Regio- and diastereoselective synthesis and X-ray structure determination of (+)-2-deoxyoryzalexin S from (+)-podocarpic acid. Structural nonidentity with its nominal natural isolated enantiomer

J Nat Prod. 2012 Nov 26;75(11):1944-50. doi: 10.1021/np300518j. Epub 2012 Oct 23.

Abstract

(+)-2-Deoxyoryzalexin S (1), the nominal enantiomer of a diterpenoid isolated in Chile from Calceolaria species, was regio- and diastereoselectively synthesized from (+)-podocarpic acid. (+)-2-Deoxyoryzalexin S (1) was characterized also as its acetyl derivative, (+)-2, whose structure was confirmed by X-ray crystallographic analysis. Surprisingly, comparison of the data recorded for (+)-1 and (+)-2 and those reported in the literature for the Calceolaria isolated diterpenoid 1 and its derivative (-)-2 showed some differences, suggesting that the latter do not possess the proposed structures.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abietanes / chemistry*
  • Chile
  • Crystallography, X-Ray
  • Diterpenes
  • Models, Molecular
  • Molecular Structure
  • Scrophulariaceae / chemistry*
  • Stereoisomerism
  • Structure-Activity Relationship

Substances

  • (+)-2-deoxyoryzalexin S
  • Abietanes
  • Diterpenes
  • podocarpic acid