α-Terpinyl Acetate: Occurrence in Essential Oils Bearing Thymus pulegioides, Phytotoxicity, and Antimicrobial Effects

The aim of this study was to evaluate occurrence of T. pulegioides α-terpinyl acetate chemotype, as source of natural origin α-terpinyl acetate, to determine its phytotoxic and antimicrobial features. Were investigated 131 T. pulegioides habitats. Essential oils were isolated by hydrodistillation and analyzed by GC-FID and GC-MS. Phytotoxic effect of essential oil of this chemotype on monocotyledons and dicotyledons through water and air was carried out in laboratory conditions; the broth microdilution method was used to screen essential oil effect against human pathogenic microorganisms. Results showed that α-terpinyl acetate was very rare compound in essential oil of T. pulegioides: it was found only in 35% of investigated T. pulegioides habitats. α-Terpinyl acetate (in essential oil and pure) demonstrated different behavior on investigated plants. Phytotoxic effect of α-terpinyl acetate was stronger on investigated monocotyledons than on dicotyledons. α-Terpinyl acetate essential oil inhibited seeds germination and radicles growth for high economic productivity forage grass monocotyledon Poa pratensis, but stimulated seed germination for high economic productive forage legume dicotyledon Trifolium pretense. α-Terpinyl acetate essential oil showed high antimicrobial effect against fungi and dermatophytes but lower effect against bacteria and Candida yeasts. Therefore, T. pulegioides α-terpinyl acetate chemotype could be a potential compound for developing preventive measures or/and drugs for mycosis.