Synthesis and evaluation of quinazoline amino acid derivatives as mono amine oxidase (MAO) inhibitors.

A series of quinazolinone amino acid ester and quinazolinone amino acid hydrazides were prepared under microwave irradiation as well as conventional condition. The microwave irradiation afforded the product in less reaction time, higher yield and purity. The structures of the synthesized compounds were confirmed by IR, NMR, and elemental analysis. The new synthesized compounds were studied for their monoamine oxidase inhibitory activity. They showed more selective inhibitory activity toward MAO-A than MAO-B. Compounds 7, 10, and 15 showed MAO-A inhibition activity (IC50=3.6×10(-9), 2.8×10(-9), 2.1×10(-9) M, respectively) comparable to that of the standard clorgyline (IC50=2.9×10(-9)M). 2-(2-(Benzo[d][1,3]dioxol-5-yl)-4-oxo-1,2-dihydroquinazolin-3(4H)-yl)acetohydrazide 15 showed selective MAO-A inhibition activity (SI=39524) superior to that of the standard clorgyline (SI=33793). The acute toxicity of the synthesized compounds was determined. In addition, computer-assisted simulated docking experiments were performed to rationalize the biological activity.