Table 3. Binding data of recombinant NlugOBPs with different plant volatiles (Alcohols, Aldehydes, Ketones, Esters and Benzoates).
| Ligand | Ligand name/ | OBP1 | OBP2 | OBP3 | |||
| Number | Structural formula | IC50 | Ki | IC50 | Ki | IC50 | Ki |
| (µM) | (µM) | (µM) | (µM) | (µM) | (µM) | ||
| Alcohols | |||||||
| 1 | 1-Hexenol /C6H14O | >50 | >50 | >50 | >50 | 29.7 | 21.2 |
| 2 | 2-Heptanol/C7H16O | >50 | >50 | >50 | >50 | >50 | >50 |
| 3 * | (+/-)Nerolidol/C15H26O | 28.4 | 24.2 | 33.9 | 29.1 | 24.8 | 17.7 |
| 4 | (E)-3-Hexen-1-ol/C6H12O | >50 | >50 | >50 | >50 | 29.6 | 21.1 |
| 5 | Farnesol/C15H26O | 22.8 | 19.5 | 23.0 | 19.8 | 6.9 | 4.9 |
| 6 | Linalool/C10H18O | 40.8 | 34.7 | >50 | >50 | >50 | >50 |
| 7 * | 2-phenylethanol /C8H10O | 39.9 | 34.0 | >50 | >50 | 36.6 | 26.1 |
| 8 | Geraniol/C10H18O | >50 | >50 | >50 | >50 | 32.6 | 23.3 |
| 9 * | Cedrol/C15H26O | 30.0 | 25.6 | 35.0 | 30.1 | 19.7 | 14.1 |
| 10 | Menthol/C10H20O | >50 | >50 | >50 | >50 | >50 | >50 |
| Aldehydes | |||||||
| 11 * | Hexenal/C6H12O | >50 | >50 | >50 | >50 | 33.8 | 24.1 |
| 12 | Dodecyl aldehyde/ C12H24O | 19.5 | 16.6 | >50 | >50 | 26.5 | 18.9 |
| 13 * | (E)-2-Hexenal/ C6H10O | >50 | >50 | 33.5 | 28.8 | 42.0 | 30.0 |
| 14 * | Benzaldehyde/ C7H6O | >50 | >50 | 38.7 | 33.3 | 41.0 | 29.3 |
| Ketones | |||||||
| 15 * | 2-Tridecanone/ C13H26O | 24.0 | 20.5 | 43.2 | 37.1 | 12.0 | 8.6 |
| 16 * | 2-Pentadecanone/ C15H30O | 29.7 | 25.3 | 19.8 | 17.0 | 13.5 | 9.6 |
| 17 * | Acetophenone/ C8H8O | 34.3 | 29.3 | 32.3 | 27.8 | 32.4 | 23.1 |
| Esters and Benzoates | |||||||
| 18 | Amyl acetate/ C7H14O2 | >50 | >50 | >50 | >50 | >50 | >50 |
| 19 | Isoamyl acetate/ C7H14O2 | 35.7 | 30.5 | >50 | >50 | >50 | >50 |
| 20 | (E)-2-Hexenyl acetate/ C8O2 | >50 | >50 | 29.3 | 25.2 | 31.3 | 22.4 |
| 21 | Hexyl acetate/ C8H16O2 | 44.4 | 37.9 | >50 | >50 | 30.8 | 22.0 |
| 22 * | (Z)-3-Hexenyl acetate/ C8O2 | >50 | >50 | 37.8 | 32.5 | 38.0 | 27.1 |
| 23 * | Ethyl benzoate/ C9H10O2 | >50 | >50 | >50 | >50 | 39.0 | 27.9 |
| 24 | Methyl benzoate/ C8H8O2 | >50 | >50 | >50 | >50 | >50 | >50 |
| 25 * | Methyl salicylate/ C8H8O3 | >50 | >50 | 37.4 | 32.2 | 44.8 | 32.0 |
*Marked ligands were identified as rice plant volatile according to literatures; “>50” for the IC50 and Ki means that IC50 or Ki cannot be accurately calculated with the ligand concentration range tested in the assay.