HPLC/MS analysis of polyphenols, antioxidant and antimicrobial activities of Artabotrys hildebrandtii O. Hffm. extracts.

The purpose of this work was to evaluate chemical constituents, antioxidant and antimicrobial activities of Artabotrys hildebrandtii, an endemic medicinal plant from Madagascar. Ethanol extracts from the leaves and stem bark were tested to evaluate DPPH free radical scavenging, using butylated hydroxytoluene and quercetin as standard antioxidants. An high-performance liquid chromatography/mass spectrometry method was developed to investigate the presence of phenolic compounds in the studied samples; gentisic acid, chlorogenic acid, hyperoside, isoquercitrin, rutin, quercitrin, quercetol, apigenin and luteolin were identified.

Pyranocoumarin and triterpene from Millettia richardiana.

From the stem bark of a Madagascan endemic plant, Millettia richardiana Baill., lonchocarpenin and betulinic acid were isolated and their structures established by spectroscopic methods. The analysis of dichloromethane fractions suggested the presence of beta-amyrin, lupeol, palmitic acid, linoleic acid and stearic acid.

Antispasmodic and antioxidant activities of fractions and bioactive constituent davidigenin isolated from Mascarenhasia arborescens.

Ethnopharmacological Relevance: Mascarenhasia arborescens A. DC. (Apocynaceae) is used in traditional medicine in the North of Madagascar to treat intestinal disorders, intestinal spasms and diarrhoea.

Flavonoid glycosides and other constituents of Psorospermum androsaemifolium BAKER (Clusiaceae).

Two new flavonoid glycosides, namely 3'-(2'',4''-dihydroxybenzyloxy)acanthophorin B (1b) and beta,2,3',4,4',6-hexahydroxy-alpha-(alpha-L-rhamnopyranosyl)dihydrochalcone (2) were isolated from the leaves of Psorospermum androsaemifolium together with quercetin (1), acanthophorin B (1a), alpha- (3) and beta-amyrine (3a), vismiaquinone (4), 12-hentriacontanol and hentriacontane. The structures of these secondary metabolites were established using detailed spectroscopic analysis and by comparison with published data. Compounds 1, 1a, 1b, 2, 3, 3a and 4 showed weak antifungal and antibacterial activities.

Anticancer effect of a new benzophenanthridine isolated from Zanthoxylum madagascariense (Rutaceline).

Fractionation of the cyclohexane extract from the stem bark powder of Zanthoxylum madagascariense led to the isolation of a new benzophenanthridine-type alkaloid, hydrochloride of 2,3-methylendioxy-8-hydroxy- 7-methoxy-benzo[C]phenanthridine (Rutaceline), characterized on the basis of its spectral data. Rutaceline was evaluated for its antiproliferative capacity on the human colorectal adenocarcinoma (Caco-2) and the African green monkey kidney (Vero) cell lines. The 50% inhibition of cell growth (IC50) obtained after 24 h incubation was similar for both cells lines (110-115 microg/ml, i.