Three new methylated Δ8-pregnene steroids from the Polyalthia laui-derived fungus Stemphylium sp. AZGP4-2

Bioorg Chem. 2020 Jan:95:102927. doi: 10.1016/j.bioorg.2019.102927. Epub 2019 Apr 16.

Abstract

Three new methylated Δ8-pregnene steroids, stemphylisteroids A-C (1-3) were isolated from the medicinal plant Polyalthia laui-derived fungus Stemphylium sp. AZGP4-2. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. The absolute configuration of 1 was determined by X-ray crystallographic analysis. Compound 1 show antibacterial activity against Escherichia coli with the MIC value of 6.25 μg/mL, and 2 exhibited a broad spectrum of antibacterial activities against six pathogenic bacteria with the MIC values ranging from 12.5 to 50 μg/mL. The discovery of three methylated Δ8-pregnene steroids 1-3 are a further addition to diverse and complex array of methylated steroids.

Keywords: Antibacterial activity; Methylated Δ(8)-pregnene steroids; Polyalthia laui; Stemphylium sp..

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / isolation & purification
  • Anti-Bacterial Agents / pharmacology*
  • Ascomycota / chemistry*
  • Crystallography, X-Ray
  • Dose-Response Relationship, Drug
  • Escherichia coli / drug effects*
  • Methylation
  • Microbial Sensitivity Tests
  • Models, Molecular
  • Molecular Conformation
  • Polyalthia / chemistry*
  • Structure-Activity Relationship

Substances

  • Anti-Bacterial Agents