INVESTIGATION OF THE COMPOSITION OF CURCUMINOIDS IN TURMERIC (CURCUMA LONGA L.) RHIZOMES

Introduction. Turmeric (Curcuma longa L.) is a perennial herbaceous plant of the Ginger family (Zingiberaceae), the rhizomes of which are well-known as a spice and traditional foodstuff in South-Eastern Asian countries and India, as well as a popular medicinal plant. Objective: to investigate the chemical composition of curcuminoids in the rhizomes of turmeric cultivated in the North Caucasus. Material and methods. The investigation objects were the rhizomes of turmeric cultivated in the North Caucasus and stored in 2007 and 2008 and commercial samples of raw materials from India and Vietnam. The investigation used thin-layer chromatography (Sorbfil PTSH-AF-A-UV plates), column chromatography (L 40/100 silica gel, eluent mixtures: hexane – chloroform in various proportions), spectrophotometry, IR, 1H-NMR, 13C-NMR spectroscopies, and mass-spectroscopy. Results. Three dominant curcuminoids, such as curcumin, demethoxycurcumin, and bisdemethoxycurcumin, were isolated from turmeric rhizomes; their structure was confirmed by UV, IR, NMR spectroscopies, mass spectrometry; and physicochemical constants were also established. An isolation scheme (the yield of the mass of air-dry raw materials was 0.6–0.7%) was proposed for curcumin regarded as a Russian standard sample. Conclusion. The chemical composition of curcuminoids and the ratio of their dominant components were found to be stable for wild and cultivated samples of turmeric rhizomes.