Histochemical localization of curcumin and its significance in chemotypic characterization of selected species of Curcuma L

Curcumin, the phenolic pigment is the main active constituent obtained from the rhizomes of many species of genus Curcuma L. (Zingiberaceae). The present study aims to develop histochemical parameters for estimation of curcumin content and its application as a chemotaxonomical marker to differentiate and characterize the different species. Accordingly, histochemical studies on fresh rhizomes of five selected species of Curcuma L. at similar stages of growth/similar ages were carried out to determine curcumin cell index, their frequency and cell diameter to elucidate quantitative estimation of curcumin, followed by quantitative validation of curcumin content by HPTLC techniques. Statistically significant positive correlation (*p < 0.05, **p < 0.01/*p < 0.05) was obtained, respectively, between curcumin cell frequency/cell diameter and curcumin content estimated by HPTLC. Observations suggest that histochemical localization could be efficiently used in quantitative estimation of curcumin content. The quantitative variation in curcumin concentration attendant in the different species could be used as a chemotaxonomic parameter to differentiate the Curcuma species. (C) 2014 Elsevier B.V. All rights reserved.