杏鲍菇多糖及其消化产物对淀粉消化酶的抑制及相互作用

【目的】以杏鲍菇多糖（PEP）为原料，探究其基本理化性质和对葡萄糖扩散和吸附能力的影响。利用体外模拟消化模型制备PEP模拟消化产物（D-PEP），探究PEP和D-PEP对与糖代谢相关的消化酶活性的影响，并进一步评价其与α-葡萄糖苷酶的相互作用。【方法】首先基于前人的研究方法对PEP的基本理化性质进行评价；然后采用DNS法测定PEP和D-PEP对α-淀粉酶活力的抑制效果，采用对硝基苯-α-D-吡喃葡萄糖苷（PNPG）法测定对α-葡萄糖苷酶抑制率；最后采用荧光光谱法研究PEP和D-PEP与α-葡萄糖苷酶的相互作用。【结果】PEP具备良好的溶解/溶胀性、持水/持油性，且其对葡萄糖扩散和吸附能力具有一定的抑制作用。PEP对麦芽糖酶和α-葡萄糖苷酶具有显著的抑制作用，对α-淀粉酶没有抑制作用，当PEP浓度为4 mg·mL-1时，其对麦芽糖酶和α-葡萄糖苷酶的抑制率分别为（77.20±2.71）%和（78.91±0.51）%。然而消化产物D-PEP对3种酶都有显著的抑制作用，4 mg·m L-1的D-PEP对α-淀粉酶、麦芽糖酶和α-葡萄糖苷酶的抑制率分别为（84.08±1.79）%、（20.58...

Inhibition and Interaction of Pleurotus eryngii Polysaccharide and Its Digestion Products on Starch Digestive Enzymes

【Objective】In the present study, the investigation on the basic physicochemical properties of Pleurotus eryngii polysaccharide (PEP) and its related effects on diffusion and adsorption of glucose were conducted. PEP mimetic digestion products (D-PEP) were prepared using an in vitro stimulated digestion model to explore the effects of PEP and D-PEP on the digestive enzymes activities associated with glucose metabolism, as well as the interaction between PEP/D-PEP and α-glucosidase. 【Method】Firstly, the basic physicochemical properties of PEP were detected based on the methods in previous studies. Then the inhibitory effects of PEP/D-PEP on α-amylase and α-glucosidase activities were evaluated by DNS method and 4-Nitrophenyl α-D-glucopyranoside (PNPG) method, respectively. Finally, the relationship between PEP/D-PEP and α-glucosidase was studied with the utilization of the fluorescence spectroscopy technique. 【Result】 PEP displayed great potential on the solubility, swelling property, water and oil holding capacities, and favorable inhibition on glucose diffusion and adsorption. Moreover, PEP had obvious inhibitory effects on maltase and α-glucosidase, while it did not suppress the activity of α-amylase. Specifically, PEP with its concentration of 4 mg·mL^-1 exhibited (77.20±2.71)% inhibition ratio on maltase activity, while (78.91±0.51)% inhibition ratio on α-glucosidase activity. However, the digestion product D-PEP showed significant inhibition on the activities of all these three enzymes, with 4 mg·mL^-1 of D-PEP inhibiting α-amylase, maltase, and α-glucosidase by (84.08±1.79)%, (20.58±1.20)%, and (95.58±0.12)%, respectively. The outcomes of fluorescence spectroscopy showed that the endogenous fluorescence of α-glucosidase was gradually decreased along with the increasing of the PEP/D-PEP concentration, and the quenching of the endogenous fluorescence of α-glucosidase by PEP/D-PEP was mainly static quenching, with the number of binding sites greater than or equal to 1. 【Conclusion】In summary, D-PEP not only inhibited maltase and α-glucosidase activities but also showed great potential inhibition effects on α-amylase activity compared with PEP. Herein, D-PEP displayed stronger inhibitory effect on amylase and could be considered affect glucose metabolism to a certain degree.