In vitro evaluation of the activity of thiosemicarbazone derivatives against mycotoxigenic fungi affecting cereals

• A panel of thiosemicarbazone derivatives were synthesized.
• The compounds were tested for their effect on crops (cereals) affecting fungi (Fusarium and Aspergillus).
• Species-specific effects on fungal growth and mycotoxin biosynthesis were observed.
• Two molecules were considered promising for fungal growth and mycotoxin containment.
• Potential deleterious effects on seed germination and on human cells were tested.

With a steadily increasing world population, a more efficient system of food production is of paramount importance. One of the major causes of food spoilage is the presence of fungal pathogens and the production and accumulation of mycotoxins. In the present work we report a study on the activity of a series of functionalized thiosemicarbazones (namely cuminaldehyde, trans-cinnamaldehyde, quinoline-2-carboxyaldehyde, 5-fluoroisatin thiosemicarbazone and 5-fluoroisatin N4-methylthiosemicarbazone), as antifungal and anti-mycotoxin agents, against the two major genera of cereal mycotoxigenic fungi, i.e. Fusarium and Aspergillus. These thiosemicarbazones display different patterns of efficacy on fungal growth and on mycotoxin accumulation depending on the fungal species. Some of the molecules display a greater effect on mycotoxin synthesis than on fungal growth.