Guangdong Provincial Key Laboratory of Marine Biotechnology, STU-UNIVPM Joint Algal Research Center, Department of Biology, College of Science, Shantou University, Shantou, Guangdong 515063, PR China.
Guangdong Provincial Key Laboratory of Marine Biotechnology, STU-UNIVPM Joint Algal Research Center, Department of Biology, College of Science, Shantou University, Shantou, Guangdong 515063, PR China.
Int J Biol Macromol. 2019 Oct 15;139:842-849. doi: 10.1016/j.ijbiomac.2019.08.053. Epub 2019 Aug 7.
The separation and purification of pumpkin polysaccharide by aqueous two-phase system combined with DEAE cellulose-52 column chromatography. There are two purified polysaccharides, neutral fractions (ATPS-PP-1) (7.67 kDa) and acidic fractions (ATPS-PP-2) (8.83 kDa), were obtained from pumpkin powder which were subsequently characterized structurally. The backbone of ATPS-PP-1 comprised of (1 → 3)-linked-Glcp having branching points at O-3 of (1 → 3,4)-linked-Glcp with terminal Glcp as side chain. ATPS-PP-2, on the other hand, comprised of 1 → Glcp, (1 → 3)-linked-Galp, (1 → 6)-linked-Glcp, (1 → 3,6)-linked-Glcp and (1 → 4)-linked-Glcp as backbone. And ATPS-PP-1with small molecular weight and the backbone consisted of (1 → 3) glycosidic linkages has better hypoglycemic activity. Significant protection was conferred on streptozotocin damaged islet β cells by ATPS-PPs (neutral fractions and acidic fractions). Such protective effect was demonstrated by ATPS-PPs' ability to lower Nitric oxide levels by inhibiting NF-κB mRNA overexpression and afterwards down regulation iNOS mRNA expression, eventually minimizing cell oxidative damage caused by STZ and restoring the normal levels of superoxide dismutase.
水相系统与 DEAE 纤维素-52 柱色谱联合分离纯化南瓜多糖。从南瓜粉中得到两种纯化多糖，中性部分（ATPS-PP-1）（7.67 kDa）和酸性部分（ATPS-PP-2）（8.83 kDa），随后对其结构进行了表征。ATPS-PP-1 的骨架由（1→3）-连接的 Glcp 组成，在（1→3,4）-连接的 Glcp 的 O-3 处具有支化点，末端 Glcp 为侧链。另一方面，ATPS-PP-2 由 1→Glcp、（1→3）-连接的 Galp、（1→6）-连接的 Glcp、（1→3,6）-连接的 Glcp 和（1→4）-连接的 Glcp 作为骨架。ATPS-PP-1 具有低分子量和（1→3）糖苷键组成的骨架，具有更好的降血糖活性。ATPS-PPs（中性部分和酸性部分）对链脲佐菌素损伤的胰岛β细胞具有显著的保护作用。这种保护作用是通过 ATPS-PPs 降低一氧化氮水平来实现的，方法是抑制 NF-κB mRNA 的过度表达，随后下调 iNOS mRNA 的表达，从而最大限度地减少 STZ 引起的细胞氧化损伤，并恢复超氧化物歧化酶的正常水平。
