title: Synthesis and antifungal activity of thiadiazole-functionalized chitosan derivatives.
abstract: A groups of novel water soluble chitosan derivatives containing 1,3,4-thiadiazole group were synthesized including 1,3,4-thiadiazole (TPCTS), 2-methyl-1,3,4-thiadiazole (MTPCTS), and 2-phenyl-1,3,4-thiadiazole (PTPCTS). Their antifungal activity against three kinds of phytopathogens was estimated by hypha measurement in vitro, and the fungicidal assessment shows that the synthesized chitosan derivatives have excellent activity against tested fungi. Of all the synthesized chitosan derivatives, MTPCTS inhibited the growth of the tested phytopathogens most effectively with inhibitory indices of 75.3%, 82.5%, and 65.8% against Colletotrichum lagenarium (Pass) Ell.et halst, Phomopsis asparagi (Sacc.) Bubak, and Monilinia fructicola (Wint.) Honey respectively at 1.0 mg/mL. These indices are higher than those of chitosan. These data also demonstrate that the hydrophobic moiety (alkyl and phenyl) and the length of alkyl substituent in thiadiazole tend to affect the antifungal activity of chitosan derivatives. It is hypothesized that thiadiazole groups enable the synthesized chitosan to possess obviously better antifungal activity and good solubility in water.
authors.affiliation: Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shangdong 264003, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.forename: Jianming
authors.initials: J
authors.lastname: Ren
authors.forename: Fang
authors.initials: F
authors.lastname: Dong
authors.forename: Yan
authors.initials: Y
authors.lastname: Feng
authors.forename: Guodong
authors.initials: G
authors.lastname: Gu
authors.forename: Zhanyong
authors.initials: Z
authors.lastname: Guo
mesh_terms: D000935:Antifungal Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D001203:Ascomycota / Q000187:drug effects; D060326:Chemistry Techniques, Synthetic; D048271:Chitosan / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D020231:Colletotrichum / Q000187:drug effects; D004353:Drug Evaluation, Preclinical / Q000379:methods; D015394:Molecular Structure; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013830:Thiadiazoles / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D014867:Water
chemical_list: D000935:Antifungal Agents; D013830:Thiadiazoles; D014867:Water; D048271:Chitosan