# Phenolic and Volatile Composition of a Dry Spearmint (_Mentha spicata_ L.) Extract
## Results and Discussion  
### Characterization of the Phenolic Profile  
The phenolic fraction of spearmint was fully characterised by means of UHPLC-ESI-MS operating in two complementary conditions. The comprehensive evaluation of the sample allowed for the tentative identification of a total of 66 compounds (Table 1), the widest phenolic characterisation of spearmint to date. More than 200 mass spectrum outputs were analysed for each analytical replicate and experimental condition. Among the classes of identified (poly)phenolic compounds in spearmint, rosmarinic acid derivatives and salvianic acids were the most prevalent (Figure 1). Different flavones, flavanones, flavonoids, phenolic acids, and lignans were also detected. In addition, other phytochemicals, such as organic acids were found. The retention times and mass spectrum data, reported as peak assignments for the identified phytochemicals, are included in Table 1. Twelve of the 66 identified compounds were identified and quantified by comparison with reference standards. The remaining 54 compounds were tentatively identified based on the interpretation of their mass spectral behaviour obtained from MS\({}^{2}\) and MS\({}^{3}\) experiments, and by comparing with data from the literature. Figure 1: Main spearmint phenolics identified in the extract. Peak numbers are based on Table 1.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**ID** & **Compounds** & \begin{tabular}{c} **RT** \\ **(min)** \\ \end{tabular}  & \ \begin{tabular}{c} \(\mathbf{[M-H]^{-}}\) \\ **(m/z)** \\ \end{tabular}  & \begin{tabular}{c} **MS\({}^{2}\) Ion Fragments (\(wt/\alpha\)) * \\ \end{tabular}  & **MS\({}^{2}\) Ion Fragments (\(wt/\alpha\)) * & **Exp. 1 * ** & **Exp. 2 * ** & **Identification * ** \\ \hline
1 & Quinite acid & 0.57 & **191** & **173**\({}^{\text{b}}\), 111, 227, 85, 93 & 111, 67 & x & x & Std \\
2 & t-malite acid & 0.67 & **133** & **115, 87** & & & x & [12] \\
3 & Citride acid & 0.77 & **191** & **111, 73** & 111, 67 & x & x & [13] \\
4 & Dihydrocopy/Inlict acid (Dunsbers) & 2.61 & **197** & **179, 73, 153 & 135 & x & & [14] \\
5 & Protocateutut acid headside & 2.75 & **315** & **153, 109, 225** & 109 & x & & [15] \\
6 & Dihydrocopy/Inlict acid & 3.35 & **167** & **123** & & x & [16] \\
7 & Hydroxyrazole acid & 4.12 & **137** & **137** & 93 & & x & [17] \\
8 & Caffe acid & 4.40 & **311** & **149, 179, 243, 135 & 103, 87, 131, 59, 149 & x & Std \\
9 & Hydroxy hemolytic acid & 4.47 & **181** & **163, 153, 73** & 119 & x & x & [18] \\
10 & Lutcolin 8-C-glucose (orientation) & 4.83 & **447** & **357, 327** & & & Std \\
11 & 3”C-Gidevelopin (neoplastic acid) & 4.96 & **353** & **191, 179, 135, 172 & 173, 85, 93 & x & Std \\
12 & THDCHMA * & 5.42 & **295** & **163, 113** & 118 & x & [19] \\
13 & Rosmund & 5.44 & **345** & **299** & 179, 119, 143, 113, 161 & x & [20] \\
14 & Communite acid & 5.52 & **163** & **119** & x & & [17] \\
15 & Salivalonic acid F & 5.56 & **313** & **269, 203, 159** & 199, 109, 254, 269 & x & [14] \\
16 & Dicentific acid & 5.74 & **341** & **281, 251, 179, 232, 137 & 179, 221, 135 & x & x & [21] \\
17 & 5”C-Gidevelopin (chlorog acid) & 6.17 & **353** & **191, 179** & 127, 173, 85, 83 & x & Std \\
18 & Caffe acid & 6.25 & **179** & **135** & 135 & x & x & Std \\
19 & Ferulic acid derivative & 6.88 &