Headspace analysis of the volatile flower scent of Zeyheria montana Mart. (Bignoniaceae)

Floral scent plays a key role for the chemical communication between fragrant flowering plants and animal pollinators. Zeyheria montana Mart. (syn. Z. digitalis) is a medicinal plant native from the Brazilian savannah “Cerrado”. The flowers are tubular in shape, yellow, nectariferous and pollinated mainly by hummingbirds. Despite the biological interest displayed by this plant, phytochemical studies so far have been done with its roots and leaves. Thus, this work was aimed to perform the chemical characterization of the floral scent in Z. montana by means of GC/MS analysis. Recently-opened flower samples were enclosed within a 20 mL borosilicate glass vial and analyzed on a Thermo Scientific Focus system, equipped with an ISQ 230ST mass spectrometer and a Triplus automatic sampler. Separations were achieved by using an OV5-MS column, under optimized conditions. Tentative identification of the volatiles was based on the comparison of their mass spectral data and retention index against those from NIST data base or literature. This approach revealed, for the first time, that the floral scent of Z. montana comprises a complex mix of at least 32 compounds. They were recognized as normal chain aldehydes, polyunsaturated ketones, non-terpenic hydrocarbons, phenylpropanoids, and sesquiterpenes. Further biological investigations are underway to elucidate the chemical-biological dynamic of its reproductive biology.