Green-Efficient Enzymatic Synthesis and Characterization of Liposoluble 6'/6″-O-Lauryl Phenolic Glycosides with Enhanced Intestinal Permeability.

Arbutin, salidroside, polydatin, and phlorizin are typically natural bioactive phenolic glycosides. To improve the liposolubility and bioavailability, highly liposoluble derivatives including 6'-O-lauryl arbutin, 6'-O-lauryl salidroside, 6″-O-lauryl polydatin, and 6″-O-lauryl phlorizin were efficiently synthesized by enzymatic acylation in a green solvent 2-MeTHF. Their reaction conversions reached 84.4, 99.5, 99.8, and 89.1%, respectively, when catalyzed by Lipozyme 435 at 20 mg/mL at 50 °C. As expected, the derivatives had high log P (1.66-2.37) and retained good antioxidant activity, making them potential alternatives to butylated hydroxytoluene (BHT) and tert-butyl-hydroquinone (TBHQ) in lipid systems. Then, the intestinal permeability characteristics and metabolism of phenolic glycosides and their derivatives were investigated based on Caco-2 monolayers. The permeability of polydatin and phlorizin was mainly through active transport, but that of arbutin and salidroside involved both passive diffusion and active uptake. The acylated derivatives suffered from severe CES-mediated hydrolysis but exhibited a larger transported amount than phenolic glycosides.

Improvement of the stability and anti-AGEs ability of betanin through its encapsulation by chitosan-TPP coated quaternary ammonium-functionalized mesoporous silica nanoparticles.

Mesoporous silica nanoparticles (MSNPs) are widely used as encapsulation materials, however, low encapsulation ability and the leakage and inactivation of the encapsulated components are two major disadvantages that limit their applications. Quaternary ammonium-functionalization and chitosan-sodium tripolyphosphate (CS-TPP) coating are used in this study to overcome these disadvantages. Betanin is a bioactive ingredient, but it is easily degraded. In this work, a new type of CS-TPP coated quaternary ammonium-functionalized MSNPs (CS@QAMSNPs) were synthesized by a reversed-phase microemulsion method, and betanin was encapsulated therein. The results of SEM, TEM, and FTIR of CS@QAMSNPs showed that MNSPs were functionalized with quaternary ammonium and coated with CS-TPP. The loading capacity of betanin-CS@QAMSNPs was 21.66 %, while that of betanin-MSNPs was 2.95 %. After encapsulation by CS@QAMSNPs, over 65 % of the antioxidant activity of betanin was retained after high-temperature and alkaline treatment, and 84.24 % of betanin was retained after ultraviolet-radiation treatment, implying an improvement in the stability of betanin. Cell viability was over 80 % in the presence of betanin and encapsulating materials, indicating their good food safety. The highest inhibition rate of betanin-CS@QAMSNPs in advanced glycation end-products in the BSA-fructose and BSA-MGO model was 47.39 % and 15 %, which was higher than those of betanin (BSA-fructose:11.38 %, BSA-MGO:0.83 %).