The extraction and in-situ separation of statins from Monascus purpureus using natural deep eutectic solvent-enzyme system

In this work, an eco-friendly and pH-oriented solvent system using deep eutectic solvents (DESs) combined with enzyme was established for the extraction and separation of statins from Monascus purpureus . Among the 58 categories of prepared DESs, benzyltributylammonium chloride/ethylene glycol (Btac/Eg, 1:2) containing cellulase was screened as the best extraction system. The major extraction conditions including liquid-solid ratio, extraction time, buffer solution pH, extraction temperature, buffer solution content, and enzyme concentration were optimized by the single-factor design and response surface methodology. Under optimized conditions, the total extraction contents of target analytes were 9.202 ± 0.311 mg/g, which was 1.5 times higher than that of methanol (6.123 ± 0.245 mg/g). Remarkably, the phase transformation of Btac/Eg based cellulase solvent system was identified as the pH-oriented reversible behavior. Moreover, molecular dynamic simulation and scanning electron microscopy analysis suggested that strong non-covalent interactions (hydrogen bonds, Van Der Waals force, etc.) were formed between the Btac/Eg based cellulase system and statins. Further AGREEprep and AGREE metric tools indicated that the developed pH-responsive DESs enzyme system possessed perfect greenness, higher extraction efficiency, and good biodegradability. In summary, the developed pH-oriented DESs based enzymatic system could efficiently extract and separate statins from Monascus purpureus , which promotes the development of statins-related drugs.