## 2 Results and Discussion
### Chemical Composition of \(O\). _mutabilis Extracts_  
The chemical composition of the extracts obtained from the SWE of \(O\). _mutabilis_ were determined using headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC/MS.) This method has become one of the basic methods for determining volatile compounds' quality [45]. The most abundant components in the above-ground part of \(O\). _mutabilis_ were hydrocarbons, aldehydes, ketones, and alcohols. Our findings are in good agreement with the published literature [46]. A higher number of compounds, especially phenolics, were identified in the extracts obtained from SWE of the above-ground part. These phenolic compounds included guaiaicol (6.78%), 2,6-dimethyl-phenol (1.05%), 2-ethyl-phenol (2.05%), 2,3-dimethyl-phenol (0.89%), 4-ethyl-2-methoxy-phenol (2.33%), 3,5-bis(1,1-dimethylethyl)-phenol, (0.71%), (E)-2-methoxy-5-(1-propenyl)-phenol (0.7%), 2-methyl-phenol (3.59%), and 2,4-dimethoxyphenol (1.04%). 3-methyl-butanal (2.11%), 2-Heptanol (2.78%), and 2,4-dimethyl-3-pentanol, (3.38%) were other major compounds. The amount of volatile phenolic components formed in extracts differed between the two different parts of the plant. The guaiaicol content was higher (11.78%) in the roots than the aboveground part, highlighting the higher lignin content of the roots. Guaiaicol, which has the highest relative abundance among the volatile compounds, exhibits proven pharmacological effects such as high antioxidant and antiinflammatory activity [47; 48]. Some pyrazine compounds were also determined such as methyl-pyrazine (1.19%), 2-ethyl-5-methyl-pyrazine (0.7%), and trimethyl-pyrazine (0.8%). Pyrazine and its derivatives, which are widely distributed in nature, have great importance in medicinal chemistry. Studies have highlighted the role of pyrazine nuclei in binding to macromolecular receptors, forming complexes with significant antinycobacterial activity [49]. The most abundant classes of volatile components occurring in the roots were alkanes (35.68%), alcohols (27.54%), and organic acids (13.04%). The extraction of more alkanes and organic acids was observed in the root part compared to the aboveground part. The production of organic acids from the roots is a natural process for most plants and is used for enhancing phosphorus acquisition, aluminum tolerance, and utilizing beneficial rhizobacteria [50]. The concentration of monoterenes was low in both samples. Pulegone was found in subcritical water extracts, 1.35 and 0.95% in the aboveground part and roots, respectively. Pulegonein, a monoterpene ketone derivative, has been reported to have antibacterial, antioxidant, and antiinflammatory properties [51]. Similar to the aboveground part, SWE of the roots yielded extracts rich in phenolics (28.96%). For comparison, the volatile phenolic content of the extracts obtained by conventional maceration was investigated. The volatile components of the maceration extracts were different to the subcritical water extracts. Alcohols (54.02%), esters (5.01%), and organic acids (3.29%) were the three main organic classes of compounds in the maceration of \(O\). _mutabilis_' \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**Aboveground Part**} & \multicolumn{2}{c}{**Roots**} \\ \cline{2-5}  & **Predicted** & **Experimental** & **Predicted** & **Experimental** \\ \hline Extraction yield (\%) & 72.78 & 71.61 \(\pm\) 0.66 & 67.08 & 64.48 \(\pm\) 0.78 \\ \hline TPC mg GAE/g & 193.9 & 193.63 \(\pm\) 0.40 & 173.96 & 173.13 \(\pm\) 0.91 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Validation of the proposed models describing the extraction yield and TPC for the aboveground part and roots, based on triplicate extractions. aboveground part. The maceration extracts of the roots yielded a reduced content of alcohols (22.76%), whereas the content of esters (12.11%) and organic acids (10.90%) was increased compared to the aboveground part.