## 3 Results and Discussion
### Antioxidant Activity of S. repens
repens_ leaves SPE-2 fraction is a blue chromatogram with active compounds numbered as **13—**schaftooside-2′′-O-glucose (sileneside E); **14—**schaftooside; **15—**isovitexin-2′′-O-glucose (meloside A); **16—**isovitexin; **17—**swertisin-2′′-O-glucose; **18—**swertisin. The value of IC\({}_{50}\) for the separate compounds displayed with the number of corresponding compounds. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Group**} & \multirow{2}{*}{**Concentration,**} & \multicolumn{3}{c}{**DPPH**-, **mg/g a \(\pm\) SD**} \\ \cline{3-6}  & & & **SPE-1** & & **SPE-2** \\ \cline{3-6}  & & **Leaves** & **Roots** & **Leaves** & **Roots** \\ \hline Control 1 (water, spraying) & - & \textless{}1 & \textless{}1 & \(46.52\pm 1.41\) & \textless{}1 \\ \hline Control 2 (watering) & - & \textless{}1 & \textless{}1 & \(45.33\pm 1.09\) & \textless{}1 \\ \hline \multirow{3}{*}{Epibrassinolide} & 1 & \textless{}1 & \textless{}1 & \(42.11\pm 1.43\) \({}^{\dagger}\) & \textless{}1 \\  & 10 & \textless{}1 & \textless{}1 & \(53.02\pm 1.48\) \({}^{\dagger}\) & \textless{}1 \\  & 100 & \textless{}1 & \textless{}1 & \(52.40\pm 1.57\) \({}^{\dagger}\) & \textless{}1 \\ \hline \multirow{3}{*}{Indole-3-butyric acid} & 1 & \textless{}1 & \textless{}1 & \(39.32\pm 1.09\) \({}^{\dagger}\) & \textless{}1 \\  & 10 & \textless{}1 & \textless{}1 & \(45.27\pm 1.03\) & \textless{}1 \\  & 100 & \textless{}1 & \textless{}1 & \(46.00\pm 1.29\) & \textless{}1 \\ \hline \multirow{3}{*}{4-Chlorophenylacetic acid} & 1 & \textless{}1 & \textless{}1 & \(45.14\pm 0.85\) \({}^{\dagger}\) & \textless{}1 \\  & 100 & \textless{}1 & \textless{}1 & \(60.92\pm 1.40\) \({}^{\dagger}\) & \textless{}1 \\  & 100 & \textless{}1 & \textless{}1 & \(78.20\pm 2.34\) \({}^{\dagger}\) & \textless{}1 \\ \hline \multirow{3}{*}{Gibberellic acids potassium salt} & 1 & \textless{}1 & \textless{}1 & \(40.06\pm 1.02\) \({}^{\dagger}\) & \textless{}1 \\  & 10 & \textless{}1 & \textless{}1 & \(36.71\pm 0.86\) \({}^{\dagger}\) & \textless{}1 \\  & 100 & \textless{}1 & \textless{}1 & \(33.75\pm 1.01\) \({}^{\dagger}\) & \textless{}1 \\ \hline \multirow{3}{*}{Arachidonic acid} & 1 & \textless{}1 & \textless{}1 & \(38.63\pm 1.19\) \({}^{\dagger}\) & \textless{}1 \\  & 100 & \textless{}1 & \textless{}1 & \(55.23\pm 1.76\) \({}^{\dagger}\) & \textless{}1 \\  & 100 & \textless{}1 & \textless{}1 & \(54.39\pm 1.57\) \({}^{\dagger}\) & \textless{}1 \\ \hline \multirow{3}{*}{Ethyl arachidate} & 1 & \textless{}1 & \textless{}1 & \(38.67\pm 1.00\) \({}^{\dagger}\) & \textless{}1 \\  & 100 & \textless{}1 & \textless{}1 & \(45.56\pm 1.23\) \({}^{\dagger}\) & \textless{}1 \\ \cline{1-1}  & 100 & \textless{}1 & \textless{}1 & \(44.14\pm 0.88\)\({}^{\dagger}\) & \textless{}1 \\ \hline \hline \end{tabular}  
* as Trolox equivalent. \({}^{\dagger}\) Values indicate statistically significant differences compared with the data of control groups at \(p<0.05\) by one-way ANOVA.  
\end{table} 
Table 3: DPPH: free radical inhibiting activity of _S. repens_ SPE fractions. data on inhibiting the DPPH: radical were compared with the HPLC-PDA profile of the _S. repens_ leaves SPE-2 fraction. According to the results obtained, the most active fraction (6.15-6.30 min) was characterized by domination of schaftooside. Sileneside E was presented in the fraction with less activity (5.45-6.00 min). Meloside A and its aglycone isovitexin provided the activity of fractions from 6.45 to 7.15 min. The less active fractions 7.15-7.45 were characterized by the presence of swertisin-2\({}^{\prime\prime}\)-O-glucose and swertisin. The values IC\({}_{50}\) were obtained to evaluate antioxidant activity of individual compounds **13-18** against the DPPH: radical. As a result, isovitexin was the most active compound (IC\({}_{50}\) 142 mM), while swertisin-2\({}^{\prime\prime}\)-O-glucose was less active (IC\({}_{50}\) 312 mM). Schaftoside and meloside A possessed moderate antioxidant activity (IC\({}_{50}\) 205 and 209 mM, respectively).