A comparative study on the antioxidant properties of curcuminoids and its rubrocurcumin analogues

Abstract

The yellow colored pigment, curcumin present in turmeric is responsible for its various biological activities like antioxidant, anti-inflammatory and anticarcinogenic activity. Different functional group present in curcumin includes a β–diketone group, carbon–carbon double bond and two phenyl rings with hydroxy and methoxy substituents. A controversy exists in literature on the site and mechanism for the antioxidant activity (AOA), the keto–enol/phenolic moiety present in curcumin. In the present work AOA of curcuminoids and its boron complex with oxalic acid – rubrocurcumin analogues were conducted which differ in the substituent in the benzene ring. Since in rubrocurcumin analogue β-diketone group is blocked through bonding with boron its influence will be absent in its antioxidant activity.