# Chemical Composition and Antioxidant Activities of Three Bulgarian Garden Thyme Essential Oils
## 3 Results
### Chemical Composition  
The chemical composition of the garden thyme essential oils is presented in Table 1 and in Figures 1-3. The data presented in Table 1 show the following:  
* In total, 42 components (99.65% of the total composition) have been identified in garden thyme essential oil (sample 1). The main compounds (over 2%) were thymol (53.55%), \(\gamma\)-terpinene (11.13%), p-cymene (14.96%), bornel (2.75%), \(\beta\)-linal (2.07%), and carvacrol (2.00%).
* In total, 39 components (99.67% of the total composition) have been identified in garden thyme essential oil (sample 2). The main compounds (over 2%) were thymol (44.09%), p-cymene (25.51%), \(\gamma\)-terpinene (6.58%), eucalypt (3.65%), thymol methyl ether (3.16%), \(\beta\)-linalool (2.31%), and carvacrol (2.33%).
* In total, 38 components (99.57% of the total composition) have been identified in garden thyme essential oil (sample 3). The main compounds (over 2%) were thymol (42.88%), p-cymene (14.25%), \(\gamma\)-terpinene (15.51%), _cis_-sabinene hydrate (4.05%), bornel (3.57%), \(\alpha\)-terpinene (3.24%), carvacrol methyl ether (3.02%), \(\beta\)-linalool (0.98%), and thymol methyl ether (2.26%).  
The data show that the essential oil of sample 1 (cultivated garden thyme) contains the highest amount of thymol; the oil of sample 2 (wild garden thyme) is richer in p-cymene, carvacrol, and \(\beta\)-linalool; and that of sample 3 of \(\gamma\)-terpinene, cis-sabinene hydrate, and borneol.  
The data for the distribution of the identified components by groups of compounds (Figure 4) shows that the garden essential oils are dominated by oxygenated phenyl propanoids (from 49.19 to 58.25%), followed by monoterpene hydrocarbons (from 10.46 to 22.11%), phenyl propanoid hydrocarbons (from 14.31 to 25.59%), and oxygenated monoterrenes (from 8.31 to 11.38%). The amounts of the other compounds (oxygenated aliphatics, monoterpene hydrocarbons, sesquiterpene hydrocarbons, and oxygenated sesqui-terpenes) are much lower.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**No**} & \multicolumn{2}{c}{**RT b,**} & \multirow{2}{*}{**RI c**} & \multirow{2}{*}{**Components**} & \multicolumn{2}{c}{**Content**} \\ \cline{5-6}  & **min** & & & **Sample 1** & & **Sample 2** & & **Sample 3** \\ \hline
1. & 6.46 & 840 & trans-2-Hexanal & 0.07 \(\pm\) 0.0 a  & nd d  & 0.06 \(\pm\) 0.0 a  \\
2. & 8.44 & 917 & Tricylene & 0.05 \(\pm\) 0.0 a  & 0.06 \(\pm\) 0.0 a  \\
3. & 8.60 & 922 & \(\beta\)-Thujene & 0.68 \(\pm\) 0.0 a  & 0.59 \(\pm\) 0.0 a  & 0.81 \(\pm\) 0.0 a  \\
4. & 8.81 & 929 & \(\alpha\)-Pinene & 0.46 \(\pm\) 0.0 a  & 0.37 \(\pm\) 0.0 a  & 0.38 \(\pm\) 0.0 a  \\
5. & 9.32 & 945 & Camphene & 0.59 \(\pm\) 0.0 a  & 0.34 \(\pm\) 0.0 a  & 0.46 \(\pm\) 0.0 a  \\
6. & 10.10 & 970 & Sabinene & 0.08 \(\pm\) 0.0 a  & 0.07 \(\pm\) 0.0 a  & 0.15 \(\pm\) 0.0 b  \\
7. & 10.22 & 974 & \(\beta\)-Pinene & 0.16 \(\pm\) 0.0 a  & 0.20 \(\pm\) 0.0 a  & 0.17 \(\pm\) 0.0 a  \\
8. & 10.45 & 981 & 1-Octen-3-ol & 0.35 \(\pm\) 0.0 a  & 0.52 \(\pm\) 0.0 a  & 1.01 \(\pm\) 0.01 b  \\
9. & 10.58 & 985 & 3-Octanone & 0.08 \(\pm\) 0.0 a  & 0.06 \(\pm\) 0.0 a  & 0.35 \(\pm\) 0.0 b  \\
10. & 10.70 & 988 & \(\beta\)-Myrcene & 0.89 \(\pm\) 0.0 a  & 0.70 \(\pm\) 0.0 a  & 0.06 \(\pm\) 0.0 a  \\
11. & 11.01 & 981 & 3-Octanol & 0.06 \(\pm\) 0.0 a  & 0.06 \(\pm\) 0.0 a [FOOTNOTE:a]Footnote a: total ion current; b retention time, min; c retention index (Kovat’s); d lower than 0.05% of TIC or not identified; values with different letters in the same row indicate significant differences (\(p<0.05\))Figure 1: Chromatogram of garden thyme essential oil, sample 1 (peak numbers correspond to those shown in Table 1).  
Figure 2: Chromatogram of garden thyme essential oil, sample 2 (peak numbers correspond to those shown in Table 1).  
The distribution of the identified components by groups of compounds is shown in Figure 4.