Efeito biocida de mandelatos organoestânicos sobre Fusarium oxysporum f. sp. cubense

Abstract

RESUMOCompostos organoestânicos são substâncias que têm sido utilizadas como biocidas. A vantagem do uso dessa classe de compostos é sua degradação em dióxido de estanho (SnO 2 ), que é atóxico para o meio ambiente. Os complexos organoestânicos foram obtidos pela reação de quantidades eqüimolares dos isômeros dos ácidos R-(-)-e S-(+)-mandélicos e de dicloreto de difenilestanho, com o objetivo de testar o efeito biocida dos novos complexos sobre culturas do fungo Fusarium oxysporum f.sp. cubense, avaliando o potencial de inibição do crescimento micelial médio do fungo em teste direto in vitro, em meio de cultura BDA, a 25 o C. Foram utilizadas as concentrações 0, 25, 100, 250 e 500 mg/kg, em quadruplicatas, com avaliações em 2, 4 e 7 dias. Os complexos R e S são insolúveis no meio BDA e os grânulos caoticamente dispersos efetivamente inibiram o crescimento fúngico. Termos para indexação:Complexos organoestânicos, efeito biocida, fungo. ABSTRACTOrganotin compounds are substances which have been utilized as biocides. The advantage of using this class of compounds is their degradation into tin dioxide (SnO 2 ), which is non-toxic to environment . The organotin complexes were obtained from the reaction of equimolar amounts of the isomers of the acids R and S mandelic and diphenyltin dichloride with the purpose of testing the biocide effect of the new complexes on cultures of the fungus Fusarium oxysporum f.sp. cubense by evaluating in in vitro direct test in BDA culture medium at 25 o C. Concentrations of 0, 25, 100, 250 and 500 mg/kg were tested in quadruplicates, with readings after 2, 4 and 7 days. The R and S complexes are insoluble in the BDA medium, the chaotically dispersed grains effectively inhibited the fungal growth.

Biological Control Agents Against Fusarium Wilt of Banana

“…Overall, fungicides have provided unsatisfactory control levels. In vitro , toxicity against Foc has been proved for phosphonate, ambuic acid, organotin mandelates, carbendazim, carboxin, propiconazole, benomyl, and difenoconazole (Davis et al, 1994; Davis and Grant, 1996; Li et al, 2001; Araujo et al, 2004; Somu et al, 2014). In planta , only a few research articles have reported a significant disease control by using fungicides (e.g., carbendazim) (Lakshmanan and Selvaraj, 1984; Eswaramurthy et al, 1988; Roy et al, 1998) or resistance inducers (e.g., indoleacetic acid and menadione sodium bisulphite) (Fernández-Falcón et al, 2003; Borges et al, 2004).…”

Synthesis and Characterization of a Tetrahedral and Monomeric Monobutyltin Compound With a-Hydroxyisobutyric Acid

“…1 In the years 1995-2005, we have developed systematic works about the synthesis and characterization of organotin compounds derived from -hydroxycarboxylic acids [2][3][4][5] , which have shown efficient microcide activity on fungi and pathogenic bacteria in agriculture and in humans. [6][7][8] The present investigation relates to the preparation and characterization of a new complex [BuSnLCl2], L = Me2C(OH) COO, characterized by elemental analysis of carbon, hydrogen, chlorine and tin, by infrared, 119m Sn-Mössbauer and 119m Sn-RMN spectroscopies, and the applications of TG and DSC techniques in dynamic helium atmosphere.…”