title: C-15-functionalized eudesmanolides from Mikania campanulata.
abstract: The aerial parts of Mikania campanulata Gardner afforded the nine new eudesmanolides (1S,4S,5S,6S,7S,10R)-1-hydroxy-15-acetoxyeudesm-11(13)-en-6,12-olide (1), (1S,4S,5S,6S,7S,10R)-1,4-dihydroxy-15-acetoxyeudesm-11(13)-en-6,12-olide (2), (1R,4S,5S,6S,7S,10R)-1,4-dihydroxy-15-acetoxyeudesm-11(13)-en-6,12-olide (3), (1R,4S,5S,6S,7S,10R)-1-hydroxy-4,15-diacetoxyeudesm-11(13)-en-6,12-olide (4), (1S,4R,5S,6S,7S,10R)-1,15-diacetoxy-4-hydroxyeudesm-11(13)-en-6,12-olide (5), (1S,5S,6S,7S,10R)-1-hydroxy-15-acetoxyeudesma-4(15),11(13)-dien-6,12-olide (6), (1S,5S,6S,7S,10R)-1,15-dihydroxyeudesma-3,11(13)-dien-6,12-olide (7a), (1S,2R,5S,6S,7S,10R)-1,2,15-trihydroxyeudesma-3,11(13)-dien-6,12-olide (8a), and (1R,6S,7S,10R)-1,15-dihydroxyeudesma-4,11(13)-dien-6,12-olide (9a), among which the last three were characterized as their corresponding peracetates (7b-9b). The structures of 1-6 and 7b-9b were elucidated using 1D and 2D NMR measurements, while that of major constituent 1 was confirmed by single-crystal X-ray diffraction analysis, and its absolute configuration evidenced from vibrational circular dichroism measurements, which were compared to results obtained from density functional theory calculations. The chemistry of the large genus Mikania is briefly analyzed.
authors.affiliation: Facultad de Agronomía y Zootecnia, Universidad Nacional de Tucumán, Avenida Roca 1900, S. M. de Tucumán, 4000 Argentina.
authors.forename: Marta
authors.initials: M
authors.lastname: Krautmann
authors.forename: Elmira C
authors.initials: EC
authors.lastname: de Riscala
authors.forename: Eleuterio
authors.initials: E
authors.lastname: Burgueño-Tapia
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Mora-Pérez
authors.forename: César A N
authors.initials: CA
authors.lastname: Catalán
authors.forename: Pedro
authors.initials: P
authors.lastname: Joseph-Nathan
mesh_terms: D001118:Argentina; D002942:Circular Dichroism; D018360:Crystallography, X-Ray; D035742:Mikania / Q000737:chemistry*; D008968:Molecular Conformation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010946:Plants, Medicinal / Q000737:chemistry*; D012717:Sesquiterpenes / Q000737:chemistry* / Q000302:isolation & purification*; D013237:Stereoisomerism
chemical_list: D012717:Sesquiterpenes; C476916:eudesmanolide