Antifungal Activity of Arginine-Based Surfactants

FAIT, M.E.; COSTA, H.; FREITAS, C.D.T.; BAKAS, L.; MORCELLE, S.R.

Current Bioactive Compounds

Bentham Science

Lugar: Sharjah; Año: 2019 vol. 15 p. 351 - 359

1573-4072

Abstract: Background: Amino acid based surfactants constitute an important class of surface activebiomolecules showing remarkable biocompatible properties. Antimicrobial activity is one of the mostremarkable biological properties of this kind of surfactants, which have been widely studied against abroad spectrum of microorganisms. However, the antifungal activity of this kind of compound has beenless well investigated. The aim of this work is the study of the antifungal activity of two novel argininebasedsurfactants (N􀀁-benzoyl-arginine decylamide, Bz-Arg-NHC10 and N􀀁-benzoyl-arginine dodecylamide,Bz-Arg-NHC12), obtained by an enzymatic strategy, against phytopathogenic filamentous fungiand dermatophyte strains.Methods: Four phytopathogenic fungi (Fusarium oxysporum, Fusarium solani, Colletotrichum gloeosporioidesand Colletotrichum lindemuthianum) and two human pathogenic fungi (dermatophytesTrichophyton rubrum and Trichophyton mentagrophytes) were tested. Inhibition of vegetative growthand conidia germination was investigated for the phytopathogenic fungi. In order to elucidate the possiblemechanism of biocide action, membrane integrity, as well as the production of reactive oxygen species(ROS) were evaluated. Additionally, the inhibition of germination of dermatophyte microconidiadue to both arginine-based surfactants was studied. Minimum inhibitory concentration, as well as theconcentration that inhibits 50% of germination were determined for both compounds and both fungalstrains.Results: For the vegetative growth of phytopathogenic fungi, the most potent arginine-based compoundwas Bz-Arg-NHC10. All the tested compounds interfered with the conidia development of the studiedspecies. Investigation of the possible mechanism of toxicity towards phytopathogenic fungi indicateddirect damage of the plasma membrane and production of ROS. For the two strains of dermatophytefungi tested, all the proved compounds showed similar fungistatic efficacy.Conclusion: Bz-Arg-NHC10 and Bz-Arg-NHC12 were demonstrated to have broad biocidal abilityagainst the proliferative vegetative form and the asexual reproductive conidia. Results suggest that bothmembrane permeabilization and induction of oxidative stress are part of the antifungal mechanismsinvolved in the interruption of normal conidia development by Bz-Arg-NHCn, leading to cell death.