In this study, ultrasonic-assisted deep eutectic solvent (DES) method was used to extract flavonoids from Dendrobium officinale . The mechanism of DESs extraction differences was investigated by physicochemical characterization and molecular dynamics simulation experiments. Moreover, flavonoids from Dendrobium officinale were rapidly identified and quantitatively analyzed by UPLC-Triple-TOF/MS without removing DES. The results showed choline chloride-lactic acid (Chol-Lac) had the best extraction effect among forty groups of DESs, the extraction yield was up to 35.23 ± 2.12 mg/g. It was speculated that the tight hydrogen bond structure was the key to the better extraction ability of Chol-Lac. Meanwhile, the viscosity was the main physical parameter reflecting the hydrogen bond structure of DES. Fourteen flavonoid glycosides were identified, among which the content of rutin (1.94 ± 0.24 mg/g) was the highest. And the results of cluster analysis showed that different DESs had great differences in the extraction of flavonoid glycosides.
Lichengcheng Ren,Qi Dong,Zhenhua Liu,Yue Wang,Nixia Tan,Honglun Wang,Na Hu
This study aimed to optimize subcritical water extraction process, characterize chemical composition and investigate the biological activities of Nitraria sibirica Pall. (NSP) anthocyanin. Overall, the optimization was achieved under following conditions: extraction temperature 140 °C, extraction time 45 min and flow rate 7 mL/min with the extraction yield of 1.075 mg/g. 3 cyanidin, 3 petunidin, 1 delphinidin and 1 pelargonidin compounds were identified in the anthocyanic extract from NSP via UPLC–Triple–TOF–MS/MS. NSP anthocyanin exhibited better DPPH free-radical scavenging activity than ascorbic acid. It displayed superior α-glucosidase inhibition activity, which was ∼14 times higher than that of acarbose. Moreover, enzyme kinetics results indicated that NSP anthocyanin behaved as a reversible, mixed-type inhibitor. Molecular docking and molecular dynamics simulation results revealed that NSP anthocyanin interacted with α-glucosidase mainly via van der Waals forces, hydrogen bond and possessed fairly stable configuration. Therefore, NSP anthocyanin is a promising α-glucosidase inhibitor for diabetes mellitus.