82695-93-0

Basic information

• Product Name: (S)-4-Hydroxy Mephenytoin
• Synonyms: (S)-4-Hydroxy Mephenytoin;(5S)-5-Ethyl-5-(4-hydroxyphenyl)-3-Methyl-2,4-iMidazolidinedione;(S)-5-Ethyl-5-(4-hydroxyphenyl)-3-Methyl-2,4-iMidazolidinedione
• CAS NO: 82695-93-0
• Molecular Formula: C12H14N2O3
• Molecular Weight: 234.25116
• Product Categories: Heterocycles;Hydantoins & Derivatives;Intermediates & Fine Chemicals;Isotope Labelled Compounds;Metabolites & Impurities;Pharmaceuticals
• Mol File: 82695-93-0.mol

Chemical Properties

• Melting Point: 188-191°C
• Appearance: /
• Storage Temp.: -20°C Freezer
• Solubility: Aqueous Base (Slightly), DMSO (Slightly), Ethyl Acetate (Slightly), Methanol （Slightly）
• CAS DataBase Reference: (S)-4-Hydroxy Mephenytoin(CAS DataBase Reference)
• NIST Chemistry Reference: (S)-4-Hydroxy Mephenytoin(82695-93-0)
• EPA Substance Registry System: (S)-4-Hydroxy Mephenytoin(82695-93-0)

Safety Data

• Hazardous Substances Data: 82695-93-0(Hazardous Substances Data)

Usage

Chemical Properties

White Solid

Uses

The S-enantiomer metabolite of Mephenytoin (M225000).

Upstream product

• 77-78-1 dimethyl sulfate 
• 61837-66-9 5-ethyl-5-(4-hydroxyphenyl)hydantoin 
• 70-70-2 4-hydroxypropiophenone 
• 70989-04-7 S-mephenytoin 
• 136232-95-6 buprenorphine hydrochloride 
• 71140-51-7 (-)-Mephenytoin 

Relevant articles and documents

Identification and functional validation of novel pharmacogenomic variants using a next-generation sequencing-based approach for clinical pharmacogenomics

Inter-individual variability in pharmacokinetics and drug response is heavily influenced by single-nucleotide variants (SNVs) and copy-number variations (CNVs) in genes with importance for drug disposition. Nowadays, a plethora of studies implement next generation sequencing to capture rare and novel pharmacogenomic (PGx) variants that influence drug response. To address these issues, we present a comprehensive end-to-end analysis workflow, beginning from targeted PGx panel re-sequencing to in silico analysis pipelines and in vitro validation assays. Specifically, we show that novel pharmacogenetic missense variants that are predicted or putatively predicted to be functionally deleterious, significantly alter protein activity levels of CYP2D6 and CYP2C19 proteins. We further demonstrate that variant priorization pipelines tailored with functional in vitro validation assays provide supporting evidence for the deleterious effect of novel PGx variants. The proposed workflow could provide the basis for integrating next-generation sequencing for PGx testing into routine clinical practice.

In vitro evaluations for pharmacokinetic drug-drug interactions of a novel serotonin-dopamine activity modulator, brexpiprazole

Brexpiprazole, a serotonin-dopamine activity modulator, is indicated for the treatment of schizophrenia and also adjunctive therapy to antidepressants for the treatment of Major Depressive Disorder. To determine the drug–drug interaction risk for cytochrome P450, and SLC and ABC transporters, brexpiprazole and its metabolite, DM-3411 were assessed in this in?vitro investigation. Brexpiprazole exhibited weak inhibitory effects (IC50 >13 μmol/L) on CYP2C9, CYP2C19, CYP2D6 and CYP3A4 activities, but had moderate inhibitor activity on CYP2B6 (IC50 8.19 μmol/L). The ratio of systemic unbound concentration (3.8 nmol/L) to the Ki value was sufficiently low. DM-3411 had comparable inhibitory potentials with brexpiprazole only for CYP2D6 and CYP3A4. The mRNA expressions of CYP1A2, CYP2B6 and CYP3A4 were not changed by the exposure of brexpiprazole to human hepatocytes. Brexpiprazole and DM-3411 exhibited weak or no inhibitory effects for hepatic and renal transporters (OATPs, OATs, OCTs, MATE1, and BSEP), except for MATE-2K (0.156 μmol/L of DM-3411), even for which the ratio to systemic unbound concentration (5.3 nmol/L) was sufficiently low. Brexpiprazole effected the functions of P-gp and BCRP with IC50 values of 6.31 and 1.16 μmol/L, respectively, however, the pharmacokinetic alteration was not observed in the clinical concomitant study on P-gp and BCRP substrates. These in?vitro data suggest that brexpiprazole is unlikely to cause clinically relevant drug interactions resulting from the effects on CYPs or transporters mediating the absorption, metabolism, and/or disposition of co-administered drugs.

Impact of cytochrome P450 variation on meperidine N-demethylation to the neurotoxic metabolite normeperidine

1. Meperidine is an opioid analgesic that undergoes N-demethylation to form the neurotoxic metabolite normeperidine. Previous studies indicate that meperidine N-demethylation is catalyzed by cytochrome P450 2B6 (CYP2B6), CYP3A4, and CYP2C19. 2. The purpose of this study was to examine the relative P450 contributions to meperidine N-demethylation and to evaluate the effect of CYP2C19 polymorphism on normeperidine generation. Experiments were performed using recombinant P450 enzymes, selective chemical inhibitors, enzyme kinetic assays, and correlation analysis with individual CYP2C19-genotyped human liver microsomes. 3. The catalytic efficiency (kcat/Km) for meperidine N-demethylation was similar between recombinant CYP2B6 and CYP2C19, but markedly lower by CYP3A4. 4. In CYP2C19-genotyped human liver microsomes, normeperidine formation was significantly correlated with CYP2C19 activity (S-mephenytoin 4′-hydroxylation). 5. CYP2C19 inhibitor (+)-N-3-benzylnirvanol and CYP3A inhibitor ketoconazole significantly reduced microsomal normeperidine generation by an individual donor with high CYP2C19 activity, whereas donors with lower CYP2C19 activity were sensitive to inhibition by ketoconazole but not benzylnirvanol. 6. These findings demonstrate that the relative CYP3A4, CYP2B6, and CYP2C19 involvement in meperidine N-demethylation depends on the enzyme activities in individual human liver microsomal samples. CYP2C19 is likely an important contributor to normeperidine generation in individuals with high CYP2C19 activity, but additional factors influence inter-individual metabolite accumulation.

Evaluation of Cytochrome P450 Selectivity for Hydralazine as an Aldehyde Oxidase Inhibitor for Reaction Phenotyping

Hydralazine has been reported as a selective mechanism-based inactivator of aldehyde oxidase (AO) and it is widely used in the pharmaceutical industry for reaction phenotyping to estimate fraction metabolized by AO and to identify AO substrates. In this study, however, hydralazine was found to inhibit CYP1A2, 2B6, 2D6, and 3A in human suspension hepatocytes under reaction phenotyping assay conditions, at concentrations that chemically knocked out most of the AO activities (≥50 μM). Furthermore, hydralazine is a time-dependent inhibitor of CYP1A2. Based on these findings, precautions need to be taken when using hydralazine as an AO inhibitor for in vitro studies because fraction metabolized by AO is likely to be overestimated and the likelihood of false positives in identifying AO substrates increases.

Effects of artemisinin antimalarials on Cytochrome P450 enzymes in vitro using recombinant enzymes and human liver microsomes: Potential implications for combination therapies

1. Cytochrome P450 enzyme system is the most important contributor to oxidative metabolism of drugs. Modification, and more specifically inhibition, of this system is an important determinant of several drug-drug interactions (DDIs). 2. Effects of the antimalarial agent artemisinin and its structural analogues, artemether, artesunate and dihydroartemisinin, on seven of the major human liver CYP isoforms (CYP1A2, 2A6, 2B6, 2C9, 2C19, 2D6 and 3A4) were evaluated using recombinant enzymes (fluorometric assay) and human liver microsomes (LC-MS/MS analysis). Inhibitory potency (IC50) and mechanisms of inhibition were evaluated using nonlinear regression analysis. In vitro-in vivo extrapolation using the [I]/Ki ratio was applied to predict the risk of DDI in vivo. 3. All compounds tested inhibited the enzymatic activity of CYPs, mostly through a mixed type of inhibition, with CYP1A2, 2B6, 2C19 and 3A4 being affected. A high risk of interaction in vivo was predicted if artemisinin is coadministrated with CYP1A2 or 2C19 substrates. 4. With respect to CYP1A2 inhibition in vivo by artemisinin compounds, our findings are in line with previously published data. However, reported risks of interaction may be overpredicted and should be interpreted with caution.

Cytochrome P450 metabolic activities in the small intestine of cynomolgus macaques bred in cambodia, china, and indonesia

Summary: Cynomolgus macaques, used in drug metabolism studies due to their evolutionary closeness to humans, are mainly bred in Asian countries, including Cambodia, China, and Indonesia. Cytochromes P450 (P450s) are important drug-metabolizing enzymes, present in the liver and small intestine, major drug metabolizing organs. Previously, our investigation did not find statistically significant differences in hepatic P450 metabolic activities measured in cynomolgus macaques bred in Cambodia (MacfaCAM) and China (MacfaCHN). In the present study, P450 metabolic activity was investigated in the small intestine of MacfaCAM and MacfaCHN, and cynomolgus macaques bred in Indonesia (MacfaIDN) using P450 substrates, including 7-ethoxyresorufin, coumarin, bupropion, paclitaxel, diclofenac, S-mephenytoin, bufuralol, chlorzoxazone, and testosterone. The results indicated that P450 metabolic activity of the small intestine was not statistically significantly different (2.0-fold) in MacfaCAM, MacfaCHN, and MacfaIDN. In addition, statistically significant sex differences were not observed (2.0-fold) in any P450 metabolic activity in MacfaCAM as supported by mRNA expression results. These results suggest that P450 metabolic activity of the small intestine does not significantly differ statistically among MacfaCAM, MacfaCHN, and MacfaIDN.

Potent Mechanism-Based Inhibition of Human CYP2B6 by Clopidogrel and Ticlopidine

The thienopyridine derivatives ticlopidine and clopidogrel are inhibitors of ADP-induced platelet aggregation. Pharmacological activity of these prodrugs depends on cytochrome P450 (P450)-dependent oxidation to the active antithrombotic agent. In this study, we investigated the interaction potential of clopidogrel and ticlopidine by using human liver microsomes and recombinantly expressed P450 isoforms. Both clopidogrel and ticlopidine inhibited CYP2B6 with highest potency and CYP2C19 with lower potency, Clopidogrel also inhibited CYP2C9, and ticlopidine also inhibited CYP1A2, with lower potency. Inhibition of CYP2B6 was time- and concentration-dependent, and as shown by dialysis experiments, it was irreversible and dependent on NADPH, suggesting a mechanism-based mode of action. Inactivation was of nonpseudo-first-order type with maximal rates of inactivation (K inact) for clopidogrel and ticlopidine in microsomes (recombinant CYP2B6) of 0.35 (1.5 min-1) and 0.5 min-1 (0.8 min -1), respectively, and half-maximal inactivator concentrations (KI) were 0.5 μM (1.1 μM) for clopidogrel and 0.2 μM (0.8 μM) for ticlopidine. Inhibition was attenuated by the presence of alternative active site ligands but not by nucleophilic trapping agents or reactive oxygen scavengers, further supporting mechanism-based action. A chemical mechanism is discussed based on the known metabolic activation of clopidogrel and on the finding that hemoprotein integrity of recombinant CYP2B6 was not affected by irreversible inhibition. These results suggest the possibility of drug interactions between thienopyridine derivates and drug substrates of CYP2B6 and CYP2C19.

Identification of human cytochrome P450s that metabolise anti-parasitic drugs and predictions of in vivo drug hepatic clearance from in vitro data

Objective: Knowledge about the metabolism of anti-parasitic drugs (APDs) will be helpful in ongoing efforts to optimise dosage recommendations in clinical practise. This study was performed to further identify the cytochrome P450 (CYP) enzymes that metabolise major APDs and evaluate the possibility of predicting in vivo drug clearances from in vitro data. Methods: In vitro systems, rat and human liver microsomes (RLM, HLM) and recombinant cytochrome P450 (rCYP), were used to determine the intrinsic clearance (CLint) and identify responsible CYPs and their relative contribution in the metabolism of 15 commonly used APDs. Results and discussion: CLint determined in RLM and HLM showed low (r2=0.50) but significant (Pint values were scaled to predict in vivo hepatic clearance (CLH) using the 'venous equilibrium model'. The number of compounds with in vivo human CL data after intravenous administration was low (n=8), and the range of CL values covered by these compounds was not appropriate for a reasonable quantitative in vitro-in vivo correlation analysis. Using the CLH predicted from the in vitro data, the compounds could be classified into three different categories: high-clearance drugs (> 70% liver blood flow; amodiaquine, praziquantel, albendazole, thiabendazole), low-clearance drugs (int drug categories. The identified CYPs for some of the drugs provide a basis for how these drugs are expected to behave pharmacokinetically and help in predicting drug-drug interactions in vivo.

Inhibition of human drug metabolizing cytochrome P450 by buprenorphine

The effects of buprenorphine, a powerful mixed agonist/antagonist analgesic, on several cytochrome P450 (CYP) isoform specific reactions in human liver microsomes were investigated to predict drug interaction of buprenorphine in vivo from in vitro data. The following eight CYP-catalytic reactions were used in this study: CYP1A1/2-mediated 7-ethoxyresorufin O-deethylation, CYP2A6-mediated coumarin 7-hydroxylation, CYP2B6-mediated 7-benzyloxyresorufin O-debenzylation, CYP2C8/9-mediated tolbutamide methylhydroxylation, CYP2C19-mediated S-mephenytoin 4-hydroxylation, CYP2D6-mediated bufuralol 1′-hydroxylation, CYP2E1-mediated chlorzoxazone 6-hydroxylation, and CYP3A4-mediated testosterone 6β-hydroxylation. Buprenorphine strongly inhibited the CYP3A4- and CYP2D6-catalyzed reactions with Ki values of 14.7 μM and 21.4 μM, respectively. The analgesic also weakly inhibited specific reactions catalyzed by CYP1A1/2 (Ki=132 μM), CYP2B6 (Ki=133 μM), CYP2C19 (Ki=146 μM), CYP2C8/9 (IC50>300 μM), and CYP2E1 (IC 50>300 μM), but not CYP2A6 mediated pathway. In consideration of the Ki values obtained in this study and the therapeutic concentration of buprenorphine in human plasma, buprenorphine would not be predicted to cause clinically significant interactions with other CYP-metabolized drugs.