Preparation, characterisation and some properties of saponins from lucerne tops and roots

Lucerne saponin extracts have been prepared from lucerne tops and roots by two different methods. The root extracts possess stronger haemolytic activity and to a certain extent are stronger foaming agents than those from the tops. Thin-layer chromatographic (t.l.c.) analyses showed that acid hydrolysates of the different preparations contain soyasapogenols A, B, C, D, E, medicagenic acid and an unidentified sapogenin-like spot. When submitted to t.l.c. and paper electrophoresis the first pair of extracts have been separated into six fractions each, and the other extracts into seven fractions each. The root extract and to a lesser extent that from the tops, depress growth of Tribolium castaneum larvae but the inhibitory effect can be reversed when cholesterol is incorporated in the diet. Germination of cotton seeds is inhibited in soils on which lucerne has been grown or on soils supplemented with lucerne meal from tops and roots.