Antimycobacterial flavonoids from the leaf extract of Galenia africana

Sannah P.N. Mativandlela, Tshilidzi Muthivhi, Haruhisa Kikuchi, Yoshiteru Oshima, Chris Hamilton, Ahmed A. Hussein, Martha L. Van Der Walt, Peter J. Houghton, Namrita Lall

Research output: Contribution to journalArticlepeer-review

38 Citations (Scopus)


The bioassay-guided fractionation of the EtOH extract of the leaves of Galenia africana led to the isolation of three known flavonoids, (2S)-5,7,2′-trihydroxyflavanone (1), (E)-3,2′,4′- trihydroxychalcone (2), and (E)-2′,4′-dihydroxychalcone (3), and the new (E)-3,2′,4′-trihydroxy-3′-methoxychalcone (4). Compounds 1 and 3 exhibited moderate antituberculosis activity. During synergistic studies, a combination of compound 4 and an existing antituberculosis drug, isoniazid, reduced their original MICs 4-fold, resulting in a fractional inhibitory concentration of 0.50. The most pronounced effect was demonstrated by compound 1 and isoniazid reducing their MICs 16-fold and resulting in an FIC of 0.12. Both EtOH extract and isolated compounds failed to exhibit any NADPH oxidase activity at 800.0 μM concentrations, indicating that mycothiol disulfide reductase is not the target for their antituberculosis activity.

Original languageEnglish
Pages (from-to)2169-2171
Number of pages3
JournalJournal of Natural Products
Issue number12
Publication statusPublished - 2009 Dec 28
Externally publishedYes

ASJC Scopus subject areas

  • Analytical Chemistry
  • Molecular Medicine
  • Pharmacology
  • Pharmaceutical Science
  • Drug Discovery
  • Complementary and alternative medicine
  • Organic Chemistry


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