Bioactive Saponins from Some Plants Used in Indian Traditional Medicine

Abstract

Saponins are naturally occurring glycosides characterised by foaming in water, and by producing haemolysis when water solutions are injected into the blood stream. The aglycone parts of these molecules are usually triterpenoids or steroids or steroidal alkaloids and the glycone parts are generally oligosaccharides, linear or branched, attached to a hydroxyl or a carboxyl group or both. The sites of attachment may be one (monodesmosides), two (bisdesmosides) or three (tridesmosides). These natural products were initially a rather neglected area of research primarily because of great difficulties in their isolation and characterisation. With the advent of more sophisticated methods of isolation and structure elucidation through the last two decades, there has been great interest in these products. The diversity of structural features, the challenges of isolation because of their occurrence as complex mixtures, the beneficial biological activities still to be discovered, and the prospect of commercialisation — these all are driving the increased interest in saponins.