Thymus pseudopulegioides plantlets were propagated in vitro via direct organogenesis by using Murashige and Skoog (MS) media containing kinetin, thidiazuron, and 6-benzyladenine (BA) individually. | Turkish Journal of Biology Turk J Biol (2017) 41: 754-764 © TÜBİTAK doi: Research Article Accumulation of phenolics in natural and micropropagated plantlets of Thymus pseudopulegioides Klokov & . with their antioxidant potentials 1 2 3 4,5 5,6, Mustafa GÜNAYDIN , Abdul Hafeez LAGHARI , Ersan BEKTAŞ , Münevver SÖKMEN , Atalay SÖKMEN 1 Gümüşhane Vocational School, Gümüşhane University, Gümüşhane, Turkey 2 National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan 3 Espiye Vocational School, Giresun University, Espiye, Giresun, Turkey 4 Department of Bioengineering, Konya Food and Agriculture University, Konya, Turkey 5 Department of Plant Production and Technologies, Konya Food and Agriculture University, Konya, Turkey 6 College of Science, King Saud University, Riyadh, Saudi Arabia Received: Accepted/Published Online: * Final Version: Abstract: Thymus pseudopulegioides plantlets were propagated in vitro via direct organogenesis by using Murashige and Skoog (MS) media containing kinetin, thidiazuron, and 6-benzyladenine (BA) individually. Methanol extracts obtained both from plantlets and wild plants were analyzed for their total phenolics and flavonoid contents, then quantified by HPLC. The highest total phenolic ( mg/g as gallic acid equivalent) and total flavonoid ( mg/mL as rutin equivalent) values were from the MS media supplemented with mg/L kinetin and mg/L BA, respectively. The plantlets grown in those media also showed remarkable antioxidant activities with an IC50 value of µg/mL in DPPH and 100% inhibition in β-carotene assays, respectively. HPLC analysis proved the production of protocatechuic, caffeic, vanillic, rosmarinic, ferulic, and o-coumaric acids and rutin. Rosmarinic acid production was predominant in natural samples ( mg/100 g dry weight), while the aforesaid phenolic acids