Synthesis and Medicinal Significance of Chalcones- A Review

Abstract

Chalcone is an aromatic ketone that forms a central core for a variety of important biological compounds, which are collectively known as chalcones. They possess different activities like antibacterial, antifungal, anti-inflammatory and anti tumor etc depending on the substitution made on them. Chalcones are 1,3-diphenyl-2-propene-1-one, in which two aromatic rings are linked by a three carbon α, β-unsaturated carbonyl system.These are abundant in edible plants and are considered to be precursors of flavonoids and isoflavonoids. Chalcones possess conjugated double bonds and a completely delocalized Π-electron system on both benzene rings. Molecules possessing such system have relatively low redox potentials and have a greater probability of undergoing electron transfer reactions. The compounds with the backbone of chalcones have been reported to possess various biological activities such as antimicrobial, anti-inflammatory, analgesic, anti platelet, anti ulcerative, anti malarial, anticancer, antiviral, anti leishmanial, antioxidant, anti tubercular, anti hyperglycemic, immunomodulatory, inhibition of chemical mediators release, inhibition of leukotriene B4, inhibition of tyrosinase and inhibition of aldose reductase activities. The presence of a reactive alpha, beta -unsatutated keto function in chalcones is found to be responsible for their antimicrobial activity. In this paper through reviewing different biological significance of chalcones and their derivatives have been reported along with their chemistry and of synthesis. Synthetically or chemically chalcones are synthesized by two reactions: a) Aldol condensation and b) Claisen Schmidt condensation. But here is a focus on chalcones synthesized by Claisen Schmidt condensation which involves the condensation between an aromatic aldehyde or ketone with an aliphatic ketone or aldehyde catalysed by the presence of dilute alkali or acid to form alpha beta unsaturated compound.