Coumarins (2H-1-benzopyran-2-ones) are well known aromatic lactones isolated from variety of plant sources [1]. Owing to their diverse bioactivities viz. anticoagulant [2], antibacterial, and antifungal [3] etc. many natural, semi synthetic and synthetic coumarins have become an important class of molecules in drug research. In this direction, several biological activities have been claimed for compounds comprising both coumarins and ...