Inhibition of aromatic amino acid decarboxylase by a group of new potential nonsteroidal anti-inflammatory drugs with antileukotrienic effects.

Possible in vitro inhibition of aromatic amino acid decarboxylase (AAD, EC 4.1.1.28) by a group of phenylsulfonylbenzoic acid derivatives VUFB 19363, 19369, 19370, 19371, and 19760 as new potential anti-inflammatory compounds was studied using the substrate L-tyrosine. Enzyme inhibition by 2.7 x 10(-5) M concentration of compound VUFB 19363 (Quinlukast) was 17%, AAD inhibition at 3.75 x 10(-5) M concentration of compounds VUFB 19369, 19370, 19371, and 19760 ranged between 9-23%. There were distinct differences between individual compounds. Evaluation of inhibition kinetics suggested full reversibility with VUFB 19369 and the uncompetitive type of inhibition in the case of compound VUFB 19363. Considering the anti-inflammatory activity of the compounds studied, the weak AAD inhibition found is rather favourable for their prospective pharmacological effect.