Chemical constituents from Acorus calamus with potent anti-diabetic and hepatoprotective activities

Three previously undescribed compounds, (+)-7S,8S-syringoylglycerol-7-O-3',4'-dihydroxylphenylethanol (1), (+)-2S,3R-piscidic acid 1-methyl-5-ethyl ester (2), and 2'S-2-acetyl-3-(2,3-dihydroxypropoxyl)furan (3), together with one new natural product, 7S,8S-4,7,8-trihydroxyl-methyl phenylpropionate (4) and a known lignan (7S,8R)-methyl-4',7-epoxy-3,3'-dimethoxy-4,9-dihydroxylignan-9'-oate (5), were isolated from the ethanol extract of Acorus calamus Linn. rhizomes. Their structures were determined based on extensive spectroscopic analyses and computational methods. All the isolated compounds were evaluated for their in vitro GK activating and hepatoprotective activities, and compound 5 exhibited significant GK activating activity at 10-5 mol/L, compound 3 exhibited moderate protective effects to APAP-induced injuries of HepG2 cells at 10-5 mol/L. Furthermore, molecular docking of compound 5 bound with GK was carried out to investigate the possible structural insights into the potential binding patterns.