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

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 <i>Catharanthus roseus</i> 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 <i>C. roseus</i> 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 <i>C. roseus</i>, contributing to our collective environmental consciousness.