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When catechins are found in plant extracts, they are almost always identified as catechin and/or epicatechin probably due to stereoselectivity of the enzymes involved in the biosynthesis of these substances. However, the lack of reports regarding to ent-catechin as well as ent-epicatechin does not necessarily mean that these compounds have not been produced. In fact, most of the previous reports used chromatographic conditions not suitable for such separation. This article describes a simple and reliable analytical HPLC-PAD-CD method for simultaneous determination of catechin diastereomers both in infusions and extracts from the leaves of Byrsonima species. The direct separation of catechin, ent-catechin, epicatechin, and ent-epicatechin was obtained in normal phase by HPLC-PAD-CD using Chiralcel OD-H as chiral stationary phase and n-hexane/ethanol with 0.1% of TFA as mobile phase., (Copyright 2010 Wiley-Liss, Inc.)

The methanolic extract of the leaves of the medicinal plant Byrsonima crassa (Malpighiaceae) contain flavonoids with antioxidant activity. They were separated in a preparative scale using high-speed counter-current chromatography. The optimum solvent system used was composed of a mixture of ethyl acetate-n-propanol-water (140:8:80 (v/v/v)) and led to a successful separation between monoglucosilated flavonoids (quercetin-3-O-alpha-L-arabinoside, quercetin-3-O-beta-D-galactoside) and the biflavonoid amentoflavone in only 3.5 h. The purities of quercetin-3-O-alpha-L-arabinoside (95 mg), quercetin-3-O-beta-D-galactoside (16 mg) and the biflavonoid amentoflavone (114 mg) were all isolated at purity over 95%. Identification was performed by 1H NMR, 13C NMR and UV analyses.

Abstract: Byrsonima intermedia is a native species of the cerrado formation (tropical American savannah). In Brazil, this plant has been used for the treatment of fever, in ulcers, as a diuretic, as antiasthmatics and in skin infections. Members of the genus Byrsonima (Malpighiaceae) are employed not only in the folk medicine but also as food to make juice, jellies and liquor. The aim of this work was to evaluate the mutagenic effects of Byrsonima intermedia, common name ‘murici’. Phytochemical analysis of methanol extract furnished (+)-catechin, (−)-epicatechin, quercetin-3-O-β-d-galactopyranoside, methyl gallate, gallic acid, quercetin-3-O-α-l-arabinopyranoside, amentoflavone, quercetin, quercetin-3-O-(2″-O-galloyl)-β-galactopyranoside and quercetin-3-O-(2″-O-galloyl)-α-arabinopyranoside. Methanol, hydromethanol and chloroform extracts were evaluated in mutagenic assay with Salmonella typhimurium (Ames test) and mice (Micronucleus test). The methanolic extract presented signs of mutagenic activity for the strains TA98 and TA100 in the Ames assay. Mutagenicity was not observed in vivo. [Copyright &y& Elsevier]