Table 2.
Effect of altitude on the chemical profile of the essential oils of S. thymbra essential oils obtained from Wasita (WEO) and Safsaf (SEO) localities during two successive years
| Compound | Retention index (RI) | Rel. abundance (%) | Methods of identifications | ||||
|---|---|---|---|---|---|---|---|
| Cal. | Reported | Wasita W1 (156 m) |
Wasita W2 (156 m) |
Safsaf S1 (661 m) |
Safsaf S2 (661 m) |
||
| Monoterpene hydrocarbons | |||||||
| α-thujene | 918 | 916 | 3.82 ± 0.51 a | 3.51 ± 0.14 a | 4.57 ± 0.21 b | 4.69 ± 0.18 b | RI, MS |
| p-cymene | 1025 | 1023 | 7.50 ± 1.01 a | 7.25 ± 0.92 a | 8.76 ± 0.21 a | 8.12 ± 0.41 a | RI, MS, AT |
| γ-terpinene | 1052 | 1053 | 1.38 ± 0.22 a | 0.98 ± 0.34 a | 2.34 ± 0.78 b | 1.96 ± 0.98 b | RI, MS, AT |
| dehydro-p-cymene | 1070 | 1067 | – | – | 0.50 ± 0.11 a | 0.94 ± 0.22 b | RI, MS |
| α-terpinolene | 1079 | 1082 | 1.85 ± 0.48 a | 1.27 ± 0.33 a | – | – | RI, MS |
| allo-ocimene | 1118 | 1119 | 2.08 ± 1.14 a | 2.11 ± 0.94 a | – | – | RI, MS, AT |
| 16.63 | 15.12 | 16.17 | 15.71 | ||||
| Oxygenated monoterpenes | |||||||
| thymol | 1291 | 1299 | 29.69 ± 3.25 a | 28.69 ± 4.12 a | 9.19 ± 2.44 b | 8.85 ± 3.12 b | RI, MS,AT |
| carvacrol | 1298 | 1302 | 2.77 ± 0.25 a | 2.54 ± 0.21 a | 14.30 ± 2.55 b | 14.78 ± 2.12 b | RI, MS, AT |
| 4,5-dimethyl-2-ethyl phenol | 1305 | – | 2.09 ± 0.45a | 2.28 ± 0.26 a | 1.86 ± 0.59 b | 1.41 ± 0.45 b | RI, MS |
| 2,3,5,6-tetramethyl phenol | 1361 | – | 1.06 ± 0.58 a | 1.06 ± 0.58 a | 3.90 ± 1.33 b | 3.52 ± 0.97 b | RI, MS |
| 2,3,5,6-tetramethyl,3,4-diethyl phenol | 1296 | 1301 | – | – | 2.93 ± 0.41 a | 3.02 ± 0.44 a | RI, MS |
| 35.61 | 34.57 | 32.18 | 31.10 | ||||
| Sesquiterpene hydrocarbons | |||||||
| trans-β- caryophellene | 1412 | 1410 | 0.51 ± 0.21 a | 0.45 ± 0.19 a | 3.57 ± 1.02 b | 3.14 ± 1.22 b | RI, MS, AT |
| aromadendrene | 1427 | 1423 | 1.42 ± 0.12 a | 1.32 ± 0.09 a | 1.47 ± 0.33 a | 1.78 ± 0.23 a | RI, MS, AT |
| α-humulene | 1441 | 1438 | 1.23 ± 0.78 a | 0.99 ± 0.95 a | 1.58 ± 1.06 a | 1.42 ± 0.96 a | RI, MS, AT |
| viridiflorine | 1491 | 1487 | 3.40 ± 1.18 a | 3.15 ± 1.21 a | – | – | RI, MS, AT |
| δ-cadinene | 1525 | 1521 | 1.01 ± 0.77 a | 1.41 ± 0.45 a | 6.48 ± 2.31 b | 6.12 ± 2.96 b | RI, MS, AT |
| 7.57 | 7.32 | 13.10 | 12.46 | ||||
| Oxygenated sesquiterpenes | |||||||
| α-cedrene oxide | 1569 | 1566 | 3.14 ± 2.11 a | 4.68 ± 1.01 a | – | – | RI, MS, AT |
| caryophllene oxide | 1570 | 1568 | 1.41 ± 0.69 a | 1.79 ± 0.25 a | – | – | RI, MS, AT |
| iso spathulenol | 1577 | 1585 | 13.45 ± 1.37 a | 12.45 ± 1.77 a | 2.18 ± 1.05 b | 2.44 ± 0.91 b | RI, MS, AT |
| β-oplopenone | 1607 | 1603 | 0.51 ± 0.33 a | 0.49 ± 0.24 a | – | – | RI, MS |
| caryophyllenol | 1645 | 1648 | 3.84 ± 2.04 a | 3.74 ± 2.47 a | – | – | RI, MS |
| valerenol | 1706 | 1711 | 4.85 ± 1.25 a | 4.54 ± 1.05 a | – | – | RI, MS |
| 27.2 | 26.69 | 2.18 | 2.44 | ||||
| Diterpenes | |||||||
| cembrene | 1948 | 1941 | – | – | 2.97 ± 0.72 a | 3.01 ± 0.55 a | RI, MS |
| Others | |||||||
| 2-tetra-butyl-4-methyl-phenol | 1513 | – | 1.16 ± 0.45 a | 3.29 ± 0.78 b | – | – | RI, MS |
| p-anisaldehyde | 1277 | 1279 | – | – | 1.37 ± 0.56 a | 2.25 ± 0.77 b | RI, MS, AT |
| 1,2-diethyl-3,4-dimethyl-benzene | 1075 | 1076 | – | – | 1.22 ± 0.44 a | 1.04 ± 0.62 a | RI, MS |
| ethyl-tetra-methyl-cyclo penta-diene | 1082 | 1085 | – | – | 4.04 ± 1.47 a | 3.94 ± 1.66 a | RI, MS |
| 4, methoxy-6-methyl-2(3′,5′-dimethoxy benzyl) benzoic acid | 1685 | – | – | – | 2.33 ± 1.22 a | 1.93 ± 1.36 a | RI, MS |
| 1,2,3,1′,2′,3′-hexamthyl-bicyclopentyl 2,2′-diene | 1122 | 1126 | – | – | 6.01 ± 2.58 a | 5.86 ± 2.98 a | RI, MS |
| 2-hydroxy-3,4,6,7-tetra methoxy phenanthrene | 1975 | – | – | – | 2.01 ± 1.03 a | 2.41 ± 0.65 a | RI, MS |
| 1.8-dimethoxy-3-methylanthracene,9,10-dione | 2035 | – | – | – | 4.85 ± 2.66 a | 3.24 ± 1.25 b | RI, MS |
| benzie-α-pyrone | 2435 | 2442 | – | – | 2.44 ± 0.89 a | 2.41 ± 0.41 a | RI, MS |
| 1.16 | 3.29 | 27.24 | 23.08 | ||||
| Total number of identified compounds | 21 | 21 | 23 | 23 | |||
| Total percentage of identified compounds | 88.17 | 86.99 | 93.84 | 87.80 | |||
MS: Identification based on mass spectral data; RI: identification based on retention index relative to standard n-alkanes; AT: Identification based on co-chromatography with authentic samples, (−) = not detected. Values are ±SEM (n = 3), means followed by different letters in same row denote significant difference at p < 0.05, paired-t-test
W1 and W2 are plants collected from Wasita during fall 2017 and 2018, respectively. S1 and S2 are plants collected from Safsaf during fall 2017 and 2018, respectively