Labdane and Clerodane Diterpenoids from Colophospermum mopane

J Nat Prod. 2015 Oct 23;78(10):2494-504. doi: 10.1021/acs.jnatprod.5b00729. Epub 2015 Oct 7.

Abstract

Five labdane (1-5), an isolabdane (6), and five clerodane diterpenoids (7-11), were isolated from seeds, husks, and leaves of Colophospermum mopane. Compounds 1-3 and 6-9 are new, and their structures were elucidated by means of physical data analysis (1D and 2D NMR, HRESIMS). The absolute configurations of 1, 7, and 10 were determined by single-crystal X-ray diffraction with Cu Kα radiation. For compounds 2 and 6, the absolute configurations were established by the modified Mosher's method and corroborated by comparison of experimental and calculated electronic circular dichroism spectra of their 3-p-bromobenzoate derivatives. The crude extracts and compounds were evaluated for antimicrobial activity. The leaf extract was the most active against Staphylococcus aureus (125 μg/mL). Compound 11 showed the best inhibitory activity, with minimum inhibitory values of 15.6 μg/mL against Escherichia coli and Staphylococcus aureus and 31.3 μg/mL against Enterococcus faecalis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / isolation & purification*
  • Anti-Bacterial Agents / pharmacology
  • Diterpenes / chemistry
  • Diterpenes / isolation & purification*
  • Diterpenes / pharmacology
  • Diterpenes, Clerodane / chemistry
  • Diterpenes, Clerodane / isolation & purification*
  • Diterpenes, Clerodane / pharmacology
  • Enterococcus faecalis / drug effects
  • Escherichia coli / drug effects
  • Fabaceae / chemistry*
  • Klebsiella pneumoniae / drug effects
  • Microbial Sensitivity Tests
  • Molecular Structure
  • Nuclear Magnetic Resonance, Biomolecular
  • Plant Leaves / chemistry
  • Seeds / chemistry
  • South Africa
  • Staphylococcus aureus / drug effects
  • Stereoisomerism

Substances

  • Anti-Bacterial Agents
  • Diterpenes
  • Diterpenes, Clerodane