Comparative Assessment of Extraction Methods and Quantitative Estimation of Thymoquinone in the Seeds of Nigella sativa L By HPLC

Abstract

The objective of the present study was to find out the best organic solvent and extraction method for the isolation of thymoquinone from Nigella sativa L. seeds. The seeds of N. sativa were authenticated by a taxonomist, washed, dried and powdered. Different extraction techniques such as maceration, soxhlet, reflux and ultrasound assisted extraction were employed for extraction of thymoquinone from seeds by using three solvents of different polarity like petroleum ether, hexane and methanol. Thymoquinone was quantified in each sample extract of seeds by simple high performance liquid chromatography technique. The content of thymoquinone was found to be higher in methanolic extract among the various techniques and solvents tried. Ultrasound assisted extraction technique was observed the best for extraction of thymoquinone. The calibration curve of standard thymoquinone demonstrated linear relationship in the concentration range of 1 to 0.0625 µg/ml with correlation coefficient, r2 of 0.9976. It can be concluded on the basis of HPLC finding that ultrasound assisted extraction technique is the best for extraction of thymoquinone . This method will be preffered in industy or academia for extraction of thymoquine from N. sativa seeds.