Table 1.
Tabulated data showing quorum sensing inhibitory (QSI) activity of essential oils used in this study, alone and in combination with 10 mg/mL of OASL. Also QSI activity of all synthesized EOSLs.
| Plant essential oil (common name) | Plant essential oil (scientific name) | Main component | Anti-QSI activity of essential oil alone (20% oil) against CV026 (inhibition zone size in mm) | Anti-QSI activity of EO + OASL against CV026 (inhibition zone size in mm)a | Anti-QSI activity of EOSL against CV026 (inhibition zone size in mm)b |
|---|---|---|---|---|---|
| Lemongrass oil | Cymbopogon citratus | Citral | 15 | 28 | 25 |
| Peppermint oil | Mentha piperita | Menthol | — | 16 | 13 |
| Cinnamon oil | Cinnamomum verum | Cinnamaldehyde | 15 (10% EO) | 20 (10% EO + OASL at 10 mg/mL) | Growth inhibition at 10 mg/mL EOSL. |
| Rosemary oil | Rosmarinus officinalis | (+) Alpha pinene | — | — | 13 |
| Basil oil | Ocimum basilicum | L-Linalool | — | 11 | 30 |
| Bergamot oil | Citrus bergamia | L-Linalool | — | — | 17 |
| Eucalyptus oil | Eucalyptus sp. | 1,8-Cineole | — | — | 23 |
| Orange oil | Citrus sinensis | Limonene | — | — | 13 |
| Citronella oil | Cymbopogon nardus | Citronellal | — | — | 12 |
| Tea tree oil | Melaleuca alternifolia | Alpha terpineol | — | — | 26 |
| Ylang ylang oil | Cananga odorata | L-Linalool | — | 12 | 33 |
| Frankincense oil | Boswellia carteri | (+) Alpha pinene | — | — | 17 |
a1 mL reaction mixture contained 20% EO and OASL at a concentration of 10 mg/mL. Also OASL alone used at a concentration of 10 mg/mL had no QSI activity.
bEOSL concentration used 20 mg/mL.