As part of a project studying the secondary metabolites extracted from the Chilean flora, we report herein three new β-agarofuran sesquiterpenes, namely (1S,4S,5S,6R,7R,8R,9R,10S)-6-acetoxy-4,9-dihydroxy-2,2,5a,9-tetramethyloctahydro-2H-3,9a-methanobenzo[b]oxepine-5,10-diyl bis(furan-3-carboxylate), C 27 H 32 O 11 , (II), (1S,4S,5S,6R,7R,9S,10S)-6-acetoxy-9-hydroxy-2,2,5a,9-tetramethyloctahydro-2H-3,9a-methanobenzo[b]oxepine-5,10-diyl bis(furan-3-carboxylate), C 27 H 32 O 10 , (III), and (1S,4S,5S,6R,7R,9S,10S)-6-acetoxy-10-(benzoyloxy)-9-hydroxy-2,2,5a,9-tetramethyloctahydro-2H-3,9a-methanobenzo[b]oxepin-5-yl furan-3-carboxylate, C 29 H 34 O 9 , (IV), obtained from the seeds of Maytenus boaria and closely associated with a recently published relative [Paz et al. (2017). Acta Cryst. C73, 451–457]. In the (isomorphic) structures of (II) and (III), the central decalin system is esterified with an acetate group at site 1 and furoate groups at sites 6 and 9, and differ at site 8, with an OH group in (II) and no substituent in (III). This position is also unsubstituted in (IV), with site 6 being occupied by a benzoate group. The chirality of the skeletons is described as 1S,4S,5S,6R,7R,8R,9R,10S in (II) and 1S,4S,5S,6R,7R,9S,10S in (III) and (IV), matching the chirality suggested by NMR studies. This difference in the chirality sequence among the title structures (in spite of the fact that the three skeletons are absolutely isostructural) is due to the differences in the environment of site 8, i.e. OH in (II) and H in (III) and (IV). This diversity in substitution, in turn, is responsible for the differences in the hydrogen-bonding schemes, which is discussed. © International Union of Crystallography, 2018
Documento: | Artículo |
Título: | Three new dihydro-β-agarofuran sesquiterpenes from the seeds of Maytenus boaria |
Autor: | Paz, C.; Heydenreich, M.; Schmidt, B.; Vadra, N.; Baggio, R. |
Filiación: | Laboratorio de Química de Productos Naturales, Facultad de Ingeniería, Universidad de La Frontera, Temuco, Chile Universität Potsdam, Institut für Chemie, Karl-Liebknecht-Strasse 24-25, Potsdam, Germany Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica, Analítica y Química Física, Buenos Aires, Argentina CONICET–Universidad de Buenos Aires, Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), Buenos Aires, Argentina Gerencia de Investigación y Aplicaciones, Centro Atómico Constituyentes, Comisión Nacional de Energía Atómica, Buenos Aires, Argentina |
Palabras clave: | Celastraceae; crystal structure; dihydro-β-agarofuran; DSC; Maytenus boaria; NMR; sesquiterpene; Aromatic compounds; Carboxylation; Chirality; Hydrogen bonds; Metabolites; Musculoskeletal system; Nuclear magnetic resonance; Olefins; Organic pollutants; Organic solvents; Acetate groups; Celastraceae; Isostructural; Maytenus boaria; NMR studies; OH group; Secondary metabolites; Sesquiterpenes; Crystal structure; dihydroagarofuran; furan; furan derivative; sesquiterpene; chemistry; hydrogen bond; isolation and purification; Maytenus; nuclear magnetic resonance spectroscopy; plant seed; stereoisomerism; X ray crystallography; Crystallography, X-Ray; Furans; Hydrogen Bonding; Magnetic Resonance Spectroscopy; Maytenus; Seeds; Sesquiterpenes; Stereoisomerism |
Año: | 2018 |
Volumen: | 74 |
Número: | 5 |
Página de inicio: | 564 |
Página de fin: | 570 |
DOI: | http://dx.doi.org/10.1107/S2053229618005429 |
Título revista: | Acta Crystallographica Section C: Structural Chemistry |
Título revista abreviado: | Acta crystallogr., C Struct. Chem. |
ISSN: | 20532296 |
CODEN: | ACSCG |
CAS: | furan, 110-00-9; dihydroagarofuran; furan; Furans; Sesquiterpenes |
Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_20532296_v74_n5_p564_Paz |