牛膝多糖的化学研究

我国传统的中草药牛膝经沸水提取,去游离蛋白质,透析,沉淀,依次进行Cellex D和Sephadex G-150柱层析,得到有免疫活性的肽多糖ABAB,分子量2.3×10⁴。是由D-葡萄糖酸,D-半乳糖,D-半乳糖酸,L-阿拉伯糖和L-鼠李糖组成,摩尔比为12:2:3:1:1。经羧基还原,甲基化反应,过碘酸盐氧化,Smith降解,IR分析,证明它有(1→4)-D-葡萄糖酸和(1→4)-D-半乳糖酸残基组成的主链。ABAB中肽的含量为24.7%,主要有甘氨酸,谷氨酸,门冬氨酸和丝氨酸组成。

CHEMICAL STUDIES ON POLYSACCHARIDE OF ACHYEANTHES BIDENTATA

A peptide-polysaccharide, ABAB showing immunological activity was isolated from Achyeanthes bidentata Bl. It was shown to be homogeneous by HPLC and optical rotation analysis. Its molecular weight was estimated to be 2.3 x 10(4). It composed of D-glucuronic acid, D-galactose, D-galacturonic acid, L-arabinose and L-rhamnose in molar ratio of 12:2:3:1:1. Reduction of carboxyl groups, methylation analysis, periodate oxidation, Smith degradation and IR analysis showed that ABAB possesses a main chain composed of (1----4)-D-glucuronic acid and (1----4)-D-galacturonic acid residues. The non-reducing terminal residues in the side chains were L-arabinose and L-rhamnose. ABAB contained 24.1% of peptides composed of glycine, glutamic acid, aspartic acid and serine.