Sustainable extraction of cannabidiol using alkaline leaching coupled with green deep eutectic solvents

Abstract

Cannabidiol (CBD), a non-psychoactive phytocannabinoid, has garnered attention owing to its paramount medicinal potential and leisure purposes. However, to meet the growing practical demand, obtaining high-purity CBD without toxic organic solvents and suitability for large-scale processing of raw materials with simple and low-cost extraction processes has become a major practical issue. This study proposes an innovative and viable technique for extracting CBD by conjugating deep eutectic solvents (DES) (ethanol and lactic acid 2:1) with alkaline leaching (NaOH). All process parameters, including leaching duration (time), pH, and extraction temperature, were optimized meticulously using response surface methodology (RSM). The CBD-rich part of the plant was identified by QE-LC/MS analysis. The outcomes were validated by repeated experiments with the highest yield of 14.8 mg/g. The adopted method produced 83.48 % pure CBD, which was 32 % more effective than ethanol leaching, as proven by HPLC analysis. Fourier transform infrared spectroscopy (FTIR) provided insight into the composition of the extracted CBD, confirming its integrity and chemical structure. Degradation kinetic analysis provided insight about the storage temperatures. The results indicated that the extracting technique was simply reliable and environmentally safe, proven by environmental impact assessment indicators, and can be utilized on an industrial scale for economically extracting bioactive compounds from various plant sources.