Self-organizing maps in chemotaxonomic studies of Asteraceae: A classification of tribes using flavonoid data

Abstract

Flavonoids have shown good chemical markers for Asteraceae. In this paper, 4,700 occurrences of flavonoids (about 800 compounds) were considered in an expert system developed for taxonomic purposes. Through the use of Self-Organizing Maps (SOM) phylogenetic relationships among the subfamilies and tribes of Asteraceae were established. These taxa were classified on the basis of their occurrences and oxidation patterns of the flavonoids. The obtained results show the separation between the two subfamilies of Asteraceae the correlation among the tribes of the Cichiroideae subfamily according to the topological tree proposed by Karis the clustering of the tribes according to the tree proposed by Jansen based on CpDNA and the separation of the tribes classified in the Asteroideae subfamily as well as the tribes based on the methoxylation x glycosylation level in flavonoids. From these results one can affirm that the method applied with chemical data can be used as a complementary tool in plant classification. ©2007 Sociedade Brasileira de Química.