College of Medicine, Dentistry and Nursing, University of Dundee
| | - Andreas Melzer
- Institute for Medical Science and Technology (IMSaT), College of Medicine, Dentistry and Nursing, University of Dundee
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Yoshii H, Sakane A, Kawamura D, Neoh TL, Kajiwara H, Furuta T. Release kinetics of (−)-menthol from chewing gum. J INCL PHENOM MACRO 2007. [DOI: 10.1007/s10847-006-9279-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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11
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Abstract
This study was designed to develop crosslinking of beta-cyclodextrin (beta-CD), and determine the optimum conditions of different factors (mixing time, mixing temperature, and mixing speed) on cholesterol reduction from milk. Crosslinked beta-CD was prepared with epichlorohydrin. When milk was treated with different conditions, the cholesterol removal rate was in the range of 79.4 to 83.3% with 1% crosslinked beta-CD addition, which were not significantly different among treatments. After cholesterol removal from milk, the used crosslinked beta-CD was washed for cholesterol dissociation and reused. For recycling study, the cholesterol removal rate in first trial was 81.8%, which was mostly same as that using new crosslinked beta-CD. With five trials repeatedly using the same sample, the mean cholesterol removal rate was 81.2%. The present study indicated that the optimum conditions on cholesterol removal using crosslinked beta-CD were 10 min mixing with 400 rpm speed at 5 degrees C with about 80% cholesterol removal. In addition, crosslinked beta-CD resulted in the effective recycling efficiency almost 100%.
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Affiliation(s)
- S H Kim
- Department of Food Science and Technology, Sejong University, Seoul 143-747, Korea
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12
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Kwak HS, Kim SH, Kim JH, Choi HJ, Kang J. Immobilized β-cyclodextrin as a simple and recyclable method for cholesterol removal in milk. Arch Pharm Res 2004; 27:873-7. [PMID: 15460451 DOI: 10.1007/bf02980182] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This study was designed to determine the optimum conditions of three different factors (mixing time, mixing temperature, and tube size) in reduction of cholesterol in milk using immobilized beta-CD beads. Immobilized beta-CD glass beads were prepared at different conditions of silanization and beta-CD immobilization reactions. In result, the glass beads (diameter 1 mm) at 20 mM 3-isocyanatopropyltriethoxysilane and 30 mM beta-CD without base showed the highest cholesterol removal rate as 41%. Using above immobilized beta-CD glass beads, the cholesterol removal rate was 40.2% with 6 h of mixing time in 7 mm diameter tube at 10 degrees C. After cholesterol removal from milk, the glass beads were washed for cholesterol dissociation and reused. In recycling study, the cholesterol removal rate was 41%, which was mostly same as that using new glass beads. These results indicated that cholesterol removal rate was about 40% with beta-CD immobilized glass beads, however, the recycling efficiency was almost 100%.
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Affiliation(s)
- H S Kwak
- Department of Food Science and Technology, Sejong University, Seoul 143-747, Korea.
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Rohde M, Müller E, Chhatwal GS, Talay SR. Host cell caveolae act as an entry-port for group A streptococci. Cell Microbiol 2003; 5:323-42. [PMID: 12713491 DOI: 10.1046/j.1462-5822.2003.00279.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This study identified caveolae as an entry port for group A streptococci into epithelial and endothelial cells. Scanning electron microscopy as well as ultrathin sections of infected cells demonstrated accumulation of small omega-shaped cavities in the host cell membrane close to adherent streptococci. During invasion, invaginations were formed that subsequently revealed intracellular compartments surrounding streptococci. Caveolin-1 was shown to be present in the membrane of invaginations and the compartment membranes. These compartments were devoid of any classic endosomal/lysosomal marker proteins and can thus be described as caveosomes. Disruption of caveolae with methyl-beta-cyclodextrin and filipin abolished host cell invasion. Importantly, streptococci inside caveosomes avoid fusion with lysosomes. Expressing of SfbI protein on the surface of the non-invasive S. gordonii resulted in identical morphological alterations on the host cell as for S. pyogenes. Incubation of HUVEC cells with purified recombinant sole SfbI protein also triggered accumulation of cavity-like structures and formation of membrane invaginations. Tagged to colloidal gold-particles, SfbI protein was shown to cluster following membrane contact. Thus, our results demonstrate that host cell caveolae initiate the invasion process of group A streptococci and that the streptococcal invasin SfbI is the triggering factor that activates the caveolae-mediated endocytic pathway.
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MESH Headings
- Adhesins, Bacterial/genetics
- Adhesins, Bacterial/metabolism
- Adhesins, Bacterial/pharmacology
- Bacterial Adhesion
- Base Sequence
- Caveolae/metabolism
- Caveolae/microbiology
- Caveolae/ultrastructure
- Caveolin 1
- Caveolins/metabolism
- Cell Compartmentation
- Cell Line
- Cells, Cultured
- Cholera Toxin/metabolism
- Cyclodextrins/pharmacology
- DNA, Bacterial/genetics
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/microbiology
- Endothelium, Vascular/ultrastructure
- Epithelial Cells/metabolism
- Epithelial Cells/microbiology
- Epithelial Cells/ultrastructure
- Filipin/pharmacology
- Humans
- Immunohistochemistry
- Microscopy, Electron
- Microscopy, Electron, Scanning
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Recombinant Fusion Proteins/pharmacology
- Streptococcus pyogenes/genetics
- Streptococcus pyogenes/pathogenicity
- Streptococcus pyogenes/ultrastructure
- beta-Cyclodextrins
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Affiliation(s)
- Manfred Rohde
- Department of Microbial Pathogenicity and Vaccine Research, GBF-German Research Centre for Biotechnology, Mascheroder Weg 1, 38124 Braunschweig, Germany.
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Eddaoudi H, Deratani A, Tingry S, Sinan F, Seta P. Fullerene membrane transport mediated by ?-cyclodextrin immobilised in poly(vinyl alcohol) films. POLYM INT 2003. [DOI: 10.1002/pi.1240] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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15
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Lima HO, De Moraes FF, Zanin GM. beta-Cyclodextrin production by simultaneous fermentation and cyclization. Appl Biochem Biotechnol 1998; 70-72:789-804. [PMID: 9627399 DOI: 10.1007/bf02920189] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Production of beta-cyclodextrin (CD) with high-dextrose equivalent (DE) starch hydrolysates by simultaneous fermentation and cyclization (SFC) gives higher yields than using only the enzyme CGTase, because fermentation eliminates glucose and maltose that inhibit CD production, while at the same time, produces ethanol that increases yield. A 10% (w/v) solution of cassava starch, liquefied with alpha-amylase, was incubated with CGTase using: only the enzyme, added ethanol (from 1 to 5%), and added yeast S. cerevisiae (12% w/v), plus nutrients, the latter being the SFC process. Reaction conditions were: 38 degrees C, pH 6.0, DE from 2 to 25, and 3.3 mL of CGTase/L. The yield of beta-CD has decreased with an increase in DE, and maximum reaction yields were found for DE equal to 3.54, reaching 5.6, 14.7, and 11.5 mM beta-CD, respectively. For an increase of DE, of approx 6 times (from 3.54 to 23.79), beta-CD yield decreased 6 times for the first, and second reaction media with 3% (v/v) ethanol, and only approx 3 times for SFC (from 11.5 to 3.73 mM), showing that this process is less sensitive to variations in the DE.
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Affiliation(s)
- H O Lima
- State University of Maringá, Chemical Engineering Department, Brazil
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16
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Matioli G, Zanin GM, Gljimarães MF, De moraes FF. Production and purification of CGTase of alkalophylicBacillus isolated from Brazilian soil. Appl Biochem Biotechnol 1998; 70-72:267-75. [DOI: 10.1007/bf02920143] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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17
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Platzer DJ, Mills KA, Ciolkowski EL, Ramstad T. Determination of impurities in α-cyclodextrin by gradient high-performance liquid chromatography with pulsed amperometric detection. J Chromatogr A 1998. [DOI: 10.1016/s0021-9673(97)00852-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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18
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Stankewich MC, Francis SA, Vu QU, Schneeberger EE, Lynch RD. Alterations in cell cholesterol content modulate Ca(2+)-induced tight junction assembly by MDCK cells. Lipids 1996; 31:817-28. [PMID: 8869884 DOI: 10.1007/bf02522977] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Transepithelial electrical resistance (TER), a measure of tight junction (TJ) barrier function, develops more rapidly and reaches higher values after preincubation of MDCK cells for 24 h with 2 microM Lovastatin (lova), an inhibitor of 3-hydroxy-3-methylglutaryl-CoA reductase. While this effect was attributed to a 30% fall in cholesterol (CH), possible effects of lova on the supply of prenyl group precursors could not be excluded. In the current study, strategies were devised to examine effects on TER of agents that simultaneously lower CH and increase the flux of intermediates through the CH biosynthetic pathway. Zaragozic acid, 20 microM, an inhibitor of squalene synthase known to increase the synthesis of isoprenoids and levels of prenylated proteins, lowered cell CH by 30% after 24 h, while accelerating development of TER in the same manner as lova. TER was also enhanced, despite a 23% increase in the rate of [3H]acetate incorporation into CH, when total CH was reduced by 45% during a 2-h incubation with 2 mM methyl beta-cyclodextrin (MBCD), an agent that stimulates CH efflux from cells. The fact that the rate of TER development was diminished when cell CH content was elevated by incubation with a complex of CH and MBCD is further evidence that this sterol modulates development of the epithelial barrier. Cell associated CH derived from the complex was similar to endogenous CH with respect to its accessibility to cholesterol oxidase. Lova's effect on TER was diminished when 5 micrograms/mL of CH was added to the medium during the last 11 h of incubation with lova.
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Affiliation(s)
- M C Stankewich
- Department of Biological Sciences, University of Massachusetts at Lowell 01854, USA
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19
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Redenti E, Pasini M, Ventura P, Spisni A, Vikmon M, Szejtli J. The terfenadine/?-cyclodextrin inclusion complex. ACTA ACUST UNITED AC 1994. [DOI: 10.1007/bf00709073] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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Bekers O, Kettenes JJ, Helden SP, Seijkens D, Beijnen JH, Bulti A, Underberg WJM. Inclusion complex formation of anthracycline antibiotics with cyclodextrins; a proton nuclear magnetic resonance and molecular modelling study. ACTA ACUST UNITED AC 1991. [DOI: 10.1007/bf01153301] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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