Inhibition of the symbiotic fungus of leaf-cutting ants by coumarins

Marizete F P Godoy,Odair C Bueno,Maurício Bacci Jr,Fernando C Pagnocca,Gisleine Guerreiro,M Fátima G F Da Silva,Sandra R Victor,Adriana M Bellini,Paulo C Vieira,Maria J A Hebling,João B Fernandes,Waldireny C Rocha

doi:10.1590/s0103-50532005000400031

Abstract

Leaf-cutting ants are known to be a serious pest for agriculture due to the high amounts of vegetal matter from crops used by them in order to cultivate a symbiotic fungus on which they rely for food and enzymes. The mutualism between the fungus and the ants is a point to be explored when alternative methods of control are being thought of. Considering that some plants are naturally resistant to phytophagous insects, some natural products (secondary metabolites) should be evaluated with respect to their insecticide and/or fungicide properties. In this paper we isolated eight coumarins from four different plant species and we determined their effect on the development of the symbiotic fungus of the leaf-cutting ant Atta sexdens. With the exception of clausarin, all the other coumarins were inhibitory from 64 µg mL-1 through 80 µg mL-1 and xanthyletin inhibited the fungus at 25 µg mL-1

Highlights

Leaf-cutting ants, the dominant herbivores in the tropics, can be found from the Southern United States to Northern Argentina.[1]
The search for specific compounds directed against these ants and their microbial partners has been the focus of our studies during the past years and natural chemicals isolated from a variety of plant species were effective against the ants and inhibited the growth of their symbiotic fungus or both.[6,7,8,9,10,11,12,13,14,15]
The aim of this study was to analyze the activity of eight coumarins isolated from different plant species on the development of the symbiotic fungus of the leaf-cutting ant Atta sexdens rubropilosa

Summary

Short Report

O mutualismo entre o fungo e as formigas é um ponto a ser explorado quando se considera sua possível aplicação em métodos alternativos para o controle desses insetos. Neste trabalho foram isoladas oito cumarinas de quatro espécies de plantas e o efeito no desenvolvimento do fungo simbionte das formigas cortadeiras Atta sexdens foi determinado. Leaf-cutting ants are known to be a serious pest for agriculture due to the high amounts of vegetal matter from crops used by them in order to cultivate a symbiotic fungus on which they rely for food and enzymes. In this paper we isolated eight coumarins from four different plant species and we determined their effect on the development of the symbiotic fungus of the leaf-cutting ant Atta sexdens. With the exception of clausarin, all the other coumarins were inhibitory from 64 μg mL-1 through 80 μg mL-1 and xanthyletin inhibited the fungus at 25 μg mL-1

Introduction

Preparation and fractioning of crude extracts

Results and Discussion

PBO c