## 2 Results
### NMR Analysis of Dried-Hop Leaves
\begin{table}
\begin{tabular}{c c c c} \hline
**Compound** & **Assignment** & **1H (ppm)** & **Multiplicity [J(Hz)]** & **13C (ppm)** \\ \hline \multirow{8}{*}{Glutamine} & \(\beta\)-CH\({}_{2}\) & 1.91 & q & 24.6 \\  & \(\gamma\)-CH\({}_{2}\) & 3.02 & t (7.6) & 40.3 \\  & COOH & & & 182.5 \\  & \(\alpha\)-CH & 3.75 & & \\  & \(\beta,\beta^{\prime}\)-CH\({}_{2}\) & 2.15 & m & \\  & \(\gamma\)-CH\({}^{2}\) & 2.46 & m & \\ Isoleucine & \(\alpha\)-CH & & 60.7 \\  & \(\beta\)-CH & 1.99 & & 36.9 \\  & \(\gamma\),\(\gamma^{\prime}\)-CH\({}_{2}\) & 1.26, 1.47 & & 25.5 \\  & \(\gamma\)-CH\({}_{3}\) & 1.02 & d (7.1) & \\  & \(\delta\)-CH\({}_{3}\) & 0.95 * & t (7.4) & \\ \multirow{4}{*}{Leucine} & \(\beta\)-CH\({}_{2}\) & & & 40.8 \\  & \(\gamma\)-CH & 1.71 & & 25.2 \\  & \(\delta\)-CH\({}_{3}\) & 0.97 * & d (6.4) & 22.9 \\  & \(\delta^{\prime}\)-CH\({}_{3}\) & 0.96 * & d (6.0) & 22.5 \\ \multirow{2}{*}{Valine} & \(\alpha\)-CH & 3.61 & & 61.3 \\  & \(\beta\)-CH & 2.28 & & 30.1 \\  & \(\gamma\)-CH\({}_{3}\) & 1.00 * & d (7.1) & 17.7 \\  & \(\gamma^{\prime}\)-CH\({}_{3}\) & 1.05 & d (6.9) & 19.0 \\ \multirow{2}{*}{Threonine} & \(\alpha\)-CH & 3.59 & & 61.4 \\  & \(\beta\)-CH & 4.25 & & 66.9 \\ \multirow{2}{*}{Asparagine} & \(\gamma\)-CH\({}_{3}\) & 1.34 * & d (6.5) & 52.3 \\  & \(\beta\),\(\beta^{\prime}\)-CH\({}_{2}\) & 2.87 *; 2.96 & dd (7.8; 17.0); dd (4.3; 17.0) & \\  & COOH & & & 175.2 \\ \multirow{2}{*}{Aspartate} & \(\beta\),\(\beta^{\prime}\)-CH\({}_{2}\) & 2.68; 2.82 * & dd (8.8; 17.6); dd (3.8; 17.6) & \\ Glutamate & \(\alpha\)-CH & 3.75 & & \\  & \(\beta\),\(\beta^{\prime}\)-CH\({}_{2}\) & 2.06; 2.14 * & m & \\  & \(\gamma\)-CH\({}_{2}\) & 2.36 & m & \\  & \(\alpha\)-CH & 4.17 & & \\  & \(\beta\),\(\beta^{\prime}\)-CH\({}_{2}\) & 2.08; 2.35 & m, m & \\  & \(\gamma\)-CH\({}_{2}\) & 2.02 * & m & \\  & \(\delta\),\(\delta^{\prime}\)-CH\({}_{2}\) & 3.43; 3.34 & & \\ \hline \multicolumn{4}{c}{**Miscellaneous**} \\ \hline Choline & +N(CH\({}_{3}\))\({}_{3}\) & 3.21 * & s & 54.9 \\  & \(\alpha\)-CH\({}_{2}\) & & & 68.4 \\ Trigonelline & CH-1 & 9.13 * & s & \\  & CH\({}_{3}\) & 4.44 & s & \\ \hline \end{tabular}
\end{table} 
Table 5: _Cont._The obtained quantitative amount of xanthohumol was 5.28 g/100 g, which represents 0.00528% of the dry weight in the analyzed hop leaves. This was in agreement with what was previously reported [16], where the xanthohumol content in leaves varied with the type of cultivar and, in any case, was lower than its content in hop cones. The obtained quantitative amount of xanthohumol was 5.28 g/100 g, representing 0.00528% of dry weight in the analyzed hop leaves. This was in agreement with what was previously reported [16], where the xanthohumol content of the leaves varied with the type of cultivar, and, in any case, it was lower than its content in the hop cones. \begin{table}
\begin{tabular}{c c c c} \hline
**Compound** & **Assignment** & **1H (ppm)** & **Multiplicity [J(Hz)]** & **13C (ppm)** \\ \hline \multicolumn{4}{c}{**Polyphenols**} \\ \hline Xanthohumol & CH\({}_{2}\)-1\({}^{\prime\prime}\) & 3.21 & \\  & OCH\({}_{3}\) & 3.90 & s & 56.0 \\  & CH-5\({}^{\prime}\) & 6.02 & s & \\  & CH-3,5 & 6.84 & (d, 8.6 Hz) & \\  & CH-2,6 & 7.49 * & (d, 8.6 Hz) & 130.6 \\  & CH-\(\alpha\) & 7.79 & (d, 15.5 Hz) & \\ \hline \end{tabular}
\end{table} 
Table 6: Metabolites identified in the 600.13 MHz \({}^{1}\)H NMR and \({}^{1}\)H-\({}^{13}\)C HSQC spectra of methanolic extracts of hop leaves in methanol-d4 acquired at 25 \({}^{\circ}\)C. Asterisks (*) indicate signals selected for integration. Figure 1: Bar charts of the metabolites identified and quantified (mg/100 g of DW \(\pm\) SD) in the \({}^{1}\)H NMR spectra of hydroalcoholic extracts of hop leaves. (**A**) amino acids, (**B**) sugars, (**C**) organic acids, (**D**) miscellaneous metabolites.