cis,cis-Germacranolides and melampolides from Mikania thapsoides

J Nat Prod. 2003 Jul;66(7):949-53. doi: 10.1021/np030055p.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Argentina
  • Cyclization
  • Lactones / chemistry*
  • Lactones / isolation & purification*
  • Mikania / chemistry*
  • Molecular Conformation
  • Molecular Structure
  • Nuclear Magnetic Resonance, Biomolecular
  • Plants, Medicinal / chemistry*
  • Sesquiterpenes, Germacrane / chemistry*
  • Sesquiterpenes, Germacrane / isolation & purification*
  • Stereoisomerism

Substances

  • Lactones
  • Sesquiterpenes, Germacrane