Occurrence of highly oxygen-substituted androgens in hemofiltrates of uremic patients

The steroid fraction of hemofiltrate contains a large number of unknown steroids, which were separated by a combination of different chromatographic procedures and finally characterized by gas chromatography mass spectrometry. Besides different isomeric 3,16,17-trihydroxyandrostanes in a rather polar fraction a 3,16,17-trihydroxy-11-ketoandrostane was detected, obviously the first naturally occurring representative of 3,11,16,17-oxygen-tetrasubstituted androstanes.