title: Labdane and Clerodane Diterpenoids from Colophospermum mopane.
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.
authors.forename: Kun
authors.initials: K
authors.lastname: Du
authors.forename: Maria
authors.initials: M
authors.lastname: De Mieri
authors.forename: Markus
authors.initials: M
authors.lastname: Neuburger
authors.affiliation: National Museum , P.O. Box 266, Bloemfontein 9300, South Africa.
authors.forename: Pieter C
authors.initials: PC
authors.lastname: Zietsman
authors.forename: Andrew
authors.initials: A
authors.lastname: Marston
authors.affiliation: Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand , Parktown 2193, South Africa.
authors.forename: Sandy F
authors.initials: SF
authors.lastname: van Vuuren
authors.affiliation: Department of Biomolecular Sciences, Division of Pharmacognosy, and Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi , University, Mississippi 38677-1848, United States.
authors.forename: Daneel
authors.initials: D
authors.lastname: Ferreira
authors.forename: Matthias
authors.initials: M
authors.lastname: Hamburger
authors.forename: Jan H
authors.initials: JH
authors.lastname: van der Westhuizen
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D045785:Diterpenes, Clerodane / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D013293:Enterococcus faecalis / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D007887:Fabaceae / Q000737:chemistry*; D007711:Klebsiella pneumoniae / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D018515:Plant Leaves / Q000737:chemistry; D012639:Seeds / Q000737:chemistry; D013019:South Africa; D013211:Staphylococcus aureus / Q000187:drug effects; D013237:Stereoisomerism
chemical_list: D000900:Anti-Bacterial Agents; D004224:Diterpenes; D045785:Diterpenes, Clerodane