Chemotypes in the volatiles of wild thyme (Thymus pulegioides L.)

Two subspecies of Thymus pulegioides L. (subsp. effusus and subsp. similialpestris) were studied. Pentane extracts were analyzed by GC and GC/MS. Twenty-nine compounds were identified. The samples were collected in Massif Central (France) in Monts Dore and Puy de Sancy, altitude 1700 m. The main volatiles of Thymus pulegioides subsp. similialpestris were found to be α-terpinyl acetate (0-76.0%), γ-terpinene (0-24.5%), carvacrol (0-55.3%) and thymol (0-39.3%), thus revealing chemotypic differences. The main hybrid volatiles were α-terpinyl acetate (0-88.0%) and thymol (0-59.6%). In contrast, the main volatiles of Thymus pulegioides subsp. effusus were found to be α-terpineol (4.7-20.2%) and α-terpinyl acetate (65.4-81.4%). Preliminary examination of the data reveals the existence of an α-terpinyl acetate chemotype, carvacrol chemotype and a thymol chemotype of Thymus pulegioides subsp. similialpestris and an α-terpinyl acetate chemotype and a thymol chemotype of the Thymus pulegioides subsp. similialpestris x Thymus pulegioides subsp. effusus hybrid.