Cuticular n-alkane in leaves of seven Neotropical species of the family Lecythidaceae: a contribution to chemotaxonomy

Abstract

Biosynthesized from very long-chain fatty acid wax precursors, n-alkanes m a k e a valuable contribution to the taxonomy of plants . Th e alk ane comp onents of foliar epicuticles of seven Neotropical s p e c i e s o f Lecythidaceae were investigated: Bertholletia excelsa, Cariniana legalis, Couroupita guianensis, Eschweilera alvimii, Eschweilera ovata, Gustavia augusta and Lecythis pisonis. Specimens were collected in the metropolitan area of Recife, Pernambuco, and their n-alkane fractions were analyzed by gas chromatography. Th e chemical relationships among the species were then evaluated using cophenetic correlation and UPGMA. Among the seven species, a total of 15 n-alkanes, with 21-35 carbon atoms, were identifi ed and formed a consistent group of B. excelsa, C. guianensis, E. ovata, G. augusta, and L. pisonis with n-C31. Th e greatest similarities were found between B. excelsa and L. pisonis, and between C. guianensis and G. augusta. Nevertheless, a phenetic analysis based on a larger number of species is needed to better understand the chemotaxonomic value of epicuticular n-alkanes within the Lecythidaceae.