Absolute configuration of labdanes and ent-clerodanes from Chromolaena pulchella by vibrational circular dichroism

Phytochemistry. 2011 Apr;72(4-5):409-14. doi: 10.1016/j.phytochem.2011.01.021.

Abstract

The aerial parts of Chromolaena pulchella biosynthesize two groups of diterpenes belonging to opposite enantiomeric series, specifically, the furanoid ent-clerodanes (5R,8R,9S,10R)-(-)-hardwikiic acid (1), methyl (5R,8R,9S,10R)-(-)-hardwikiate (2), (5S,8R,9S,10R)-(-)-hautriwaic acid lactone (3), methyl (5R,8R,9S,10R)-(-)-nidoresedate (4) and methyl (8R,9R)-(-)-strictate (5), as well as the labdanes (5S,8R,9R,10S)-(+)-(13E)-labd-13-ene-8,15-diol (6) and (5S,8R,9R,10S)-(+)-isoabienol (7). The absolute configuration of the two groups of diterpenes was unambiguously assigned by comparison of the vibrational circular dichroism spectra of 3 for ent-clerodanes, and of 7 for labdanes with their theoretical spectra obtained by density functional theory calculations. The results support a biogenetic proposal to diterpenes found in the studied botanical species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromolaena / chemistry*
  • Circular Dichroism / methods*
  • Diterpenes / chemistry*
  • Diterpenes / isolation & purification*
  • Diterpenes, Clerodane / chemistry*
  • Diterpenes, Clerodane / isolation & purification*
  • Mexico
  • Molecular Structure
  • Stereoisomerism

Substances

  • Diterpenes
  • Diterpenes, Clerodane