The Preparation Of New Derivatives Of Chitosan (Contained Sulfur And Phosphor Elements) And Study On The Relationship Between Their Structures And Antibacterial Activities

Environmental and human health question were threatened by leftover of chemical agricultural bactericide and traditional antibacterial veterinary. The preparation of the biologic agricultural bactericide has been stared us in the face. Chitosan is a kind of natural polysaccharide, which is reproducible and it has non-toxicity, good biocompatibility and biodegradability, their researches have received considerable interests. However, the most concentration was put on the molecular weight and degree of deacetylation of chitosan on its antibacterial activity, little work has been reported on the antibacterial activity of chitosan derivatives. In this paper, about 40 kinds of derivatives of chitosan which contained sulfur and phosphor elements were prepared. The compounds include 3 classes such as sulfanimide, acyl thiourea andɑ-arylamino phosphonate derivatives of chitosan. Based on the results of the antibacterial activity of the above three kinds of derivatives, we found 4 derivatives against 6 kinds of fungi (Fusarium oxysporum f. sp. Vasinfectum, Colletotrichum gloeosporioides (Penz.) Saec, Pseudoperonospora cubeneis (Berk et cort) Rostuv, Aiternaria solani, Phyllistictasp zingiberi,Phomopsis asparagi) showed strong bactericidal activity. The inhibition activities are close to or more than that of wuyiencin. More than 10 derivatives such as 4-HBSA(l)CMCS,4-HBSA(l)CSS against four kinds of bacteria (Staphylococcus aureus, Sarcina, Eschercichia coli, Pseudomonas aeruginosa) showed strong bactericidal activity. Their inhibition activities are broad-spectrum, moreover, the inhibition activities are close to or more than that of Norfloxacin.The rule and influence reason of antifungal and antibacterial activities of the derivatives was studied, and the mechanism of their antibacterial activities was further discussed in this paper. The factors of the derivatives such as molecular weight, concentration, water-solubility, steric effect ofα-carbon atom, the enhancement of alkyl and so on were important on their antibacterial activities.The above results are theoretically fundamental to further develop and make use of chitin resources and prepare new agricultural bactericide and antibacterial veterinary.