An approach to chemotaxonomy to the fatty acid content of some Malvaceae species

Malvales is an order of flowering plants with a controversial circumscription. The relationships 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 quantitative 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.

Cluster similarities of some species of Malvaceae based on the distributions of fatty acids indicated that there were two distinct groups: 1) species rich in palmitic acid (Herissantia tiubae, Sidastrum paniculatum, and Sida rhombifolia) and 2) species rich in linoleic acid (Sida cordifolia, Sida spinosa, Sida salzmanii, and Sida galheirensis). Figure optionsDownload as PowerPoint slideResearch highlights
► A cluster analysis based on the distributions of fatty acids showed species of Malvaceae rich in palmitic and linoleic acids.
► Linoleic acid could be a good marker for distinction between Sida species and other Malvaceae genera.
► The fatty acid profiles of seed oils do not clearly support the placement of Sida rhombifolia within the Sida core.
► Our data support a distinction between Sida and Sidastrum.