Fig. 28.1.

Structures of plant saponins. Triterpenoid saponins (top panel  ): avenacin A-1 from oat roots (Avena spp.), chromosaponin I from pea seed (Pisum sativum), ginsenoside Rg₁ from ginseng roots (Panax spp.), soyasaponin I (also known as soyasaponin Bb) from soya (Glycine max), avicin D from Acacia victoriae seed pods, glycyrrhizin from liquorice roots (Glycyrrhiza spp.) and QS21 from Quillaja saponaria bark. Examples of both monodesmosidic (one sugar chain) and bisdesmosidic (two sugar chains) saponins are shown. Bottom panels: Steroidal glycoalkaloid α-tomatine from tomato leaves (Solanum lycopersicum); the steroidal saponin avenacoside A from oat leaves (Avena spp.)