Antioxidant constituents from Ribes glaciale Wall.: bioassay targeted in-vitro and in-silico evaluation

Bioassay targeted phyto-investigation of dried green walnut husk of Ribes glaciale Wall. yielded one new compound as beta-D-glucopyrano (4 '-> 3)-beta-D-glucopyranose (1) and four known compounds namely scoparone (2), apigenin (3), beta-sitosterol (4) and beta-sitosterol-D-glucoside (5). The structure of new compound was elucidated with the help of 1D, 2D and HRESIMS analysis. The antioxidant activity of extract, fractions and pure were evaluated using 2, 2 '-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric ion reducing antioxidant power (FRAP) assays that found in the following order: butanol fr. (BF) > chloroform fr. (CF) > ethylacetate fr. (EF) > Petroleum ether fr. (PF). To search for potent antioxidant agents in extract, the isolated compounds 1, 2, 3, 4 and 5 were docked on the enzyme human NADPH oxidase, lipoxygenase, cytochrome P450 and myeloperoxidase. The compound 1 was found a potent inhibitor of target enzyme revealing its high free radical scavenging potential. [GRAPHICS] .