An update on natural occurrence and biological activity of chromones.

The chemistry of chromones is very well known. This system is widely used in organic chemistry as an intermediate compound for the synthesis of numerous hetrocycles. On the other hand, chromones were extensively studied as bioactive compounds. They possess remarkable biological activities, such as antimicrobial, antiviral, anticancer, anti-inflammatory, antioxidant, etc. This comprehensive review describes the current status and knowledge of natural occurrence, and biological activities of chromones. Recent advances made over the last decade i.e. January 1999 to December 2009 are critically discussed and we have covered about 176 references and more than 350 compounds reported during this period.