Figure 1
Figure 2
Figure 3
Figure 4
Evaluation of the antioxidant activity of essential oils, as assessed by DPPH radical scavenging and FRAP tests
| DPPH (IC50 = µg/mL) | FRAP (EC50 = µg/mL) | |
|---|---|---|
| Thymus zygis L. ssp. Gracilis | 57.292 ± 0.001 | 7.207 ± 0.001 |
| E. camaldulensis Dehnh. | 238.851 ± 0.001 | 11.834 ± 0.001 |
| Quercitin | 5.499 ± 0.019 | |
| Catechin | 13.904 ± 0.023 |
Antimicrobial activities of EOs against various bacterial strains assessed using the disk diffusion method
| ID (mm) | ||||||
|---|---|---|---|---|---|---|
| Microorganisms | T. zygis L. ssp. gracilis (5 µl/disc) | E. camaldulensis Dehnh. (5 µl/disc) | Tetracycline | Ampicillin | Penicillin | |
| Gram-negative bacteria | E. coli (ATCC 8739) | 16.11 ± 0.96 | 19.11 ± 0.30 | 24 ± 0.33 | NZ | NZ |
| M. luteus (ATCC 9341) | 16,22 ± 0.30 | 21.78 ± 0.30 | 20.67 ± 0.44 | NZ | NZ | |
| Gram-positive bacteria | B. subtilis (ATCC 6633) | 17,11 ± 0.30 | 22.56 ± 0.59 | 21.67 ± 0.44 | NZ | NZ |
| S. aureus (ATCC 6538) | 18.33 ± 0.89 | 25.00 ± 0.22 | 25.5 ± 0.33 | NZ | NZ | |
MIC and MBC of T_ zygis and E_ camaldulensis EOs against S_ aureus, B_ subtilis, M_ luteus, and E_ coli
| CMI/CMB (µL/mL) | ||||||||
|---|---|---|---|---|---|---|---|---|
| M. luteus (ATCC 9341) | B. subtilis (ATCC 6633) | E. coli (ATCC 8739) | S. aureus (ATCC 6538) | |||||
| CMI | CMB | CMI | CMB | CMI | CMB | CMI | CMB | |
| T. zygis L. ssp. gracilis | 0.25 | 4 | 0.062 | 2 | 0.5 | 8 | 0.125 | 2 |
| E. camaldulensis Dehnh. | 0.5 | — | 0.25 | 4 | 1 | — | 0.25 | 8 |
Chemical composition of EOs of T_ zygis and E_ camaldulensis
| No | Compounds | RI | Area % | |
|---|---|---|---|---|
| Thymus zygis L. ssp. gracilis | E. camaldulensis Dehnh. | |||
| 1 | Heptanal | 901 | 0.14 | — |
| 2 | Tricyclene | 921 | 1.45 | — |
| 3 | α-Thujene | 924 | 0.05 | 3.49 |
| 4 | α-Pinene | 932 | 3.98 | 0.32 |
| 5 | Norbornen-2-ol | 939 | 0.11 | — |
| 6 | Verbenene | 961 | 1.65 | — |
| 7 | Sabinene | 968 | 0.13 | 0.25 |
| 8 | trans-Pinane | 969 | 0.13 | — |
| 9 | β-Pinene | 974 | 0.24 | 0.35 |
| 10 | Myrcene | 988 | 0.07 | — |
| 11 | 2-Octanol | 994 | — | 0.1 |
| 12 | δ-2-Carene | 1,001 | 0.37 | 0.1 |
| 13 | δ-3-Carene | 1,008 | 15.7 | 0.06 |
| 14 | α-Terpinene | 1,014 | 0.42 | — |
| 15 | p-Cymene | 1,020 | 2.44 | 4.93 |
| 16 | 1,8-Cineol | 1,026 | — | 43.61 |
| 17 | E-β-Ocymene | 1,044 | 1.85 | — |
| 18 | γ-Terpinene | 1,054 | 0.72 | 11.71 |
| 19 | cis-Sabinene hydrate | 1,065 | — | 0.13 |
| 20 | cis-Linalool oxide | 1,067 | 0.6 | — |
| 21 | Camphenilone | 1,078 | 1.38 | 0.85 |
| 22 | Terpinoline | 1,086 | 0.48 | 2.3 |
| 23 | Linalool | 1,095 | 0.16 | — |
| 24 | trans-Sabinene hydrate | 1,098 | — | 0.27 |
| 25 | 6-Camphenol | 1,111 | 0.23 | — |
| 26 | Dehydrolinalool | 1,131 | 4.99 | — |
| 27 | trans-Dihydro β-terpineol | 1,134 | — | 0.39 |
| 28 | cis-Pinene hydrate | 1,139 | — | 1.42 |
| 29 | δ-Terpineol | 1,162 | 27.64 | 1.16 |
| 30 | Thujanol | 1,164 | 1.12 | — |
| 31 | cis-Linalool oxide | 1,170 | 0.93 | — |
| 32 | Terpinene-4-ol | 1,174 | — | 3.91 |
| 33 | iso-Verbanol | 1,176 | 0.31 | — |
| 34 | neo-Verbanol | 1,182 | 0.84 | — |
| 35 | α-Terpineol | 1,186 | — | 10.58 |
| 36 | γ-Terpineol | 1,199 | — | 0.22 |
| 37 | Verbinone | 1,204 | 0.05 | — |
| 38 | trans-Piperitol | 1,207 | — | 0.11 |
| 39 | trans-Carveol | 1,215 | 2.14 | — |
| 40 | cis-Sabinene hydrate acetate | 1,219 | 0.37 | |
| 41 | cis-Carveol | 1,226 | 1.77 | — |
| 42 | Pulegone | 1,233 | — | 1.02 |
| 43 | Carvone | 1,239 | — | 0.23 |
| 44 | trans-Sabinene hydrate acetate | 1,253 | — | 0.13 |
| 45 | iso-3-Thujanol acetate | 1,267 | — | 0.33 |
| 46 | trans-Carvone oxide | 1,273 | 4.13 | 0.6 |
| 47 | neo-iso-3-Thujanol acetate | 1,281 | — | 0.2 |
| 48 | Thymol | 1,289 | 14.17 | — |
| 49 | p-Cymen-7-ol | 1,290 | — | 1.35 |
| 50 | trans-Verbenyl acetate | 1,291 | 0.06 | — |
| 51 | iso-Verbanol acetate | 1,308 | 0.31 | — |
| 52 | δ-Terpinyl acetate | 1,316 | — | 0.08 |
| 53 | δ-Elemene | 1,335 | — | 0.95 |
| 54 | α-Terpinyl acetate | 1,346 | — | 0.51 |
| 55 | α-Copaene | 1,374 | 0.08 | — |
| 56 | β-Longipinene | 1,400 | 0.07 | — |
| 57 | Longifoline | 1,407 | — | 0.05 |
| 58 | E-Caryophyllene | 1,417 | 2.75 | 0.35 |
| 59 | Carvone hydrate | 1,422 | — | 0.26 |
| 60 | γ-Elemene | 1,434 | 0.07 | — |
| 61 | Aromadendrene | 1,439 | — | 0.24 |
| 62 | α-Humulene | 1,452 | 0.12 | 0.23 |
| 63 | Sesquisabinene | 1,457 | 0.17 | — |
| 64 | 9-epi-E-Caryophyllene | 1,464 | — | 0.09 |
| 65 | β-Thujaplicin | 1,475 | 0.16 | — |
| 66 | γ-Muurolene | 1,478 | — | 0.25 |
| 67 | β-Selinene | 1,489 | 0.39 | — |
| 68 | δ-Selinene | 1,492 | — | 0.2 |
| 69 | α-Muurolene | 1,500 | — | 0.38 |
| 70 | β-Bisabolene | 1,505 | 0.13 | — |
| 71 | γ-Cadinene | 1,513 | 0.27 | 0.07 |
| 72 | δ-Cadinene | 1,522 | — | 0.09 |
| 73 | Elemol | 1,548 | — | 2.11 |
| 74 | β-Calacorene | 1,564 | — | 0.22 |
| 75 | Caryophyllenyl alcohol | 1,570 | 0.21 | — |
| 76 | Germacrene D-4-ol | 1,574 | — | 0.07 |
| 77 | trans-Sesquisabinene hydrate | 1,577 | 0.22 | — |
| 78 | Caryophyllene oxide | 1,582 | 2.24 | 0.3 |
| 79 | Davanone | 1,587 | — | 1.1 |
| 80 | cis-β-Elemenone | 1,589 | 0.12 | — |
| 81 | Widdrol | 1,599 | — | 0.23 |
| 82 | trans-β-Elemenone | 1,601 | 0.09 | — |
| 83 | cis-Isologifolanone | 1,612 | — | 0.08 |
| 84 | trans-Isologifolanone | 1,625 | — | 0.28 |
| 85 | α-Acorenol | 1,632 | — | 0.15 |
| 86 | cis-Cadin-4-en-7-ol | 1,635 | 0.69 | — |
| 87 | epi-α-Muurolol | 1,644 | — | 0.18 |
| 88 | β-Eudesmol | 1,649 | 0.35 | — |
| 89 | α-Eudesmol | 1,652 | 0.28 | — |
| 90 | Dihydroeudesmol | 1,661 | — | 0.54 |
| 91 | 14-Hydroxy-Z-caryophyllene | 1,666 | 0.39 | — |
| 92 | Davanol acetate | 1,689 | 0.09 | — |
| 93 | 2E,6Z-Farnesol | 1,714 | — | 0.1 |
| Total | 99.65% | 99.6% | ||
| Monoterpenes | 94.18% | 90.57% | ||
| Sesquiterpenes | 5.47% | 9.03% | ||
| Phenols | 19.73% | 0.11% | ||
| Aldehydes | 0.14% | — | ||
| Ketones | 7.42% | 4.04% | ||
| Alcohols | 37.55% | 22.22% | ||
| Ethers | — | 43.61% | ||
| Hydrocarbons | 34.93% | 29.03% | ||
| Esters | 0.06% | 0.59% | ||