Chemical Diversity and Chemotypic Variation of <i>Mentha spicata</i> Essential Oils from Different Regions of Iran

Abstract Aim This study investigated the chemical diversity of essential oils (EOs) extracted from eight Mentha spicata samples collected across different regions of Iran. Material and Methods Essential oils obtained by hydrodistillation were analyzed using gas chromatography mass spectrometry (GC-MS), and their compositional patterns were examined through principal component analysis (PCA). Results Essential oil yields ranged from 0.3% to 1.6% (v/w), consistent with previously reported values for Iranian mints. Oxygenated monoterpenes were the dominant constituents, with carvone, D-limonene, and 1,8-cineole as major compounds. PCA explained 94.47% of the total variance and revealed clear clustering of samples, indicating significant chemical differentiation among populations. Three chemotypic patterns were identified: (1) a carvone-limonene (spearmint-type) profile found in most samples, (2) a mixed carvone/carvone oxide type, and (3) a 1,8-cineole-rich type. Conclusion The chemical variation observed among Iranian M. spicata populations may result from both genetic diversity and environmental influences on essential oil biosynthesis. These findings expand the understanding of Iranian M. spicata chemotypic diversity and provide a basis for selecting desirable chemotypes for pharmaceutical, aromatic, and flavor applications.