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Elshamy AI, Mohamed TA, Swapana N, Kasai Y, Noji M, Efferth T, Imagawa H, Hegazy MEF, Umeyama A. Ternifolipyrons A-J: new cytotoxic α-pyrones from Isodon ternifolius (D. Don) Kudô. RSC Adv 2023; 13:19710-19720. [PMID: 37396835 PMCID: PMC10309080 DOI: 10.1039/d3ra03146b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 06/07/2023] [Indexed: 07/04/2023] Open
Abstract
Isodon ternifolius (D.Don) Kudô is an important Asian herb used in traditional medicine against several diseases. Nineteen compounds were isolated from the dichloromethane-methanol (1 : 1) extract of I. ternifolius roots, including ten new α-pyrone derivatives, named ternifolipyrons A-J. The chemical structures of the isolates were determined by a combination of 1D and 2D NMR, along with LR- and HRMS spectroscopy. The absolute configurations of the α-pyrone derivatives were constructed based upon the X-ray signal crystal of the bromobenzoyl derivative of 1 as well as the electronic circular dichroism (ECD). All isolates (1-19) were investigated for their growth-inhibitory potential towards CCRF-CEM-leukemia cells at a fixed concentration of 30 μM. The compounds which exerted more than 50% inhibition at this concentration, compounds (7, 10, 12, 15-17), were tested at a different concentration range to determine their IC50 values in CCRF-CEM leukemia, MDA-MB-231 triple-negative breast cancer, and MCF7 breast cancer cell lines. Ursolic acid (16) showed the most potent activity against the three cancer cell lines with IC50 values of 8.37, 18.04, and 18.93 μM, respectively.
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Affiliation(s)
- Abdelsamed I Elshamy
- Chemistry of Natural Compounds Department, National Research Centre 33 El Bohouth St., Dokki Giza 12622 Egypt
| | - Tarik A Mohamed
- Chemistry of Medicinal Plants Department, National Research Centre 33 El-Bohouth St., Dokki Giza 12622 Egypt
| | - Ningombam Swapana
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University Yamashiro-cho Tokushima 770-8514 Japan
- Department of Chemistry, Manipur Technical University Takyelpat Imphal 795004 Manipur India
| | - Yusuke Kasai
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University Yamashiro-cho Tokushima 770-8514 Japan
| | - Masaaki Noji
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University Yamashiro-cho Tokushima 770-8514 Japan
| | - Thomas Efferth
- Department of Pharmaceutical Biology, Institute of Pharmaceutical and Biomedical Sciences, University of Mainz Staudinger Weg 5 55128 Mainz Germany
| | - Hiroshi Imagawa
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University Yamashiro-cho Tokushima 770-8514 Japan
| | - Mohamed-Elamir F Hegazy
- Chemistry of Medicinal Plants Department, National Research Centre 33 El-Bohouth St., Dokki Giza 12622 Egypt
- Department of Pharmaceutical Biology, Institute of Pharmaceutical and Biomedical Sciences, University of Mainz Staudinger Weg 5 55128 Mainz Germany
| | - Akemi Umeyama
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University Yamashiro-cho Tokushima 770-8514 Japan
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Perea-Domínguez XP, Mendoza-Espinoza JA, Solano González JM, Leyva-Morales JB, Espinosa-Alonso LG, Valdez-Morales M. Antioxidant and anti-proliferative activity of free, conjugates and bound phenolic compounds from tomato and industrial tomato by-product. JOURNAL OF FOOD SCIENCE AND TECHNOLOGY 2022; 59:2361-2369. [PMID: 35602438 PMCID: PMC9114191 DOI: 10.1007/s13197-021-05252-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 08/16/2021] [Accepted: 08/21/2021] [Indexed: 06/03/2023]
Abstract
The aim of this study was to evaluate the antioxidant and anti-proliferative activity of different fractions of phenolic compounds from tomato and tomato by-product. Soluble free phenolics and bound phenolics (BP) fractions from saladette tomato and industrial tomato by-product as well as, conjugated acid-hydrolysable phenolics (AHP) and alkaline-hydrolysable phenolics (AKHP) from saladette tomato, grape tomato and industrial tomato by-product, were tested. The scavenging effects of phenolic fractions on superoxide anion were determined using the PMS-NADH-NBT system. The myoglobin protection ratios of samples against hydroxyl radical were evaluated and the anti-proliferative effects in the MCF-7 breast cancer cell line were determined. AHP fraction from tomato by-product and AKHP fraction from grape and saladette tomato showed the highest inhibitory capacity of the superoxide anion (p ≤ 0.05). All samples had a myoglobin protection ratio from 30 to 50%. Regarding to cytotoxicity assays, all phenolic fractions from tomato by-product, as well as, BP, AHP, AKHP from saladette tomato and AHP from grape tomato showed important anti-proliferative activity against MCF-7 breast cancer cell line (IC50 < 20 μg/mL). From the results, we can conclude that tomato and tomato by-product are a good source of natural compound with important antioxidant and anti-proliferative activity.
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Affiliation(s)
- Xiomara Patricia Perea-Domínguez
- Doctorado en Sustentabilidad y Departamento de Salud-Licenciatura en Ciencias Biomédicas, Universidad Autónoma de Occidente, Unidad Regional Guasave, Av Universidad S/N, Fraccionamiento Villa Universidad, C.P. 81048 Guasave, Sinaloa México
| | - José Alberto Mendoza-Espinoza
- Colegio de Ciencias y Humanidades, Universidad Autónoma de la Ciudad de México, Casa Libertad. Ermita Iztapalapa 4263, Lomas de Zaragoza, C.P. 09620 Ciudad de México, México
| | - Jesús Martin Solano González
- Tecnológico Nacional de México, Instituto Tecnológico de Los Mochis, Blvd Juan de Dios Bátiz and 20 de Noviembre, El Parque, C.P. 81250 Los Mochis, Sinaloa México
| | - José Belisario Leyva-Morales
- Lab. Alimentos Funcionales y Departamento de Biotecnología Agrícola, Instituto Politécnico Nacional, CIIDIR-IPN Unidad Sinaloa, Blvd Juan de Dios Bátiz Paredes 250, Guasave, Sin México
| | - Laura Gabriela Espinosa-Alonso
- Lab. Alimentos Funcionales y Departamento de Biotecnología Agrícola, Instituto Politécnico Nacional, CIIDIR-IPN Unidad Sinaloa, Blvd Juan de Dios Bátiz Paredes 250, Guasave, Sin México
| | - Maribel Valdez-Morales
- Departamento de Biotecnología Agrícola, CONACyT-Instituto Politécnico Nacional-CIIDIR-IPN Unidad Sinaloa, Lab. Alimentos Funcionales-Área de Metabolómica Agrícola, Blvd. Juan de Dios Bátiz Paredes 250, Guasave, Sinaloa México
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Total Hyptolide of Indonesian Hyptis pectinata extracts in a various solvent using HPLC and UV-Vis spectroscopy and their toxicities. JURNAL KIMIA SAINS DAN APLIKASI 2019. [DOI: 10.14710/jksa.22.6.305-309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The bioactive compound of hyptolide has been isolated from an Indonesian plant Hyptis pectinata using various solvents. The pure compound was then used as a standard in quantitative analysis using HPLC and UV-Vis spectroscopy in ethanol (EEth), ethyl acetate (EEa), acetone (Eac) and hexane (Ehex) extract each earned 3.14%, 0.01%, 1.33% and 0.04% (dry weight per sample). The standard curve of hyptolide using UV spectroscopy has been obtained with the coefficient of relationship (r) of 0.997. However, the use of spectroscopy was not recommended for the standardization of hyptolide in the extract due to interference from other compounds that absorb the same wavelength. Furthermore, the toxicity test using the Brine Shrimp lethality test shows LC50 value of 92-181 ppm, which was in EEa compared to EEth, Eac, and Ehex.
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Ochi R, Nishiwaki H, Yamauchi S. Syntheses and Phytotoxicity of All Stereoisomers of 6-(2-Hydroxy-6-phenylhex-1-yl)-5,6-dihydro-2 H-pyran-2-one and Determination of the Effect of the α,β-Unsaturated Carbonyl Structure and Hydroxy Group Bonding to Chiral Carbon. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:12558-12564. [PMID: 31609622 DOI: 10.1021/acs.jafc.9b05507] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
All four stereoisomers of naturally occurring 6-(2-hydroxy-6-phenylhex-1-yl)-5,6-dihydro-2H-pyran-2-one (1) were synthesized by employing yeast-reduction products with high optical purity [from 95% enantiomeric excess (ee) to more than 99% ee], and then their phytotoxicities against lettuce and Italian ryegrass were evaluated. In the Italian ryegrass seedlings test, (6S,2'R)-1 showed the most potent and stereospecific activity against the shoots (IC50 = 260 μM) and roots (IC50 = 43.2 μM), with a significant difference from other stereoisomers. The highest seed germination inhibitory activity against Italian ryegrass seed was also observed in (6S,2'R)-1, showing a 53% germination ratio from the control at 1000 μM. This advantageous (6S,2'R) stereochemistry was employed in the syntheses of α,β-dihydro, 2'-dehydroxy, and 2'-methoxy derivatives 13-15. By the test using these derivatives, the importance of the α,β-unsaturated double bond and hydroxy group bonding to a chiral center on the 6-alkyl chain of 5,6-dihydro-α-pyrone for phytotoxicity was determined. In the test against lettuce, the 6S configuration and (6S,2'S) configuration were necessary for growth inhibition (IC50 = ca. 60 μM) and germination inhibition (63% germination ratio at 1000 μM), respectively.
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Affiliation(s)
- Ryota Ochi
- Graduate School of Agriculture , Ehime University , 3-5-7 Tarumi , Matsuyama , Ehime 790-8566 , Japan
| | - Hisashi Nishiwaki
- Graduate School of Agriculture , Ehime University , 3-5-7 Tarumi , Matsuyama , Ehime 790-8566 , Japan
| | - Satoshi Yamauchi
- Graduate School of Agriculture , Ehime University , 3-5-7 Tarumi , Matsuyama , Ehime 790-8566 , Japan
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Silva-García EM, Cerda-García-Rojas CM, Del Río RE, Joseph-Nathan P. Parvifoline Derivatives as Tubulin Polymerization Inhibitors. JOURNAL OF NATURAL PRODUCTS 2019; 82:840-849. [PMID: 30883116 DOI: 10.1021/acs.jnatprod.8b00860] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A series of functionalized sesquiterpenoids derived from benzocyclooctene, including natural parvifoline (1), isoparvifoline (3), epoxyparvifoline (5), epoxyisoparvifoline (7), 8,12-oxyparfivoline (9), 8,14-oxyparvifoline (11), and the respective benzoyl derivatives 2, 4, 6, 8, 10, and 12, were prepared and tested for their inhibitory effect on the in vitro α,β-tubulin polymerization process. The structural analysis and characterization of the new compounds 5-7 and 9-12 were achieved by 1D and 2D NMR spectroscopy, mass spectrometry, and X-ray diffraction analysis of 6, 7, and 9. Preparation of 9 and 12 involved molecular rearrangements of the epoxide group with transannular 1,5-hydride shifts. At 10 μM compounds 1, 5, and 8 inhibited the polymerization of the α,β-tubulin heterodimer by 24%, 49%, and 90% as compared to colchicine. These compounds were subjected to docking analysis that supported their interactions in a colchicine binding site located in the α-tubulin subunit, in the pocket formed by Phe296, Pro298, Pro307, His309, Tyr312, Lys338, Thr340, Ile341, and Gln342. Competitive inhibition assays with colchicine were also performed for the three compounds, which supported their binding at the colchicine secondary site in α-tubulin. Also, evaluations of their cytotoxicity on MCF7 breast carcinoma, HeLa cervix carcinoma, and HCT 116 colon carcinoma cell lines were carried out and showed that 8 is active against the HeLa and HCT 116 cell lines with IC50 3.3 ± 0.2 and 5.0 ± 0.5 μM, respectively.
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Affiliation(s)
- Edna M Silva-García
- Departamento de Química y Programa de Posgrado en Farmacología , Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional , Apartado 14-740 , Mexico City 07000 , Mexico
| | - Carlos M Cerda-García-Rojas
- Departamento de Química y Programa de Posgrado en Farmacología , Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional , Apartado 14-740 , Mexico City 07000 , Mexico
| | - Rosa E Del Río
- Instituto de Investigaciones Químico-Biológicas , Universidad Michoacana de San Nicolás de Hidalgo , Ciudad Universitaria , Morelia , Michoacán 58030 , Mexico
| | - Pedro Joseph-Nathan
- Departamento de Química y Programa de Posgrado en Farmacología , Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional , Apartado 14-740 , Mexico City 07000 , Mexico
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6
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Mata R, Figueroa M, Navarrete A, Rivero-Cruz I. Chemistry and Biology of Selected Mexican Medicinal Plants. PROGRESS IN THE CHEMISTRY OF ORGANIC NATURAL PRODUCTS 2019; 108:1-142. [PMID: 30924013 DOI: 10.1007/978-3-030-01099-7_1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Herbal medicines are an integral element of alternative medical care in Mexico, and the best testimony to their efficacy and cultural value is their persistence in contemporary Mexican marketplaces where the highest percentages of medicinal and aromatic plants are sold. This chapter summarizes current trends in research on medicinal plants in Mexico, with emphasis on work carried out at the authors' laboratories. The most relevant phytochemical and pharmacological profiles of a selected group of plants used widely for treating major national health problems are described.From this contribution, it is evident that in the last five decades a significant amount of research on medicinal plants has been performed by Mexican scientists. Such efforts have led to the publication of many research papers in noted peer-reviewed journals and technical books. The isolation and structural characterization of hundreds of bioactive secondary metabolites have been accomplished, and most importantly, these studies have tended to support the ethnomedical uses of many different species. A multidisciplinary approach for investigating these plants has led to an increased emphasis on areas such as phytopharmacology, phytotoxicology, quality control, regulation, and conservation issues for these valuable resources. The medicinal plants analyzed so far have shown a very broad chemical diversity of their constituents, which have a high potential for exhibiting novel mechanistic effects biologically. The chapter shows also that there is need to conduct additional clinical studies on herbal drugs, in particular because the longstanding traditional evidence for their safety is not always sufficient to assure their rational use. There is also need to move to "omics" approaches for investigating the holistic effect and the influence of groups of phytochemicals on the whole organism. Mexican scientists may be expected to have bright prospects in this regard, which will imbue medicinal plant research with a new dynamism in the future.
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Affiliation(s)
- Rachel Mata
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México, México.
| | - Mario Figueroa
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México, México.
| | - Andrés Navarrete
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Isabel Rivero-Cruz
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México, México
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7
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Aarland RC, Bañuelos-Hernández AE, Fragoso-Serrano M, Sierra-Palacios EDC, Díaz de León-Sánchez F, Pérez-Flores LJ, Rivera-Cabrera F, Mendoza-Espinoza JA. Studies on phytochemical, antioxidant, anti-inflammatory, hypoglycaemic and antiproliferative activities of Echinacea purpurea and Echinacea angustifolia extracts. PHARMACEUTICAL BIOLOGY 2017; 55:649-656. [PMID: 27951745 PMCID: PMC6130640 DOI: 10.1080/13880209.2016.1265989] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 08/23/2016] [Accepted: 11/22/2016] [Indexed: 05/31/2023]
Abstract
CONTEXT Echinacea (Asteraceae) is used because of its pharmacological properties. However, there are few studies that integrate phytochemical analyses with pharmacological effects. OBJECTIVE Evaluate the chemical profile and biological activity of hydroalcoholic Echinacea extracts. MATERIALS AND METHODS Density, dry matter, phenols (Folin-Ciocalteu method), flavonoids (AlCl3 method), alkylamides (GC-MS analysis), antioxidant capacity (DPPH and ABTS methods), antiproliferative effect (SRB assay), anti-inflammatory effect (paw oedema assay, 11 days/Wistar rats; 0.4 mL/kg) and hypoglycaemic effect (33 days/Wistar rats; 0.4 mL/kg) were determined in three Echinacea extracts which were labelled as A, B and C (A, roots of Echinacea purpurea L. Moench; B, roots, leaves, flowers and seeds of Echinacea purpurea; C, aerial parts and roots of Echinacea purpurea and roots of Echinacea angustifolia DC). RESULTS Extract C showed higher density (0.97 g/mL), dry matter (0.23 g/mL), phenols (137.5 ± 2.3 mEAG/mL), flavonoids (0.62 ± 0.02 mEQ/mL), and caffeic acid (0.048 mg/L) compared to A and B. A, B presented 11 alkylamides, whereas C presented those 11 and three more. B decreased the oedema (40%) on day 2 similar to indomethacin. A and C showed hypoglycaemic activity similar to glibenclamide. Antiproliferative effect was only detected for C (IC50 270 μg/mL; 8171 μg/mL; 9338 μg/mL in HeLa, MCF-7, HCT-15, respectively). DISCUSSION AND CONCLUSION The difference in the chemical and pharmacological properties among extracts highlights the need to consider strategies and policies for standardization of commercial herbal extracts in order to guarantee the safety and identity of this type of products.
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Affiliation(s)
- Rayn Clarenc Aarland
- Postgraduate Program in Experimental Biology, Universidad Autónoma Metropolitana, Iztapalapa, Ciudad de México, México
| | | | - Mabel Fragoso-Serrano
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México, México
| | | | | | - Laura Josefina Pérez-Flores
- Departamento de Ciencias de la Salud DCBS, Universidad Autónoma Metropolitana-Iztapalapa, Ciudad de México, México
| | - Fernando Rivera-Cabrera
- Departamento de Ciencias de la Salud DCBS, Universidad Autónoma Metropolitana-Iztapalapa, Ciudad de México, México
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8
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Suárez-Ortiz GA, Cerda-García-Rojas CM, Fragoso-Serrano M, Pereda-Miranda R. Complementarity of DFT Calculations, NMR Anisotropy, and ECD for the Configurational Analysis of Brevipolides K-O from Hyptis brevipes. JOURNAL OF NATURAL PRODUCTS 2017; 80:181-189. [PMID: 28099005 DOI: 10.1021/acs.jnatprod.6b00953] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Brevipolides K-O (1-5), five new cytotoxic 6-(6'-cinnamoyloxy-2',5'-epoxy-1'-hydroxyheptyl)-5,6-dihydro-2H-pyran-2-ones (IC50 values against six cancer cell lines, 1.7-10 μM), were purified by recycling HPLC from Hyptis brevipes. The structures, containing a distinctive tetrahydrofuran ring, were established by comprehensive quantum mechanical calculations and experimental spectroscopic analysis of their NMR and ECD data. Detailed analysis of the experimental NMR 1H-1H vicinal coupling constants in comparison with the corresponding DFT-calculated values at the B3LYP/DGDZVP level confirmed the absolute configuration of 3 and revealed its conformational preferences, which were further strengthened by NOESY correlations. NMR anisotropy experiments by the application of Mosher's ester methodology and chemical correlations were also used to conclude that this novel brevipolide series (1-5) share the same absolute configuration corresponding to C-6(R), C-1'(S), C-2'(R), C-5'(S), and C-6'(S).
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Affiliation(s)
- G Alejandra Suárez-Ortiz
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Circuito Exterior Ciudad Universitaria , Mexico City 04510, Mexico
| | - Carlos M Cerda-García-Rojas
- Departamento de Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional , A. P. 14-740, Mexico City 07000, Mexico
| | - Mabel Fragoso-Serrano
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Circuito Exterior Ciudad Universitaria , Mexico City 04510, Mexico
| | - Rogelio Pereda-Miranda
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Circuito Exterior Ciudad Universitaria , Mexico City 04510, Mexico
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9
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Conformational and reactivity study of dithiophenyl-fucosyl ketals with theoretical chemical methods. J Mol Model 2016; 22:212. [DOI: 10.1007/s00894-016-3079-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 08/03/2016] [Indexed: 10/21/2022]
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Rivera-Chávez J, Figueroa M, González MDC, Glenn AE, Mata R. α-Glucosidase Inhibitors from a Xylaria feejeensis Associated with Hintonia latiflora. JOURNAL OF NATURAL PRODUCTS 2015; 78:730-735. [PMID: 25706243 DOI: 10.1021/np500897y] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Two new compounds, pestalotin 4'-O-methyl-β-mannopyranoside (1) and 3S,4R-(+)-4-hydroxymellein (2), were isolated from an organic extract of a Xylaria feejeensis, which was isolated as an endophytic fungus from Hintonia latiflora. In addition, the known compounds 3S,4S-(+)-4-hydroxymellein (3), 3S-(+)-8-methoxymellein (4), and the quinone derivatives 2-hydroxy-5-methoxy-3-methylcyclohexa-2,5-diene-1,4-dione (5), 4S,5S,6S-4-hydroxy-3-methoxy-5-methyl-5,6-epoxycyclohex-2-en-1-one (6), and 4R,5R-dihydroxy-3-methoxy-5-methylcyclohexen-2-en-1-one (7) were obtained. The structures of 1 and 2 were elucidated using a set of spectroscopic and spectrometric techniques. The absolute configuration of the stereogenic centers of 1 and 2 was determined using ECD spectroscopy combined with time-dependent density functional theory calculations. In the case of 1, comparison of the experimental and theoretical (3)J6-7 coupling constants provided further evidence for the stereochemical assignments. Compounds 2 and 3 inhibited Saccharomyces cerevisiae α-glucosidase (αGHY), with IC50 values of 441 ± 23 and 549 ± 2.5 μM, respectively. Their activity was comparable to that of acarbose (IC50 = 545 ± 19 μM), used as positive control. Molecular docking predicted that both compounds bind to αGHY in a site different from the catalytic domain, which could imply an allosteric type of inhibition.
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Affiliation(s)
- José Rivera-Chávez
- †Facultad de Química, Universidad Nacional Autónoma de México, México DF 04510, Mexico
| | - Mario Figueroa
- †Facultad de Química, Universidad Nacional Autónoma de México, México DF 04510, Mexico
| | | | | | - Rachel Mata
- †Facultad de Química, Universidad Nacional Autónoma de México, México DF 04510, Mexico
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Yamauchi S, Isozaki Y, Nishiwaki H, Akiyama K. Syntheses of natural 1,3-polyol/α-pyrone and its all stereoisomers to estimate antifungal activities against plant pathogenic fungi. Bioorg Med Chem Lett 2015; 25:2189-92. [PMID: 25872981 DOI: 10.1016/j.bmcl.2015.03.055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 03/19/2015] [Accepted: 03/20/2015] [Indexed: 11/24/2022]
Abstract
All stereoisomers of 1,3-polyol/α-pyrone 1-8 with more than 99% ee were synthesized to estimate the effect of stereochemistry on the antifungal activity. The absolute configuration of natural compound was determined as (6R,2'S,4'R)-2. The eight stereoisomers showed the antifungal activity against plant pathogenic Alternaria alternata Japanese pear pathotype and Colletotrichum lagenarium. The large difference of activity level was not observed between stereoisomers, showing 43-72% of growth ratio against control at 0.5mM. The most potent stereoisomer was (6S,2'S,4'S)-8 and the activity of (6R,2'S,4'S)-1 was weakest against both fungi.
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Affiliation(s)
- Satoshi Yamauchi
- Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan; South Ehime Fisheries Research Center, 1289-1 Funakoshi, Ainan, Ehime 798-4292, Japan.
| | - Yasuyoshi Isozaki
- Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan
| | - Hisashi Nishiwaki
- Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan
| | - Koichi Akiyama
- Integrated Center for Sciences, Tarumi Station, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan
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12
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Juárez-González F, Suárez-Ortiz GA, Fragoso-Serrano M, Cerda-García-Rojas CM, Pereda-Miranda R. DFT 1H-1H coupling constants in the conformational analysis and stereoisomeric differentiation of 6-heptenyl-2H-pyran-2-ones: configurational reassignment of synargentolide A. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2015; 53:203-212. [PMID: 25353378 DOI: 10.1002/mrc.4178] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 10/05/2014] [Accepted: 10/08/2014] [Indexed: 06/04/2023]
Abstract
Density functional theory (DFT) (1) H-(1) H NMR coupling constant calculations, including solvation parameters with the polarizable continuum model B3LYP/DGDZVP basis set together with the experimental values measured by spectral simulation, were used to predict the configuration of hydroxylated 6-heptenyl-5,6-dihydro-2H-pyran-2-ones 1, 2, 4, and 7, allowing epimer differentiation. Modeling of these flexible compounds requires the inclusion of solvation models that account for stabilizing interactions derived from intramolecular and intermolecular hydrogen bonds, in contrast with peracetylated derivatives (3, 5, and 6) in which the solvation consideration can be omitted. Using this DFT NMR integrated approach as well as spectral simulation, the configurational reassignment of synargentolide A (8) was accomplished by calculations in the gas phase among four possible diastereoisomers (8-11). Calculated (3) JH,H values established its configuration as 6R-[4'S,5'S,6'S-(triacetyloxy)-2E-heptenyl]-5,6-dihydro-2H-pyran-2-one (8), in contrast with the incorrect 6R,4'R,5'R,6'R-diastereoisomer previously proposed by synthesis (12). Application of this approach increases the probability for successful enantiospecific total syntheses of flexible compounds with multiple chiral centers.
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Affiliation(s)
- Francisco Juárez-González
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, 04510, DF, Mexico
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13
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Del Valle P, Figueroa M, Mata R. Phytotoxic eremophilane sesquiterpenes from the coprophilous fungus Penicillium sp. G1-a14. JOURNAL OF NATURAL PRODUCTS 2015; 78:339-342. [PMID: 25603174 DOI: 10.1021/np5009224] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Bioassay-directed fractionation of an extract from the grain-based culture of the coprophilous fungus Penicillium sp. G1-a14 led to the isolation of a new eremophilane-type sesquiterpene, 3R,6R-dihydroxy-9,7(11)-dien-8-oxoeremophilane (1), along with three known analogues, namely, isopetasol (2), sporogen AO-1 (3), and dihydrosporogen AO-1 (4). The structure of 1 was elucidated using 1D and 2D NMR and single-crystal X-ray diffraction. Assignment of absolute configuration at the stereogenic centers of 1 was achieved using ECD spectroscopy combined with time-dependent density functional theory calculations. Sporogen AO-1 (3) and dihydrosporogen AO-1 (4) caused significant inhibition of radicle growth against Amaranthus hypochondriacus (IC50 = 0.17 mM for both compounds) and Echinochloa crus-galli (IC50 = 0.17 and 0.30 mM, respectively).
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Affiliation(s)
- Paulina Del Valle
- Facultad de Química, Universidad Nacional Autónoma de México , México DF 04510, México
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14
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Bañuelos-Hernández AE, Mendoza-Espinoza JA. Synthesis of the 2,3,4-triacetyl-1,6-dideoxy-L-mannose and tetracetyl-3,6-dideoxy-L-mannitol and the study of the reaction mechanism by molecular modeling. RUSS J GEN CHEM+ 2014. [DOI: 10.1134/s1070363214070342] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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15
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16
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Suárez-Ortiz GA, Cerda-García-Rojas CM, Hernández-Rojas A, Pereda-Miranda R. Absolute configuration and conformational analysis of brevipolides, bioactive 5,6-dihydro-α-pyrones from Hyptis brevipes. JOURNAL OF NATURAL PRODUCTS 2013; 76:72-78. [PMID: 23282042 DOI: 10.1021/np300740h] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The (6'S)-configuration of brevipolides A-J (1-10), isolated from Hyptis brevipes, was established by X-ray diffraction analysis of 9 in conjunction with Mosher's ester analysis of the tetrahydro derivative 11 obtained from both geometric isomers 8 and 9 as well as by chemical correlations. The structure of the new brevipolide J (10) was characterized through NMR and MS data as having the same 6-heptyl-5,6-dihydro-2H-pyran-2-one framework possessing the cyclopropane moiety of all brevipolides but substituted by an isoferuloyl group instead of the p-methoxycinnamoyl moiety found in 8 and 9. Conformational analysis of these cytotoxic 6-heptyl-5,6-dihydro-α-pyrones was carried out on compound 9 by application of a protocol based on comparison between experimental and DFT-calculated vicinal (1)H-(1)H NMR coupling constants. Molecular modeling was used to correlate minimum energy conformers and observed electronic circular dichroism transitions for the isomeric series of brevipolides. Compounds 7-10 exhibited moderate activity (ED(50) 0.3-8.0 μg/mL) against a variety of tumor cell lines.
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Affiliation(s)
- G Alejandra Suárez-Ortiz
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Circuito Exterior Ciudad Universitaria, México City, D. F. 04510 México
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17
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Sarotti AM. Successful combination of computationally inexpensive GIAO 13C NMR calculations and artificial neural network pattern recognition: a new strategy for simple and rapid detection of structural misassignments. Org Biomol Chem 2013; 11:4847-59. [DOI: 10.1039/c3ob40843d] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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18
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Sarotti AM, Pellegrinet SC. Application of the Multi-standard Methodology for Calculating 1H NMR Chemical Shifts. J Org Chem 2012; 77:6059-65. [DOI: 10.1021/jo3008447] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Ariel M. Sarotti
- Instituto de Química Rosario (CONICET), Facultad
de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario
(2000), Argentina
| | - Silvina C. Pellegrinet
- Instituto de Química Rosario (CONICET), Facultad
de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario
(2000), Argentina
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19
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Dyson BS, Burton JW, Sohn TI, Kim B, Bae H, Kim D. Total Synthesis and Structure Confirmation of Elatenyne: Success of Computational Methods for NMR Prediction with Highly Flexible Diastereomers. J Am Chem Soc 2012; 134:11781-90. [DOI: 10.1021/ja304554e] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Bryony S. Dyson
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K
| | - Jonathan W. Burton
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K
| | - Te-ik Sohn
- The Research Institute of Pharmaceutical
Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
| | - Byungsook Kim
- The Research Institute of Pharmaceutical
Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
| | - Hoon Bae
- The Research Institute of Pharmaceutical
Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
| | - Deukjoon Kim
- The Research Institute of Pharmaceutical
Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
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20
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Pauli GF, Chen SN, Friesen JB, McAlpine JB, Jaki BU. Analysis and purification of bioactive natural products: the AnaPurNa study. JOURNAL OF NATURAL PRODUCTS 2012; 75:1243-55. [PMID: 22620854 PMCID: PMC3381453 DOI: 10.1021/np300066q] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Based on a meta-analysis of data mined from almost 2000 publications on bioactive natural products (NPs) from >80000 pages of 13 different journals published in 1998-1999, 2004-2005, and 2009-2010, the aim of this systematic review is to provide both a survey of the status quo and a perspective for analytical methodology used for isolation and purity assessment of bioactive NPs. The study provides numerical measures of the common means of sourcing NPs, the chromatographic methodology employed for NP purification, and the role of spectroscopy and purity assessment in NP characterization. A link is proposed between the observed use of various analytical methodologies, the challenges posed by the complexity of metabolomes, and the inescapable residual complexity of purified NPs and their biological assessment. The data provide inspiration for the development of innovative methods for NP analysis as a means of advancing the role of naturally occurring compounds as a viable source of biologically active agents with relevance for human health and global benefit.
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Affiliation(s)
- Guido F Pauli
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
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21
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Li S, Zhou W, Gao H, Zhou Z. Density functional theory study of (13)C NMR chemical shift of chlorinated compounds. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2012; 50:106-113. [PMID: 22354788 DOI: 10.1002/mrc.2837] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 06/25/2011] [Accepted: 08/25/2011] [Indexed: 05/31/2023]
Abstract
The use of the standard density functional theory (DFT) leads to an overestimation of the paramagnetic contribution and underestimation of the shielding constants, especially for chlorinated carbon nuclei. For that reason, the predictions of chlorinated compounds often yield too high chemical shift values. In this study, the WC04 functional is shown to be capable of reducing the overestimation of the chemical shift of Cl-bonded carbons in standard DFT functionals and to show a good performance in the prediction of (13)C NMR chemical shifts of chlorinated organic compounds. The capability is attributed to the minimization of the contributions that intensively increase the chemical shift in the WC04. Extensive computations and analyses were performed to search for the optimal procedure for WC04. The B3LYP and mPW1PW91 standard functionals were also used to evaluate the performance. Through detailed comparisons between the basis set effects and the solvent effects on the results, the gas-phase GIAO/WC04/6-311+G(2d,p)//B3LYP/6-31+G(d,p) was found to be specifically suitable for the prediction of (13)C NMR chemical shifts of chlorides in both chlorinated and non-chlorinated carbons. Further tests with eight molecules in the probe set sufficiently confirmed that WC04 was undoubtedly effective for accurately predicting (13) C NMR chemical shifts of chlorinated organic compounds.
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Affiliation(s)
- Songqing Li
- Department of Applied Chemistry, China Agricultural University, Beijing, 100193, China
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22
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Lodewyk MW, Siebert MR, Tantillo DJ. Computational prediction of 1H and 13C chemical shifts: a useful tool for natural product, mechanistic, and synthetic organic chemistry. Chem Rev 2011; 112:1839-62. [PMID: 22091891 DOI: 10.1021/cr200106v] [Citation(s) in RCA: 892] [Impact Index Per Article: 68.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Michael W Lodewyk
- Department of Chemistry, University of California-Davis, Davis, California 95616, USA
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23
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24
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López-Vallejo F, Fragoso-Serrano M, Suárez-Ortiz GA, Hernández-Rojas AC, Cerda-García-Rojas CM, Pereda-Miranda R. Vicinal 1H–1H NMR Coupling Constants from Density Functional Theory as Reliable Tools for Stereochemical Analysis of Highly Flexible Multichiral Center Molecules. J Org Chem 2011; 76:6057-66. [DOI: 10.1021/jo200637g] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Fabian López-Vallejo
- Departamento de Química y Programa de Posgrado en Farmacología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, A.P. 14-470, México, D. F. 07000 Mexico
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, D. F. 04510 Mexico
| | - Mabel Fragoso-Serrano
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, D. F. 04510 Mexico
| | - Gloria Alejandra Suárez-Ortiz
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, D. F. 04510 Mexico
| | - Adriana C. Hernández-Rojas
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, D. F. 04510 Mexico
| | - Carlos M. Cerda-García-Rojas
- Departamento de Química y Programa de Posgrado en Farmacología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, A.P. 14-470, México, D. F. 07000 Mexico
| | - Rogelio Pereda-Miranda
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, D. F. 04510 Mexico
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25
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Rosas-Ramírez D, Escalante-Sánchez E, Pereda-Miranda R. Batatins III-VI, glycolipid ester-type dimers from Ipomoea batatas. PHYTOCHEMISTRY 2011; 72:773-780. [PMID: 21453944 DOI: 10.1016/j.phytochem.2011.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2010] [Revised: 01/18/2011] [Accepted: 03/02/2011] [Indexed: 05/30/2023]
Abstract
Batatins III-VI (1-4), glycolipid ester-type dimers, were isolated from the tuberous roots of sweet potato (Ipomoea batatas) using recycle high performance liquid chromatography. Their structures were characterized by means of several high-resolution NMR and mass spectrometry techniques. These compounds are the first examples of ester-type dimers which consist of two units of the heterotetrasaccharide operculinic acid C. Each unit was esterified by a different amount and type of acid residues: (2S)-methylbutanoic, cinnamic, decanoic (capric) and dodecanoic (lauric) acids. Batatins III-VI (1-4) are an example of the presence of a large number of resin glycoside congeners in each morning glory species caused by partial acylation of their constitutive saccharide cores.
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Affiliation(s)
- Daniel Rosas-Ramírez
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico, DF, Mexico
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26
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Castañeda-Gómez J, Pereda-Miranda R. Resin glycosides from the herbal drug jalap (Ipomoea purga). JOURNAL OF NATURAL PRODUCTS 2011; 74:1148-1153. [PMID: 21446661 DOI: 10.1021/np200080k] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Three new resin glycosides, purginosides I and II (1 and 2) and purgin I (3), were isolated from the aerial parts of Ipomoea purga and purified by preparative-scale recycling HPLC from a chloroform-soluble extract. Their structures were established through NMR spectroscopy and mass spectrometry. Purginosides I and II (1 and 2) are partially acylated branched pentasaccharides derived from operculinic acid A, which is composed of one D-fucose, one D-glucose, and three l-rhamnose units. The site of the aglycon macrolactonization is at C-2 of the second saccharide (rhamnose). In both compounds 1 and 2, three different esterifying residues were located at C-2 of the second rhamnose unit and at C-2 (or C-3) and C-4 on the third rhamnose moiety. The acylating residues were characterized as trans-cinnamic, n-decanoic, and either (+)-(2S)-2-methylbutanoic or n-hexanoic acid. Purgin I (3) was found to be an ester-type dimer of operculinic acid A, acylated by n-dodecanoic, (+)-(2S)-2-methylbutanoic, and trans-cinnamic acids at the same oligosaccharide core positions found in compounds 1 and 2. The site of lactonization by the aglycon in unit A was placed at C-2 of the second saccharide. The position for the ester linkage for the monomeric unit B on the macrocyclic unit A was identified as C-4 of the terminal glucose. This is the first report on the isolation, purification, and structure elucidation of intact individual resin glycoside constituents from the herbal drug jalap.
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Affiliation(s)
- Jhon Castañeda-Gómez
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México , Ciudad Universitaria, Mexico City 04510 D.F., Mexico
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27
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Bally T, Rablen PR. Quantum-Chemical Simulation of 1H NMR Spectra. 2. Comparison of DFT-Based Procedures for Computing Proton–Proton Coupling Constants in Organic Molecules. J Org Chem 2011; 76:4818-30. [DOI: 10.1021/jo200513q] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Thomas Bally
- Department of Chemistry, University of Fribourg, CH-1700 Fribourg, Switzerland
| | - Paul R. Rablen
- Department of Chemistry & Biochemistry, Swarthmore College, Swarthmore, Pennsylvania 19081-1397, United States
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28
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Smith SG, Goodman JM. Assigning stereochemistry to single diastereoisomers by GIAO NMR calculation: the DP4 probability. J Am Chem Soc 2011; 132:12946-59. [PMID: 20795713 DOI: 10.1021/ja105035r] [Citation(s) in RCA: 624] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
GIAO NMR shift calculation has been applied to the challenging task of reliably assigning stereochemistry with quantifiable confidence when only one set of experimental data are available. We have compared several approaches for assigning a probability to each candidate structure and have tested the ability of these methods to distinguish up to 64 possible diastereoisomers of 117 different molecules, using NMR shifts obtained in rapid and computationally inexpensive single-point calculations on molecular mechanics geometries without time-consuming ab initio geometry optimization. We show that a probability analysis based on the errors in each (13)C or (1)H shift is significantly more successful at making correct assignments with high confidence than are probabilities based on the correlation coefficient and mean absolute error parameters. Our new probability measure, which we have termed DP4, complements the probabilities obtained from our previously developed CP3 parameter, which applies to the case of assigning a pair of diastereoisomers when one has both experimental data sets. We illustrate the application of DP4 to assigning the stereochemistry or structure of 21 natural products that were originally misassigned in the literature or that required extensive synthesis of diastereoisomers to establish their stereochemistry.
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Affiliation(s)
- Steven G Smith
- Unilever Centre for Molecular Science Informatics, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
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29
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Smith SG, Channon JA, Paterson I, Goodman JM. The stereochemical assignment of acyclic polyols: a computational study of the NMR data of a library of stereopentad sequences from polyketide natural products. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.06.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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30
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Sarotti AM, Pellegrinet SC. A multi-standard approach for GIAO (13)C NMR calculations. J Org Chem 2009; 74:7254-60. [PMID: 19725561 DOI: 10.1021/jo901234h] [Citation(s) in RCA: 177] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The influence of the reference standard employed in the calculation of (13)C NMR chemical shifts was investigated over a large variety of known organic compounds, using different quantum chemistry methods and basis sets. After detailed analysis of the collected data, we found that methanol and benzene are excellent reference standards for computing NMR shifts of sp(3)- and sp-sp(2)-hybridized carbon atoms, respectively. This multi-standard approach (MSTD) performs better than TMS in terms of accuracy and precision and also displays much lower dependence on the level of theory employed. The use of mPW1PW91/6-31G(d)//mPW1PW91/6-31G(d) level is recommended for accurate (13)C NMR chemical shift prediction at low computational cost.
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Affiliation(s)
- Ariel M Sarotti
- Instituto de Química Rosario (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario (2000), Argentina.
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31
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Smith SG, Goodman JM. Assigning the stereochemistry of pairs of diastereoisomers using GIAO NMR shift calculation. J Org Chem 2009; 74:4597-607. [PMID: 19459674 DOI: 10.1021/jo900408d] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
GIAO NMR chemical shifts have been calculated for a set of 28 pairs of diastereoisomers in order to test the ability of NMR shift calculation to distinguish between diastereomeric structures. We compare the performance of several different parameters for quantifying the agreement between calculated and experimental shifts from the point of view of assigning structures and introduce a new parameter, CP3, based on comparing differences in calculated shift with differences in experimental shift, which is significantly more successful at making correct structure assignments with high confidence than are the currently used parameters of the mean absolute error and the correlation coefficient. Using our new parameter in conjunction with Bayes' theorem, stereostructure assignments can be made with quantifiable confidence using shifts obtained in single point calculations on molecular mechanics geometries without computationally expensive ab initio geometry optimization.
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Affiliation(s)
- Steven G Smith
- Unilever Centre for Molecular Science Informatics, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
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