First synthesis and in vitro biological assessment of isosideroxylin, 6,8-dimethylgenistein and their analogues as nitric oxide production inhibition agents

A modular and efficient first synthesis of the biologically active C-methylisoflavones isosideroxylin (1), 6,8-dimethylgenistein (2) and their analogues (3-8) is achieved in 7-8 steps with overall yields of 16%-24%. Next, in their nitric oxide (NO) production inhibition assay in lipopolysaccharide-induced RAW 264.7 macrophages as an indicator of anti-inflammatory activity, all compounds showed moderate to good inhibitory activity in a concentration-dependent manner without notable cytotoxicity and IC50 values are found in the range from 10.17 μmol/L to 33.88 μmol/L.