Mentha longifolia and Citrus reticulata Essential Oils: Potential wood-biofungicide and MNDO Quantum Chemical Studies

Abstract Essential oils (EOs) from aerial parts from Mentha longifolia (Saudi cultivar) and Citrus reticulata grown in Egypt, were analyzed by GC/MS to identify their chemical compounds. The EOs were tested for their antifungal activity against four common fungi Aspergillus flavus, A. niger, A. fumigatus, and Fusarium culmorum. The most abundant compounds identified in the EO from M. longifolia were menthone, and eucalyptol with percentages of 48.00%, and 21.66%, respectively. The main chemical compounds from C. reticulata EO were β-caryophyllene, β-caryophyllene oxide, and β-elemene with values of 15.57%, 7.04%, and 6.39%, respectively. At the concentrations of 500 and 250 µL/mL, the EOs from M. longifolia and C. reticulata showed potent antifungal activity against A. flavus and A. fumigatus with 100% fungal mycelial inhibition growth (FMIG). FMIG with values of 98% and 95% were observed against A. fumigatus by C. reticulata and M. longifolia EOs, respectively, at 125 µL/mL. At 500 and 250 µL/mL levels of concentration from the EO of M. longifolia, potent antifungal activity found against A. niger with 100% FMIG. F. culmorum completely inhibited (100% FMIG) as EOs from M. longifolia and C. reticulata applied at 500 µL/mL. Pinus halepensis wood treated with M. longifolia at 125 µL/mL showed inhibition zone values of 7.33 mm, 21.33 mm A. flavus and Aspergillus niger, respectively. The results suggested the potential values of the EOs as potent antifungal activity against some common molds that grows over wood packaging during transportation of vegetables and fruits or can cause food spoilage.