Isolation and characterization of auronlignan derivatives with hepatoprotective and hypolipidemic activities from the fruits of Hippophae rhamnoides L.

The fruit of Hippophae rhamnoides L. is not only used as delicious food with nutritional values, but also served as traditional Chinese medicine with multiple bioactivities. In order to find structurally interesting and bioactive isolates from the fruits of H. rhamnoides L., a bioassay-guided investigation was applied to seek the hepatoprotective and hypolipidemic ingredients in this study. As a result, three new (10 -> 10 '')-biauronlignans (1-3), three new 10-(4 ''-hydroxy-benzyl)-auronlignans (4-6), three new 10-O-beta-D-glucopyranosyl-auronlignans (7-9), and eleven known auronlignan derivatives (10-20) were isolated from the fruits of H. rhamnoides L. for the first time, and their structures were determined by extensive and comprehensive IR, UV, NMR, MS spectral analyses and compared with the reported references. Among them, compounds 1, 4, 7, 11, 15, and 19 showed moderate hepatoprotective activities against the damage in acetaminophen-induced HepG2 cells; compounds 2, 5, 8, and 12 exhibited moderate inhibition of pancreatic lipase activity, and decreased the moderately FFA-induced lipid accumulation in HepG2 liver The plausible biogenetic pathway and preliminary structure-activity relationship of the selected compounds are scientifically summarized and discussed in this study.