Improved HPLC Method for the Determination of Curcumin, Demethoxycurcumin, and Bisdemethoxycurcumin

TLDR

Commercially available curcumin is a mixture of three curcuminoids: curcumin, demethoxycurcumin, and bisdemethoxycurcumin. The authors isolated the three curcuminoids by column chromatography and quantified their purity and concentrations using an improved HPLC method on a C18 column with methanol, 2 % AcOH, and acetonitrile, detecting at 425 nm, applied to four turmeric varieties. In four turmeric samples, the concentrations ranged from 1.06 ± 0.061 to 5.65 ± 0.040 % for curcumin, 0.83 ± 0.047 to 3.36 ± 0.040 % for demethoxycurcumin, 0.42 ± 0.036 to 2.16 ± 0.06 % for bisdemethoxycurcumin, with total curcuminoids between 2.34 ± 0.171 % and 9.18 ± 0.232 %.

Abstract

Commercially available curcumin, a bright orange-yellow color pigment of turmeric, consists of a mixture of three curcuminoids, namely, curcumin, demethoxycurcumin, and bisdemethoxycurcumin. These were isolated by column chromatography and identified by spectroscopic studies. The purity of the curcuminoids was analyzed by an improved HPLC method. HPLC separation was performed on a C(18) column using three solvents, methanol, 2% AcOH, and acetonitrile, with detection at 425 nm. Four different commercially available varieties of turmeric, namely, Salem, Erode, Balasore, and local market samples, were analyzed to detect the percentage of these three curcuminoids. The percentages of curcumin, demethoxycurcumin, and bisdemethoxycurcumin as estimated using their calibration curves were found to be 1.06 +/- 0.061 to 5.65 +/- 0.040, 0.83 +/- 0.047 to 3.36 +/- 0.040, and 0.42 +/- 0.036 to 2.16 +/- 0.06, respectively, in four different samples. The total percentages of curcuminoids are 2.34 +/- 0.171 to 9.18 +/- 0.232%.