• Journal of Microbiology and Biotechnology
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• v.18 no.10
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• pp.1729-1734
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• 2008

Chitosan, a cationic polysaccharide, has been widely used as a dietary supplement and in a variety of pharmacological and biomedical applications. The antifungal activity and mechanism of action of low molecular weight water-soluble chitosan (LMWS-chitosan) were studied in fungal cells and vesicles containing various compositions of fungal lipids. LMWS-chitosan showed strong antifungal activity against various pathogenic yeasts and hyphae-forming fungi but no hemolytic activity or cytotoxicity against mammalian cells. The degree of calcein leakage was assessed on the basis of lipid composition (PC/CH; 10:1, w/w). Our result showing that LMWS-chitosan interacts with liposomes demonstrated that chitosan induces leakage from zwitterionic lipid vesicles. Confocal microscopy revealed that LMWS-chitosan was located in the plasma membrane. Finally, scanning electron microscopy revealed that LMWS-chitosan causes significant morphological changes on fungal surfaces. Its potent antibiotic activity suggests that LMWS-chitosan is an excellent candidate as a lead compound for the development of novel anti-infective agents.

• Applied Chemistry for Engineering
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• v.31 no.5
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• pp.475-480
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• 2020

Chelates synthesized with Cu(II) ion and lactic acid or chitosan were applied to the hydrolysis of organophosphate simulant, DFP (diisopropyl fluorophosphate). Under the homogeneous reaction condition, Cu(II)-lactic acid chelate hydrolyzed DFP with the half life time of 37.1 min. Cu(II)-LMWS chitosan chelate was synthesized with 1 kDa molecular weight of chitosan, which showed low solubility, and then crystallized. The half life time for hydrolyzing DFP using Cu(II)-LMWS chitosan was 32.9 h indicating that the reaction rate is enhanced as much as 16 times more than that of using 18 kDa chitosan-Cu(II) complex. Under the homogeneous reaction condition, the half life time of Cu(II)-LMWS chitosan was 8.75 h. Therefore, we found out that the solubility of Cu(II)-LMWS chitosan makes the difference in the reaction rate as much as 4 times.