Tyramine Derivatives as Potent Therapeutics for Type 2 Diabetes: Synthesis and In Vitro Inhibition of α-Glucosidase Enzyme.

Abstract

Tyramine derivatives 3-16 were prepared and tested first time for their α- glucosidase (Sources: Saccharomyces cerevisiae) inhibitory activity by using an in vitro mechanismbased biochemical assay. All the compounds were found to be new, except compounds 3, 10-12 and 16. In continuation of our research to synthesize and identify potent inhibitors of α-glucosidase enzyme, we intended to synthesize new inhibitors of α-glucosidase enzyme with enhanced efficacy in order to provide the basis for the better treatment of the type-II diabetic. Tyramine (1) was allowed to react with a variety of aryl chlorides (2) to yield the corresponding amides. Synthesized compounds were then purified through normal phase column chromatography. Compounds 3-16 were then assessed for their α-glucosidase inhibitory activity in an in vitro biochemical assay. The cytotoxicity of compounds 3-16 was determined by using 3T3 mouse fibroblast cell lines. Compounds 3-5, 8, 13, and 15-16 were found to be more active (IC50 = 103.1±0.46, 37.3±4.51, 56.7±4.2, 23.9±2.31, 43.6±2.88, 55.8±1.73, and 38.2±0.86 μM, respectively) than the acarbose, the standard inhibitor of α-glucosidase enzyme, (IC50= 840.0±1.73 μM). To determine the dissociation constants and mode of inhibition, the kinetic studies were also performed for compounds 4 and 8 (the most potent inhibitors). It was observed that compounds 4 and 8 possess noncompetitive properties as the inhibitors of α-glucosidase. All the compounds were found to be noncytotoxic, except 5 and 12 (IC50= 14.7± 0.24 and 6.6± 0.38 μM, respectively). The current study gives the facile synthesis and identification of potent inhibitors of α- glucosidase. The new inhibitors reported here may be investigated further for the designing and development of novel anti-diabetic agents.