A novel series of falvonols (16a-s) were synthesized by the reaction of respective chalcones (2a-s) and hydrogen peroxide. The structures of all the compounds were confirmed by spectral data and tested for their antimicrobial activities against both gram positive B.subtilis, gram negative E.coli bacteria and antifungal activity against P.notatum C. tropicalis, A. niger and C. albicans by using cup plate method. Among the synthesized compounds, Flavanol derivatives bearing electron releasing functional group (16b, 16n and 16s) showed good activity against E.Coli . Derivative bearing dimethoxy group (16n) showed good activity againest B. Subtilis. Flavonol derivatives showed moderate to weak activity against A. niger, C. albicans and Penicillium notatum fungi.