Coumestan glycosides from the stem bark of Cylicodiscus gabunensis.

Two new coumestan glycosides, coumestoside C (1) and coumestoside D (2), were isolated from the stem bark of Cylicodiscus gabunensis Harms. Their structures were established by spectroscopic means and chemical transformations as 9-O-alpha-L-rhamnopyranosyl-3-hydroxy-4-(5'-hydroxy-3'-methylbut-2'E-enyl) coumestan (1) and 9-O-beta-D-galactopyranosyl-3-O- prenyl-4-hydroxycoumestan. Coumestoside C exhibited antimicrobial activity against Proteus vulgaris.

Isoflavonoids from Erythrina poeppigiana: evaluation of their binding affinity for the estrogen receptor.

Five new isoflavones, named 5,4'-dihydroxy-7-methoxy-3'-(3-methylbuten-2-yl)isoflavone (1), 5,2',4'-trihydroxy-7-methoxy-5'-(3-methylbuten-2-yl)isoflavone (2), 5,4'-dihydroxy-7-methoxy-3'-(3-methyl-2-hydroxybuten-3-yl)isoflavone (3), 3'-formyl-5,4'-dihydroxy-7-methoxyisoflavone (4), and 5-hydroxy-3''-hydroxy-2'',2''-dimethyldihydropyrano[5'',6'':3',4']isoflavone (5), as well as six known compounds, wighteone (6), 3'-isoprenylgenistein (7), isolupabigenin (8), alpinumisoflavone (9), erypoegin D (10), and crystacarpin (11), were isolated from Erythrina poeppigiana. The structures of the isolated compounds were elucidated on the basis of chemical and spectroscopic analysis. The affinity of these compounds for the estrogen receptors ERalpha and ERbeta was evaluated using a receptor binding assay.

Globulixanthone F, a new polyoxygenated xanthone with an isoprenoid group and two antimicrobial biflavonoids from the stem bark of Symphonia globulifera.

Bioassay-guided fractionation of the stem bark of Symphonia globulifera has yielded three known xanthones, ugaxanthone (1), mbarraxanthone (2) and gentisein (3), two biflavonoid derivatives named GB2 (4) and manniflavanone GB3 (5), and one new polyoxygenated xanthone with an isoprenoid group, named globulixanthone F (6). The structures of these compounds were elucidated by means of spectroscopic methods. The spectral data of 1 and 2 are reported here for the first time, as well as the antimicrobial activity of globulixanthone F against a range of microorganisms.

A new Erythrinan alkaloid from the seed of Erythrina addisoniae.

Phytochemical study on the EtOAc extract of the seed of Erythrina addisoniae (Leguminosae) resulted in the isolation of a new erythrinan alkaloid, erysovine-N-oxide (1), along with eight known alkaloids, erysosalvinone (2), erysodine (3), 1H-indole-3-propanamide (4), glucoerysodine (5), erysotrine (6), erysovine (7), erythraline (8) and erysopine (9). Their chemical structures were identified on the basis of physicochemical and spectroscopic analyses.

Amides from the stem bark of Fagara macrophylla.

Five new amide alkaloids, N-(4-hydroxyphenethyl)octacosanamide (1), N-(4-hydroxyphenethyl)hexacosanamide (2), N-(4-hydroxyphenethyl)decanamide (3), N-vanilloyltyramine (4), and N-[O-docosanoylvanilloyl]tyramine (5), were isolated from Fagara macrophylla, together with 15 known compounds. Their structures were established by using spectroscopic techniques, chemical reactions, and comparison with previously known analogues. A cytotoxicity assay was performed with the isolates, in which compounds 4, 8, and 9 were found to possess moderate to weak activity, with IC(50) values of 30.