Ferric reducing, antiradical and beta-carotene bleaching activities of nicotinic acid and picolinic acid bioconjugates of curcumin.

Although curcumin displays several beneficial properties, its medicinal use is limited by its low bioavailability. In the present study we report the antioxidant potentials of two bioconjugates of curcumin with nicotinic acid and picolinic acid: di-O-nicotinoyl curcumin [1,7-bis (4-O nicotinoyl-3-methoxyphenyl)-1,6-heptadiene-3, 5-dione] and di-O-picolinoyl curcumin [1,7-bis (4-O-picolinoyl-3-methoxyphenyl)-1,6-heptadiene-3, 5-dione], in terms of ferric reducing, radical scavenging and beta-carotene bleaching abilities, and comparing the observed activity with that of curcumin. Results demonstrate that both the bioconjugates possess higher antioxidant potentials as evidenced by enhanced ferric reducing, radical scavenging and beta-carotene bleaching abilities, in comparison with curcumin. On the basis of our results we conclude that these bioconjugates of curcumin may be better than curcumin for medicinal and pharmacological applications.