Enhanced and green extraction betulin from Celtis sinensis leaves using hydrophobic deep eutectic solvent

The green extraction and separation of natural produce is a significant part in pharmaceutical industry which has received extensive attention. Comparing with the extraction of hydrophilic products, hydrophobic natural products are further challenging. An extraction means depended in high efficiency hydrophobic deep eutectic solvent (HDES, TCP) was screened by designing ternary HDES. Utilizing the established method, the hydrophobic compound betulin was successfully extracted and recovered from Celtis sinensis leaves. The results showed that HDESs were further productive in extracting hydrophobic compounds than hydrophilic DES. The extractions of TPC were statistically optimized by response surface methodology and central composite design. Under the optimum conditions, the extraction rate of betulin was increased by 125.00% compared with the initial yield. At the same time, it was proved that among the six resins, D-101 macroporous resin had the highest recovery rate of 71.12% for betulin, which was the most effective enrichment and purification method. To sum up, HDES has obvious advantages in the extraction of hydrophobic natural products due to its mild extraction conditions, high yield, and environmental friendliness. At the same time, limitless feasibilities of HDES compositions and their associations furnish a plentiful selection space for the extraction about hydrophobic compounds.