THE METABOLIC FATE OF 5-ETHYL-1-METHYL-5-PHENYL HYDANTOIN (1-METHYLNIRVANOL) AND THAT OF 3,5-DIETHYL-5-PHENYL HYDANTOIN (3-ETHYLNIRVANOL)

¹ Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina

The metabolic fate in the dog of 5-ethyl-1-methyl-5-phenyl hydantoin (1-methylnirvanol) and that of 3,5-diethyl-5-phenyl hydantoin (3-ethylnirvanol) have been investigated.

Both of these compounds are in part dealkylated to yield 5-ethyl-5-phenyl hydantoin (Nirvanol), which has been isolated from urine and identified. The Nirvanol isolated from urine consisted of unequal mixtures of the optical isomers. The preponderant isomer after administration of Nirvanol was levorotatory, after 3-ethylnirvanol dextrorotatory, and after 1-methylnirvanol dextrorotatory in one dog and levorotatory in another.

The amount of Nirvanol isolated from urine was much smaller after administration of the 1-methyl and 3-ethyl derivatives of Nirvanol than after administration of Nirvanol itself. It was concluded that these derivatives of Nirvanol, unlike Mesantoin (3-methylnirvanol), are only in part converted to Nirvanol and that they undergo reactions other than dealKylation.