Considerações sobre os gêneros Ouratea e Luxemburgia, estudo químico de duas espécies de Ochnceae: Ouratea hexasperma St. Hil e Ouratea cuspidata St. Hil e atividades biológicas

Abstract

Besides the considerations concerning the flavonoidic biodiversity of Ouratea and Luxemburgia genera, the chemical study of two Ouratea (Ochnaceae) species was achieved. O. cuspidata, collected in the beach ridge of Barra de Maricá township, RJ and O. hexaseperma, collected in tabuleiro region, João Pessoa township, PB, Brazil. The described substances in this phytochemical investigation were isolated using solvent partition and chromatographyc technique of the extract obtained by cold maceration with hexane, ethyl acetate and methanol. The structures were determined by IR, MS and 1H and 13C NMR (1D and 2D techniques) analysis of natural substances and of some derivatives. From the inflorescence methanol extract of O. hexasperma were isolated campesterol, sitosterol, stigmasterol, 3-β-O-acyl-olean-12-en-28-oic acid, sitosterol-3-O-βD-glycopyranoside, the flavonoids, orientin, vitexin, rutin, swertisin and swertiajaponin; from the methanolic extract of stem of this specie the 1,5-dihydroxyphenylacethyc acid, flavanone-3,4 ,5-trihydroxi-6- prenyl-7-O-βD-glycopyranoside, and flavone-3,4 ,5-trihydroxi-6-prenyl-7-O-βDglycopyranoside were isolated. From the O. cuspidata leaves were isolated lupeol, α-amyrin, β-amyrin, amentoflavone, putraflavone and 5,7,4 -trihydroxy-3 ,5 -dimethoxy-flavone. The same study of the stem of this specie yielded 4 ,3,5,7,-tetrahydroxy-3 -methoxy-flavonol, 4 ,3,5,7-tetrahydroxy-3 -methoxy-3-β-OD-galactopiranosyl-flavone and methyl-βDglycopiranoside. The glycopiranosyl-prenyl-flavonoids are new in the literature. The extracts of O. cuspidata were avaluated as antiparasitic against Leishmania brasiliensis.