Genus Astragalus saponins from

Advances in research are performed on the genus Astragalus and about 100 different species have been chemically studied imtill now [249]. The genus appears highly uniform from a chemical point of view, with three kinds of biologically active principles and three diffent groups of toxic compounds. The active constituents are saponins, flavonoids, and polysaccharides, while nitro-compoimds, indolizidine alkaloids and the seleniferous derivatives are included in the poisonous groups. 

Structure determination of sapogenins and saponins from genus Astragalus originally involves a combination of chromatographic, chemical and spectral methods nuclear magnetic resonance spectroscopy (NMR) with chemical transformation and enzymatic degradation, as well as MS (mass spectroscopy). 

Astragalus genus is one of the richest source of cycloartane saponins. Oleanane type saponins are also found in Astragalus sp., but their occurrence is limited to structures common to Leguminosae. Fig (3) shows the naturally occurring cycloartanes and oleananes which have been isolated from different Astragalus species. 

During the almost 20-years of research on Astragalus sapogenins and saponins, more than 40 species from this genus have been studied and above 40 triterpenoid sapogenins and up to 130 saponins have been isolated and identified until now, and for some of them the biological activity has also been studied. 

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