Estudo fitoquímico da fração n-butanólica de Lippia Alba (Mill.) N. E. Br.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

Lippia alba is a medicinal plant wich is find in all regions of Brazil. This especie is largely used in the folk medicine, especially as a tranquilizer. It needs cientific studies about isolation and identification of its constituents. In previous studies, the n-butanolic fraction, obtained from a hidroalcoolic extract showed sedative and anticonvulsant effects. The objective of this work was the study of the same fraction, searching the isolation and identification from its chemical constituents, the qualitative seasonal accompaniment of this substances and the achievement from pharmacological experiments (verification of the body temperature and sedative activity, through the induction with pentobarbital and ether). Thus, from a hidroalcoolic extract of the leaves from the vegetable material, followed by partition with solvents of increasing polarity, the n-butanolic fraction was obtained. After purification of subfractions, was possible to isolate the substances LA-1 (verbascoside), LA-2, LA-3 (3 , 16 , 23 trihydroxiolean-12-en-28 oic acid bidesmosidic) and LA-4. To the elucidation of the substance LA-2, is necessary wait for the NMR spectrum; to the substance LA-4, is necessary the purification from CLAE to its elucidation. About the pharmacological trials, it is no possible to assure that the n-butanolic fraction shows sedative activity; it increased the barbiturate sleeping time (300 mg/ Kg body wt., 1 h after the treatment v.o.) but not increased the ether sleeping time, at the same previously dose and time; not modified significative the latency of the sleep, including the control group; decreased the body temperature (100 and 300 mg/ Kg wt., 1 and 2 h after the treatment v.o.) but it is no possible to say that is because a central effect. In that way, L. alba is shown as a viable source of potentially active secondary metabolites. The chemical constituents analysed in this work could be find in all assessments, so there is no qualitative seasonal variation. Posterior studies could achieve more researches about the pharmacological activities from the n-butanolic fraction and from its chemical constituents isolated and from the infusion. Furthermore, could elucidate the structures not yet identified.

ASSUNTO(S)

farmacia lippia alba farmácia

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