The alkaloids of tylophora crebriflora characterization and structural determination of tylocrebrine

Examination of the whole plant of Tylophora c r e b r i - f l o r a , an Australian Tyiophora species of the Asclepiadaceae family, showed the presence of two alkal o i d s » Traces of a third "base were also detected hut the "base i t s e l f could not be isolated and i t s presence was estab3j.shed only by paper chromatograms in the i n i t i a l crude extracts. A small-scale laboratory extraction indicated an alkaloidal content of 0.33?i dry weight, but large-scale extractions from l a t e r c o l l e c t - ions did not exceed a t o t a l y i e l d of 0#159i. The two alkaloids were separated by p a r t i