Chemotaxonomic analysis of Astragalus caprinus (Fabaceae) based on the flavonic patterns

In previous work, 14 flavonol glycosides were characterised in the leaves of Astragalus caprinus, an endemic Fabaceae, widely distributed in North West Africa. These compounds included quercetin and kaempferol derivatives, glycosylated by two, three or four sugars with an aliphatic or aromatic acyl moiety. In this paper, we describe the flavonoid patterns of 404 individual plants investigated by HPLC and subjecting the resulting data to cluster analysis. This analysis highlighted four chemotypes associated with a high accumulation of a kaempferol triglycoside, a kaempferol tetraglycoside with its acylated derivatives, two quercetin tetraglycoside derivatives and methylated diglycoside derivatives, respectively. A discriminant analysis validated the chemotaxonomic value of the four chemical polymorphisms. These chemotypes were more or less abundant according to geographical sites which corresponded to different climatic conditions.