Estudo químico de plantas amazônicas: Coupeia bracteosa, Licaria puchury-major, Bauhinia splendens

Abstract

Trunk wood of Couepia bracteosa Benth. family Chrysobalanaceae, was extracted with ethanol. Chromatography ot the extract gave an aliphatic ester (Cb-1), sitosterol+ stigmasterol (CB-2), betulinic acid (Cb-3) and 5-hydroxy-7,4'-dimethoxyflavone (Cb-4). The benzene extract ot the bark ot Licaria puchury-major (Mart.) Kosterm., family Lauraceae, gave by the same process, sitosterol + stigmasterol (Lpm-2D), safrol (Lpm-4D):, eugenol (Lpm-5D), 1-hydroxy-3,6-dimethoxy-8-methylxanthone (lichexanthone) (Lpm-1D), 1,8-dihydroxy-3-methoxy-6-methylanthraquinone (physcion) (Lpm-3D)). Thin layer chromatography demlonstrated the presence of 3,4-methylenedioxycinnamaldehyde. 3,4-methylenedioxicinamyl alcohol and 4-hydroxy-3,5-dimethoxybenzaldehyde. These three compounds were previously isolated from the wood of the species by Soares Maia. Examining the bark visually we found it overgrown by the lichen Graphina confluens Fée, famiily Graphidaceae. Lichexanthone and physcion are metabolites of this lichen and do not occur in the bark. Lichexanthone has previously been found by Wirth and Hale Jr. in Graphina confluens. The presence ot physcion, however, is not reported for the first time. The benzene and ethanol extracts of the trunk wood of Bauhinia splendens H. B. K. subfamily Leguminosae-Caesalpinioideae, contain stearic acid (Bs-1), sitosterol + stigmasterol (Bs-2), and the novel 5-methoxy-7,8,3',4'-dimethylenedioxyflavone (Bs-3).