Ethnopharmacological relevance: Mexican people employed infusion of leaves of Choisya ternata Kunth for their antispasmodic and "simulative properties". Aim of the study:In the present study the detailed GC and GC-MS analyses of the essential oil of Choisya ternata Kunth (Rutaceae) were performed. The presence of a minor constituent isopropyl N-methylanthranilate (1) was revealed among other identified volatiles. A synthesis of 1 was undertaken in order to corroborate this find and obtain gram quantities that would allow the testing of its biological activity (peripheral and central antinociceptive activity). Material and methods:The oils were investigated by GC and GC-MS. Synthesized compounds were spectrally characterized (UV-Vis, IR, 1D and 2D NMR, MS). The obtained synthetic samples of compounds were assayed for peripheral and central antinociceptive activity in two models (effects on acetic acid induced writhing in mice and the hot plate test for nociception). showed the lowest activity (with the methyl ester at 3 mg/kg still better than acetylsalicylic acid, at 200 mg/kg, in the first, or comparable with morphine, at 5 mg/kg, in the second test). Conclusion:This study once again revealed that detailed investigations of plant species with ethnopharmacologically documented activity may yield new natural compounds -a new alkaloid (ternanthranin), a volatile simple anthranilate that can be considered responsible for the antinociceptive activity of the crude plant extracts.

RESUMO: "Atividade hipoglicemiante de duas espécies de Bauhinia brasileira: Bauhinia forfi cata L. and Bauhinia monandra Kurz.". Extratos aquosos das folhas de Bauhinia forfi cata L. e Bauhinia monandra Kurz (10% p/v) foram testados em camundongos normoglicêmicos, objetivando averiguar a sua atividade hipoglicemiante. Ambos os extratos mostraram atividade hipoglicemiante na metodologia empregada. Ainda, foi possível isolar de B. forfi cata L. dois fl avonóides, quercetina-3,7-O-dirhamnosido e kaempferol-3,7-O-dirhamnosido, sendo as estruturas estabelecidas por técnicas clássicas de RMN. Apenas o derivado da quercetina foi identifi cado no extrato aquoso de Bauhinia monandra por CLAE.Unitermos: Bauhinia forfi cata, Bauhinia monandra, Leguminosae, atividade hipoglicemiante, fl avonoides, CLAE. ABSTRACT:The hypoglycemic activity of aqueous extracts from Bauhinia forfi cata L. and Bauhinia monandra Kurz leaves (10% w/v) was evaluated in normoglycemic mice. Both extracts have shown hypoglycemic activity using this methodology. It was also possible to isolate two fl avonoids from B. forfi cata L., 3,7-di-O-α-rhamnopyranosylquercetin and 3,7-di-O-α-rhamnopyranosylkaempferol (kaempferitrin), whose structures were elucidated by usual NMR techniques. Only the quercetin derivative was identifi ed in B. monandra aqueous extract by HPLC.

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Plants of the genus Bauhinia are used in several countries worldwide for the treatment of diabetes, and several related species have been shown to have hypoglycaemic effects in vivo in both normoglycaemic and alloxan- and streptozotocin-treated animal models. In this study, the insulin-secreting cell line INS-1 was used to examine the effects of the crude ethanolic extract of leaves of B. variegata L. var. Candida Voidt and its major metabolite (6 S,7 E,9 R)-9-hydroxymegastigma-4,7-dien-3-one-9- beta-glycopyraroside (roseoside) on insulinotropic activity. The crude extracts and the major metabolite were shown to increase insulin secretion in a dose-dependant manner.