Satureja kitaibelii Wierzb. ex Heuff. or Rtanj tea is an endemic species of the Carpathian
mountain chain on the Balkan Peninsula. It grows in Eastern Serbia, Northwest Bulgaria, and
Southwest Romania. As traditional remedy, it is used for treatment of different stomach
discomforts such as pains in the lower abdomen, upset stomach, diarrhoea and nausea, for the
regulation of the menstrual cycle and fertility, for muscle relaxation, and in the treatment of the
upper respiratory tract infections. Therefore, the aim of this research was to examine the
phytochemical composition and antioxidant activity of S. kitaibelii in form of subcritical water
extract (SWE). HPLC analysis of SWE of S. kitaibelii showed the presence of ten compounds in
a total concentration of 89.33 mg/g of the extract. It was demonstrated that the polarity of
subcritical water was the most selective for extracting syringic acid (37.88 mg/g), caffeic acid
(18.06 mg/g), and epicatechin (10.04 mg/g). Flavonoids like rutin, luteolin, and apigenin were the
least abundant in this extract (<2 mg/g). Additionally, this study investigated in vitro antioxidant
activities of S. kitaibelii SWE by five antioxidant assays. Four assays present radical scavenging
activity while the last assay indicates transitional metal reduction. The highest scavenging
abilities were observed against superoxide anion and ABTS•+ radicals (437.35 and 412.09 μmol
TE/g), followed by lipid radicals (69.61 μmol TE/g), and DPPH• (32.28 μmol TE/g)
