Structure activity relationship of bergenin, p-hydroxybenzoyl bergenin, 11-O-galloylbergenin as potent antioxidant and urease inhibitor isolated from Bergenia ligulata

摘要

Ethanol extract of the aerial parts of Bergenia ligulata was subjected to solvent-solvent separation followed by various chromatographic techniques that lead to isolation of bergenine (1), p-hydroxybenzoyl bergenin (2), 11-O-galloylbergenin (3) and methyl gallate (4) as major constituents. Ethyl acetate fraction showed a dose-dependent urease inhibitory pattern with IC50 value of 54g/mL. Structures of compounds 1 and 3 were established by XRD and 2, 4 by NMR. All these compounds were subjected to DPPH scavenging activity, reducing power assay and urease inhibitory activity. The EC50 7.45 +/- 0.2g/mL and 5.39 +/- 0.28g/mL values in terms of antioxidant and reducing power, respectively, were less for 3. Compounds 1-3 showed moderate to significant urease inhibitory potential with IC50 57.1 +/- 0.7, IC50 48.4 +/- 0.3 and 38.6 +/- 1.5. Antioxidant activities and urease inhibitory potential were investigated and compound 3 was found to be the most active.