Author(s): Anuja Chopra, ManpreetKaur, Navpreet, Divneet, Lalit
ABSTRACT Oxygen containing heterocycles are abundantly found in nature. Flavone, isoflavones, flavanones, catechins, anthocyanins are some phytoconstituents collectively grouped as flavonoids and iso flavonoids. Chemically, they are categorized as chromenes, chromenones, dihydrofurobenzofurans, chromanochromanones, benzofurochromans, xanthones and amphipyrones. Chromones (4H-Benzopyran-4-ones) are the heterocyclic compounds with benzopyron network with substituated keto group on pyron ring. It is an isomer of coumarin. Chromone nucleus is recognised as pharmacophore having a number of biological activities such as anticancer, antiviral, antifungal, antimicrobial, antioxidant, antidepressant, antiobesity. These derivatives also possess enzymetic inhibition properties towards different systems such as oxidoreductase, kinase, lipoxygenase and cycloxygenase. Chromone moiety is obtained from number of sources such as plants, marine and synthetic sources. These are khellin, aloesin, kaemferol, hormothamnione, asperginone and flavopiridol. So, this chromone nucleus find use as valuable synthetic intermediates in the preparation of pharmacologically relevant products and new heterocyclic systems.