Antifungal jujubogenin saponins from Colubrina retusa

J Nat Prod. 1999 May;62(5):674-7. doi: 10.1021/np9803169.

Abstract

Antifungal assay-guided isolation of the 95% ethanol extract of the stems of Colubrina retusa yielded jujubogenin 3-O-alpha-L-arabinofuranosyl(1-->2)-[beta-D-glucopyranosyl (1-->3)]-alpha-L-arabinopyranoside (1), which showed modest growth-inhibitory effects against Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus (MICs, 50 microg/mL). In addition, two new minor saponins, jujubogenin 3-O-alpha-L-arabinofuranosyl(1-->2)-[2-O-(trans, cis)p-coumaroyl-beta-D-glucopyranosyl(1-->3)]-alpha-L-arabinopy ranosi de (2), and jujubogenin 3-O-(5-O-malonyl)-alpha-L-arabinofuranosyl (1-->2)-[beta-D-glucopyranosyl(1-->3)]-alpha-L-arabinopyranoside (3), were obtained. Saponin 2 was marginally active against only C. neoformans, with a MIC of 50 microg/mL, while 3 was inactive. NMR spectroscopy was used extensively for the structure determination of these compounds. The previously reported ambiguity of the NMR assignments of jujubogenin saponins for carbons -26 to -29 was clarified by a comprehensive analysis of the NMR spectra of 1.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Antifungal Agents / isolation & purification
  • Antifungal Agents / pharmacology*
  • Carbohydrate Sequence
  • Fungi / drug effects
  • Hydrolysis
  • Magnetic Resonance Spectroscopy
  • Microbial Sensitivity Tests
  • Molecular Sequence Data
  • Plant Stems / chemistry
  • Plants / chemistry*
  • Saponins / isolation & purification
  • Saponins / pharmacology*

Substances

  • Antifungal Agents
  • Saponins