Salama Hend E, Saad Gamal R, Sabaa Magdy W
Department of Chemistry, Faculty of Science, Cairo University, 12613, Egypt.
Department of Chemistry, Faculty of Science, Cairo University, 12613, Egypt.
Int J Biol Macromol. 2017 Aug;101:438-447. doi: 10.1016/j.ijbiomac.2017.03.075. Epub 2017 Mar 18.
Chitosan biguanidine hydrochloride (ChG) and low molecular weight poly[(R)-3-hydroxybutyrate] (PHB) were successfully prepared to overcome the solubility problem of chitosan and PHB and also to enhance antimicrobial activity of chitosan. The graft copolymers based on ChG and PHB (ChG-grafted PHB) were then prepared via condensation reaction of the carboxylic groups of PHB with the amino groups of ChG. These graft copolymers swell in water. The prepared graft copolymers were characterized by FTIR, H NMR, X-ray diffraction (XRD) and thermal analyses (TGA and DSC). TGA and DSC results revealed that the thermal stability and crystallinity of the graft copolymers were found to increase as the content of PHB increased. The antimicrobial activity of both ChG and ChG-grafted PHB, against Streptococcus pneumoniae, Bacillus subtilis, Escherichia coli (as examples of bacteria) and Aspergillus fumigatus, Geotricum candidum and Syncephalastrum recemosum (as examples of fungi), were tested. Among them, ChG and ChG-grafted PHB with the highest grafting percent investigated showed to possess relatively higher antimicrobial activity with low MIC values in the range of 0.49-3.90μgmL.
成功制备了壳聚糖盐酸双胍（ChG）和低分子量聚（R）-3-羟基丁酸酯（PHB），以克服壳聚糖和PHB的溶解性问题，并提高壳聚糖的抗菌活性。然后通过PHB的羧基与ChG的氨基的缩合反应制备了基于ChG和PHB的接枝共聚物（ChG接枝的PHB）。这些接枝共聚物在水中溶胀。通过傅里叶变换红外光谱（FTIR）、核磁共振氢谱（H NMR）、X射线衍射（XRD）和热分析（热重分析（TGA）和差示扫描量热法（DSC））对接枝共聚物进行了表征。TGA和DSC结果表明，接枝共聚物的热稳定性和结晶度随PHB含量的增加而增加。测试了ChG和ChG接枝的PHB对肺炎链球菌、枯草芽孢杆菌、大肠杆菌（作为细菌的例子）以及烟曲霉、白地霉和总状共头霉（作为真菌的例子）的抗菌活性。其中，所研究的接枝率最高的ChG和ChG接枝的PHB在0.49-3.90μg/mL范围内显示出相对较高的抗菌活性和较低的最低抑菌浓度（MIC）值。
