Antibacterial and cytotoxic triterpenoids from the roots of Combretum racemosum

Fitoterapia. 2016 Apr:110:89-95. doi: 10.1016/j.fitote.2016.03.002. Epub 2016 Mar 2.

Abstract

A new pentacyclic triterpenoid glucoside, together with fourteen known compounds, was isolated from the roots of Combretum racemosum. Combretaceae). The structure of the new compound was established as 28-O-β-d-glucopyranosyl-2α,3β,21β,23-tetrahydroxyolean-18-en-28-oate (1) on the basis of detailed spectroscopic data including MS, 1D, and 2D NMR. The inhibitory activity of compounds 1-15 against promyelocytic leukemia HL-60 and human erythromyeloblastoid leukemia K562 cell lines was evaluated. Compounds 11 (3-O-β-acetyl-ursolic acid), 14 (betulinic acid), and 15 (quadranoside II) exhibited significant cytotoxicity, with IC50 values of 13 to 50 μM. Among the isolated triterpenes, compounds 1, 3 (arjungenin), 5 (terminolic acid), and 11 exhibited moderate antibacterial activity against Staphylococcus aureus, Escherichia coli and Enterococcus faecalis (MICs within a range of 64 and 256 μg/mL).

Keywords: Antibacterial activity; Combretaceae; Combretum racemosum; Cytotoxic activity; Triterpenes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / chemistry*
  • Anti-Bacterial Agents / isolation & purification
  • Combretum / chemistry*
  • Cote d'Ivoire
  • Enterococcus faecalis / drug effects
  • Escherichia coli / drug effects
  • Glucosides / chemistry*
  • Glucosides / isolation & purification
  • HL-60 Cells
  • Humans
  • Inhibitory Concentration 50
  • K562 Cells
  • Magnetic Resonance Spectroscopy
  • Microbial Sensitivity Tests
  • Molecular Structure
  • Plant Roots / chemistry
  • Staphylococcus aureus / drug effects
  • Triterpenes / chemistry*
  • Triterpenes / isolation & purification

Substances

  • 28-O-beta-d-glucopyranosyl-2alpha,3beta,21beta,23-tetrahydroxyolean-18-en-28-oate
  • Anti-Bacterial Agents
  • Glucosides
  • Triterpenes