降解前后异枝麒麟菜硫酸多糖对草酸钙晶体生长的调控作用

采用过氧化氢法降解产于印尼的海藻异枝麒麟菜硫酸多糖(ESPS). 降解前ESPS的平均分子量为1410000, 硫酸基(OSO2-3)含量为16.0%(w); 而降解后其分子量显著下降至4819, 硫酸基含量则略微下降至15.2%. 采用体外模拟方法研究了降解前后ESPS对草酸钙晶体生长的抑制作用. 扫描电子显微镜(SEM)和X射线衍射(XRD)结果表明, 降解后ESPS能使一水草酸钙(COM)晶体数量进一步减少, 晶粒尺寸进一步减小. 当降解ESPS浓度从0.006 g·L-1分别增加到0.010 和0.050 g·L-1时, COM晶体平均尺寸由11.5 μm×2.9 μm分别减小到9.2 μm×2.9μm 和6.0 μm×2.5 μm, 晶体数量由3357 mm-2分别减少到2298和1532 mm-2, COM 的(101)面衍射峰强度I(101)与(010)面对应的(020)衍射峰强度I(020)之比(I(101)/I(020))由5.54 分别增加到16.2 和20.0. 结果显示, 具有小分子量的降解ESPS对草酸钙晶体成核与生长的抑制效果明显优于大分子量的未降解ESPS.

Modulation of Eucheuma Striatum Sulfated Polysaccharide before and after Degradation on Crystal Growth of Calcium Oxalates

Algal eucheuma striatumsulfated polysaccharide (ESPS) collected from Indonesian sea was degraded by hydrogen peroxide (H2O2).After degradation the averagemolecularweight of ESPSwas decreased from1410000 to 4819, and the content of sulfate (OSO2-3) was lightly decreased from 16.0%to 15.2% (w). The effect of ESPS before and after degradation on the growth of calcium oxalate crystal was investigated in vitro by using scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Compared with the undegraded ESPS, the size and number of calcium oxalatemonohydrate (COM) crystal induced by the degraded ESPS weremuch smaller.With increasing the concentration of degraded ESPS from0.006 g·L-1 to 0.010 and 0.050 g·L-1, the average size of COMcrystals decreased from 11.5 μm×2.9 μm to 9.2 μm×2.9 μm and 6.0 μm×2.5 μm, respectively, and the number of COM crystals decreased from 3357 per mm2 to 2298 and 1532 per mm2, and the diffraction peak intensity ratio of the (101) plane to (010) plane of COM crystals (I(101)/I(020)) increased from5.54 to 16.2 and 20.0. The result showed that the inhibition efficiency of the degraded ESPS with a low-molecular-weight on the nucleation and growth of CaOxa crystal was obviously superior to that of the undegraded ESPS.