An approach to chemotaxonomy to the fatty acid content of some Malvaceae species Ana Carolina Oliveira da Silva a , Antonio Fernando Morais de Oliveira b , Déborah Yara Alves Cursino dos Santos c , Suzene Izídio da Silva a, * a Department of Botany, Federal Rural University of Pernambuco, 52171-900 Recife, PE, Brazil b Department of Botany, Federal University of Pernambuco, 50670-901 Recife, PE, Brazil c Department of Botany, University of Sao Paulo, 05422-970 São Paulo, SP, Brazil article info Article history: Received 5 August 2010 Accepted 9 October 2010 Available online 30 October 2010 Keywords: Caatinga Oilseeds Phenetic Taxonomy abstract Malvales is an order of flowering plants with a controversial circumscription. The rela- tionships between taxa, particularly Malvaceae, Bombacaceae, Sterculiaceae, and Tiliaceae, are not well delineated. Several studies have reported the fatty acid compositions of Malvaceae plants but not for taxonomic purposes. In the present study, the fatty acid composition of oilseeds from seven species belonging to the Malvaceae family was determined by capillary gas chromatography/mass spectrometry (GC/MS), and the quan- titative distribution of fatty acids was analyzed by a cluster analysis with Euclidean Distance and UPGMA. The oil content in the seeds was very low (8.3–11.8%). The profile of fatty acids showed that there were two distinct groups: species rich in palmitic acid (Herissantia tiubae, Sidastrum paniculatum and Sida rhombifolia) and species rich in linoleic acid (other Sida species). The fatty acid profiles found for Sida species are consistent with other reported data. Although our data support a distinction between Sida and Sidastrum, more species should be analyzed to evaluate the real taxonomic value of differences in fatty acid content for distinguishing Malvaceae. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction The Malvaceae comprises a family with 250 genera and 4230 species (Simpson, 2006) that are distributed worldwide and are particularly abundant in tropical South America (Heywood, 1993). In Brazil, the family is represented by 31 genera and 200 species (Barroso et al., 2002). The Malvales contains taxa consisting of four traditional families - Malvaceae, Bombacaceae, Sterculiaceae, and Tiliaceae, but molecular analyses have revealed that these families do not form natural monophyletic groups (Alverson et al., 1998; Bayer et al., 1999). Thus, the understanding of evolutionary relationships within these groups is still inadequate, and more studies are needed (Alverson et al., 1999; Fryxell, 1997). An alternative classification of Malvaceae (tribe Malveae, ca. 60 genera), the most diverse family among the five currently recognized, was proposed by Bates (1968) based on chromosome numbers; this proposal arranged the tribe into 54 genera and 13 generic alliances. New alliances have been proposed by other authors, including the generic alliance of Sida with 11 genera (Akrosida, Allosidastrum, Dendrosida, Krapovickasia, Malvella, Meximalva, Rhynchosida, Sida, Sidasodes, Sidastrum, and Tetrasidas). This alliance is characterized by basic chromosome numbers and morphologies of fruits and pollen (Fryxell, 1988; Fryxell and Fuertes, 1992). * Corresponding author. Tel.: þ55 81 33206350; fax: þ55 81 33206360. E-mail address: suzene@db.ufrpe.br (S. Izídio da Silva). Contents lists available at ScienceDirect Biochemical Systematics and Ecology journal homepage: www.elsevier.com/locate/biochemsyseco 0305-1978/$ – see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.bse.2010.10.006 Biochemical Systematics and Ecology 38 (2010) 1035–1038