Volatile profile of Catharanthus roseus (L.) G. Don plant determined by Solid-phase microextraction and Gas Chromatography/Mass Spectrometry

A total of 126 volatile and semi-volatile components were identified and semi-quantified in flowers, leaves and stems of Catharanthus roseus (L.) G. Don (formerly Vinca rosea L., Apocynaceae), by headspace solid-phase microextraction (HS-SPME) combined to gas chromatography-mass spectrometry (GC-MS). The identification was achieved by comparing the retention times of the chromatographic peaks with those of authentic standards, the retention indices (as Kovats indices) and by comparison of the MS fragmentation pattern of the compounds with a mass spectrum database (NIST05). Some of the identified components have proved biological activity. These include some diterpenic compounds (manool and manoyl-oxides), a sesquiterpen (α-bisabolol), some pyridine, pyrazine, indol and carotenoid derivatives compounds. By applying multivariate analysis (principal component analysis and agglomerative hierarchic cluster analysis) to the HS-SPME-GC-MSMS results it was possible to characterize each part of the vegetal material using a relative small number of compounds. Hence, flowers were richer in terpen molecules (including limonene), α-bisabolol, methyljasmonate, cis-jasmone, 2-phenylethanol, phenylaceteldehyde, trans-2-octenal, benzylic alcohol and 2-isobutyl-3-methoxypyrazine. Leaves can be characterized by the methyl and propyl esters of fatty acids (C14-C18), mono and di-saturated, trans-phytol, carotenoid derivative compounds, hydrofarnesylacetone, methylanthranilate, manool and epi-manool oxide, while stems have high levels of volatile aldehydes, such as, C6, C7, C8 and C10, 2,6-nonadienal and 2,4-decadienal.

Acknowledgements: Fundação Calouste Gulbenkian, Patrícia Valentão.