Extraction and Identification of Volatile Organic Compounds in Scentless Flowers of 14 Species Using HS-SPME/GC-MS.

VOCs emitted by flowers play an important role in plant ecology. In the past few years, the genus has been scarcely studied according to the VOCs emitted by flowers. Hence, we decided to enlarge the VOCs composition study already undergone in our laboratory on fragrant 3 species to 12 unscented and 2 faint-scented species and hybrids. The headspace solid phase microextraction (HS-SPME) coupled with gas chromatography combined with the mass spectrometry (GC-MS) method was used to explore the chemical diversity of the VOCs. This study allowed the identification of 65 VOCs among the 14 species and between 6 to 25 compounds were identified in each of the species. The aromatic profile of 10 of the species and hybrids are similar to each other's and show 8 predominant compounds: benzaldehyde, benzacetaldehyde, hexanol, hexanal, heptanal, octanal, nonanal, and furan-2-pentyl. Some specific compounds are present only in some unique species such as trans-calamenene, α-muurolene, and α-guaiene trans-β-bergamotene. The two faint-scented species studied present an original aromatic profile with a high number of monoterpenes or phenylpropanoids/benzenoids. Our studies allow a better understanding of the ecological role and function of these VOCs in the interactions between these plants with their environment.