PREGNANE GLYCOSIDES FROM CARALLUMA-RETROSPICIENS

Two pregnane ester glycosides were isolated and identified from the al cohol extract of the aerial parts of Caralluma retrospiciens. Their st ructures were established as 12 beta-benzoyloxy-20-isovaleroyloxy-8 be ta,14 ->4)-beta-D-(3-O-methyl-6-deoxy)galactopyranoside] (caretroside A) and the bioside 12 beta-benzoyloxy-8 beta,14 leandropyranosyl-(1--> 4)-beta-D-cymaropyranoside]. They were characterized through physical and chemical methods in addition to standard spectroscopic techniques especially 2D NMR (COSY, HMQC and HMBC). This is the first report of t he isolation of these compounds from a natural source.