Alkaloids from Annona dioica

Abstract

From the ethanolic extract of the wood of Annona dioica were isolated the known 1-aza-4methylanthraquinone, lasiodiplodin, liriodenine, a mixture of 1-aza-5,9,10-trimethoxy-4-methyl-2-oxo-1,2-dihydroanthracene and 1-aza-8,9,10-trimethoxy-4-methyl-2-oxo-1,2-dihydroanthracene (geovanine) and the new alkaloid 1,2-methylenedioxy-6α,7-dehydroaporphine-4(S)-(4-hydroxy-3,5- dimethoxyphenyl)-3,4-dihydro-2(1H)-pyridinone. The structures of these natural products were elucidated on the basis of their spectral data, including NOE experiments and homonuclear 1H-1H- COSY e heteronuclear 1H-13C-COSY-nJCH (HMQC, n=1 and HMBC, n=2 and 3) 2D-shift-correlated NMR spectra.