## 3 Results  
Major essential oil components of _Satureja hotternsis_ L. raw material were determined using SPME and gas chromatography-mass spectrometry technique. Totally 21 volatile compounds were identified and quantified. Results of this analysis revealed five dominating compounds, which are: \(\beta\)-myrcene, p-cymene, \(\gamma\)-terpinene, carvacrol, and \(\beta\)-caryophyllene. Essential oil quantitative composition and its dependence on the vegetation phase are presented in Figure 1. The major compound in all the vegetation phases was carvacrol. Carvacrol is predominant and its amount accumulates during all vegetation phases from 47% in V1 to 87% in F3. The maximum concentration of \(\gamma\)-terpinene observed during the intensive growth is later considerably decreased (circa 10 times) and is only 6% at the F2 and F3 phases. The results of the spectrophotometric analysis are presented in Figure 2. Total phenolic content did not change significantly during F1-F3 vegetation phases. The ratio between total phenolic content and total flavonoid content remained constant, ca. 1:4. The highest amounts of phenolic compounds (46.01 RE mg/g) and flavonoids (12.81 RE mg/g) were observed in _S. hortensis_ L. raw material extracts at the V2 phase. The highest radical scavenging activity was determined in the samples of V2 phase (47.49 RE mg/g). The obtained results between total phenolic content and radical scavenging activity were statistically dependent on each other. The results from the present study indicate a strong correlation between the radical scavenging activity and the content of total phenolics (\(r^{2}=0.798\)) as well as between radical scavenging activity and total flavonoid content (\(r^{2}=0.894\)). HPLC analysis revealed 5 phenolic compounds dominating in _S. hortensis_ L. extracts. Following phenolic acids were identified in the extracts: _trans_-synpacic acid, _trans_-p-comamic acid, rosmarinic acid as well as flavonoids--rutin and hesperetin (Figure 3). Rutin and rosmarinic acid are the most abundant nonvolatile compounds in _Satureja hortensis_ L. herbal raw material. The results of present research show that the amount of rosmarinic acid varies from 3.79 RE mg/g to 7.79 RE mg/g. The amounts of rutin is ranging from 3.83 RE mg/g to 8.16 RE mg/g in the air-dried raw material. In addition, a steady increase of rutin is observed from early V1 to late F2 vegetation phase. _Trans_-synpacic acid, _trans_-p-comamic acid, and hesperetin were determined at significantly lower quantities. Figure 1: Dynamics of essential oil major components of _Satureja hortensis_ L. during the vegetation determined using gas chromatography—mass spectrometry. Vegetation phases: V1—intensive growth, V2—budding, F1—beginning of flowering, F2—massive flowering, F3—end of flowering. Mean values \(\pm\) SD from three independent experiments are presented. a statistically significant differences versus V1, (\(p\) < 0.05). Plant extracts of summer savory (_S. hortensis_ L.) were analyzed using high-performance liquid chromatography coupled with DPPH radical scavenging detector (Figure 4). Chromatogram shows two signals plotted as mirror image. Upper chromatogram shows separated compounds detected using UV detector and negative chromatogram shows DPPH radical scavenging activity of the separated compounds [34]. Figure 3: Variation of the main phenolic compounds in _Satureja hortensis_ L. herb samples during vegetation phases determined using high-performance liquid chromatography—DPPH. V1—intensive growth, V2—budding, FI—beginning of flowering, F2—massive flowering, F3—end of flowering. Mean values \(\pm\) SD from three independent experiments are presented. \({}^{\mathrm{a}}\) statistically significant differences, (_p_ < 0.05). Figure 2: Variation of total flavonoid and phenolic compounds and radical scavenging activity of methanolic extracts of _S. hortensis_ L. from different vegetation phases, determined using spectrophotometric methods. Mean values \(\pm\) SD from three independent experiments are presented.