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 α-amylase inhibitory activity. So, the current study is based on the evaluation of this class for the identification of new leads as α-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 1H NMR. CHN analysis was carried out and found in agreement with the calculated values. All compounds were evaluated for in vitro α-amylase inhibitory activity and demonstrated good activities in the range of IC50 = 1.25 ± 1.05-2.40 ± 0.09 µM as compared to the standard acarbose (IC50 = 1.04 ± 0.3 µM). 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 α-amylase enzyme, in silico studies were also conducted.