Structural identification of prostaglandin A1 biotransformation products from tumor cells.

Rat B104 neuroblastoma and C6 glioma cells are able to metabolize prostaglandin A1 (PGA1). Four metabolites were isolated by high performance liquid chromatography. Their structure was elucidated by fast atom bombardment mass spectrometry and 1H nuclear magnetic resonance. It appears that these biotransformation products are two sets of stereoisomers: the two isomers that eluted first are 9 alpha- and 9 beta-hydroxy-11 alpha-cysteinylglycyl adducts whereas the other two are 9 alpha- and 9 beta-hydroxy-11 alpha-cysteinyl derivatives. These compounds were compared with authentic samples prepared by Michael addition of the corresponding thiol onto PGA1, then by reduction with sodium borohydride.