Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China; Weifang Inspection and Testing Center, Shandong, Weifang 261000, China.
Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China.
Int J Biol Macromol. 2021 May 15;179:292-298. doi: 10.1016/j.ijbiomac.2021.02.184. Epub 2021 Feb 27.
In this study, a series of chitosan derivatives bearing active halogenated aromatic imines were successfully synthesized via Schiff bases with the high degrees of substitution. Detailed structural characterization was carried out using Fourier transform infrared (FTIR) spectroscopy, solid-state C nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis. Besides, the antifungal activity against three common plant pathogenic fungi, including Botrytis cinerea, Fusarium oxysporum f. sp. cucumerinum, and Fusarium oxysporum f. sp. niveum, was investigated using in vitro hyphal measurements. The results showed that double Schiff bases of chitosan derivatives exhibited enhanced antifungal activity compared with chitosan, especially at 1.0 mg/mL. The double Schiff bases of chitosan bearing halogeno-benzenes showed >95% inhibitory indices at 1.0 mg/mL against Botrytis cinereal since halogens had the stronger electron-withdrawing property. The higher degree of substitution was another positive effect to improve the antifungal activity. This study provides a practical strategy to synthesize new double Schiff bases of chitosan derivatives bearing halogeno-benzenes, which could be developed into stronger antifungal agents.
在这项研究中，通过希夫碱成功合成了一系列带有活性卤代芳亚胺的壳聚糖衍生物，取代度较高。详细的结构表征采用傅里叶变换红外（FTIR）光谱、固态 C 核磁共振（NMR）光谱和元素分析进行。此外，还采用体外菌丝测量法研究了它们对三种常见植物病原菌（包括灰葡萄孢、黄瓜枯萎病菌和尖孢镰刀菌）的抗真菌活性。结果表明，壳聚糖衍生物的双希夫碱表现出比壳聚糖更强的抗真菌活性，尤其是在 1.0mg/mL 时。带有卤代苯的壳聚糖双希夫碱在 1.0mg/mL 时对灰葡萄孢的抑制指数超过 95%，因为卤素具有更强的吸电子性。较高的取代度是提高抗真菌活性的另一个积极因素。本研究为合成带有卤代苯的壳聚糖衍生物的新型双希夫碱提供了一种实用策略，这些双希夫碱可能被开发成更强的抗真菌剂。
