Synthesis of Novel 4-Methylcoumarins and Comparative Specificities of Substituted Derivatives for Acetoxy Drug: Protein Transacetylase

Our laboratory has been credited for the discovery of a unique membrane bound enzyme termed Acetoxy Drug: Protein Transacetylase (TAase) catalyzing the transfer of acetyl group from polyphenolic peracetates (PA) to certain functional proteins resulting in the modulation of their catalytic activity. In this report, we have synthesized eight novel 4-methylcoumarins and demonstrated the comparisons of acetoxy derivatives of 4-methylcoumarin with their propoxy and butoxy derivatives for the modulation of some receptor proteins such as cytochrome P-450 (Cyt.P-450), NADPH cytochrome c reductase and cytosolic glutathione S-transferase (GST). The results clearly indicated that acetoxy derivatives have very high efficacy for the modulation of above mentioned functional proteins as compared to their other derivatives. We have also compared the acetoxy derivatives of 4-methylcoumarin with their acid substituted acetoxy derivatives and found that inclusion of carboxylic acid groups on the benzenoid rings of the coumarins system hardly affected TAase mediated catalytic activity.