Estudo químico e avaliação biológica de Bauhinia acuruana Moric

Abstract

The present work reports the chemical research of the roots, stem and leaves from Bauhinia acuruana. In this study were obtained the extracts in hexane, ethyl acetate and methanol of the leaves and ethanol extracts of the roots and stems. The chromatographic fractionation of extracts allowed the isolation of sesquiterpenes 1β, 6α- dihydroxy 4-(14)-eudesmene (BA-1) and aromadendrane-4β,10α-diol (BA-2); the steroid glycosylated sitosterol (BA-4); the bibenzys 2-hydroxy-2’,3’,5’- trimethoxybybenzyl (BA-5) and 2-hydroxy-3’,5'-dimethoxybybenzyl (BA-6); the oxepin derivatives pacharin (BA-7) and bauhiniastatin 1 (BA-8); the flavonoids quercitrin (BA-3), (-)-fisetinidol (BA-9), (2R, 3S)-2-(3’,4’-dihydroxiphenyl)-5-methoxycroman-3,7-diol (BA-10), (2R,3S)-2-(3’,4’-dihydroxiphenyl)-5-methoxy-6-methylcroman-3,7-diol (BA-11) and astilbin (BA-13), as well as the steroidal mixture sitosterol and stigmasterol (BA-12). It is worth noting that the secondary metabolites BA-1 and BA-2 are unprecedented in the genus, while BA-5 and BA-11 unprecedented in the literature and BA-10 unpublished as natural product. The structures of the compounds were elucidated through spectroscopic techniques (IV, NMR 1D and 2D), mass spectrometry and comparison with data reported in literature. Ethanol extracts of the roots and of the stems were evalueted for antioxidant activity, showing significant activity at concentrations of 0.1 mg/mL and 1.0 mg/mL, respectively. BA-7 was evaluated for its larvicidal activity against Aedes aegypti and presented LC50 value of 78.9 ± 1.8 µg/mL. In addition, BA-5, BA-7, BA-8, BA-9, BA-10 and BA-11 were submitted to evaluation of cytotoxic activity and BA-5, BA-7 and BA-8 presented significant cytotoxic activity.