# Phenolic Compound Composition and Biological Activities of Fractionated Soybean Pod Extract
## 3 Results and Discussion
The presence of caffeic acids derivatives in soybean pods was previously confirmed by [PERSON] et al. [24]. The derivatives of ferulic and \(p\)-coumaryl acid has been described for the first time in soybean pods. The fractionation of the ethanol extract allowed separation of most of the compounds present in the ethanol extract. For this reason, each of the fractions had a different qualitative (Table 1) and quantitative composition, which was confirmed by the spectrophotometric analyses (Table 2). In the present study, 10, 30 and 22 phenolic compounds were found in F1, F2 and F3 fractions, respectively. Hydrophilic compounds dominated in the F1 fraction, which is characteristic for this type of extraction as it is effective in removing sugars and organic acids. The F2 fraction contained mainly isoflaves, however their acetyl derivatives were found in the F3 fraction where the presence of apigenin and its derivatives has also been confirmed. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline
**Time Retention** & **Tentative Identification** & **Published Classes** & **Molecular Forms** & **Mow Powers** & **Toretical** & **Error (ppm)** & **m/z** & **E** & **F1** & **F2** & **F3** \\ \hline
0.288 & 3-derivative acid & Phenolic acid & C\({}_{\rm C}\)H\({}_{\rm O}\)H\({}_{\rm O}\)O\({}_{\rm 3}\) & 368.1111 & 368.1107 & 1.09 & 369.1817 & + & + & - & - \\ \hline
0.393 & Dihydrocentric acid 3-O-glucuron & Phenolic acid & C\({}_{\rm C}\)H\({}_{\rm O}\)O\({}_{\rm 3}\) & 358.0099 & 358.089 & 2.64 & 359.1001 & + & + & - & - \\ \hline
0.538 & \(p\)-hydroxybenzoic acid & Phenolic acid  
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline
The initial ethanol extract contained all identified phenolic compounds; among the fractions with variable lipophilicity, the F2 fraction was the most abundant in these compounds. This was directly reflected in the quantitative analysis, as a result of which the highest total content of phenolic compounds was found in extract (E) and in the F2 fraction (24.649 and 14.510 mg GAE/g, respectively). The water fraction (F1) contained the lowest amount of phenolic compounds, which was confirmed in qualitative (LC-QTOF-MS) analyses (Table 1). The present results are consistent with those obtained by [PERSON] et al. [33], who also noted the lowest content of phenolic compounds in the aqueous fraction obtained from soybean seed extract. The ethanol extracts from the soybean pods and their fractions both constitute a multi-component composition of active compounds. The variable concentrations and interactions of these compounds determine their biological activity, measured by antioxidant and cytotoxicity activity (Table 2). All analyzed fractions and their produced extracts exhibited an ability to neutralize DPPH\({}^{\bullet}\) and ABTS\({}^{\star\bullet}\), depending on the concentration (Table 2). The F2 fraction with the highest content of phenolic compounds exhibited the most pronounced antiradical activity determined for DPPH\({}^{\bullet}\) and ABTS\({}^{\star\bullet}\) (IC\({}_{50}\) 320.2 and 154.7 \(\mathrm{\SIUnitSymbolMicro m}\), respectively). The value of the Pearson correlation coefficient (r = \(-\)0.99 for the method with DPPH\({}^{\bullet}\) and ABTS\({}^{\star\bullet}\); Table 3) suggests a strong correlation between the content of phenolic compounds and the antioxidant activity expressed as the IC\({}_{50}\) value. These results are in agreement with the available literature [31; 33; 34]. One of the main current directions in pharmacology and oncology is the search for new anticancer drugs that do not damage normal cells as much as the widely used chemotherapy drugs, or not at all. Therefore, the research on natural compounds that can be used as an adjunct in the treatment of certain cancers is of great importance. The results presented below constitute the first stage of this type of analysis.