Journal: Xenobiotica; the fate of foreign compounds in biological systems

Article Title: In vitro metabolism of piperaquine is primarily mediated by CYP3A4

doi: 10.3109/00498254.2012.693972

Figure Lengend Snippet: The effect of isoform selective P450 inhibitors on piperaquine metabolism. The data is expressed as percent piperaquine remaining (mean ± SD of triplicate determinations) as a function of time following human liver microsome incubations in the presence of isoform selective P450 inhibitors. The starting concentration of piperaquine was 0.6 µM. The following concentrations of inhibitors were used: 1 µM ketoconazole (CYP3A4), 5 µM ticlopidine (CYP2C19), 20 µM furafylline (CYP1A2), 20 µM sulfaphenazole (2C9), and 25 µM quercetin (CYP2C8).

Article Snippet: Sulfaphenazole and furafylline were purchased from BD Biosciences (San Jose, CA).

Techniques: Concentration Assay

Journal: Cell

Article Title: Discovery of natural-product-derived sequanamycins as potent oral anti-tuberculosis agents

doi: 10.1016/j.cell.2023.01.043

Figure Lengend Snippet:

Article Snippet: Ketoconazole , BD Gentest , Cat#451023.

Techniques: Mutagenesis, Recombinant, Cell Culture, Methylation, Amplification, Software, Microscopy, RNA Extraction, Real-time Polymerase Chain Reaction

Journal: Drug Metabolism and Disposition

Article Title: Identification and Characterization of CINPA1 Metabolites Facilitates Structure-Activity Studies of the Constitutive Androstane Receptor

doi: 10.1124/dmd.116.071993

Figure Lengend Snippet: Metabolite formation in HLMs in the presence of specific P450 enzyme inhibitors. Specific inhibitors of various P450 isoforms (or DMSO control) were preincubated at the indicated concentrations with HLMs (0.5 mg/ml) and an NADPH regenerating system at 37°C for 15 minutes. (A and B) 5 µM CINPA1 (A) or Met1 (B) was added to the reaction mixtures, which were then incubated for an additional 30 minutes at 37°C. The reactions were terminated with acetonitrile and analyzed by LC/MS. The enzyme activity was calculated by measuring the amount of metabolite (Met1 or Met2) formed. (C) An esterase inhibitor, BNPP (250 µM), or DMSO (control) was preincubated with HLMs and an NADPH regenerating system at 37°C for 15 minutes as described earlier. Met1 (5 µM) was added to this mixture as the substrate, and the reaction was terminated after an additional 30 minutes of incubation at 37°C. The percent enzyme activity was calculated by normalizing the amount of metabolite formed in the absence of the inhibitor (DMSO) to 100%. Each bar represents the average of triplicate reaction wells ± S.D. One-way analysis of variance was used to compare the percent enzyme activity in the presence of each inhibitor to DMSO control. *P < 0.05. Unmarked bars indicate no significant change observed. The inhibitors used were ketoconazole (KTZ; CYP3A4), quinidine (Quin; CYP2D6), ticlopidine (Ticlo; CYP2C19), sulfaphenazole (SFZ; CYP2C9), quercetin (Querc; CYP2C8), thioTEPA (TT; CYP2B6), PCPA (CYP1A2), and BNPP (esterase). ns, not significant.

Article Snippet: Substrates, metabolite standards, internal standards, inhibitors, and other materials were obtained from the following sources: all anhydrous solvents, dimethylsulfoxide (DMSO), ketoconazole, N , N ′, N ′′-triethylenethiophosphoramide (thioTEPA), ticlopidine, quinidine, efavirenz, tolbutamide, phenacetin, bis( p -nitrophenyl) phosphate (BNPP), and acetaminophen (Sigma-Aldrich, St. Louis, MO); tranylcypromine (PCPA), quercetin, dextromethorphan, 1′-hydroxymidazolam, dextrorphan, hydroxytolbutamide, and (±)4-hydroxymephenytoin (Cayman Chemical, Ann Arbor, MI); sulfaphenazole, midazolam, and the NADPH regenerating system (Corning, Tewksbury, MA); S -mephenytoin (Santa Cruz Biotechnology, Dallas, TX); and 8-hydroxyefavirenz (Toronto Research Chemicals, Toronto, Canada).

Techniques: Control, Incubation, Liquid Chromatography with Mass Spectroscopy, Activity Assay