High-performance thin layer chromatographic method for quantitative determination of curcuminoids in Curcuma longa germplasm

Phytochemical investigation of the rhizomes of Curcuma longa leads to the isolation of pharmacologically active curcuminoids viz Curcumin, demethoxycurcumin and bisdemethoxycurcumin. These were isolated from turmeric rhizomes by soxhlet extraction followed by column chromatography, crystallisation and identified by spectroscopic studies. The purity of the curcuminoids was analysed by HPTLC method. The method employed TLC aluminium plates precoated with silica gel 60GF254 as the stationary phase. The solvent system consisted of chloroform: methanol (48:2, v/v). This system was found to give compact spots for curcumin, demethoxycurcumin and bisdemethoxycurcumin (RF value of 0.66 ± 0.02, 0.48 ± 0.02 and 0.30 ± 0.02), respectively. Densitometric analysis of curcuminoids was carried out in the absorption–reflection detection mode at 425 nm. Seven different germplasm of turmeric were analysed to detect the percentage of these three curcuminoids.