Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, PR China.
Department of Critical Care Medicine, Zhongda Hospital, Southeast University, Nanjing 210009, PR China.
Int J Biol Macromol. 2019 Jul 1;132:641-650. doi: 10.1016/j.ijbiomac.2019.03.228. Epub 2019 Mar 30.
Two proteoglycans (HPP and LPP) with different ratios of protein/polysaccharide were extracted from S. glabra. The chemical compositions, relative average molecular weights, monosaccharide compositions, FT-IR spectra, and rheological properties of the two proteoglycans were determined. The results exhibited that the two proteoglycans had pseudoplastic fluids properties and displayed shear-thinning behavior. The apparent viscosity of the two proteoglycans both increased with increasing concentrations. The temperature had different effects on the viscosity of the two proteoglycans. As temperature increased from 25 to 85 °C, the viscosity of LPP descended while the HPP's viscosity rose first and then dropped slightly. The effects of CaCl addition on the two samples were like that of the temperature. The viscosities of HPP and LPP had different tolerances to acidity and alkalinity. HPP solution was more sensitive to pH changes due to its high protein content. The addition of sucrose increased the viscosities of samples. The modulus G' and G″ of HPP and LPP were increased with the increase of oscillation frequency, while the crossover points of G' and G″ values decreased with the increasing concentrations of HPP and LPP. The above data presented that the two proteoglycans could be promising candidates for food industries and pharmacological applications.
从甘草中提取出两种蛋白聚糖（HPP 和 LPP），其蛋白/多糖比例不同。测定了两种蛋白聚糖的化学成分、相对平均分子量、单糖组成、FT-IR 光谱和流变性能。结果表明，两种蛋白聚糖均具有假塑性流体特性，并表现出剪切变稀行为。两种蛋白聚糖的表观粘度均随浓度的增加而增加。温度对两种蛋白聚糖的粘度有不同的影响。随着温度从 25°C 升高到 85°C，LPP 的粘度下降，而 HPP 的粘度先升高后略有下降。氯化钙对两种样品的影响与温度相似。HPP 和 LPP 的粘度对酸碱性有不同的耐受性。由于 HPP 含有较高的蛋白质，其溶液对 pH 值的变化更敏感。蔗糖的添加增加了样品的粘度。随着振荡频率的增加，HPP 和 LPP 的模量 G'和 G″增加，而 G'和 G″值的交叉点随着 HPP 和 LPP 浓度的增加而降低。上述数据表明，这两种蛋白聚糖可能是食品工业和药理学应用的有前途的候选物。
