Zhang L, Zhang M, Zhou Q, Chen J, Zeng F
Department of Chemistry, Wuhan University, China.
Biosci Biotechnol Biochem. 2000 Oct;64(10):2172-8. doi: 10.1271/bbb.64.2172.
Four fractions of a water-insoluble alpha-(1-->3)-D-glucan GL extracted from fruiting bodies of Ganoderma lucidum were dissolved in 0.25 M LiCl/DMSO, and then reacted with sulfur trioxide-pyridine complex at 80 degrees C to synthesize a series of water-soluble sulfated derivatives S-GL. The degree of substitution of DS was measured by using IR infrared spectra, elemental analysis, and 13C NMR to be 1.2-1.6 in the non-selective sulfation. Weight-average molecular weight Mw and intrinsic viscosity [eta] of the sulfated derivatives S-GL were measured by multi-angle laser light scattering and viscometry. The Mw value (2.4 x 10(4)) of sulfated glucan S-GL-1 was much lower than that (44.5 x 10(4)) of original alpha-(1-->3)-D-glucan GL-1. The Mark-Houwink equation and average value of characteristic ratio C(infinity) for the S-GL in 0.2 M NaCl aqueous solution at 25 degrees C were found to be: [eta] = 1.32 x 10(-3) Mw(1.06) (cm3 g(-1)) and 16, respectively, in the Mw range from 1.1 x 10(4) to 2.4 x 10(4). It indicated that the sulfated derivatives of the alpha-(1-->3)-D-glucan in the aqueous solution behave as an expanded chain, owing to intramolecular hydrogen bonding or interaction between charge groups. Interestingly, two sulfated derivatives synthesized from the alpha-(1-->3)-D-glucan and curdlan, a beta-(1-->3)-D-glucan, all had significant higher antitumor activity against Ehrlich ascites carcinoma (EAC) than the originals. The effect of expanded chains of the sulfated glucan in the aqueous solution on the improvement of the antitumor activity could not be negligible.
从灵芝子实体中提取的水不溶性α-(1→3)-D-葡聚糖GL的四个级分溶解于0.25 M LiCl/DMSO中，然后在80℃下与三氧化硫-吡啶络合物反应，合成了一系列水溶性硫酸化衍生物S-GL。在非选择性硫酸化中，通过红外光谱、元素分析和13C NMR测定取代度DS为1.2-1.6。通过多角度激光光散射和粘度测定法测量硫酸化衍生物S-GL的重均分子量Mw和特性粘度[η]。硫酸化葡聚糖S-GL-1的Mw值（2.4×104）远低于原始α-(1→3)-D-葡聚糖GL-1的Mw值（44.5×104）。发现在25℃下0.2 M NaCl水溶液中S-GL的Mark-Houwink方程和特性比C(∞)的平均值分别为：[η]=1.32×10-3 Mw(1.06)（cm3 g-1）和16，Mw范围为1.1×104至2.4×104。这表明α-(1→3)-D-葡聚糖的硫酸化衍生物在水溶液中表现为伸展链，这是由于分子内氢键或电荷基团之间的相互作用。有趣的是，由α-(1→3)-D-葡聚糖和β-(1→3)-D-葡聚糖可得然胶合成的两种硫酸化衍生物对艾氏腹水癌（EAC）的抗肿瘤活性均明显高于其原始物。硫酸化葡聚糖在水溶液中的伸展链对抗肿瘤活性改善的作用不可忽略。
