Total characterization of some commonly growing forest plants (Alkanna tinctoria (L.) Tausch subsp. tinctoria, Thymus longicaulis C. Presl subsp. longicaulis var. longicaulis ve Phlomis bourgaei Boiss.) based on chemical contents

This study was outlined to examine the chemical composition of hydrodistilled essential oil and in vitro antioxidant potentials of the essential oil and different solvent extracts of Thymus longicaulis C. Presl subsp. longicaulis var. longicaulis, Alkanna tinctoria (L.) Tausch subsp. tinctoria and Turkish endemic Phlomis bourgae. Boiss. For extraction, four different solvents (hexane, ethyl acetate, methanol and water) were used to fractionate the soluble compounds from the plants in ascending polarity.The chemical composition of the oils was analyzed by GC and GC-MS and the predominant components in the oils were found to be ? -terpinene (27.80%), thymol (27.65%) and p-cymene (19.38%) for T. longicaulis C. Presl subsp. longicaulis var. longicaulis, pulegone (22.27%), 1,8-cineole (13.03%), ? -terpinyl acetate (6.87%) and isophytol (6.83%) for A. tinctoria (L.) Tausch subsp. tinctoria and ß-caryophyllene (37.37%), (Z)-ß-farnesene (15.88%) and germacrene D (10.97%) for P. bourgaei. Antioxidant activities of the samples were determined by four different test systems namely ? -carotene/linoleic acid, DPPH, reducing power and chelating effect. As well as the antioxidant activities of the extracts, they were evaluated in terms of their total phenolic and flavonoid contents.