Gao Yang, Yang Xianling, Zheng Wei, Gao Miaomiao, Gao Qipin, Xu Duoduo
Jilin Institute of Ginseng Science, Changchun University of Chinese Medicine, Changchun, China.
Key Laboratory of Pharmacodynamic Constituents of Dao-di Herbs in Changbai Mountain, Changchun, China.
J Food Biochem. 2020 Jul;44(7):e13212. doi: 10.1111/jfbc.13212. Epub 2020 Apr 16.
The Tremella fuciformis Berk polysaccharides (TP) have significant cytokine-stimulating activity and low oral bioavailability owing to their large molecular volume. Identifying and studying the smallest active structure of TP can potentially be beneficial for further utilization and research, therefore, TP was hydrolyzed and fractionated to obtain its (1→3)-mannan backbone fragments. The fragments were further isolated by ion-exchange resin, ultrafiltration, gel, and HPLC chromatography, and three oligosaccharide fractions, named TL4-1, TL4-2, TL4-3, were obtained. According to the determination of their physicochemical properties, they were composed of Man, and after methylation analysis they were mainly characterized as (1→3)-mannan oligosaccharides with a straight chain. TL4-1 contained di-, trisaccharides, TL4-2 included tetra-, penta-saccharides, and TL4-3 was made up of hex-, hepta-, octa-saccharides, according to LC-ESI/MS analysis. Cytokine stimulation experiments showed that the degree of polymerization (DP) should be more than six to maintain the activity of mannosan. Therefore, the smallest active unit of oligo-mannose was determined. PRACTICAL APPLICATIONS: This paper reports the physical and chemical parameters, structure and biological potential of oligosaccharides from T. fuciformis Berk, a common edible fungus. Tremella has been used as an improving immunity drug in China with good effect. Oligosaccharides are more easily digested and utilized by human body, and maintain good activity. These results can increase people's interest in the product, and thus have a positive impact on the oligosaccharides of Tremella as health food.
银耳多糖（TP）因其分子体积大而具有显著的细胞因子刺激活性，但口服生物利用度低。鉴定和研究TP的最小活性结构可能有利于其进一步利用和研究，因此，对TP进行水解和分级分离以获得其（1→3）-甘露聚糖主链片段。通过离子交换树脂、超滤、凝胶和高效液相色谱法进一步分离这些片段，得到三个寡糖级分，命名为TL4-1、TL4-2、TL4-3。根据其理化性质测定，它们由甘露糖组成，甲基化分析后主要表征为直链的（1→3）-甘露寡糖。根据液相色谱-电喷雾电离/质谱分析，TL4-1含有二糖、三糖，TL4-2包括四糖、五糖，TL4-3由六糖、七糖、八糖组成。细胞因子刺激实验表明，聚合度（DP）应大于6才能维持甘露聚糖的活性。因此，确定了寡聚甘露糖的最小活性单位。实际应用：本文报道了常见食用菌银耳中寡糖的理化参数、结构和生物活性。银耳在中国已被用作提高免疫力的药物，效果良好。寡糖更易被人体消化利用，并保持良好的活性。这些结果可提高人们对该产品的兴趣，从而对银耳寡糖作为保健食品产生积极影响。
