*2.2. Chemical Composition of Mentha EOs*

Selected GC–MS analysis chromatograms of the two studied EOs are shown in Figures 2 and 3. The component relative concentrations (calculated as GC peak area percentages and retention index) are shown in Tables 1 and 2. GC–MS results identified that the principal bioactive components belonged to different chemical groups. The major constituents in *M. spicata* EO included thymol (28.19%), adipic acid (25.82%), piperitone (24.76%), and menthol (24.18%), whereas, the major constituents in *M. longifolia* EO included menthol (51.4%), menthyl acetate (20.5%), and d-limonene (11.15%).

**Figure 2.** GC–MS chromatogram of *M. spicata* EO. Where (\*) is the Total Ion Current.

**Figure 3.** GC–MS chromatogram of *M. longifolia* EO. Where (\*) is the Total Ion Current.



MS: Mass spectrometry (GC–MS).

