Facile NMR approach for profiling curcuminoids present in turmeric.

Curcumin, together with demethoxycurcumin and bisdemethoxycurcumin as a whole called curcuminoids, is an active phytochemical constituent present in the turmeric. When it comes to their analysis, most will rely on UV-Visible spectroscopy, HPLC and LC-MS methods. Looking to improve productivity, time and simplicity, we are proposing a ¹ H NMR based approach for curcuminoids analysis and its applications to different geographical regions. In the present work, sample preparation protocol is reported for the simultaneous determination of curcuminoids using ¹ H NMR. For the quantification of curcuminoids, 6-7 ppm vinylic proton region in the ¹ H NMR spectrum was used, where acetone was observed as the suitable solvent in terms of curcuminoids solubility and proper resolution of peak. The result shows that curcumin (46.8-59.50%) was major among all varieties, followed by DMC (22.15-27.70%) and BDMC (17.52-30.29%) except in Andhrapradesh variety, where BDMC (30.29%) was more than DMC (22.89%). These studies were further supported by HPLC analysis.
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