B. Bodo

The in-vitro antimicrobial activities of some medicinal plants from Cameroon

The antimicrobial activities of 10 plant species (Voacanga africana, Crepis cameroonica, Plagiostyles africana, Crotalaria retusa, Mammea africana, Lophira lanceolata, Ochna afzelii, Ouratea elongata, Ou. flava and Ou. sulcata), each of which is currently used in the traditional medicine of Cameroon, were investigated in vitro. The activities of a methanol extract of each plant were tested, in disc-diffusion assays, against 37 reference or laboratory strains of seven species of microorganism (Staphylococcus aureus, S. epidermidis, Enterococcus hirae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Candida albicans). The minimal inhibitory concentrations of each extract were then estimated, against each of the more susceptible microorganisms (i.e. those giving an inhibition zone measuring at least 9 mm in diameter in the disc-diffusion assays), by agar dilution. Although, in the disc-diffusion assays, each of the 10 methanol extracts investigated displayed some degree of antimicrobial activity against at least one species of microorganism, no activity against the Gram-negative bacteria (Es. coli, K. pneumoniae and Ps. aeruginosa) was observed. The extract with the greatest antimicrobial activity was that of Pl. africana (Euphorbiaceae).

Mandassidione and other sesquiterpenic ketones from Cyperus articulatus

Abstract A new monocyclic sesquiterpenic diketone, mandassidione, was isolated from the rhizomes of Cyperus articulatus , along with mustakone and isopatchoul-4(5) en-3-one. The structures were established from spectroscopic and chemical evidence.

Structure of the chalcone dimers lophirone F, G and H from Lophira lanceolata stem bark.

Abstract Structural elucidation of three chalcone dimers, (lophirones F, G and H) isolated from Lophira lanceolata stem bark, and their permethylethers, is discussed using spectral chemical evidence.

Biflavonoids from Ochna calodendron

Abstract The biflavonoids, lophirone K and calodenins A and B, were isolated from the stem bark of Ochna calodendron along with lophirone C. Their structures were determined from spectroscopic and chemical evidence.

Structure of lophirones B and C, biflavonoids from the bark of Lophira lanceolata.

Abstract Two new isomeric biflavonoids, lophirone B and lophirone C have been isolated from the stem bark of Lophira lanceolata . Their structures were determined by the use of chemical and spectroscopic methods including 2D NMR techniques.

A new benzoylglucoside and a new prenylated isoflavone from lophira lanceolata

A new benzoylglucoside, lanceoloside A (1), and a new prenylated isoflavone, lanceolone (2), have been isolated from the air-dried leaves of Lophira lanceolata. Both structures were established from spectroscopic and chemical evidence.

Seco-ring-A-triterpenoids from the rootwood of Musanga cecropioides

Abstract From the rootwood of the African tree Musanga cecropioides, three seco-triacidic triterpenes, cecropiacic acid, musangic acids A and B were isolated as their trimethyl esters. Their structures were determined on the basis of a spectral analysis.

Musancropic acids A and B: A-ring contracted triterpenes from Musanga cecropioides

Abstract Two A-ring contracted triterpenes, musancropic acids A and B, having a new triterpene backbone, were isolated as their methyl esters from the rootwood of the African tree Musanga cecropioides . Their structures were determined by spectroscopic studies.

Millettonine, a guanidine alkaloid from Millettia laurentii

Abstract Millettonine, a guanidine alkaloid with a new skeleton, has been isolated from the stem bark of Millettia laurentii and its structure determined from a spectrometric study including mass spectrometry and NMR.

Tetraflavonoids of Lophira alata

Abstract A new tetraflavonoid, lophiroflavan A, was isolated from the stem bark of Lophira alata along with lophirochalcone. Both compounds were obtained as their permethyl ether derivatives and their structures determined from spectroscopic and chemical evidence.