## 3 Results and Discussion
\begin{table}
\begin{tabular}{l c c c c c c c c c c c c c c c c c c} \hline
**Compounds** & **Syrah** & **CV** & **Merlot** & **CV** & **Nero** & **CV** & **Frappato** & **CV** & **Petit** & **CV** & **Refosc** & **CV** & **Barbarossa** & **CV** & **Sagrantino** & **CV** & **Malbec** & **CV** \\
**(ug L-)** & & **\%** & & **\%** & **d’Avola** & **\%** & & **\%** & **\%** & **Verdot** & **\%** & & **\%** & **\%** & **\%** & **\%** & **\%** & **\%** \\ \hline \(\alpha\)-Gurjenne & tr & - & - & - & tr & - & tr & - & tr & - & - & - & - & - & - & - & - & - \\ \(\alpha\)-Cdeme & - & - & - & - & - & - & - & - & tr & - & - & - & - & - & - & - & - & - \\ \(\alpha\)-Aromadrendre & - & - & - & - & - & - & - & - & - & - & 0.21 & 5 & - & - & - & - & - & - \\ (E)-\(\beta\)-Famesene & tr & - & - & - & tr & - & tr & - & - & - & - & - & - & - & - & - & - & - \\ D Germacrene & 1.01 & 11 & 0.70 & 16 & 0.41 & 6 & 0.20 & 9 & tr & - & 0.13 & 7 & 0.19 & 13 & 0.34 & 13 & 0.19 & 6 \\ Valencene & 0.10 & 7 & - & - & tr & - & - & - & 0.12 & 7 & - & - & - & tr & - & tr & - \\ \(\gamma\)-Gurjenne & 1.40 & 14 & - & - & - & - & - & - & - & - & - & - & - & - & - & - & - \\ (E)-\(\beta\)-Bisabolene & tr & - & - & - & tr & - & - & - & - & - & - & - & - & - & - & - & - \\ \(\delta\)-Cdeme & tr & - & tr & - & 0.10 & 9 & tr & - & - & - & - & - & - & - & - & - & - \\ \(\beta\)-Selience & - & - & - & - & - & - & - & - & tr & - & - & - & - & - & - & - & - \\ \(\alpha\)-Muoruene & 1.69 & 12 & 0.11 & 8 & 0.98 & 12 & 0.24 & 12 & 0.97 & 6 & 0.28 & 14 & 0.30 & 9 & tr & - & 1.25 & 4 \\ \(\alpha\)-Selience & - & - & 0.12 & 17 & - & - & - & - & - & - & - & 0.31 & 16 & 0.38 & 9 & - & - \\ (Z)-\(\alpha\)-Bisabolene & - & - & - & - & - & - & - & tr & - & - & - & - & tr & - & 0.19 & 14 \\ (E)-Nerolidol & 5.43 & 5 & - & - & - & - & - & - & - & - & - & - & - & 2.39 & 6 & - & - \\ Virridiflorol & - & - & - & - & 2.76 & 13 & - & - & - & - & - & - & - & - & - & - & - \\ \(\gamma\)-Fudesmol & - & - & - & - & - & - & - & - & - & - & - & - & - & - & tr & - & - \\ _All_ & _9.63_ & _0.93_ & _4.25_ & _0.44_ & _1.09_ & _0.62_ & _0.81_ & _3.11_ & _1.63_ & & & & & & & & \\ \hline \end{tabular}
\end{table} 
Table 3: Average amount * of sesquiterpennes in the red wines analysed. Figure 1: Structure of the sesquiterpenes identified in the analyzed wines samples. Figure 2: Headspace Solid-Phase Microextraction coupled with Gas Chromatography–Mass Spectrometry (HS-SPME-GC-MS) chromatogram (SIM: \(m/z=161.0+189.0+204.0\)) of a wine sample. For peak identification see Table 2.  
As regards the acyclic sesquiterpenes, \(\beta\)-farnesene and (E)-nerolidol were identified: \(\beta\)-farnesene was present only as traces in Syrah, Nero d'Avola and Frappato wines, whereas (E)-nerolidol in Syrah and Sagrantino with 5.43 \(\mu\)g L\({}^{-1}\) and 2.39 \(\mu\)g L\({}^{-1}\) respectively. These sesquiterpene compounds can be related with the floral characteristics of wines and derives from farnesyl diphosphate, an intermediate in isoprenoid and ergosterol biosynthesis at acidic pH, the instability of the diphosphate group leads to the release of Farnesol and its isomer Nerolidol [20]. They were identified in different wine varieties and in the Italian white wines Grillo, Inzolia and Cataratto [1, 10, 16]. As regards the monocyclic sesquiterpenes, two compounds with the bisabolane skeleton, (E)-\(\beta\)-bisabolene and (Z)-\(\alpha\)-bisabolene, and one with the germacrene skeleton, Germacrene D, were identified. Bisabolenes derive from farnesyl diphosphate. (E)-\(\beta\)-bisabolene was identified in traces in Syrah and in Nero d'Avola wines, (Z)-\(\alpha\)-bisabolene was present in Malbec (0.19 \(\mu\)g L\({}^{-1}\)) and, as traces, in Petiti Verdot and Sagrantino. Germacrene D was identified in all the wine samples analysed with an amount ranged between traces and 1.01 \(\mu\)g L\({}^{-1}\).