title: Synthesis, characterization and antifungal activity of quaternary derivatives of chitosan on Aspergillus flavus.
abstract: Two series of new chitosan derivatives were synthesized by reaction of deacetylated chitosan (CH) with propyl (CH-Propyl) and pentyl (CH-Pentyl) trimethylammonium bromides to obtain derivatives with increasing degrees of substitution (DS). The derivatives were characterized by (1)H NMR and potentiometric titration techniques and their antifungal activities on the mycelial growth of Aspergillus flavus were investigated in vitro. The antifungal activities increase with DS and the more substituted derivatives of both series, CH-Propyl and CH-Pentyl, exhibited antifungal activities respectively three and six times higher than those obtained with commercial and deacetylated chitosan. The minimum inhibitory concentrations (MIC) were evaluated at 24, 48 and 72 h by varying the polymer concentration from 0.5 to 16 g/L and the results showed that the quaternary derivatives inhibited the fungus growth at polymer concentrations four times lower than that obtained with deacetylated chitosan (CH). The chitosans modified with pentyltrimethylammonium bromide exhibited higher activity and results are discussed taking into account the degree of substitution (DS).
authors: Department of Chemistry and Environmental Sciences, Institute of Biosciences, Humanities and Exact Sciences-IBILCE, São Paulo State University-UNESP, São José do Rio Preto, São Paulo, Brazil.
authors: Rafael
authors: R
authors: de Oliveira Pedro
authors: Mirelle
authors: M
authors: Takaki
authors: Teresa Cristina Castilho
authors: TC
authors: Gorayeb
authors: Vanildo Luiz
authors: VL
authors: Del Bianchi
authors: João Cláudio
authors: JC
authors: Thomeo
authors: Marcio José
authors: MJ
authors: Tiera
authors: Vera Aparecida
authors: VA
authors: de Oliveira Tiera
mesh_terms: D000935:Antifungal Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D001231:Aspergillus flavus / Q000187:drug effects*; D048271:Chitosan / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D011199:Potentiometry; D013329:Structure-Activity Relationship; D013997:Time Factors
chemical_list: D000935:Antifungal Agents; D048271:Chitosan