Effect of different extraction solvents on the content of Thymoquinone content of Nigella sativa L. seeds using UV-Visible spectroscopy and evaluation of the free radical scavenging activity

To develop and validate HPLC UV-visible spectroscopy methods for the determination of Thymoquinone (TMQ) content in different solvent extracts N. sativa L. seed. The evaluation free radical scavenging effect TMQ was investigated. Extraction done by adding 20 mL (hexane, methanol, ethanol, ethyl acetate, water) to 1 g blackseed a conical flask, respectively. mixtures were then incubated water bath at 40°C 2 4 h, centrifuged 4000 rpm 10 min 4°C. quantitatively analyzed using spectrophotometry. activity studied 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. results obtained from indicate that extracted hexane h (0.075 mg/mL, P <0.05) significantly higher compared other extraction solvents used. UV-vis analysis methanol extract (0.00957 Methanol showed highest (95.8%) solvents. show most h. demonstrated activity.