Hydrophobic Effect of Amphiphilic Derivatives of Chitosan on the Antifungal Activity against Aspergillus flavus and Aspergillus parasiticus

Autor(es)

Felix Viegas de Souza, Ricchard Hallan ^[1] ; Takaki, Mirelli ^[1] ; Pedro, Rafael de Oliveira ^[1] ; Gabriel, Juliana dos Santos ^[1] ; Tiera, Marcio Jose ^[1] ; de Oliveira Tiera, Vera Ap. ^[1]

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ UNESP, Inst Biosci Humanities & Exact Sci IBILCE, Dept Chem & Environm Sci, BR-15054000 Sao Jose Do Rio Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Molecules; v. 18, n. 4, p. 4437-4450, APR 2013.
• Citações Web of Science: 11

Resumo

Low molecular weight amphiphilic derivatives of chitosan were synthesized, characterized and their antifungal activities against Aspergillus flavus and Aspergillus parasiticus were tested. The derivatives were synthesized using as starting material a deacetylated chitosan sample in a two step process: the reaction with propyltrimethylammonium bromide (Pr), followed by reductive amination with dodecyl aldehyde. Aiming to evaluate the effect of the hydrophobic modification of the derivatives on the antifungal activity against the pathogens, the degree of substitution (DS1) by Pr groups was kept constant and the proportion of dodecyl (Dod) groups was varied from 7 to 29% (DS2). The derivatives were characterized by H-1-NMR and FTIR and their antifungal activities against the pathogens were tested by the radial growth of the colony and minimum inhibitory concentration (MIC) methods. The derivatives substituted with only Pr groups exhibited modest inhibition against A. flavus and A. parasiticus, like that obtained with deacetylated chitosan. Results revealed that the amphiphilic derivatives grafted with Dod groups exhibited increasing inhibition indexes, depending on polymer concentration and hydrophobic content. At 0.6 g/L, all amphiphilic derivatives having from 7.0 to 29% of Dod groups completely inhibited fungal growth and the MIC values were found to decrease from 4.0 g/L for deacetylated chitosan to 0.25-0.50 g/L for the derivatives. These new derivatives open up the possibility of new applications and avenues to develop effective biofungicides based on chitosan. (AU)

• Processo FAPESP: 12/03619-9 - Biofungicidas: síntese e caracterização de derivados anfifílicos de quitosana para aplicação contra fungos do gênero Aspergillus
• Beneficiário: Vera Aparecida de Oliveira Tiera
• Modalidade de apoio: Auxílio à Pesquisa - Regular