Influence of growth phase on the essential oil composition of Hyptis suaveolens Ma´rcio J. Oliveira a , Irani F.P. Campos b , Carolina B.A. Oliveira a , Marisa R. Santos a , Paulo S. Souza a , Suzana C. Santos a , Jose´ C. Seraphin c , Pedro H. Ferri a, * a Laborato ´rio de Bioatividade Molecular, Instituto de Quı´mica, Universidade Federal de Goia ´s, C.P. 131, 74001-970 Goia ˆnia, GO, Brazil b Instituto de Cieˆncias Biolo ´gicas, Universidade Federal de Goia ´s, C.P. 131, 74001-970 Goia ˆnia, GO, Brazil c Nu ´cleo de Estatı´stica Aplicada, Instituto de Matema ´tica e Estatı´stica, Universidade Federal de Goia ´s, C.P. 131, 74001-970 Goia ˆnia, GO, Brazil Received 9 June 2003; accepted 20 August 2004 Abstract The chemical composition of the essential oils of seven populations of Hyptis suaveolens in vegetative, flowering and fruiting stages and their interpopulation variability were investigated by GC–MS. Sabinene, limonene, 1,8-cineole, (E )-caryophyllene and spathulenol were the principal constituents. The results from the chemical analysis were submitted to Principal Component and Chemometric Cluster Analysis which allowed five groups of populations to be distinguished with respect to the stage of growth and high content of bicyclogermacrene/ terpin-4-ol, sabinene, 1,8-cineole/spathulenol, limonene/g-terpinene and spathulenol/(E )- caryophyllene. Pattern of geographic-variation in essential oil composition indicated that monoterpene hydrocarbons were mainly produced in plants from sampling sites located in higher latitudes and altitudes regardless of the phase of growth, while sesquiterpenes were * Corresponding author. Tel./fax: C55 21 62 521 1167. E-mail address: pedro@quimica.ufg.br (P.H. Ferri). 0305-1978/$ - see front matter Ó 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.bse.2004.10.001 Biochemical Systematics and Ecology 33 (2005) 275–285 www.elsevier.com/locate/biochemsyseco