Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China.
Int J Biol Macromol. 2019 May 15;129:1127-1132. doi: 10.1016/j.ijbiomac.2018.09.099. Epub 2018 Sep 17.
Chemical modification is one of the prominent methods used to improve the water solubility and bioactivity of chitosan. In this paper, a series of quaternary ammonium chitosan derivatives based on 6-O-chloroacetylated chitosan (CAClC) were successfully designed and synthesized. Detailed structural characterization was carried out by means of FT-IR, H NMR spectroscopy, and elemental analysis. Furthermore, the antifungal activity against Botrytis cinerea, Gibberella zeae, and Physalospora piricola Nose was estimated using in vitro hypha measurements. Most of the quaternary ammonium chitosan derivatives showed an inhibitory index of >90% at 1.0 mg/mL and exhibited enhanced antifungal activity when compared to chitosan. On one hand, the higher density of positive charge contributed to the antifungal action. In addition, the inhibitory activity decreased roughly in the order of TriM [(CH)] > TriE [(CHCH)] > TriP [(CHCHCH)] > TriB [(CHCHCHCH)]; NNTE [(CH)(CHCH)] > NNTB [(CH)(CHCHCHCH)] > NNTK [(CH)((CH)CH)] at 1.0 mg/mL. The antifungal properties of all the quaternary ammonium chitosan derivatives against the targeted fungi decreased upon increasing the alkyl chain length.
化学修饰是提高壳聚糖水溶性和生物活性的一种主要方法。本文设计并成功合成了一系列基于 6-O-氯乙酰化壳聚糖（CAClC）的季铵化壳聚糖衍生物。通过傅里叶变换红外光谱（FT-IR）、核磁共振波谱（H NMR）和元素分析对其进行了详细的结构表征。此外，还通过体外菌丝生长法测定了它们对灰葡萄孢菌、禾谷镰刀菌和梨叶点霉的抑菌活性。在 1.0mg/mL 时，大多数季铵化壳聚糖衍生物的抑制指数均>90%，抑菌活性明显优于壳聚糖。一方面，较高密度的正电荷有助于发挥抑菌作用。此外，抑菌活性大致按 TriM [(CH)]>TriE [(CHCH)]>TriP [(CHCHCH)]>TriB [(CHCHCHCH)]；NNTE [(CH)(CHCH)]>NNTB [(CH)(CHCHCHCH)]>NNTK [(CH)((CH)CH)]的顺序递减。在 1.0mg/mL 时，所有目标真菌对季铵化壳聚糖衍生物的抑菌活性均随烷基链长的增加而降低。
