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Abstracts - Renan R. Schorr

NATURAL PRODUCTS AND THEIR DERIVATIVES AS CANDIDATES TO BROWN ROT CONTROL IN PEACH 

 

Meira J. Ballesteros G. 1 , Renan R. Schorr1, Marina Krasniak1, Larissa May-De-Mio2 and Francisco A. Marques1*,

 

Laboratório de Ecologia Química e Síntese de Produtos Natura is, UFPR;

meira.ballesteros@ufpr.br

2  Laboratório de Epidemiologia e Manejo Integrado de Doenças  de Plantas, UFPR.

 

Brown rot caused by Monilinia fructicola is the main disease with economic impact inpeach (Prunus persicae) crop. The pathogen can infect flowers and fruits in pre and post-harvest achieving damage up to 60% of the production. The most used fungicides in Brazil in the last decade were based on the active ingredients azoxistrobin, thiophanate-methyl and tebuconazole. Because of this, a decrease in sensibility in the pathogen has been reported. The main objective in this work was to develop a low-toxicity fungicide to the control of Monilinia fructicola. Several compounds present in essential oils, such as eugenol and isoeugenol, have demonstrated good results to the control of the pathogens and we decided to evaluate the effect of some esters derivatives of these phenolic substances. Esterification of the phenolic moiety was carried out by reaction with acetic, butyric and benzylic anhydrides using pyridine as solvent. The products of the reactions were purified by column chromatography. Compounds identification was performed by GC-MS and by 1H and 13C NMR. In vitro mycelial growth inhibition and germination inhibition tests were made using three M. fructicolaisolates (RB-57, C-43 and C-3) from LEMID - UFPR collection, to the all 8 compounds, in the concentration of 1000, 600 and 200 mg L-1. Another test in water were carried out using the isolate RB-57 in the concentrations of 1000 mg L-1 and 600 mg L-1to observe the action of eugenol and eugenyl acetate on conidia germination. After 24 h and 5-day incubation periods, one drop (20 μL) of the mixture were evaluated by light microscopy, and it was possible to observe the effect of the eugenyl acetate in the conidia, leading to an asymmetric distribution of the cell content until the destruction of the cell wall. The activity study of the esters derivatives demonstrate that the acetate function improved the results when compared with the phenolic compounds. In micelial growth inhibition, eugenyl acetate and eugenol showed 100% of inhibition in the concentrations of 1000 and 600 mg L-1, whereas isoeugenyl acetate and isoeugenol showed an inhibition of 77% and 49% in the concentration of 1000 mg L-1. Benzoate and butyric esters did not show good results to control this pathogen. Refs. 1.Oliveira L.L. et al., J. Agric. Food Chem., 64, 20, 2016.

 2.Lazar-Baker, E. E. et al. Lett. Appl. Microbiol, 52, 3, 2011.

3.May-De Mio, L. L. et al. Plant Disease, 95, 7, 2011.