Optimisation and utilization of deep eutectic solvents for the green extraction of anticancer alkaloids from Catharanthus roseus

The extraction of vinca alkaloids, such as vinblastine and vincristine, has traditionally been a challenge due to their low concentrations in natural sources and lengthy, low-yielding procedures. In this study, we explored a high-yield, efficient method for extracting vinblastine and vincristine from Catharanthus roseus using deep eutectic solvents (DES). We prepared various choline chloride (ChCl) based DESs with different hydrogen bond donors (HBD) and used them to extract leaves and flowers of C. roseus under ultrasonication. The extracts were evaluated for vinblastine and vincristine content using UV-spectroscopic analysis. Using response surface methodology, various parameters were optimised, including water content, sonication time, and solid-to-liquid ratio. Under optimised conditions, DES based on organic acids was found to extract 27.94 μg/ml of vinblastine in Choline chloride: citric acid DES and 30.84 μg/ml of vincristine in Choline chloride: oxalic acid. These results highlight the eco-friendliness of Choline chloride: citric acid and Choline chloride: oxalic acid DESs, which are effective, sustainable alternatives to conventional solvents for extracting these alkaloids from C. roseus, contributing to our collective environmental consciousness.