Chalcones and bis-chalcones: As potential α-amylase inhibitors; synthesis, in vitro screening, and molecular modelling studies

Despite of a diverse range of biological activities associated with chalcones and bis-chalcones, they are still neglected by the medicinal chemist for their possible alpha-amylase inhibitory activity. So, the current study is based on the evaluation of this class for the identification of new leads as alpha-amylase inhibitors. For that purpose, a library of substituted chalcones 1-13 and bis-chalcones 14-18 were synthesized and characterized by spectroscopic techniques EI-MS and H-1 NMR. CHN analysis was carried out and found in agreement with the calculated values. All compounds were evaluated for in vitro alpha-amylase inhibitory activity and demonstrated good activities in the range of IC50 = 1.25 +/- 1.05-2.40 +/- 0.09 mu M as compared to the standard acarbose (IC50 = 1.04 +/- 0.3 mu M). Limited structure-activity relationship (SAR) was established by considering the effect of different groups attached to aryl rings on varying inhibitory activity. SMe group in chalcones and OMe group in bis-chalcones were found more influential on the activity than other groups. However, in order to predict the involvement of different groups in the binding interactions with the active site of alpha-amylase enzyme, in silico studies were also conducted.