Application of QNMR for Simultaneous Quantification of Curcumin in Turmeric Extracts

Abstract

Curcumin, the main active compound of turmeric (Curcuma longa L.), requires a high- efficiency extraction strategy for its uses in the pharmaceutical and food industries. In this study, curcumin was extracted from turmeric using reflux, maceration, and Soxhlet methods (with ethanol and acetone as solvents) and their efficiency were evaluated by a quantitative Nuclear Magnetic Resonance spectroscopy (QNMR), which offers advantages such as no need for external standards, simultaneous analysis of multiple compounds, and simple sample preparation. Maleic acid was used as the internal standard, and deuterated acetone served as the solvent. Calculations were performed based on the ratio of the peak area of curcumin to the standard. Results demonstrated that the Soxhlet extract with 80% acetone achieved the highest curcumin extraction efficiency (based on dry weight). This study highlights the superiority of QNMR as a rapid and reliable analytical method for standardizing natural compounds.