Synthesis of acyl thiourea derivatives of chitosan and their antimicrobial activities in vitro.
Three different acyl thiourea derivatives of chitosan (CS) were synthesized and their structures were characterized by FT-IR spectroscopy and elemental analysis. The antimicrobial behaviors of CS and its derivatives against four species of bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Sarcina) and four crop-threatening pathogenic fungi (Alternaria solani, Fusarium oxysporum f. sp. vasinfectum, Colletotrichum gloeosporioides (Penz.) Saec, and Phyllisticta zingiberi) were investigated. The results indicated that the antimicrobial activities of the acyl thiourea derivatives are much better than that of the parent CS. The minimum value of MIC and MBC of the derivatives against E. coli was 15.62 and 62.49 microg/mL, respectively. All of the acyl thiourea derivatives had a significant inhibitory effect on the fungi in concentrations of 50-500 microg/mL; the maximum inhibitory index was 66.67%. The antifungal activities of the chloracetyl thiourea derivatives of CS are noticeably higher than the acetyl and benzoyl thiourea derivatives. The degree of grafting of the acyl thiourea group in the derivatives was related to antifungal activity; higher substitution resulted in stronger antifungal activity.
Zhong
Zhimei
Z
Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China. zhimeihappy@126.com
Xing
Ronge
R
Liu
Song
S
Wang
Lin
L
Cai
Shengbao
S
Li
Pengcheng
P
D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D000935:Antifungal Agents / Q000138:chemical synthesis / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D048271:Chitosan / Q000737:chemistry*; D005658:Fungi / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D017550:Spectroscopy, Fourier Transform Infrared; D013329:Structure-Activity Relationship; D013890:Thiourea / Q000737:chemistry*
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D000935:Antifungal Agents; D048271:Chitosan; D013890:Thiourea