Essential oil components and antioxidant activities of some thyme taxa in Yozgat Flora.

In this study, essential oil components and antioxidant activities of some thyme taxa in Yozgat flora were investigated. A total of seven different thyme taxa were collected and identified during the flowering period. One of the taxa is in the genus Origanum L. (O. vulgare subsp. gracile (K.Koch) letsw)), three are in the genus Satureja L.( S. cuneifolia Ten., S. hortensis S. wiedemanniana (Avé-Lall.) Velen) and three are in the genus Thymus L. (T. leucotrichus Hal., T. longicaulis C.pres L., subsp. longicaulis T. sipyleus Boiss). The hydrodistilled essential oils from dried plants were analyzed by GC-MS. The essential oil yields ranged from 0,12 (T. leucotrichus) to 1,55% (S. hortensis). The major components in essential oils of seven taxa were identified as caryophyllene (14.78%) and germacrene-D (14.74%) for O. vulgare, carvacrol (15.36%) for S. cuneifolia, thymol (37.94%) and γ-terpinene (21.34%) for S. hortensis, β-terpinyl acetate (12.47%) and (-)-spatulenol (10.01%) for S. wiedemanniana, caryophyllene (23.28%) and carvacrol (16.12%) for T. leucotrichus, 1.8-cineole (10.36%) for T. longicaulis, 1.8-cineole (13.80%), trans-caryophyllene (11.73%) and camphor (11.51%) for T. sipyleus. Carvacrol and thymol compounds representing thyme species were detected together in S. cuneifolia, S.hortensis, T.leucotrichus and T. longicaulis, while only carvacrol was detected in O. vulgare and S. wiedemanniana. These compounds were not recorded in T. sipyleus. The ability of the tested essential oils to scavenge DPPH radicals varied between 36.9-88.9%. Among the standards, ascorbic acid was the highest with 89.2%, while thymol was the lowest with 6.0%. The essential oils of all thyme taxa showed higher activity than thymol and butylhydroxytoluene (BHT) (24.2%). S. hortensis and S. cuneifolia taxa showed higher antioxidant activity than carvacrol (84.5%) standard, but lower activity than ascorbic acid. S. hortensis, S. cuneifolia and T. longicaulis taxa showed stronger activity than trolox standard. The most promising taxa for use in the pharmaceutical and food industries may be S. hortensis, S. cuneifolia and T. longicaulis.