Abstract

The quantitative structure-activity relationship (QSAR) studies conducted by us earlier revealed the cardinal role of the pyran ring carbonyl group in the acetoxy polyphenolic compounds for the acetoxy polyphenol: protein transacetylase (TAase) activity. Hence, an attempt was made to examine whether such substrate analogues of benzopyran acetates which lack in the pyran ring carbonyl group, such as 7-acetoxy-2,3-dihydro-2,2-dimethylbenzopyran (BPA), cetachin pentaacetate (CPA) and hematoxylin pentaacetate (HPA) could inhibit the 7,8-diacetoxy-4-methylcoumarin (DAMC):protein (glutathione-S-transferase) transacetylase activity. These compounds were indeed found to remarkably inhibit the TAase activity in a concentration dependent manner and exerted their inhibitory action very rapidly. Further BPA, CPA and HPA were found to abolish the TAase mediated activation of NADPH cytochrome C reductase as well as the inhibition of liver microsome catalyzed aflatoxin B, (AFB(1))-DNA binding by DAMC very effectively. These results strongly suggest that the acetoxybenzopyrans merit as potent inhibitors of TAase. (C) 2002 Elsevier Science Ltd. All rights reserved.