# Phytochemical Analysis of _Symphytum officinal_ Root Culture Extract
## 4 Discussion  
This work established the presence of (5Z,9Z,12Z)-octadecatrienoic acid in the studied ethanol extract samples of _Symphytum officinal_ callus cultures. Pinolenic acid was first detected in conifers of the pine family (_Pinaceae_), its greater amount in seed lipids. In recent studies carried out in vitro, in animal models, and in humans, pinolenic acid exhibits anti-inflammatory and immunomodulatory activity, and is a potent dual agonist of free fatty acid receptors in vitro [18]. In addition, a significant amount of squalene was found in the comfrey sample. The detection of this biologically active component with pronounced antioxidant properties, in our opinion, is quite natural, considering the fact that comfrey produces significant amounts of triterpenenopus and other plant-steroid-like substances [12; 14], which are synthesized from squalene [19]. A non-reducing sugar, xylitol, was found in the distillate. This carbohydrate is quite often a structural component of the glycosyl fragment of cardiotonic glycosides--cardenolides [20]. The presence of deoxysugar was confirmed by a positive Keller-Kiliani reaction with the formation of a cornflower blue ring. Moreover, a unique polymer has been identified--a derivative of caffe acid, which is a new class of natural polyether with 3-(3,4-dihydroxyphenyl) glyceric acid as a repeating unit. Two types of this polymer were identified depending on the samples. The extracted polymer samples were characterized by individual structural features. According to Fourier-transform infrared spectroscopy (FTIR) data, two types of polymer were isolated from the studied samples, differing according to the FTIR data (Appendix A). Type I \begin{table}
\begin{tabular}{c c} \hline \hline
**Sample** & **Antioxidant Activity**, **mg AA/g** \\ \hline I & 113.6 \(\pm\) 6.56 \\ II & 112.8 \(\pm\) 6.54 \\ \hline \hline \end{tabular}  
I-extract samples of _Symphytum officinal_, containing type I polymer; IL-extract samples of _Symphytum officinal_, containing type II polymer. Data presented as a mean \(\pm\) SD (\(n=3\)). Values in columns followed by the same letter do not differ significantly (\(p>0.05\)).  
\end{table} 
Table 5: The results of determining the antioxidant activity of the _Symphytum officinal_ extract samples. polymers are characterized by the presence of absorption bands: (KBr, v, cm\({}^{-1}\)): 3390-3410 (OH); 2928 (CH); 1740 C=O; 1617 (COO-); 1509, 1443 (C=C \({}_{\rm B}\) Ar); 1377, 1215 (ArOH); 1269, 1122, 1074, 1023 (R-O-R'); 867 (C-H in an aromatic ring with one isolated H atom); and 816 (C-H in an aromatic ring with neighboring H atoms). Type II polymers are characterized by the presence of absorption bands: (KBr, v, cm\({}^{-1}\)): 3417 (OH); 2922 (CH); 1707; 1632; 1509, 1455; 1404, 1263 (ArOH); 1263, 1221, 1095, 1017 (R-O-R'); 864 (C-H in an aromatic ring with one isolated H atom); and weak 816 (C-H in an aromatic ring with neighboring H atoms). According to preliminary data, the molecular weight of the isolated polymer was \(>\)1000 Da. The quantitative yield of the polymer depended on the characteristics of the extraction process (Table 1). Some extract samples contained a minimum amount of polymer (no more than 0.01 mg/mL). Phenolcarboxylic acids were found in all studied samples. In samples containing type I polymer, m-methoxybenzoic acid and m-hydroxybenzoic acid were found in amounts of 14.07 and 16.15 mg, which is 1.3-1.6 times higher than for extract samples obtained in other technological modes. Samples of extract containing type II polymer showed 3,4-dimethoxybenzoic acid (Figure 2) and a quantitatively higher content of rosmarinic acid by 1.6 times. Samples with a high polymer content showed a relatively lower content of low molecular weight phenol carboxylic acids. It was found that the quantitative (qualitative) content of phenylpropanoic acids was inversely proportional to the content of the polymer. There is data on the identification of such polymers from water-ethanol extract samples of the roots of native comfrey plants.