（S）-Mephenytoin是乙内酰脲小分子，最初因其抗惊厥作用而发现并实施。个人表现出可变的能力来执行与CYP2C19中的多态性相关的4'-位（S）-甲妥英羟化反应，CYP2C19是细胞色素P-450系统中的一种氧化酶。较弱的代谢物表型，即那些不能通过4'-羟基化代谢（S）-Mephenytoin的表型，也显示出清除其他药物和异种生物素的能力降低，并且已使用该（S）-Mephenytoin代谢实验来探索其含义。药物设计中常见的表型病状和毒性预期。（S）-Mephenytoin是CYP2B6和CYP2C 应用： S-美芬妥因已被用作 CYP2C19 底物，用于分析细胞色素 P450 代谢。S-美芬妥因也被用作基于 LC/MS 的相对活性因子（RAF）分析的探针底物。 (S)-Mephenytoin is a hydantoin small molecule, originally discovered and implemented for its anticonvulsant effects. Individuals present a variable ability to perform hydroxylation of (S)-Mephenytoin at the 4'-position associated with polymorphism in CYP2C19, an oxidase in the cytochrome P-450 system. The poor metabolizer phenotype, those incapable of metabolizing (S)-Mephenytoin by 4'-hydroxylation, also show a reduced ability to clear other pharmaceuticals and xenobiotics, and this (S)-Mephenytoin metabolism experiment has been used to explore the implications of this common phenotypic condition in drug design and toxicity expectations. (S)-Mephenytoin is a substrate of CYP2B6 and CYP2C19. Application： 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).