Table 2.
Nocturnal headspace composition of A. cadetii (sect. Hadrangis, orthopteran pollination) and A. leonis (sect. Humblotiangraecum, sphingophily)
| Composition (%)† |
|||
|---|---|---|---|
| Compounds | RI* | A. cadetii | A. leonis |
| Aldehydes | |||
| Nonanal | 1116 | 2·0 | 0·2 |
| Decanal | 1218 | tr | 0·3 |
| Esters | |||
| 2-Hydroxy-3-methyl methylbutanoate‡ | 908 | 8·9 | – |
| 2-Hydroxy-3-methyl methylpentanoate | 1008 | 1·6 | – |
| Ketones | |||
| 6-Methyl-5-hepten-2-one | 999 | tr | – |
| Monoterpene hydrocarbons | |||
| Myrcene | 1004 | 1·1 | – |
| Limonene | 1045 | 0·9 | – |
| (E)-β-Ocimene | 1061 | 52·6 | – |
| γ-Terpinene | 1070 | tr | – |
| 2,6-Dimethyl-1,3,5,7-octatetraene | 1146 | tr | – |
| Neo-allo-ocimene | 1157 | tr | – |
| Oxygenated monoterpenes | |||
| 1,8-Cineole | 1051 | 7·1 | – |
| α-Terpineol | 1211 | 4·7 | – |
| Geraniol | 1268 | 18·3 | – |
| Sesquiterpene hydrocarbons | |||
| γ-Muurolene | 1508 | tr | – |
| Germacrene D | 1514 | 2·8 | – |
| γ-Cadinene | 1545 | tr | – |
| δ-Cadinene | 1552 | tr | – |
| Aromatic compounds | |||
| Benzaldehyde | 978 | – | tr |
| Benzyl alcohol | 1048 | – | 0·4 |
| p-Cresol | 1085 | – | 0·2 |
| Methyl benzoate | 1113 | – | tr |
| Benzyl acetate | 1179 | – | tr |
| Methyl salicylate | 1215 | – | tr |
| Chavicol | 1269 | – | 72·4 |
| Chavicol isomer | 1325 | – | tr |
| Chavicol isomer | 1356 | – | 3·6 |
| Benzyl butanoate | 1363 | – | tr |
| 4-Hydroxybenzaldehyde | 1375 | – | 1·9 |
| Eugenol | 1377 | tr | – |
| α-Ethylbenzenemethanol‡ | 1386 | – | 0·8 |
| Vanillin | 1421 | – | tr |
| (E)-Cinnamyl acetate | 1463 | – | 0·4 |
| 2-Butylphenol‡ | 1466 | – | tr |
| (E)-Isoeugenol | 1471 | – | tr |
| Benzyl tiglate | 1519 | – | 0·3 |
| Benzyl benzoate | 1797 | – | 5·5 |
| Benzyl salicylate | 1905 | – | 7·3 |
| Nitrogenous aromatic compounds | |||
| Methyl nicotinate | 1155 | – | 5·3 |
| 4-Quinolinecarboxaldehyde | 1513 | – | 0·6 |
| Unidentified compounds | |||
| Unidentified 1 | 1666 | – | 0·5 |
| Unidentified 2 | 1701 | – | 0·3 |
* RI: Retention indices relative to C5–C22 n-alkanes on SPB-5 non-polar capillary column.
† Relative percentage obtained from peak area: tr, trace (< 0·1 %); –, absent.
‡ Tentatively identified.