School of Pharmacy, Zunyi Medical University, 201 Dalian Road, Zunyi 563000, PR China; Glycochemistry and Glycobiology Lab, Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, PR China; University of Chinese Academy of Science, No. 19A Yuquan Road, Beijing 100049, PR China.
Glycochemistry and Glycobiology Lab, Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, PR China; University of Chinese Academy of Science, No. 19A Yuquan Road, Beijing 100049, PR China; Nano Science and Technology Institute, University of Science and Technology of China, No. 96, Jinzhai Road Baohe District, Hefei, Anhui, 230026, PR China.
Int J Biol Macromol. 2017 Oct;103:533-542. doi: 10.1016/j.ijbiomac.2017.05.097. Epub 2017 May 18.
Dendrobium officinale Kimura et Migo (Tie-Pi-Shi-Hu), a precious folk medicine exhibiting multiple bioactivities, including antitumor, immune-enhancing and so on. Although evidences showed polysaccharide is one of the major bioactive substances from this herb, several of them were homogenous with fine structures elucidated. In this study, we showed a novel homogeneous heteroxylan obtained from alkali-extracted crude polysaccharide. It composed of arabinose, xylose, glucose and 4-O-methylglucuronic acid (4-MGA) as well as trace amount of rhamnose and galactose in a ratio of 8.9:62.7:8.5:12.3:3.9:3.7. We further showed that it contained a backbone of 1,4-linked β-d-xylan, with branches of 1,4-linked α-d-glucose, 1,3-linked α-l-rhamnose, and terminal-linked α-l-arabinose, β-d-galactose, 4-MGA, and β-d-xylose directly or indirectly attached to C-2 position of glycosyl residues on backbone. The sulfated derivative with substitution degree about 0.9 was prepared according to the chlorosulfonic acid (CSA)-pyridine method. Bioactivity tests suggested that the sulfated polysaccharide could significantly disrupt tube formation and inhibit the migration of human microvascular endothelial cells (HMEC-1) at a low concentration (0.29μM) in a dose-dependent way without significant cytotoxity.
铁皮石斛（Dendrobium officinale Kimura et Migo）是一种珍贵的民间药物，具有多种生物活性，包括抗肿瘤、增强免疫力等。虽然有证据表明多糖是这种草药的主要生物活性物质之一，但其中有几种具有精细结构的同质性。在这项研究中，我们从碱性提取的粗多糖中得到了一种新型均一的杂木聚糖。它由阿拉伯糖、木糖、葡萄糖和 4-O-甲基葡萄糖醛酸（4-MGA）以及少量鼠李糖和半乳糖组成，摩尔比为 8.9:62.7:8.5:12.3:3.9:3.7。我们进一步表明，它含有 1,4-连接的β-d-木聚糖的主链，带有 1,4-连接的α-d-葡萄糖、1,3-连接的α-l-鼠李糖和末端连接的α-l-阿拉伯糖、β-d-半乳糖、4-MGA 和β-d-木糖直接或间接连接到主链上糖基残基的 C-2 位。根据氯磺酸（CSA）-吡啶法制备取代度约为 0.9 的硫酸化衍生物。活性测试表明，硫酸化多糖在低浓度（0.29μM）下可显著破坏管形成，并呈剂量依赖性抑制人微血管内皮细胞（HMEC-1）的迁移，而没有明显的细胞毒性。
