Bio-derived solvent based salt-responsive system for simultaneous extraction and in-situ enrichment of polysaccharides and phenolics from Carthamus tinctorius L. flower

Despite the considerable application potential of bio-derived solvents in natural product extraction, the extraction and in-situ enrichment of polysaccharides and phenolics simultaneously using bio-derived solvents have not been reported. To address this issue, a systematic evaluation was conducted to assess the performance of bio-derived solvents in simultaneously extracting polysaccharides and phenolic substances form Carthamus tinctorius. Among them, ethyl lactate (24.7%) exhibited superior efficacy. A comprehensive investigation was also conducted on the salt response behavior of ethyl lactate and its in-situ enrichment efficiency for polysaccharides and phenolics, demonstrating that the recovery yield, enrichment factor, and separation factor can be finely tuned by manipulating the system composition. Based on these findings, we have developed a highly efficient ultrasound-assisted method that is responsive to salt and enables simultaneous extraction and in situ enrichment of polysaccharides and phenolics. In comparison with the method in Chinese Pharmacopoeia (2020), the extraction yield of Carthamus tinctorius quality markers is increased by more than 1.14 times, while the extraction time is shortened by over 4 times. Additionally, the amount of solvent used is reduced by a factor of 5.73, eliminating the need for methanol and corrosive HCl that are harmful to the environment. The findings of this study will provide crucial theoretical guidance for the application of bio-derived solvents, demonstrating significant potential in terms of quality control and large-scale preparation of natural medicines.