## 3 Results and Discussion
### NMR and HPLC-MS\({}^{n}\) Analysis of Secondary Metabolites
\begin{table}
\begin{tabular}{l l l l l l} \hline
**N.** & **R.T. (min)** & _m/z \({}^{*}\) & **MS2 Fragments (m/z)** & **Tentative Identification** & **Class \({}^{**}\)** & **mg/g DW** \\ \hline
1 & 2.56 & 539 & 503 341 281 251 221 179 & Caffeoyl dihexoside & PA & 0.35 \(\pm\) 0.03 \\
2 & 2.65 & 193 & 179 149 & Ferulic acid & PA & 0.07 \(\pm\) 0.00 \\
3 & 9.33 & 301 & 179 151 & Quercetin & FV & 0.04 \(\pm\) 0.00 \\
4 & 10.85 & 341 & 179 161 135 & Caffeoyl hexoside & PA & 0.05 \(\pm\) 0.00 \\
5 & 11.88 & 353 & 191 173 127 & Chlorogenic acid & PA & 0.29 \(\pm\) 0.01 \\
6 & 13.00 & 533 & 371 209 191 & Clacaffeoylhexaric acid & PA & 0.12 \(\pm\) 0.00 \\
7 & 13.50 & 533 & 371 209 191 & Dicaffeoylhexaric acid isomer 1 & PA & 0.11 \(\pm\) 0.00 \\
8 & 13.89 & 479 & 317 299 271 & Myricetin hexoside & FV & 0.09 \(\pm\) 0.01 \\
9 & 13.96 & 367 & 191 173 & Feruloylquinic acid & PA & 0.07 \(\pm\) 0.00 \\
10 & 14.40 & 533 & 371 209 191 & Dicaffeoylhexaric acid isomer 2 & PA & 0.16 \(\pm\) 0.01 \\
11 & 14.46 & 639 & 331 & Patuletin-rhamnopyrananoyl-galactopyranoside & FV & 0.09 \(\pm\) 0.01 \\
12 & 14.65 & 533 & 371 209 191 & Dicaffeoylhexaric acid isomer 3 & PA & 0.08 \(\pm\) 0.00 \\
13 & 14.78 & 609 & 301 & Rutin & FV & 0.22 \(\pm\) 0.02 \\
14 & 15.05 & 533 & 371 209 191 & Dicaffeoylhexaric acid isomer 4 & PA & 0.12 \(\pm\) 0.00 \\
15 & 15.18 & 493 & 331 & Patuletin galactoside & FV & 0.15 \(\pm\) 0.00 \\
16 & 15.38 & 503 & 341 323 221 179 161 & Caffeoyl diglucoside & PA & 0.24 \(\pm\) 0.02 \\
17 & 15.95 & 515 & 353 191 173 & 3,5-Dicaffeoylquinic acid & PA & 1.04 \(\pm\) 0.04 \\
18 & 16.36 & 491 & 329 315 300 & Tricin 7-glucose & FV & 0.26 \(\pm\) 0.01 \\
19 & 16.92 & 695 & 533 371 209 & Tricafeoylhexaric acid & PA & 1.76 \(\pm\) 0.10 \\
20 & 18.66 & 857 & 695 533 371 209 & Tetracaffeoylhexaric acid & PA & 1.41 \(\pm\) 0.66 \\
21 & 19.66 & 285 & 270 255 & Kaempfer & FV & 0.13 \(\pm\) 0.00 \\
22 & 21.56 & 269 & 151 117 107 & Apigenin & FV & 0.18 \(\pm\) 0.00 \\
23 & 22.60 & 329 & 314 329 299 & Tricin & FV & 0.24 \(\pm\) 0.01 \\ \hline  & & & & Total identified & & 7.26 \(\pm\) 0.66 \\  & & & & Phenolic acids & & 5.83 \(\pm\) 0.65 \\  & & & & Flavonoids & & 1.42 \(\pm\) 0.01 \\ \hline \end{tabular} \({}^{*}\)_m/z_ values of [M-H]\({}^{*}\) ions are reported, except for metabolite 1, which was identified as [M-H+HCl]\({}^{-}\) adduct. \({}^{**}\) PA: phenolic acid; FV: flavonoid.  
\end{table} 
Table 3: Results from the HPLC-MS\({}^{\text{n}}\) characterization of secondary metabolites extracted from the aerial parts of _P. spinosa_. Results are reported as means \(\pm\) standard deviation (n = 3). The number associated with each metabolite refers to the corresponding peak in the chromatogram shown in Figure 7. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Class** & **Chemical Constituent** & **Bioactivities** & **References** \\ \hline \multirow{4}{*}{**Phenolic acids**} & Ferulic acid & Anti-hyperlipidemic, antioxidant, and anti-inflammatory & [26] \\  & & effects in vivo & \\  & Chlorogenic acid & Anti-inflammatory, antioxidant, antibacterial, protection of & \\  & & liver and kidney in vivo & [27] \\  & 3,5-Dicaffeoylquinic acid & Anti-inflammatory and memory enhancer in vivo & [28; 29] \\ \hline \multirow{4}{*}{**Flavonoids**} & Apigenin & Antitumor, antioxidant, decreases levels of blood glucose, & \\  & & improves cognitive performance in vivo & [30] \\  & Quercetin & Antioxidant, antimicrobial, anti-inflammatory, antitumor & [31] \\  & & effects in vivo & \\  & Kaempfer & Antimicrobial and beneficial cardiovascular properties & [32] \\  & Tricin & Antitumor properties & [33] \\  & Rutin & Anticancer properties & [34] \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Main bioactivities of polyphenols detected in the methanol crude extract of _P. spinosa_. Information is taken from the literature, and the references for each compound are reported in the Table. Figure 7: Exemplificative chromatogram obtained from the HPLC-MS analysis of the _P. spinosa_ methyl extract.