The coumarin (benzopyran-2-one, or chromen-2-one) ring system, present in many natural
products, displays diverse pharmacological properties. It has attracted the attention of chemists and
medicinal chemists for decades. Many molecules based on the coumarin ring system have been described
utilizing innovative synthetic methods. These synthetic routes have led to interesting analogues
of coumarins which possess pharmacological activities like anti-HIV, antimicrobial, antiinflammatory,
anticancer, anti-TB, anticonvulsant and MAO inhibitory properties. Details of these
studies, correlating structure with biological activity are described in this review.