Peng Yanfei, Han Baoqin, Liu Wanshun, Xu Xiaojuan
Department of Marine Biological Engineering, Ocean University of China, Qingdao 266003, China.
Carbohydr Res. 2005 Aug 15;340(11):1846-51. doi: 10.1016/j.carres.2005.05.009.
Water-soluble hydroxypropyl chitosan (HPCS) derivatives with different degrees of substitution (DS) and weight-average molecular weight (Mw) were synthesized from chitosan and propylene epoxide under basic conditions. Their structure was characterized by IR spectroscopy, NMR spectroscopy, and elemental analysis, which showed that both the OH groups at C-6 and C-3 and the NH2 group of chitosan were alkylated. The DS value of HPCS ranged from 1.5 to 3.1 and the Mw was between 2.1x10(4) and 9.2x10(4). In vitro antimicrobial activities of the HPCS derivatives were evaluated by the Kirby-Bauer disc diffusion method and the macrotube dilution broth method. The HPCS derivatives exhibited no inhibitory effect on two bacterial strains (Escherichia coli and Staphylococcus aureus); however, some inhibitory effect was found against four of the six pathogenic fruit fungi investigated. Some derivatives (HPCS1, HPCS2, HPCS3, HPCS3-1, and HPCS4) were effective against C. diplodiella and F. oxysporum. HPCS3-1 is the most effective one with MIC values of 5.0, 0.31, 0.31, and 0.16mg/mL against A. mali, C. diplodiella, F. oxysporum, and P. piricola, respectively. Antifungal effects were also observed for HPCS2 and HPCS3-1 against A. mali, as well as HPCS3 and HPCS3-1 against P. piricola. The results suggest that relatively lower DS and higher Mw value enhances the antifungal activity of HPCS derivatives.
在碱性条件下，以壳聚糖和环氧丙烷为原料合成了具有不同取代度（DS）和重均分子量（Mw）的水溶性羟丙基壳聚糖（HPCS）衍生物。通过红外光谱、核磁共振光谱和元素分析对其结构进行了表征，结果表明壳聚糖C-6和C-3位的OH基团以及NH2基团均发生了烷基化。HPCS的DS值在1.5至3.1之间，Mw在2.1×10⁴至9.2×10⁴之间。采用 Kirby-Bauer 纸片扩散法和大管稀释肉汤法对HPCS衍生物的体外抗菌活性进行了评价。HPCS衍生物对两种细菌菌株（大肠杆菌和金黄色葡萄球菌）没有抑制作用；然而，在所研究的六种致病水果真菌中，对其中四种发现了一些抑制作用。一些衍生物（HPCS1、HPCS2、HPCS3、HPCS3-1和HPCS4）对葡萄座腔菌和尖孢镰刀菌有效。HPCS3-1是最有效的一种，对苹果轮纹病菌、葡萄座腔菌、尖孢镰刀菌和梨火疫病菌的最低抑菌浓度（MIC）值分别为5.0、0.31、0.31和0.16mg/mL。还观察到HPCS2和HPCS3-1对苹果轮纹病菌有抗真菌作用，以及HPCS3和HPCS3-1对梨火疫病菌有抗真菌作用。结果表明，相对较低的DS和较高的Mw值可增强HPCS衍生物的抗真菌活性。
