Composition and chemical polymorphism of the essential oils from Piper lanceaefolium.

Essential oils obtained by hydrodistillation from leaves and spikes of Piper lanceaefolium H.B.K. of Costa Rica were analysed by GC-FID, GC-MS and 13C-NMR methods. Main constituents found in the oil from leaves were sesquiterpene hydrocarbons - especially beta-caryophyllene and germacrene D - and phenylpropanoids, of which elemicin and parsley apiol were the major ones. The volatile oil from spikes showed monoterpene hydrocarbons, namely alpha- and beta-pinene, and the same phenylpropanoids as in the oil from leaves as the major constituents. Results obtained in the analysis by GC-FID and GC-MS of the essential oils from individual plants of different geographic origin were submitted to chemometric cluster analysis and principal component analysis, showing the presence of three different types of oils (i) parsley apiol/elemicin, (ii) elemicin/parsley apiol/dill apiol, and (iii) parsley apiol/dill apiol.