Extraction assisted by far infrared radiation and hot air circulation with deep eutectic solvent for bioactive polysaccharides from Poria cocos (Schw.) wolf.

Poria cocos polysaccharides (PCPs) are of high research value because of their important biological functions. However, the ways to extract a PCP are limited and its yield is relatively low in current reports. In this study, a new ternary deep eutectic solvent (DES) composed of choline chloride, 1,3-butanediol and D -sorbitol was used to efficiently extract bioactive polysaccharides from poria cocos assisted by the new tool of far infrared radiation (FIR) together with hot air circulation (HAC). The yield of a polysaccharide (PCP-DL) obtained by this new method was 55.02 ± 0.87% under the optimized conditions of sieving mesh (300 mesh), liquid–solid ratio (30 mL g⁻¹), intensity of FIR (300 W m⁻²), and circulated air temperature (80 °C). Meanwhile, the extraction mechanism of PCP-DL was investigated by comprehensive characterization studies and extraction kinetics. The recovered DES still retained its performance after recycling five times by dialysis. A laboratory-scale life cycle assessment (LCA) was applied to analyze the potential environmental profiles and the results showed that this new extraction process possessed environmental impact reductions of 93.61% waste solids and 69.72% fossil fuel depletion potential in contrast to the traditional method. Furthermore, chromatographic and spectral analyses were used to analyze the product and confirm the presence of α-,β-pyranose, as well as five kinds of glycosidic linkages, in target polysaccharides with a molecular weight (M_w) of 2.05 × 10⁴ Da. Scanning electron microscopy (SEM) revealed that it was an amorphous aggregate with an irregular spherical shape and loose porous surface. Finally, the product exhibited a similar inhibitory activity to that of donepezil against acetylcholinesterase (AChE, 73.82 ± 0.60%) and butyrylcholinesterase (BChE, 63.85 ± 0.54%) at 500 μg mL⁻¹ as a mixed-type competitive inhibitor for these enzymes. The interaction sites between AChE and the fragment of PCP-DL were simulated by molecular docking, which provided a theoretical basis for the above inhibition assays. [ABSTRACT FROM AUTHOR]