Chemical Properties
White Crystalline Solid
Uses
S-Mephenytoin has been used as a CYP2C19 substrate for the analysis of cytochrome P450 metabolism. S-Mephenytoin has also been used as probe substrates for LC/MS-based analysis of relative activity factor (RAF).
Uses
(S)-Mephenytoin can be used as an anticonvulsant agent.
Definition
ChEBI: (S)-Mephenytoin is an imidazolidine-2,4-dione.
Biological Activity
(s)-mephenytoin is an anticonvulsive drug which is metabolized by n-demethylation and 4-hydroxylation (of the aromatic ring). (s)-mephenytoin is a substrate of the cytochrome p450 (cyp) isoform cyp2c19, also known as mephenytoin 4-hydroxylase [1].cyp2c19 is the main mephenytoin 4-hydroxylase in humans implicated in metabolizing a variety of therapeutic agents, such as omeprazole, proguanil, diazepam, propranolol, citalopram, imipramine, and certain barbiturates [2].
Biochem/physiol Actions
CYP2B6 & CYP2C19 substrate. Methenytoin isomer. Anticonvulsant; antiepileptic.
in vitro
in the presence of cytochrome b5, the km value for s-mephenytoin was 1.25 mm with all five purified cytochrome p-450s preparations, and vmax values were 0.8-1.25 nmol of 4-hydroxy product formed per min/nmol of p-450 [1].
References
[1] shimada t, misono k s, guengerich f p. human liver microsomal cytochrome p-450 mephenytoin 4-hydroxylase, a prototype of genetic polymorphism in oxidative drug metabolism. purification and characterization of two similar forms involved in the reaction[j]. journal of biological chemistry, 1986, 261(2): 909-921.
[2] ferguson r j, de morais s m f, benhamou s, et al. a new genetic defect in human cyp2c19: mutation of the initiation codon is responsible for poor metabolism of s-mephenytoin[j]. journal of pharmacology and experimental therapeutics, 1998, 284(1): 356-361.
