## 3 Results  
### Chemical Analysis  
As presented in Table 2, the EOs of the under-investigation _Hypericum_ spp., namely _H. empetrifolium_ (HE), _H. amblycalyx_ (HA) and _H. jovis_ (HJ), were complex mixtures; in total 123 individual compounds were identified representing more than 94% of the total EOs, while even the main constituents never exceeded 19% (\(\alpha\)-pinene in HE). More specifically, 94.2%, 94.5% and 95.2% of the total EOs were identified regarding HE, HA and HJ, respectively. The main compounds have been revealed as follows: HE: \(\alpha\)-pinene (19.0%), germacrene D (12.5%), \(\beta\)-pinene (8.7%), E-caryophyllene (5.3%); HA: \(\beta\)-elemene (17.4%), \(\beta\)-selinene (10.5%), \(\alpha\)-pinene (10.2%), E-caryophyllene (8.8%), \(\alpha\)-selinene (8.7%); HJ: _trans_-calamenene (13.5%), \(\alpha\)-selinene (8.3%), \(\beta\)-elemene (7.6%). Chemical structures of the most abundant compounds are presented in Figure 2. The under investigation _Hypericum_ spp. yielded EO 0.9%, 0.4% and 0.5_v/w_ for HE, HA and HJ respectively, which was calculated in dry weight (Table 1). \begin{table}
\begin{tabular}{l c c c c c} \hline \hline  & **Compounds** & **RI** & **HE** & **HA** & **HJ** \\ \hline
1 & (3E)-2.3-dimethylhepta-1.3-diene & 902 & 0.2 & - & - \\
2 & \(\alpha\)-thujene & 913 & 1.0 & - & - \\
3 & \(\alpha\)-pinene & 928 & 19.0 & 10.2 & - \\
4 & \(\alpha\)-fenchene & 938 & 0.5 & 0.1 & - \\
5 & camphene & 940 & 0.3 & 0.3 & - \\
6 & 3-methyl-nonane & 962 & 3.5 & - & - \\
7 & \(\beta\)-pinene & 972 & 8.7 & 1.5 & - \\
8 & 6-methyl-5-hepten-2-one & 979 & - & 0.1 & 0.1 \\
9 & myrecne & 984 & 1.8 & 0.5 & \\
10 & hexenyl acetate & 985 & - & - & 0.1 \\
11 & n-decane & 994 & 0.2 & - & - \\
12 & \(\alpha\)-phellandrene & 1001 & tr & - & - \\
13 & \(\alpha\)-terpinene & 1011 & 0.1 & - & - \\
14 & p-cymene & 1018 & 0.8 & 0.2 & - \\
15 & limonene & 1022 & 1.6 & 1.2 & 0.1 \\
16 & _cis_-ocimene & 1030 & 0.7 & 0.2 & - \\
17 & _trans_-ocimene & 1040 & 1.9 & 0.5 & - \\
18 & \(\gamma\)-terpinene & 1050 & 0.3 & 0.1 & tr \\
19 & 2-methyl-decane & 1056 & 1.8 & - & - \\
20 & terpinolene & 1080 & 0.2 & 0.2 & - \\
21 & n-undecane & 1094 & 1.0 & 2.0 & 1 \\
22 & n-nonanal & 1097 & - & 0.2 & 0.2 \\
23 & endo-fenchol & 1108 & 0.2 & 0.1 & \\
24 & \(\alpha\)-ampholenal & 1119 & 0.1 & - & - \\
25 & allo-ocimene & 1128 & 0.1 & - & - \\
26 & _trans_-pinocarveol & 1129 & 0.2 & 0.2 & - \\
27 & neo-allo-ocimene & 1133 & - & 0.1 & - \\
28 & _trans_-verbenol & 1135 & 0.2 & - & - \\
29 & camphor & 1137 & tr & - & - \\
30 & camphene hydrate & 1141 & tr & - & - \\
31 & isoborneol & 1152 & 0.1 & - & - \\
32 & pinocarvone & 1153 & - & 0.2 & - \\
33 & bornel & 1158 & 0.3 & 0.3 & - \\
34 & 3-methyl-undecane & 1162 & - & - & - \\
35 & terpinen-4-ol & 1167 & 0.1 & - & - \\
36 & \(\alpha\)-terpineol & 1181 & 0.2 & 0.5 & - \\
37 & myrtenol & 1186 & 0.2 & - & - \\
38 & verbenone & 1198 & 0.1 & - & - \\
39 &itronellol & 1219 & tr & - & - \\
40 & linalool acetate & 1246 & 0.4 & - & - \\
41 & 2-undecanone & 1285 & 0.1 & - & - \\
42 & trideene & 1290 & 0.1 & - & - \\
43 & caravcrol & 1292 & - & 0.2 & - \\
44 & \(\alpha\)-longipinene & 1337 & 2.1 & 0.3 & - \\
45 & \(\alpha\)-cubebene & 1338 & - & - & 0.4 \\
46 & cycloastivene & 1359 & - & - & 0.2 \\
47 & \(\alpha\)-ylangene & 1360 & 0.3 & - & 0.6 \\
48 & \(\alpha\)-copaene & 1363 & 0.4 & 0.2 & 0.6 \\
49 & \(\beta\)-bourbonene & 1370 & 0.4 & - & - \\
50 & geranyl acetate & 1373 & 0.1 & - & - \\
51 & \(\beta\)-cubebene & 1376 & 0.1 & - & - \\
52 & \(\beta\)-elemene & 1380 & 0.2 & 17.4 & 7.6 \\
53 & \(\beta\)-longipinene & 1384 & 0.3 & - & - \\
54 & \(\alpha\)-cedrene & 1389 & 0.1 & - & - \\
55 & E-caryophyllene & 1406 & 5.3 & 8.8 & 2.9 \\
56 & \(\beta\)-cedrene & 1409 & 0.9 & 0.2 & 0.5 \\
57 & \(\beta\)-gurjunene & 1424 & 0.5 & 0.3 & 0.2 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Qualitative and quantitative composition (% %) of EOs.