RSM-rCCD Optimizing for Paclitaxel Extraction from Taxus chinensis by Natural Deep Eutectic Solvents and Studying Antioxidant Activity

Background: Paclitaxel from Taxus chinensis contains medicinal properties to treat various cancer diseases. Thus, extracting paclitaxel from Taxus chinensis had aroused a wide of research interests. Methods: Ultrasonic-assisted extraction (UAE) has high extraction efficiency, and natural deep eutectic solvents (NADESs) have the advantages of being green, natural, and non-toxic. As a result, the UAE-NADESs were introduced to extract paclitaxel from Taxus chinensis. The ideal NADES composed of choline chloride and malic acid was achieved at a molar ratio of 1:1, with the optimal extraction parameters identified through single-factor experiments. Response Surface Methodology of rotatable Central Composite Design (RSM-rCCD) was applied to further optimize the extraction conditions. Results: The ultimate optimum circumstances of ultrasonic power is 240 W, extraction time is 49 min, solid/liquid ratio is 1:18, extraction temperature is 38°C, and the maximum extraction yield reached 5.94 mg/g. Their IC50 values of paclitaxel extract for free radicals of DPPH (2,2-diphenyl-1- picrylhydrazyl), ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) and OH (Hydroxyl) were 20.53, 40.79 and 270.98 mg/L, respectively. Discussion: Compared with traditional solvents, NADES has higher extraction efficiency and yield for paclitaxel from Taxus chinensis. Conclusion: This article demonstrates the increased extraction yield of paclitaxel, which has strong antioxidant activity.