Chemical profiling and synergistic antifungal activity of essential oils from Moroccan aromatic plants against peanut-associated fungi

Abstract

As part of the valorization of Aromatic and Medicinal Plants (AMP) in Morocco, we evaluated the chemical composition and the antifungal activity of Four Essential Oils (Eos) from Northern Morocco, including: Origanum compactum, Mentha pulegium, Lavandula officinalis and Myrtus communis. After extraction of the Eos by hydro-distillation process, the study of their chemical composition was carried out by GC/MS (gas chromatography- mass spectrometry). Additionally, the evaluation of individual and combined antifungal activity was assessed against Aspergilus flavus (A.flavus) and other fungi species isolated from peanuts, including Aspergillus niger, Penicillium sp, Rhizopus sp, Fusarium sp and Alternaria sp. The yields after extraction by hydro-distillation were 2,7 %, 3.2 %, 2.65 % and 0.6 % for Origanum compactum, Mentha pulegium, Lavandula officinalis and Myrtus communis respectively. The binary combinations demonstrated strong antifungal activity across a broad spectrum of fungi compared to the individual antifungal assay. Additionally, these combinations were effective in inhibiting aflatoxin B₁ (AFB₁) production. This bioactivity is primarily attributed to the interactions among the components of the various Eos, including thymol, carvacrol, linalool, pulegone, and eucalyptol. The current investigation appears to be unique as it combines various Eos and assesses their binary antifungal efficacy against fungi isolated from peanuts, which has not been extensively documented in existing literature.