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 β-D-glucopyrano (4'→3)-β-D-glucopyranose ( 1 ) and four known compounds namely scoparone ( 2 ), apigenin ( 3 ), β-sitosterol ( 4 ) and β-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.