Estudo químico de Licaria armeniaca (Nees) Kosterm

Abstract

Chrornatography of a benzenic extract of Licaria armeniaca (Nees} Kosterm., Lauraceae; (wood) gave five compounds: 1-hydroxy-3,6-dimethoxy-8-methyl-xanthone (B-1), sitosterol (B-2) , 6,7-dimethoxycoumarin (B-3), (1R,5S,6R,7S,8S)-8-acetoxy-5-allyl-6--methyl-1,3-dimethoxy-7 (3',4 '-methylenedioxyphenyl) bicyclo(3,2,1)oct-3-en-2-one (B-4) and 1,2,3-trimethoxy-7-oxoaporphine (B-5). Chromatography of a ethanolic extract gave: sitosterol, 1-hydroxy-3,6-dimethoxy-8-methyl-xanthone, 1,2,3-trimethoxy-7-oxoaporphine, isolate of the benzenic extract, and a lignan 2-(3,4,5-trimethoxyphenyl)-6-(3,4-dimethoxyphenyl)-3~7-dioxabicyclo[3,3,0] octan (E-3}. The correlation of spectral data of bicyclo 3,2,1 octanoid neolignans led to the establishment of a scheme for the structural determination. The application of these data allowed structural determination of the new neolignan (1R,5S,6R,7S,8S)-8-acetoxy-5-allyl-6-methyl-1,3-dimethoxy-7(3'-4'-methylenedioxyphenyl) bicyclo[3,2,1]oct-3-en-2-one (B-4). Comparative analysis of the 1H N.M.R., 13C N.N.R., I. R. and mass spectra of two derivatives obtained by alkaline hydrolysis was also consistent with the structural proposal of the new neolignan. The probable course of biogenesis leading to bicyclo [3,2,1]octanoid neolignans and oxoaporphine alkaloids is discussed.