Chemical characterization, antifungal, and anticorrosive properties of essential oils from Origanum compactum, Eucalyptus camaldulensis, and Cedrus atlantica from Morocco

Essential oils were analysed to determine profiles and related data by GC/MS. Carvacrol (72.97%), p-Cymene (35.11) and β-Himachalene (54.21%) presented the highest content of compounds for Origanum comapctum, Eucalyptus camaldulensis and Cedrus atlantica oils respectiveley. The 1.8 cineole compound was only present in E. camaldulansis oil. The results showed an interesting activity of EOs against the majority of the fungal strains tested, even at low doses. The essential oil of oregano offered the greatest inhibition of mycelial growth. Regarding the anticorrosive effect of EOs, polarisation curves displayed the effectiveness of EOs from the three plants as mixed-type inhibitors. Their inhibition efficiency (%IE) increases to 99%, 91%, and 92% at the concentration of 2 g/L at 298°K, respectively for O. compactum, E. camaldulensis, and C. atlantica. The resulting inhibition is due to the formation of a protective film on the metal surface against corrosion. Quantum chemical computations were used to determine the adsorption capability.