Rare prenylated isoflavones from Tephrosia calophylla

Nat Prod Commun. 2014 Jul;9(7):937-40.

Abstract

Chemical re-examination of the roots of T. calophylla led to the isolation of four isoflavones, namely 2',4',5-trihydroxy-6,7-(2",2"-dimethylchromene)-8-gamma,gamma-dimethylallylisoflavone (1a, auriculatin), 2',5-dihydroxy-6,7-(2",2"-dimethylchromene)-4'-gamma,gamma-dimethylallyloxyisoflavone (2a, isoauriculatin), 3',4',5-trihydroxy-6,7-(2",2"-dimethylchromene)-8-gamma,gamma-dimethylallylisoflavone (1b, auriculasin), and 3',5-dihydroxy-6,7-(2",2"-dimethylchromene)-4'-gamma,gamma-dimethylallyl-oxyisoflavone (2b, isoauriculasin). Auriculasin and isoauriculasin are reported for the first time with full NMR assignments. All metabolites were fully characterized by 1D and 2D NMR techniques including COSY, HSQC, HMBC experiments, mass spectra and in part on the basis of X-ray diffraction. Accurate 'invariom' refinements with aspherical scattering factors were carried out for 1a, 1b and 2a.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Isoflavones / chemistry*
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Tephrosia / chemistry*

Substances

  • Isoflavones