Department of Natural Products Chemistry, Jinan University, Guangzhou, PR China.
Int J Biol Macromol. 2010 May 1;46(4):436-9. doi: 10.1016/j.ijbiomac.2010.02.002. Epub 2010 Feb 11.
A novel polysaccharide (GBP50S2) with antioxidant activity was isolated from Ginkgo biloba. The structure of GBP50S2 was elucidated on the basis of physico-chemical and instrumental analyses, and its average molecular weight (Mw=2.30x10(5)) was determined by gel permeation chromatography. The backbone of GBP50S2 was composed of (1-->4)-linked alpha-d-mannopyranosyl residues which branched at O-3. The three branches consisted of beta-l-rhamnopyranosyl residues, (1-->4)-linked alpha-d-galactopyranosyl terminated with beta-l-rhamnopyranosyl residues, and (1-->3,4)-linked alpha-d-mannopyranosyl terminated with beta-l-rhamnopyranosyl residues, respectively. In the in vitro antioxidant assay, GBP50S2 was found to possess DPPH radical-scavenging activity and hydroxyl radical-scavenging activity with an IC(50) value of 0.412 mg/mL and 0.482 mg/mL, respectively.
从银杏中分离得到一种具有抗氧化活性的新型多糖（GBP50S2）。基于物理化学和仪器分析，阐明了 GBP50S2 的结构，其平均分子量（Mw=2.30x10(5)）通过凝胶渗透色谱法确定。GBP50S2 的主链由（1-->4）-连接的α-d-吡喃甘露糖基残基组成，这些残基在 O-3 处分枝。三个支链分别由β-l-鼠李吡喃糖基残基、以β-l-鼠李吡喃糖基结尾的（1-->4）-连接的α-d-半乳糖吡喃糖基残基和以β-l-鼠李吡喃糖基结尾的（1-->3,4）-连接的α-d-吡喃甘露糖基残基组成。在体外抗氧化测定中，发现 GBP50S2 具有 DPPH 自由基清除活性和羟基自由基清除活性，IC(50) 值分别为 0.412mg/mL 和 0.482mg/mL。
