- no.42, pp.517-522, 2000-10-01
In the course of screening for liver injury preventing activity of 22 fruits, we found strong activity of avocado. We describe the isolation, structure determination, and biological activity of the liver injury preventing substances from the fruit Lyophilized materials were extracted with hexane. The hexane extract was chromatographed on a silica gel column followed by HPLC using an ODS column, giving five compounds 1-5. FAB-MS (positive) of 1 showed the [M+H]^+ ion at m/z 351. Its ^<13>C-NMR and DEPT experiment exhibited the presence of a carbonyl group (δ189.2), 4 double bonds (δ126.3, 127.8, 128.3, 129.2, 129.8, 130.3, 144.8, 148.7), 11 methylene groups, and a methyl one (δ14.09). Finally, the structure of the compound was determined by the interpretation of HMBC spectrum and its EI-MS fragmentation. Compounds 2 and 3 have been already isolated as an antifungal substance and/or radical scavengers. Elucidation of the structures of compounds 4 and 5 is now in progress. In vivo assay was done as follows. After direct administration of each compound (100mg/kg weight) into rats' stomachs by using catheters, liver injury was induced by treatment of the rats with D-GalN. All the compounds suppressed the increase of ALT and AST activity in the serum of the rats.