RT Journal Article SR Electronic T1 EXCRETION AND STEREOSELECTIVE BIOTRANSFORMATIONS OF dl-, d-AND /-NORGESTREL IN WOMEN JF Drug Metabolism and Disposition JO Drug Metab Dispos FD American Society for Pharmacology and Experimental Therapeutics SP 180 OP 188 VO 3 IS 3 A1 SAMUEL F. SISENWINE A1 HAZEL B. KIMMEL A1 ANN L. LIU A1 HANS W. RUELIUS YR 1975 UL http://dmd.aspetjournals.org/content/3/3/180.abstract AB Excretion data and urinary metabolite patterns of dl-. d-. and /-norgestrel were obtained from women who received a single. oral 1 .5-mg dose of 14C-labeled racemic norgestrel ( Ng) or one of its enantiomers. The average percentage of administered radioactivity ± SD recovered in the urine after 7 days was 58. 1 ± 7.9% for dl-Ng. 44.8 ± 8.9% for d-Ng. and 63.6 ± 1 5. 1% for l-Ng; in feces it was 23.4 ± 7.7% ( dl-Ng). 31.6 ± 8.2% ( d-Ng). and 24.8 ± 10.7% (l-Ng). Different metabolite patterns were observed for each enantiomer in urine. and the pattern for the racemate appeared to be an approximate composite of the metabolite patterns of the two enantiomers. These differences in the metabolite pattern result from stereoselective transformations; notably 1 6f3-hydroxylation of l-Ng and ring A reduction of d-Ng. Other stereoselective pathways noted were: 1 6α-and 1β-hydroxylation as well as D-homoannulation of l-Ng and sulfate conjugation of I-16β-hydroxynorgestrel; 2α-hydroxylation of d-Ng. formation of a labile neutral. polar compound which contained the norgestrel moiety in the d-form. and formation of a glucuronide of d-16β-hydroxynorgestrel. The formation of phenolic derivatives occurred to a very minor degree from transformations of the biologically inactive l-enantiomer. With d-norgestrel. this formation occurred to an even lesser extent. if at all. Copyright © 1975 by The American Society for Pharmacology and Experimental Therapeutics