RESUMEN
Two new lignans, (8R,8'R)-8- hydroxy-3,4-dimethoxy-3',4'-methylenedioxy-7-oxolignan (1) and (7'R,8'S)-3,4-methylenedioxy-3',4'-dimethoxy -7,8-seco-7,7'-epoxylignan-7,8-dione (2), were isolated from the EtOAc extract of the fruits of Schisandra sphenanthera, along with ten known compounds. The structures of these compounds were elucidated on the basis of NMR and MS analysis. This is the first report of the occurrence of secolignans in Schisandra.
Asunto(s)
Frutas/química , Lignanos/química , Schisandra/química , Conformación de Carbohidratos , Cromatografía en Capa Delgada , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Extractos Vegetales/química , Espectrometría de Masa por Ionización de Electrospray , Espectrofotometría Infrarroja , Espectrofotometría UltravioletaRESUMEN
Three new naphthoquinones, astropaquinones A-C (1-3), were isolated from cultures of the freshwater fungus Astrosphaeriella papuana YMF 1.01181, together with the known compound, 6-hydroxy-2,4-dimethoxy-7-methylanthraquinone (4). The structures of the compounds were settled mainly by interpretation of their 1D and 2D NMR spectra. Astropaquinone B (2) and C (3) were found to possess a rare pyranonaphthoquinone skeleton containing a lactol ring. Furthermore, compounds 1-4 showed moderate antagonistic activity against nine fungi and four bacterial strains.