cis,cis-Germacranolides and melampolides from Mikania thapsoides.
The aerial parts of Mikania thapsoides afforded six new cis,cis-germacranolide-type sesquiterpene lactones (1-6), of which three (1-3) have an unusual 3,4-epoxy function, and also afforded two new melampolides (7 and 8). All compounds have a trans C-8 lactone ring closure. Their structures were elucidated using 1D and 2D NMR measurements, and the absolute configuration of 1 was determined using the Mosher ester method.
Catalán
César A N
CA
Instituto de Química Orgánica, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 491, S M de Tucumán, 4000, Argentina.
Del R  Cuenca
María
M
Hernández
Luis R
LR
Joseph-Nathan
Pedro
P
D001118:Argentina; D003500:Cyclization; D007783:Lactones / Q000737:chemistry* / Q000302:isolation & purification*; D035742:Mikania / Q000737:chemistry*; D008968:Molecular Conformation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010946:Plants, Medicinal / Q000737:chemistry*; D045788:Sesquiterpenes, Germacrane / Q000737:chemistry* / Q000302:isolation & purification*; D013237:Stereoisomerism
D007783:Lactones; D045788:Sesquiterpenes, Germacrane