## 3 Results  
The head of the capitate trichomes does not contain volatile compounds and this in accordance with the numerous histochemical observations made on this type of trichomes [25; 26]. The observed composition of the volatile compounds of \(O\). _basilicum_ hydrodistilled leaf oils (LEO) is presented in Table 1 and a chromatogram is shown in Figure 1. \begin{table}
\begin{tabular}{c c c c c c} \hline
**Peak** & **a** **Compounds** & **LEO\%** & **VOC\%** & **RI** & **RI*** \\ \hline
1 & alpha-pinene & 0.19 \(\pm\) 0.02 & 0.02 \(\pm\) 0.01 & 938 & 939 \\
2 & camphene & 0.02 \(\pm\) 0.01 & —— & 954 & 954 \\
3 & sabinene & 0.23 \(\pm\) 0.02 & 0.02 \(\pm\) 0.01 & 976 & 975 \\
4 & beta-pinene & 0.54 \(\pm\) 0.05 & 0.04 \(\pm\) 0.01 & 979 & 979 \\
5 & octan-3-one & 0.03 \(\pm\) 0.01 & —— & 983 & 984 \\
6 & myrcene & 0.17 \(\pm\) 0.02 & 0.03 \(\pm\) 0.01 & 990 & 991 \\
7 & delta-2-carene & 0.01 \(\pm\) 0.01 & —— & 1003 & 1002 \\
8 & 1.8-cineole & 5.84 \(\pm\) 0.54 & 5.71 \(\pm\) 0.53 & 1031 & 1031 \\
9 & (E)-beta-ocimene & 1.06 \(\pm\) 0.12 & 0.16 \(\pm\) 0.02 & 1050 & 1050 \\
10 & gamma-terpinene & 0.03 \(\pm\) 0.01 & —— & 1060 & 1060 \\
11 & n-octanol & 0.04 \(\pm\) 0.01 & —— & 1067 & 1068 \\
12 & terpione & 0.27 \(\pm\) 0.02 & —— & 1087 & 1089 \\
13 & linalool & 32.05 \(\pm\) 2.57 & 28.99 \(\pm\) 2.32 & 1097 & 1097 \\
14 & camphor & 0.07 \(\pm\) 0.01 & 0.93 \(\pm\) 0.09 & 1144 & 1146 \\
15 & borneol & 0.76 \(\pm\) 0.06 & —— & 1169 & 1169 \\
16 & terpinen-4-ol & 0.03 \(\pm\) 0.01 & —— & 1179 & 1177 \\
17 & alpha-terpineol & 0.67 \(\pm\) 0.07 & 0.55 \(\pm\) 0.05 & 1187 & 1189 \\
18 & borny acetate & 2.77 \(\pm\) 0.22 & —— & 1289 & 1289 \\
19 & alpha-terpinyl acetate & 0.14 \(\pm\) 0.01 & —— & 1349 & 1349 \\
20 & eugenol & 15.47 \(\pm\) 1.05 & 41.89 \(\pm\) 2.83 & 1359 & 1359 \\
21 & alpha-copaene & 0.18 \(\pm\) 0.02 & 0.17 \(\pm\) 0.02 & 1378 & 1377 \\
22 & beta-cubebene & 0.21 \(\pm\) 0.02 & —— & 1388 & 1388 \\
23 & beta-elemene & 0.69 \(\pm\) 0.06 & 1.7 \(\pm\) 0.15 & 1391 & 1391 \\
24 & beta-longipinene & 0.04 \(\pm\) 0.01 & —— & 1401 & 1401 \\
25 & methyl eugenol & 0.3 \(\pm\) 0.01 & 0.45 \(\pm\) 0.05 & 1404 & 1404 \\
26 & (Z)-caryophyllene & 0.22 \(\pm\) 0.02 & —— & 1409 & 1409 \\
27 & cis-alpha-bergamotene & 9.35 \(\pm\) 0.79 & 6.34 \(\pm\) 0.54 & 1414 & 1413 \\ \hline \end{tabular}
\end{table} 
Table 1: Chemical composition (as percentages) of \(O\). _basilicum_ leaf essential oil (LEO%) and peltale trichomes (VOC %). The compounds are listed in order of elution on the HP5 column. Fifty-nine volatile compounds were detected in the LEO and 50 were identified with peak weight percentages of 99.81 \(\pm\) 0.11% (mean \(\pm\) S.E.). Oxygenated monoterepene hydrocarbons accounting for 39.42 \(\pm\) 3.02% of the total composition of oil were the predominant volatile group in LEO, followed by sesquiterpene hydrocarbons (27.34 \(\pm\) 2.12%). Among the six oxygenated monoterepene hydrocarbons identified in LEO, linalool, was the most prominent (32.05 \(\pm\) 2.57%). The relatively abundant oxygenated monoterepene in LEO was 1,8-cineole (5.84 \(\pm\) 0.54%). Twenty sesquiterpene hydrocarbons were identified in LEO. Among them, cis-alpha-bergamotene was the most abundant, accounting for 9.35 \(\pm\) 0.79%, followed by alpha-amorphene (4.24 \(\pm\) 0.36%) and gamma-cadinene (3.88 \(\pm\) 0.35%). In addition, amounts of allybenzenes such as eugenol (15.47 \(\pm\) 1.05%) and oxygenated sesquiterpenes such as epi-alpha-cadinol (9.97 \(\pm\) 0.85%) were detected in LEO, along with nine monoterepenes, one ketone, and one alcohol. The ketone and the alcohol were present at trace levels. The composition of LEO was compared with that of trichomes pellet heads (VOC). The observed composition of VOC is presented in Table 1 and a chromatogram is shown in Figure 1.  
Twenty-four volatile compounds were detected in the VOC and all were identified with peak weight percentages of 100 \(\pm\) 0.01%. Figure 1: Chromatographic profiles of \(O\). _hasilicum_ VOC (**A**) and LEO (**B**).