RT Journal Article SR Electronic T1 Metabolic fate of phenobarbital in man. N-Glucoside formation. JF Drug Metabolism and Disposition JO Drug Metab Dispos FD American Society for Pharmacology and Experimental Therapeutics SP 315 OP 318 VO 7 IS 5 A1 B K Tang A1 W Kalow A1 A A Grey YR 1979 UL http://dmd.aspetjournals.org/content/7/5/315.abstract AB 1-(beta-D-Glucopyranosyl)phenobarbital was identified as the major metabolite of phenobarbital in man. Proof of structure was based on the comparison of the UV, NMR, and mass spectrometry and TLC data for the acetylated metabolite with an authentic compound. The previous erroneous structure assignment of this metabolite as N-hydroxyphenobarbital was based on insufficient data. After oral administration of 14C-labeled phenobarbital to two healthy male subjects, most of the radioactivity (87 and 78% of the dose) was recovered in urine over a period of 16 days. The N-glucopyranoside, p-hydroxyphenobarbital, and unchanged phenobarbital accounted for 30 and 24%, 18 and 19%, and 33 and 25% of the dose, respectively.