Antifungal efficacy of some natural phenolic compounds against significant pathogenic and toxinogenic filamentous fungi

•The antifungal efficacy of the 21 different phenols on 6 filamentous fungi was investigated.•MIC50 and MIC100 revealed different pathogen interspecies sensitivities.•Thymol and carvacrol showed the highest antifungal efficacy on target pathogens.•Most of the phenolic acids possess little or no antifungal activity.•The antifungal efficacy depends mainly on chemical structures and OH group position. In terms of food safety, species of the Fusarium, Aspergillus and Penicillium genera are considered the most significant because they produce the great majority of known mycotoxins. Developing resistance against commonly used fungicides have become a critical problem in area such as agriculture, the storage and production of food and even in human medicines. The need for research and development of new alternative antifungal treatment based on natural antifungal substances is obvious. Here, the antifungal efficacy of 21 phenolic components of essential oils and plant substances were tested against these filamentous fungi with respect to their different molecular structures. Minimum inhibitory concentration values MIC50 and MIC100 were successfully estimated for 15 substances by means of probit analysis. Thymol and carvacrol were evaluated as the most effective. The MIC50 values for thymol ranged from 30 to 52μgmL−1. The MIC100 values for thymol ranged from 76 to 255μgmL−1, respectively. For carvacrol, the MIC50 values ranged from 37 to 76μgmL−1, and the MIC100 ranged from 131 to 262μgmL−1. The results also revealed differences in the efficacy of phenols depending on molecular structures and different inter-species sensitivity.