Dihydropyrimidinone and coumarin derivatives: synthesis and evaluation against the symbiotic fungus Leucoagaricus gongylophorus

Leaf-cutting ants cause serious damage to a wide variety of plants and are a serious crop pest. They cut plant material and use it as the main substrate for the development of their symbiotic fungus Leucoagaricus gongylophorus.1 Thus, inhibition of this fungus is considered an alternative to control the ants. In this work, we have evaluated the activity of dihydropyrimidinones (DHPMs)2 against the symbiotic fungus. The DHPMs were obtained via Biginelli reaction, performed as described in the literature,3,4 furnishing compounds 5a-i and 6a with yields between 26-82%. The adducts obtained had their fungicidal activity evaluated at 100µg/mL, showing inhibition halos between 6.50-70.00 mm and xanthyletin (7) was used as positive control.5 Among them, it was observed that 6 compounds showed fungicidal potential. In this perspective, new derivatives will be synthesized to contribute with the structure-activity relationship as well as further bioassays will be carry out to determine the IC50 values.