## 3 Results and Discussion
### GC-MS Analysis of Maca Extracts
\begin{table}
\begin{tabular}{c c c c c c} \hline \multirow{2}{*}{**No.**} & \multirow{2}{*}{**Compound**} & \multirow{2}{*}{**RT (min)**} & \multicolumn{2}{c}{**MS Signals *, _m/z_**} & \multicolumn{2}{c}{**Content **[\%]**} \\ \cline{4-6}  & & & **[M*]\({}^{\dagger}\)** & **Characteristic Fragment Ions** & **E** & **W** \\ \hline
6 & Hexadecanoic acid & 23.30 & 256 & 43, 73, 60, 41, 57 & 3.1 & nd \\
7 & linoleic acid & 26.54 & 280 & 67, 81, 82, 95, 55 & 3.8 & nd \\
8 & Hexadecanamide & 27.32 & 255 & 59, 72, 43, 86, 41 & 1.1 & nd \\
9 & (9Z)-Octadecenamide & 30.18 & 281 & 59, 72, 55, 41, 43 & 7.7 & nd \\
10 & Octadecanamide & 30.66 & 283 & 86 & 1.3 & nd \\
11 & \(N\)-Benzylhexadecanamide & 37.47 & 345 & 149, 91, 162, 106, 43 & 4.2 & nd \\
12 & \(N\)-Benzyl-(9Z,12Z)-octadecanamide & 39.84 & 369 & 91, 106, 149, 162, 67 & 1.3 & nd \\
13 & \(N\)-Benzyl-(9Z)-octadecanamide & 39.99 & 371 & 91, 149, 106, 162, 79 & 1.6 & nd \\
14 & Campesterol & 42.18 & 400 & 43, 55, 57, 81, 107 & 1.4 & 0.1 \\
15 & \(\beta\)-Sitosterol & 43.27 & 414 & 43, 57, 55, 41, 107 & 5.2 & 0.2 \\
16 & Unknown III & 51.46 & 505 & 55, 43, 57, 69, 41 & 3.0 & nd \\ \hline \end{tabular}  
* [M*]\({}^{\dagger}\)—molecular ion; base peak ion underlined; ** relative content, based on percentage of peak area in total ion chromatogram of ethanolic (E) and water (W) extract; nd—not detectable.  
\end{table} 
Table 3: _Cont._Figure 5: Mass spectra of macamides: \(N\)-benzylhexadecanamide (**a**), \(N\)-benzyll-(9Z)-octadecanamide (**b**), and \(N\)-benzyll-(9Z,12Z)-octadecanamide (**c**), identified in ethanolic extracts of maca (_L. meveuili_) root. Because of the high polarity due to the presence of hydroxyl groups, direct analysis of polysaccharides by the GC-MS method is not possible, but visible on the chromatograms are non-symmetric wide peaks indicated as the unknown compounds I and II (No. 4 and 5), could probably be products of their degradation, what can be deduced from the characteristic for saccharides signals in their mass spectra (e.g., 57, 73, 43, 31 _m/z_) and a specific wide shape of their peaks, characteristic for highly polar compounds. Besides polysaccharides, observed antioxidant activity can also be related to other important bioactive compounds from the group of glucosinolates, which were identified in maca by HPLC and UPLC-ESI-MS methods [18; 24]. Due to the high polarity, their analysis by the GC-MS method was also not possible, but identified in both ethanolic and water extracts, benzyl nitryl and benzyl isothiocyanate are probably the products of enzymolytic decomposition of maca glucosinolates. As described in the literature, naturally occurring maca enzyme myrosinase is stored in myosin cells, and during the crushing of plant tissues, it is released, causing hydrolysis of glucosinolates, which results in the formation of isothiyanates, thiocyanates, nitryles, and other products [25]. Another compound identified in maca extracts by the GC-MS method is 5-hydroxymethylfurral (5-HMF), and its relative content in water extract (6.6%) was about 2.5-times higher than in ethanolic extract (2.6%). 5-HMF was found in various food samples as a product of the Maillard reaction between amino acids and reducing sugars. Apart from some controversial information related to the possible toxicity of this compound, there are studies indicating its high antioxidant and antiproliferative activity [26]. Summarizing, despite the limitations of the direct GC-MS analysis, the application of this method enabled the identification of some important bioactive compounds and the comparison of their content in water and ethanolic extracts from maca, which has not been reported in the literature so far.