Synthesis of substituted DL-3(5-benzazolyl)alanines as dopa and alpha-methyldopa analogs and their effects on dopamine beta-hydroxylase, tyrosinase and diphenoloxidase.

The influence of bioisosteric replacement of catechol moiety of L-Dopa and alpha-Methyldopa with benzimidazole and benzotriazole ring has been examined on dopamine beta-hydroxylase and tyrosinase, in order to evidentiate an inhibitory activity on the synthesis of catecholamines and a possible antihypertensive action. The preliminary results obtained so far showed that inhibition of dopamine hydroxylase occurs at 5 x 10(-4) M concentration for the most active compounds bearing a trifluoromethyl group in the azole ring (2a,c). An analogous result was observed in the case of tyrosinase inhibition with compound 2c, while other compounds (2a,e) were equiactive (92% inhibition) at higher concentration (1 x 10(-3) M). Compound 2c was also the most active in inhibition of diphenoloxidase (83% at 6 x 10(-5) M concentration).