传统化学农药的过度使用及其残留，严重影响了环境以及人类健康。因此，新型生物杀菌剂的开发迫在眉睫。菊糖是自然界中分布广泛、天然可再生的生物资源，可以作为许多植物的储能物质，具有生物相容好、可降解等特性，同时还具有降血酯、肠道益生素、促进矿物质吸收、预防肥胖等多种生理功能。目前菊糖仍然被直接作为添加剂使用，有关菊糖衍生物及其生物活性方面的研究很少，致使其附加值低，应用范围受限。而化学修饰则是改善化合物生物活性、促进其高值化应用的有效手段之一。因此，本文对菊糖这一多羟基化合物利用活性叠加原理，进行了合理的选择性化学改性，以期发掘其在抑菌方面的应用，达到长效缓释的目的，为新型农药开发奠定理论基础。

    本研究以菊糖为骨架，通过定位导入、接枝共聚技术接入高活性基团制备了三类共计十余种含 1,2,3-三氮唑的菊糖衍生物，并采用红外光谱、核磁光谱等技术手段对制备的菊糖衍生物进行结构鉴定。三类衍生物分别为 C-6-1, 2, 3-三氮唑乙酰化菊糖衍生物、C-6-1, 2, 3-三氮唑桥连水杨醛类席夫碱菊糖衍生物以及C-6-1, 2, 3-三氮唑桥连苯甲酸酯类乙酰化菊糖衍生物，并且研究了它们对 3 种植物真菌（黄瓜炭疽病菌、西瓜枯萎病菌、芦笋茎枯杆菌）以及 2 种细菌（金黄色葡萄球菌、大肠杆菌）的抑制活性。主要研究工作如下：

    三类菊糖衍生物的合成是通过激活 C-6 位的羟基，使之成为易离去基团，利用叠氮基亲核置换易离去基团，然后将含有叠氮基团的菊糖分子与含有端基炔的配体通过 Sharpless 等报道的“点击反应”环合，生成稳定的 1, 2, 3-三氮唑化合物。

 

    文中比较了菊糖和所制备的菊糖衍生物的抑菌活性。结果表明：菊糖原料没有明显的抑菌活性，1, 2, 3-三氮唑的引入赋予菊糖一定的抑菌活性；C-6-1, 2, 3-三氮唑桥连水杨醛类席夫碱菊糖衍生物的抑菌活性最显著，其中 C-6-（4-（5-溴水杨醛席夫碱）-1, 2, 3-三氮唑）菊糖（BSHTIL）在浓度为 1000 μg/mL 时，对于金黄色葡萄球菌和大肠杆菌培养 8 小时的抑制率可达 100%，说明席夫碱官能团和 1, 2, 3-三氮唑官能团有明显的活性叠加效果；C-6-1, 2, 3-三氮唑桥连苯甲酸酯类乙酰化菊糖衍生物抑菌活性没有明显提高，同时其水溶性明显降低，推测水溶性差可能抑制了衍生物抑菌活性的表达。

    The overuse and leftover of traditional chemical pesticides have affected the environment and human health seriously. Therefore, it is imminent to develop new biological fungicide alternatives. Inulin is an abundant and renewable plant preserved polysaccharides, which is biocompatible and biodegradable. Meanwhile, inulin has exhibited some biological functional properties, such as lipid-lowering activity, intestinal probiotics, prevention of obesity, promotion of mineral absorption and so on. However, inulin is still used as additives directly, and there are few reports about the properties of inulin derivatives, which limits the application of inulin. Chemical modification is the most efficient technique to improve the biological activities and applications of compounds. Hence, according to the activity superposition principle, we made some reasonable chemical modifications for inulin, in order to explore its antimicrobial activities and achieve the purpose of long-term slow-release, making the theoretical foundation for developing new pesticides.

 

    In this study, three kinds of inulin derivatives with 1, 2, 3-triazole groups, containing C-6-1, 2, 3-triazole inulin derivatives, C-6-1, 2, 3-triazole Shiff bases inulin derivatives and C-6-1, 2, 3-triazole benzoyl ester inulin derivatives, were designed via localization of importing active group and strategy of graft copolymerization. Totally, more than 10 kinds of novel derivatives of inulin were obtained. Their structures were confirmed by FT-IR, NMR. Antifungal activities of them against Colletotrichum lagenarium, Fusarium oxysporium, Phomopsis asparagi were assayed, as well as their antibacterial activities against S. aureus and E.coli. The major experimental work was listed as follows:

    To prepare C-6-1, 2, 3-triazole ester inulin derivatives, C-6-1, 2, 3-triazole Shiff bases inulin derivatives, 6-azido-6-deoxyinulin was an excellent intermediate of the project as azide could conveniently transform to 1, 2, 3-triazole groups with alkyne ester or Shiff bases ligands via “click” chemistry, developed by Sharpless. Meanwhile, 6-azido-6-deoxyinulin could obtain through SN reaction by azide ion displacing appropriate leaving groups.

    We discussed the antimicrobial activity of inulin and its derivatives. The results demonstrated that inulin barely exhibited the inhibition against microorganism. All the synthesized 1, 2, 3-triazole inulin derivatives had obvious inhibitory effects on the growth of microorganism. The antimicrobial activity of C-6-1, 2, 3-triazole Shiff bases inulin derivatives were remarkable. At the concentration of 1000 μg/mL, the inhibitory index of C-6（- 4（- 5-Br-salicylaldehyde schiff base）-1, 2, 3- triazole）inulin （BSHTIL） against S. aureus and E.coli. was at 100% when they were incubated about 8 hours. This means the superposition of Shiff bases and 1, 2, 3-triazole is remarkable. The inhibitory effect of C-6-1, 2, 3-triazole-benzoyl esters inulin derivatives exhibited no obvious enhancement, while the water solubility decreased after chemical modification. Maybe the poor water-solublity inhibit the expression of antimicrobial activity of the derivatives.