Biflavanones, Chalconoids, and Flavonoid Analogues from the Stem Bark of Ochna holstii

J Nat Prod. 2021 Feb 26;84(2):364-372. doi: 10.1021/acs.jnatprod.0c01017. Epub 2021 Jan 29.

Abstract

Two new biflavanones (1 and 2), three new bichalconoids (3-5), and 11 known flavonoid analogues (6-16) were isolated from the stem bark extract (CH3OH-CH2Cl2, 7:3, v/v) of Ochna holstii. The structures of the isolated metabolites were elucidated by NMR spectroscopic and mass spectrometric analyses. The crude extract and the isolated metabolites were evaluated for antibacterial activity against Bacillus subtilis (Gram-positive) and Escherichia coli (Gram-negative) as well as for cytotoxicity against the MCF-7 human breast cancer cell line. The crude extract and holstiinone A (1) exhibited moderate antibacterial activity against B. subtilis with MIC values of 9.1 μg/mL and 14 μM, respectively. The crude extract and lophirone F (14) showed cytotoxicity against MCF-7 with EC50 values of 11 μg/mL and 24 μM, respectively. The other isolated metabolites showed no significant antibacterial activities (MIC > 250 μM) and cytotoxicities (EC50 ≥ 350 μM).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / isolation & purification
  • Anti-Bacterial Agents / pharmacology*
  • Antineoplastic Agents, Phytogenic / isolation & purification
  • Antineoplastic Agents, Phytogenic / pharmacology*
  • Bacillus subtilis / drug effects
  • Chalcones / isolation & purification
  • Chalcones / pharmacology*
  • Escherichia coli / drug effects
  • Flavonoids / isolation & purification
  • Flavonoids / pharmacology*
  • Humans
  • MCF-7 Cells
  • Microbial Sensitivity Tests
  • Ochnaceae / chemistry*
  • Phytochemicals / isolation & purification
  • Phytochemicals / pharmacology
  • Plant Bark / chemistry
  • Plant Extracts / chemistry
  • Tanzania

Substances

  • Anti-Bacterial Agents
  • Antineoplastic Agents, Phytogenic
  • Chalcones
  • Flavonoids
  • Phytochemicals
  • Plant Extracts