In vitro and QSAR evaluation of the antifungal activity of terpenoids that constitute essential oils against Alternaria alternata and Fusarium oxysporum

Introduction. Fungal genera Alternaria and Fusarium include human and plant pathogenic species. Several antifungals have been used for its control, but its excessive use has contributed to the development of resistant pathogens. An alternative for searching for and developing new antifungal agents is using essential oils and their main components, which have biological activities of interest in medicine and food production. Objective. Evaluate in vitro and in silico the antifungal activities of terpenoids against A. alternata and F. oxysporum. Materials and methods. Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) of 27 constituent of essential oils against A. alternata and F. oxysporum were evaluated in vitro. In addition, using genetic algorithms, quantitative models of the structure-activity relationship were used to identify the structural and physicochemical properties related to the antifungal activity. Results. The evaluated compounds proved effective antifungals, with thymol being the most active, with a MIC value of 91.6 +/- 28.8 mu g/mL for both A. alternata and F. oxysporum. QSAR models include the octanol-water cleavage ratio as the molecular property and the phenolic group as the main functional group contributing to antifungal activity. Conclusion. Terpenoids have relevant antifungal activities to be incorporated into the study of medicinal chemistry. Incorporating in silico assays to in vitro evaluation is a valuable tool for searching, andrational design of terpene derivatives as new potential antifungal agents.