Simple HPLC Method for Resolution of Curcuminoids with Antioxidant Potential

Development of methodology for qualitative analysis and quantitative separation of individual curcuminoids
in curcumin removed turmeric oleoresin (CRTO) and study of antioxidant activity of individual curcuminoids
have been achieved in the present study. A simple HPLC protocol was outlined for optimal resolution of
curcuminoids (I), (II), and (III) on an Exil-NH2 column using isocratic elution with a mixture of isopropanol and
water. CRTO is shown to be good source for the compounds II and III, as they are in an enriched form. The optimum
resolution of the curcumin and its analogs in the present method developed, affords a facile method for estimation
of individual curcuminoids in turmeric samples, which is an improvement over the standard AOAC method which
estimates only total curcuminoids. The free radical scavenging capacity of pure curcuminoids I, II, and III, as determined
by DPPH method at 100 ppm concentration was 88%, 80%, and 68% with IC50 values being 56, 62, and
73 ppm, respectively. Their antioxidant potential could render them useful as important nutraceuticals or functional
food ingredients.