## 2 Results  
### Chemical Compositions of the R. canina Essential Oil by GC-MS Analysis  
The chemical composition of essential oil extracted from _R. canina_ petals by hydrodistillation was analyzed by GC-MS. Two petal color variants, white and dark pink, were compared. The GC-MS analysis detected 32 and 15 compounds in the white and dark pink samples, respectively (Tables 1 and 2). These compounds belonged to four classes: aliphatic hydrocarbons, aldehydes/ketones, alcohols, and esters. Aliphatic hydrocarbons predominated in both samples, accounting for 76.8% and 99% of the total oil composition in the white and dark pink samples, respectively. The white sample also contained two monotterpenes, linalool and gerani, and their corresponding acetate esters, citronellyl acetate and linalool acetate. Pentacosane was the most abundant hydrocarbon in the white sample (22.34%). Moreover, bis(2-ethylhexyl) terephthalate (DEHT), a natural diester of terephthalatic acid and 2-ethylhexanol, was identified in the white sample. DEHT, also known as octyl, has a similar chemical formula and structure to the synthetic plasticizer bis(2-ethylhexyl) phthalate (DEHP) [32]. DEHT is a natural constituent of rose oil, as reported in previous studies [33; 34; 35; 36; 37]. Figure 1 indicates the Total Ion Chromatogram (TIC) of white and dark pink _R. canina_ L. petals and Figure 2 shows the relative percentages of the volatile compounds in the two samples.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**No.** & **Compound Name** & **RI** & **Percentage Peak Area** \\ \hline
1 & Nonanal & 1116 & 0.21 \\
2 & Linalool & 1118 & 0.31 \\
3 & Linalool acetate & 1268 & 1.06 \\
4 & Gerani & 1279 & 0.82 \\
5 & Undecanal & 1313 & 0.14 \\
6 & Citronellyl acetate & 1352 & 0.24 \\
7 & Tetradecane & 1397 & 0.21 \\
8 & Dauca-5,8-diene & 1472 & 0.91 \\
9 & \(\gamma\)-Himachalene & 1480 & 0.25 \\
10 & 2-Tridecanone & 1497 & 0.3 \\
11 & Isodoucene & 1504 & 0.41 \\
12 & Tridecanal & 1515 & 0.83 \\
13 & Dodecanoic acid & 1588 & 1.03 \\
14 & Hexadecane & 1596 & 0.73 \\
15 & Heptadecane & 1696 & 0.48 \\
16 & Pentadecanal & 1718 & 0.41 \\
17 & Benzyl benzoate & 1789 & 2.03 \\
18 & Octadecane & 1800 & 0.54 \\
19 & Nonadecane & 1903 & 3.49 \\
20 & Eicosane & 2003 & 8.16 \\
21 & Hexadecenoic acid & 2009 & 2.77 \\
22 & Octadecanal & 2029 & 0.48 \\
23 & Heneicosane & 2114 & 13.84 \\
24 & Linoleic acid & 2166 & 0.73 \\
25 & 4 Docosane & 2203 & 1.69 \\
26 & Eicosanal & 2234 & 1.26 \\
27 & Triacoasane & 2317 & 19.74 \\
28 & Tetracosane & 2396 & 1.61 \\
29 & 1-Docosanol & 2432 & 0.32 \\
30 & Pentacosane & 2496 & 22.34 \\
31 & Dioctyl phthalate & 2532 & 12.49 \\
32 & Hexacosane & 2595 & 0.17 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Percentage composition of the essential oils isolated from white _R. canina_ petals.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**No.** & **Compound Name** & **RI** & **Percentage Peak Area** \\ \hline
1 & Benzyl benzoate & 1787 & 0.04 \\
2 & Octadecane & 1797 & 0.02 \\
3 & Nonadecane & 1897 & 0.09 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Percentage composition of the essential oils isolated from pink _R. canina_ petals.  
\begin{table}
\begin{tabular}{c c c c} \hline
**No.** & **Compound Name** & **RI** & **Percentage Peak Area** \\ \hline
4 & Hexadecenoic acid & 1982 & 0.13 \\
5 & Eicosane & 1997 & 0.06 \\
6 & Heneicosane & 2101 & 1.11 \\
7 & Octadecanoic acid & 2185 & 1.12 \\
8 & Docosane & 2223 & 92.63 \\
9 & Tricosane & 2299 & 1.2 \\
10 & Tetracosane & 2396 & 0.08 \\
11 & Docosanal & 2432 & 0.11 \\
12 & Data MS & 2472 & 0.43 \\
13 & Pentacoasane & 2496 & 2 \\
14 & Disooclyl phthalate & 2532 & 0.88 \\
15 & Hexacosane & 2595 & 0.1 \\ \hline \end{tabular}
\end{table}
Table 2: _Cont._  
Figure 1: Total Ion Chromatogram (TIC) of white and dark pink _R. canina_ L. petals.