1
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Fuentes-Figueroa MÁ, Joseph-Nathan P, Burgueño-Tapia E. Absolute configuration assignment of stigmasterol oxiranes. Chirality 2021; 34:396-420. [PMID: 34788903 DOI: 10.1002/chir.23390] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 10/06/2021] [Accepted: 10/23/2021] [Indexed: 12/28/2022]
Abstract
Diastereoisomeric stigmasterol oxiranes 4, 5, 8, and 9 are known phytosterol oxidation products (POPs) that have been evaluated for their cytotoxicity, although the results are of limited significance since, in most cases, they were evaluated as mixtures. Consequently, to establish biological activity hierarchy of these oxides, it is critical to evaluate individual pure POPs. Therefore, we now describe the obtention of individual molecules and their absolute configuration (AC) determination. The two acetylated C-5-C-6 oxiranes 6 and 7; the two acetylated C-22-C-23 oxides 10 and 11, obtained by means of Δ5 double bond protection-deprotection; and the four C-5-C-6, C-22-C-23 diepoxystigmasteryl acetates 19-22 were now individually gained and their AC determined by vibrational circular dichroism. Vibrational modes associated with the C-5-C-6 and the C-22-C-23 bonds were identified in dioxiranes 19-22 and used to assign the AC of monoepoxides 6, 7, 10, and 11. The AC of biological active non-acetylated molecules follows immediately. Due to the scarce spectroscopic information available for these POPs, the 1 H and 13 C NMR chemical shifts of 3-22 were assigned using 1D- and 2D-NMR experiments.
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Affiliation(s)
- Miguel Á Fuentes-Figueroa
- Departamento de Química Orgánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Pedro Joseph-Nathan
- Departamento de Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Eleuterio Burgueño-Tapia
- Departamento de Química Orgánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
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2
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Esquivel B, Burgueño-Tapia E, Bustos-Brito C, Pérez-Hernández N, Quijano L, Joseph-Nathan P. Absolute configuration of the diterpenoids icetexone and conacytone from Salvia ballotaeflora. Chirality 2017; 30:177-188. [PMID: 29110401 DOI: 10.1002/chir.22781] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 10/03/2017] [Accepted: 10/04/2017] [Indexed: 11/10/2022]
Abstract
Detailed literature inspections regarding the diterpenoids icetexone (1) and conacytone (3) reveal that the absolute configuration (AC) of these natural occurring compounds is not rigorously proven, despite they were originally isolated in 1976. This task is now completed by single-crystal X-ray diffraction Flack and Hooft parameters determination after processing data collected with Cu Kα graphite monochromated radiation. The AC of both compounds is further determined by vibrational circular dichroism measurements performed on icetexone acetate (2) and conacytone triacetate (4) since the solubility of 1 and 3 is limited. Comparison of the substituent chemical shifts (SCS) induced by acetylation of 1 and 3 to afford 2 and 4, respectively, reveals that in the case of icetexone, all six SCS values of the quinone ring are in excellent agreement with the expected values, while in the case of conacytone, three agree and three do not agree due to the presence of additional acetates near the quinone ring. Density functional theory calculations performed on 3-hydroxythymoquinone (6) and its tautomer 4-hydroxy-1,2-quinone 7, on 6-hydroxythymoquinone (8) and its tautomer ortho-quinone 9, and on icetexone (1) and the claimed natural occurring ortho-quinone tautomer romulogarzone (5) indicate that 2-hydroxy-1,4-quinones are more stable, by some 11-14 kcal/mol, than their 4-hydroxy-1,2-quinone tautomers, and therefore, romulogarzone (5) is inexistent.
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Affiliation(s)
- Baldomero Esquivel
- Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Eleuterio Burgueño-Tapia
- Departamento de Química Orgánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Celia Bustos-Brito
- Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Nury Pérez-Hernández
- Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Leovigildo Quijano
- Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Pedro Joseph-Nathan
- Departamento de Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
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3
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Julio LF, Burgueño-Tapia E, Díaz CE, Pérez-Hernández N, González-Coloma A, Joseph-Nathan P. Absolute configuration of the ocimene monoterpenoids from Artemisia absinthium. Chirality 2017; 29:716-725. [PMID: 28840973 DOI: 10.1002/chir.22741] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 07/06/2017] [Accepted: 07/09/2017] [Indexed: 12/13/2022]
Abstract
The absolute configuration (AC) of the naturally occurring ocimenes (-)-(3S,5Z)-2,6-dimethyl-2,3-epoxyocta-5,7-diene (1) and (-)-(3S,5Z)-2,6-dimethylocta-5,7-dien-2,3-diol (2), isolated from the essential oils of domesticated specimens of Artemisia absinthium, followed by vibrational circular dichroism (VCD) studies of 1, as well as from the acetonide 3 and the monoacetate 4, both derived from 2, since secondary alcohols are not the best functional groups to be present during VCD studies in solution due to intermolecular associations. The AC follows from comparison of experimental and calculated VCD spectra that were obtained by Density Functional Theory computation at the B3LYP/DGDZVP level of theory. Careful nuclear magnetic resonance (NMR) measurements were compared with literature values, providing for the first time systematic 1 H and 13 C chemical shift data. Regarding homonuclear 1 H coupling constants, after performing a few irradiation experiments that showed the presence of several small long-range interactions, the complete set of coupling constants for 3, which is representative of the four studied molecules, was determined by iterations using the PERCH software. This procedure even allowed assigning the pro-R and pro-S methyl group signals of the two gem-dimethyl groups present in 3.
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Affiliation(s)
- Luis F Julio
- Instituto de Ciencias Agrarias, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Eleuterio Burgueño-Tapia
- Departamento de Química Orgánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Carmen E Díaz
- Instituto de Productos Naturales y Agrobiología, Consejo Superior de Investigaciones Científicas, La Laguna, Tenerife, Spain
| | - Nury Pérez-Hernández
- Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Azucena González-Coloma
- Instituto de Ciencias Agrarias, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Pedro Joseph-Nathan
- Departamento de Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
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4
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Burgueño-Tapia E, Sánchez-Castellanos M, Joseph-Nathan P. Optimization of the Number of Considered Conformers for the Absolute Configuration Determination of Catechin and Epicatechin Peracetates by VCD. Nat Prod Commun 2017. [DOI: 10.1177/1934578x1701200510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Epimeric catechin and epicatechin peracetates offer the possibility to explore the number of conformers needed for the absolute configuration determination without affecting the reliability of the assignment. Comparisons between experimental and DFT B3PW91/DGDZVP calculated curves showed that, in molecules where the conformational flexibility generates a large number of conformers, it is possible to significantly reduce the number of conformers needed to generate VCD results that provide secure absolute configuration assignment.
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Affiliation(s)
- Eleuterio Burgueño-Tapia
- Departamento de Química Orgánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala, Col. Santo Tomás, Mexico City, 11340 Mexico
| | - Mariano Sánchez-Castellanos
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, Mexico City, Mexico
| | - Pedro Joseph-Nathan
- Departamento de Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado 14-740, Mexico City, 07000 Mexico
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5
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Bustos-Brito C, Sánchez-Castellanos M, Esquivel B, Calderón JS, Calzada F, Yépez-Mulia L, Joseph-Nathan P, Cuevas G, Quijano L. ent-Kaurene Glycosides from Ageratina cylindrica. JOURNAL OF NATURAL PRODUCTS 2015; 78:2580-2587. [PMID: 26517282 DOI: 10.1021/acs.jnatprod.5b00488] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The aqueous extract of the leaves of Ageratina cylindrica afforded six new ent-kaurenoic acid glycosides together with the known diterpenoid paniculoside V, the flavonoid astragalin, chlorogenic acid, and L-chiro-inositol. The structures were elucidated mainly by NMR and MS methods, and the absolute configuration was established by vibrational circular dichroism spectroscopy. The new compounds showed moderate antiprotozoal activity against Entamoeba histolytica and Giardia lamblia trophozoites.
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Affiliation(s)
- Celia Bustos-Brito
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria , México, D.F. 04510, México
| | - Mariano Sánchez-Castellanos
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria , México, D.F. 04510, México
| | - Baldomero Esquivel
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria , México, D.F. 04510, México
| | - José S Calderón
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria , México, D.F. 04510, México
| | - Fernando Calzada
- Unidad de Investigación Médica en Farmacología, 2° Piso CORCE, UMAE Hospital de Especialidades, Centro Médico Nacional Siglo XXI, IMSS , Avenida Cuauhtémoc 330, Col. Doctores, México, D.F. 06725, México
| | - Lilian Yépez-Mulia
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, UMAE Hospital de Pediatría, Centro Médico Nacional Siglo XXI, IMSS , Avenida Cuauhtémoc 330, Col. Doctores, México, D.F. 06725, México
| | - Pedro Joseph-Nathan
- Departamento de Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional , Apartado 14-740, México, D.F. 07000, México
| | - Gabriel Cuevas
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria , México, D.F. 04510, México
| | - Leovigildo Quijano
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria , México, D.F. 04510, México
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6
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Sánchez-Castellanos M, Bucio MA, Hernández-Barragán A, Joseph-Nathan P, Cuevas G, Quijano L. Vibrational Circular Dichroism (VCD), VCD Exciton Coupling, and X-ray Determination of the Absolute Configuration of an α
,β
-Unsaturated Germacranolide. Chirality 2015; 27:247-52. [DOI: 10.1002/chir.22420] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 12/04/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Mariano Sánchez-Castellanos
- Instituto de Química; Universidad Nacional Autónoma de México; Circuito Exterior, Ciudad Universitaria 04510 México D.F. Mexico
| | - María A. Bucio
- Departamento de Química; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional; Apartado 14-740 México D.F., 07000 Mexico
| | - Angelina Hernández-Barragán
- Departamento de Química; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional; Apartado 14-740 México D.F., 07000 Mexico
| | - Pedro Joseph-Nathan
- Departamento de Química; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional; Apartado 14-740 México D.F., 07000 Mexico
| | - Gabriel Cuevas
- Instituto de Química; Universidad Nacional Autónoma de México; Circuito Exterior, Ciudad Universitaria 04510 México D.F. Mexico
| | - Leovigildo Quijano
- Instituto de Química; Universidad Nacional Autónoma de México; Circuito Exterior, Ciudad Universitaria 04510 México D.F. Mexico
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7
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Batista Jr. JM, Blanch EW, Bolzani VDS. Recent advances in the use of vibrational chiroptical spectroscopic methods for stereochemical characterization of natural products. Nat Prod Rep 2015; 32:1280-302. [DOI: 10.1039/c5np00027k] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A comprehensive look into application of vibrational optical activity methods for conformational and configurational assignments in natural product molecules over the last 15 years is provided.
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Affiliation(s)
- João M. Batista Jr.
- Department of Chemistry
- Federal University of São Carlos – UFSCar
- São Carlos
- Brazil
| | - Ewan W. Blanch
- School of Applied Sciences
- RMIT University
- Melbourne
- Australia
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8
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Bustos-Brito C, Sánchez-Castellanos M, Esquivel B, Calderón JS, Calzada F, Yepez-Mulia L, Hernández-Barragán A, Joseph-Nathan P, Cuevas G, Quijano L. Structure, absolute configuration, and antidiarrheal activity of a thymol derivative from Ageratina cylindrica. JOURNAL OF NATURAL PRODUCTS 2014; 77:358-363. [PMID: 24502360 DOI: 10.1021/np400964w] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The leaves of Ageratina cylindrica afforded a thymol derivative that was characterized by physical and spectroscopical methods as (8S)-8,9-epoxy-6-hydroxy-l0-benzoyloxy-7-oxothymol isobutyrate (1). The absolute configuration of 1 was established as 8S by vibrational circular dichroism spectroscopy in combination with density functional theory calculations and by evaluation of the Flack and Hooft X-ray parameters. Compound 1 showed weak antiprotozoal activity against Entamoeba histolytica and Giardia lamblia trophozoites and a high inhibitory effect on hyperpropulsive movement of the small intestine in rats.
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Affiliation(s)
- Celia Bustos-Brito
- Instituto de Química, Universidad Nacional Autónoma de México , Circuito Exterior, Ciudad Universitaria, D.F., 04510 México
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9
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Batista JM, da Silva Bolzani V. Determination of the Absolute Configuration of Natural Product Molecules Using Vibrational Circular Dichroism. STUDIES IN NATURAL PRODUCTS CHEMISTRY 2014. [DOI: 10.1016/b978-0-444-63294-4.00013-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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10
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Gordillo-Román B, Camacho-Ruiz J, Bucio MA, Joseph-Nathan P. Vibrational Circular Dichroism Discrimination of Diastereomeric Cedranol Acetates. Chirality 2013; 25:939-51. [DOI: 10.1002/chir.22238] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 08/11/2013] [Indexed: 11/10/2022]
Affiliation(s)
- Bárbara Gordillo-Román
- Departamento de Química; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional; México D. F. México
| | - Jorge Camacho-Ruiz
- Departamento de Química; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional; México D. F. México
| | - María A. Bucio
- Departamento de Química; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional; México D. F. México
| | - Pedro Joseph-Nathan
- Departamento de Química; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional; México D. F. México
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11
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Silva AL, Toscano RA, Maldonado LA. An Enantioselective Approach to Furanoeremophilanes: (+)-9-Oxoeuryopsin. J Org Chem 2013; 78:5282-92. [DOI: 10.1021/jo400399q] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ana L. Silva
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito
Exterior, Ciudad Universitaria, Coyoacán, México DF
04510, Mexico
| | - Rubén A. Toscano
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito
Exterior, Ciudad Universitaria, Coyoacán, México DF
04510, Mexico
| | - Luis A. Maldonado
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito
Exterior, Ciudad Universitaria, Coyoacán, México DF
04510, Mexico
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12
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Abbate S, Lebon F, Longhi G, Boiadjiev SE, Lightner DA. Vibrational and Electronic Circular Dichroism of Dimethyl Mesobilirubins-XIIIα. J Phys Chem B 2012; 116:5628-36. [DOI: 10.1021/jp3013255] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sergio Abbate
- Dipartimento
di Scienze Biomediche
e Biotecnologie, Università di Brescia, 25123 Brescia, Italy
| | - France Lebon
- Dipartimento
di Scienze Biomediche
e Biotecnologie, Università di Brescia, 25123 Brescia, Italy
| | - Giovanna Longhi
- Dipartimento
di Scienze Biomediche
e Biotecnologie, Università di Brescia, 25123 Brescia, Italy
| | - Stefan E. Boiadjiev
- Department of Chemistry and
Biochemistry, Medical University-Pleven, 1 St. Kliment Ohridski Street, 5800 Pleven, Bulgaria
| | - David A. Lightner
- Department of Chemistry, University of Nevada, Reno, Nevada 89557-0020, United
States
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13
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Gutiérrez-Nicolás F, Gordillo-Román B, Oberti JC, Estévez-Braun A, Ravelo AG, Joseph-Nathan P. Synthesis and anti-HIV activity of lupane and olean-18-ene derivatives. Absolute configuration of 19,20-epoxylupanes by VCD. JOURNAL OF NATURAL PRODUCTS 2012; 75:669-676. [PMID: 22462772 DOI: 10.1021/np200910u] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Lupane triterpenoids 2 and 5-12 and oleanene derivatives 13 and 14 were prepared from lupeol (1), betulin (3), and germanicol (4). They were tested for anti-HIV activity, and some structure-activity relationships were outlined. The 20-(S) absolute configuration of epoxylupenone (8) was assessed by comparison of the observed and DFT-calculated vibrational circular dichroism spectra. The CompareVOA algorithm was employed to support the C-20 configuration assignment. The 20,29 double bond in lupenone (2) and 3-epilupeol (15) was stereoselectively epoxidized to produce 20-(S)-8 and 20-(S)-16, respectively, an assignment in agreement with their X-ray diffraction structures.
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Affiliation(s)
- Fátima Gutiérrez-Nicolás
- Instituto Universitario de Bio-Orgánica Antonio González, Departamento de Química Orgánica, Universidad de La Laguna, La Laguna 38206 Tenerife, Spain
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14
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Burgueño-Tapia E, Zepeda LG, Joseph-Nathan P. Absolute configuration of (-)-myrtenal by vibrational circular dichroism. PHYTOCHEMISTRY 2010; 71:1158-1161. [PMID: 20457457 DOI: 10.1016/j.phytochem.2010.04.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Revised: 03/09/2010] [Accepted: 04/07/2010] [Indexed: 05/29/2023]
Abstract
The VCD spectrum of the monoterpene (-)-myrtenal (1) was compared with theoretical spectra using ab initio density functional theory (DFT) calculations at the B3LYP/6-31G(d,p), B3LYP/6-31G+(d,p), B3LYP/6-311G+(d,p), B3LYP/DGDZVP, and B3PW91/DGTZVP levels of theory. Conformational analysis of 1 indicated that the lowest energy conformer was s-trans-C2-C10, which contributes more than 98.5% to the total conformational population regardless of the employed level of theory. The use of a recently developed confidence level algorithm demonstrated that VCD spectra calculated for the main conformer, using the indicated hybrid functionals and basis set, gave no significant changes, from where it follows that B3LYP/DGDZVP calculations provide a superior balance between computer cost and VCD spectral accuracy. The DGDZVP basis set demanded around a quarter the time than the 6-311G+(d,p) basis set while providing similar results. The spectral comparison also provided evidence that the levorotatory enantiomer of myrtenal has the 1R absolute configuration.
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Affiliation(s)
- Eleuterio Burgueño-Tapia
- Departamento de Química Orgánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala, Col. Santo Tomás, México, D.F. 11340, Mexico
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15
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Muñoz MA, Muñoz O, Joseph-Nathan P. Absolute configuration determination and conformational analysis of (-)-(3S,6S)-3alpha,6beta-diacetoxytropane using vibrational circular dichroism and DFT techniques. Chirality 2010; 22:234-41. [PMID: 19408333 DOI: 10.1002/chir.20734] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The absolute configuration of semisynthetic (-)-3alpha,6beta-acetoxytropane 1, prepared from (-)-6beta-hydroxyhyoscyamine 2, has been determined using vibrational circular dichroism (VCD) spectroscopy. The vibrational spectra (IR and VCD) were calculated using DFT at the B3LYP/DGDZVP level of theory for the eight more stable conformers which account for 99.97% of the total relative abundance in the first 10 kcal/mol range. The calculated VCD spectra of all considered conformations showed two distinctive spectral ranges, one between 1300 and 1200 cm(-1), and the other one in the 1150-950 cm(-1) region. When compared with the experimental VCD spectrum, the first spectral region confirmed the calculated conformational preferences, whereas the second region showed little change with conformation, thus allowing the determination of the absolute configuration of 1 as (3S,6S)-3alpha,6beta-diacetoxytropane. Also, the bands in the second region showed similarities between 1 and 2 in both the experimental and calculated VCD spectra, suggesting that these bands are mainly related to the absolute configuration of the rigid tropane ring system, since they show conformational independency, no variations with the nature of the substituent, and are composed by closely related vibrational modes.
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Affiliation(s)
- Marcelo A Muñoz
- Instituto de Química, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
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16
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Reina M, Burgueño-Tapia E, Bucio MA, Joseph-Nathan P. Absolute configuration of tropane alkaloids from Schizanthus species by vibrational circular dichroism. PHYTOCHEMISTRY 2010; 71:810-815. [PMID: 20189614 DOI: 10.1016/j.phytochem.2010.02.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Revised: 02/01/2010] [Accepted: 02/03/2010] [Indexed: 05/28/2023]
Abstract
The absolute configuration (AC) of 6beta-hydroxy-3alpha-senecioyloxytropane (1), 3alpha-hydroxy-6beta-tigloyloxytropane (2), 3alpha-hydroxy-6beta-senecioyloxytropane (3), and 3alpha-hydroxy-6beta-angeloyloxytropane (4) was assigned as (1R,3R,5S,6R) using density functional theory (DFT) calculations at the B3LYP/DGDZVP level of theory in combination with experimental vibrational circular dichroism (VCD) measurements and comparison with the spectra of similar tropanes. The AC of 1 followed from a sample isolated from Schizanthus grahamii, while those of the mixture of 2 and 3, isolated from the same source, were determined by comparing the VCD measurement to a weighted calculation of the individual VCD spectra according to a 69:31 ratio of 2:3 determined by (1)H NMR signal integration. In turn, Schizanthus pinnatus provided a 7:3 mixture of 1:4 whose AC was determined using the experimental VCD absorptions in the 1150-950 cm(-1) spectral region which were compared with those observed for 1-3 and with those described for other 3alpha,6beta-tropanediol derivatives.
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Affiliation(s)
- Matías Reina
- Instituto de Productos Naturales y Agrobiología (IPNA), CSIC, La Laguna, Tenerife, Spain
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Rojas-Pérez RE, Cedillo-Portugal E, Joseph-Nathan P, Burgueño-Tapia E. A New Longipinene Diester from Stevia Monardifolia Kunth. Nat Prod Commun 2009. [DOI: 10.1177/1934578x0900400603] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Nonpolar and medium polarity fractions from whole plant methanolic extracts of Stevia monardifolia afforded the new 7β-angeloyloxy-8α-isovaleroyloxylongipin-2-en-1-one 1 along with known 7β,8α-diangeloyloxylongipin-2-en-1-one 2 and 7β,8α-diangeloyloxylongipinan-1-one 3. Alkaline hydrolysis of a mixture of 1 and 2 gave 7β,8α-dihydroxylongipin-2-en-1-one 4 which was subjected to a single crystal X-ray diffraction study. The new compound 1, which is the third 7β,8α-dihydroxylongipin-2-en-1-one diester natural product isolated from a Stevia especies, was fully characterized by one-and two-dimensional NMR spectroscopy and its absolute configuration was confirmed as the 4R,5S,7S,8S,10R,11 R enantiomer by vibrational circular dichroism (VCD) measurements in comparison to calculation at the B3LYP/DGDZVP level of theory.
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Affiliation(s)
- Rodrigo E. Rojas-Pérez
- Departamento de Química Orgánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala, Col. Santo Tomás, México, D.F., 11340 Mexico
| | | | - Pedro Joseph-Nathan
- Departamento de Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado 14-740, México, D.F., 07000 México
| | - Eleuterio Burgueño-Tapia
- Departamento de Química Orgánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala, Col. Santo Tomás, México, D.F., 11340 Mexico
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Taniguchi T, Martin CL, Monde K, Nakanishi K, Berova N, Overman LE. Absolute configuration of actinophyllic acid as determined through chiroptical data. JOURNAL OF NATURAL PRODUCTS 2009; 72:430-432. [PMID: 19220031 PMCID: PMC2992953 DOI: 10.1021/np800665s] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The absolute configuration of actinophyllic acid (-)-1, an alkaloid with an unprecedented 2,3,6,7,9,13c-hexahydro-1H-1,7,8-(methanetriyloxymethano)pyrrolo[1',2':1,2]azacino[4,3-b]indole-8(5H)-carboxylic acid skeleton isolated from Alstonia actinophylla, was determined through the study of its corresponding methyl ester 2. Racemic 2 was separated into (+)-2 and (-)-2 enantiomers, and they were assigned unambiguously as 15S,16R,19R,20R,21S and 15R,16S,19S,20S,21R, respectively, by the use of optical rotation and electronic circular dichroism. Finally, (-)-2 was characterized as the methyl ester of naturally occurring (-)-1. The assigned 15R,16S,19S,20S,21R-configuration of (-)-1 is consistent with a proposed biosynthetic pathway.
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Affiliation(s)
- Tohru Taniguchi
- Department of Chemistry, Columbia University, New York, New York 10027
| | - Connor L. Martin
- Department of Chemistry, 1102 Natural Sciences II, University of California, Irvine, California 92697-2025
| | - Kenji Monde
- Graduate School of Advanced Life Science, Frontier Research Center for Post-Genome Science and Technology, Hokkaido University, Sapporo 001-0021, Japan
| | - Koji Nakanishi
- Department of Chemistry, Columbia University, New York, New York 10027
| | - Nina Berova
- Department of Chemistry, Columbia University, New York, New York 10027
| | - Larry E. Overman
- Department of Chemistry, 1102 Natural Sciences II, University of California, Irvine, California 92697-2025
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Bodensieck A, Fabian WM, Kunert O, Belaj F, Jahangir S, Schühly W, Bauer R. Absolute configuration of eremophilane sesquiterpenes fromPetasites hybridus: Comparison of experimental and calculated circular dichroism spectra. Chirality 2009; 22:308-19. [DOI: 10.1002/chir.20743] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Muñoz MA, Chamy C, Carrasco A, Rovirosa J, San Martín A, Joseph-Nathan P. Diastereoisomeric assignment in a pacifenol derivative using vibrational circular dichroism. Chirality 2009; 21 Suppl 1:E208-14. [DOI: 10.1002/chir.20801] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Torres-Valencia JM, Chávez-Ríos OE, Cerda-García-Rojas CM, Burgueño-Tapia E, Joseph-Nathan P. Dihydrofurochromones from Prionosciadium thapsoides. JOURNAL OF NATURAL PRODUCTS 2008; 71:1956-1960. [PMID: 18954117 DOI: 10.1021/np800387w] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Chemical investigations of Prionosciadium thapsoides roots led to the isolation of the new dihydrofurochromones (S)-(+)-4'-O-angeloyl-5-O-methylvisamminol (1) and (S)-(+)-4'-O-senecioyl-5-O-methylvisamminol (2), together with the known coumarins jatamansin, buchtormin, isopteryxin, isosamidin, psoralen, and bergapten. The structures of 1 and 2 were determined by 1D and 2D NMR experiments, and their absolute configuration was established by chemical correlation with (+)-5-O-methylvisamminol (3), whose structure was secured by single-crystal X-ray diffraction analysis and its absolute configuration was established as S by vibrational circular dichroism spectroscopy in comparison to DFT B3LYP/DGDZVP calculations.
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Affiliation(s)
- J Martín Torres-Valencia
- Centro de Investigaciones Químicas, Universidad Autónoma del Estado de Hidalgo, km. 4.5 Carretera Pachuca-Tulancingo, Ciudad Universitaria, Pachuca, Hidalgo, 42076 Mexico.
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