Abstract:
Pachystigma pygmaeum is a rubiaceous plant which causes heart failure after ingestion by ruminants.
Isolation or characterization of a toxic entity has hitherto been unsuccessful. Extraction of the plant material with
water or organic solvents gave poor yields of toxicity in guinea-pigs because of some unusual properties of the
toxic entity. We present a method whereby liberation of a toxic entity from the plant material was achieved by
fermentation with baker's yeast to give a crude extract with sufficient yield of toxicity for use in further isolation
work.