PDF(Pubmed)
Abstract：
In this study, the α-glucosidase (maltase-glucoamylase: MGAM) and α-amylase inhibitory properties elicited by xylooligosaccharides (XOSs) prepared from dulse xylan were analysed as a potential mechanism to control postprandial hyperglycaemia for type-2 diabetes prevention and treatment. Xylan was purified from red alga dulse powder and used for enzymatic hydrolysis using Sucrase X to produce XOSs. Fractionation of XOSs produced xylobiose (X2), β-(1→3)-xylosyl xylobiose (DX3), xylotriose (X3), β-(1→3)-xylosyl-xylotriose (DX4), and a dulse XOS mixture with n ≥ 4 xylose units (DXM). The different fractions exhibited moderate MGAM (IC50 = 11.41-23.44 mg/mL) and α-amylase (IC50 = 18.07-53.04 mg/mL) inhibitory activity, which was lower than that of acarbose. Kinetics studies revealed that XOSs bound to the active site of carbohydrate digestive enzymes, limiting access to the substrate by competitive inhibition. A molecular docking analysis of XOSs with MGAM and α-amylase clearly showed moderate strength of interactions, both hydrogen bonds and non-bonded contacts, at the active site of the enzymes. Overall, XOSs from dulse could prevent postprandial hyperglycaemia as functional food by a usual and continuous consumption.
摘要：
在这项研究中,分析了由dulse木聚糖制备的低聚木糖（XOSs）引起的α-葡萄糖苷酶（麦芽糖-葡糖淀粉酶：MGAM）和α-淀粉酶抑制特性，作为控制2型糖尿病预防和治疗的餐后高血糖的潜在机制。从红色藻类石粉中纯化木聚糖，并使用蔗糖酶X进行酶水解以生产XOSs。XOS产生的木二糖的分馏（X2），β-(1→3)-木糖酰木二糖(DX3)，木三糖（X3），β-（1→3）-木糖酰-木三糖（DX4），和n≥4木糖单位(DXM)的dulseXOS混合物。不同组分表现出中等的MGAM（IC50=11.41-23.44mg/mL）和α-淀粉酶（IC50=18.07-53.04mg/mL）抑制活性，低于阿卡波糖。动力学研究表明，XOS与碳水化合物消化酶的活性位点结合，通过竞争性抑制限制对底物的访问。XOSs与MGAM和α-淀粉酶的分子对接分析清楚地显示出中等强度的相互作用，氢键和非键合接触，在酶的活性位点。总的来说,来自dulse的XOS可以通过常规和连续食用来预防餐后高血糖作为功能性食物。
