Neolignanas de Licaria rigida e Osteophloeum platispermum

• Ano de defesa: 1980
• Autor(a) principal: Carvalho, M?rio Geraldo de
• Orientador(a): Braz Filho, Raimundo
• Banca de defesa: Braz Filho, Raimundo
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal Rural do Rio de Janeiro
• Programa de Pós-Graduação: Programa de P?s-Gradua??o em Qu?mica
• Departamento: Instituto de Ci?ncias Exatas
• País: Brasil
• Palavras-chave em Português: Licaria rigida; Osteophloeurn platyspermum; neolignanas
• Área do conhecimento CNPq: Qu?mica
• Link de acesso: https://tede.ufrrj.br/jspui/handle/jspui/4345

The benzene extract of the trunk wood of Licaria rigida Kosterm. (Lauraceae), after cromatographic fracionation, gave, besides sitosterol, four neolignans, two benzodioxanoid compounds: eusiderin B rel-(7R, 8R)- delta8'-5'-methoxy-3,4-methyenodioxy-7.0.3',8.0.4'-lignan and eusiderin A rel-(7R, 8R)-delta8'-5'-rnethoxy-3,4,5-trimethoxy-7.0.3',8.0.4'-lignan and two bicyclooctanoid compounds: canelin A (7R,8S,1'S,2'R,3'S.4'S,5'R)-delta8'-2',4'-dihydroxy-3',5'-dimethoxy-3,4-metilenodioxi-8,1',7,3'lignana e canelin C rel-(7R,8S,1'S,2'R,3'S,4'R)- delta8'2',4'-dihydroxy-5'-oxo-3,4-rnethylenodioxy-8.1',7.3'-lignan. The structural proposals resulted from spectral (u.v., n.m.r.1H, n.m.r.13C, mass and O.R.D.) analysis of the original substances and their acetylated derivates. The 4'-O-acetyl and 2',4'-di-O-acetyl derivatives of canellin A were obtained using pyridin and acetic anhydride, at different reaction times temperatures. The benzene extract of the fruit from Osteophloeum platysperrnum (A.DC.) Warb. (Myristicaceae) gave, after crystalization from methanol, a triglycerid (90% of extract): lauro-dimyristin. Cromatographic fracionation of the mother-licquor of the extract gave, besides lauro-dimyristin and sitosterol, a diglycerid-(glyceryl-1-lauro-3-myristate) and five neolignans: dihydroguaiaretic acid (4,4'-dihydroxy-3,3'-dimethoxy-8.8'-lignan; a guaiacin isomer, rel-{7R,8R,8'S)-4,3'-dihydroxy-3,4'-dimethoxy-8.8',7.2'-lignan; an otobaphenol isomer, rel-(7R,8R,8'S)-4'-methoxy-3'-hydroxy-3,4-methylenedioxy-7-hydroxy-8.8',7.2'-lignan, hydroxy-otobain, rel-(7R,8R,8'S)-3,4,3',4'-dimethylenedioxy-7-hydroxy-8.8',7.2'-lignan and hydroxy-oxo-otobain, rel-(7S,8R,8'R)-3,4,3',4'-dimethylenedioxy-7-hydroxy-7'-oxo-8.8',7.2'-lignan. The structural proposals were based on spectral (u.v., i.v., n.m.r.1H, n.m.r.13C and mass) analysis of the original substances and their derivatives obtained by acetylation. The relative configurations ano conformations of (7R,8R,8'S)-4,3'-dihydroxy-3,4'-dimethoxy-8.8',7.2'-lignan; (7R,8R,8'S)-4'-methoxy-3'-hydroxy-3,4-methylenedioxy-8,2',7.2'- lignan; (7S,8R,8'S) -3,4,3',4'-dimethylenedioxy-7-hydroxy-8. 8', 7.2'-lignan and (7R,8R,8'R)-3,4,3',4'-dimethylenedioxy-7-hydroxy-7'-oxo-8.8',7.2'-lignan were defined by the analysis of n.m.r.1H and n.m.r.13C spectra. The dehydration of hydroxyotobain was obtained by treatment with acetic anhydride unders reflux during 48 hours. The derivative obtained by acetylation involved the use of pyridin and acetic anhydride. The structures of the known substances were confirmed bydirect comparison with authentic samples. The direct comparison involved melting point, spectral data and s?lica TLC.