Day: November 15, 2022

Rademacher, Peter M. published the artcileDifferential Oxidation of Two Thiophene-Containing Regioisomers to Reactive Metabolites by Cytochrome P450 2C9, HPLC of Formula: 40180-04-9, the main research area is oxidation thiophene regioisomer metabolite cytochrome P450 2C9.

The uricosuric diuretic agent tienilic acid (TA) is a thiophene-containing compound that is metabolized by P 450 2C9 to 5-OH-TA. A reactive metabolite of TA also forms a covalent adduct to P 450 2C9 that inactivates the enzyme and initiates immune-mediated hepatic injury in humans, purportedly through a thiophene-S-oxide intermediate. The 3-thenoyl regioisomer of TA, tienilic acid isomer (TAI), is chem. very similar and is reported to be oxidized by P 450 2C9 to a thiophene-S-oxide, yet it is not a mechanism-based inactivator (MBI) of P 450 2C9 and is reported to be an intrinsic hepatotoxin in rats. The goal of the work presented in this article was to identify the reactive metabolites of TA and TAI by the characterization of products derived from P 450 2C9-mediated oxidation In addition, in silico approaches were used to better understand both the mechanisms of oxidation of TA and TAI and/or the structural rearrangements of oxidized thiophene compounds Incubation of TA with P 450 2C9 and NADPH yielded the well-characterized 5-OH-TA metabolite as the major product. However, contrary to previous reports, it was found that TAI was oxidized to two different types of reactive intermediates that ultimately lead to two types of products, a pair of hydroxythiophene/thiolactone tautomers and an S-oxide dimer. Both TA and TAI incorporated 18O from 18O2 into their resp. hydroxythiophene/thiolactone metabolites indicating that these products are derived from an arene oxide pathway. Intrinsic reaction coordinate calculations of the rearrangement reactions of the model compound 2-acetylthiophene-S-oxide showed that a 1,5-oxygen migration mechanism is energetically unfavorable and does not yield the 5-OH product but instead yields a six-membered oxathiine ring. Therefore, arene oxide formation and subsequent NIH-shift rearrangement remains the favored mechanism for formation of 5-OH-TA. This also implicates the arene oxide as the initiating factor in TA induced liver injury via covalent modification of P 450 2C9. Finally, in silico modeling of P 450 2C9 active site ligand interactions with TA using the catalytically active iron-oxo species revealed significant differences in the orientations of TA and TAI in the active site, which correlated well with exptl. results showing that TA was oxidized only to a ring carbon hydroxylated product, whereas TAI formed both ring carbon hydroxylated products and an S-oxide.

Chemical Research in Toxicology published new progress about Enzyme functional sites, active. 40180-04-9 belongs to class benzothiophene, name is 2-(2,3-Dichloro-4-(thiophene-2-carbonyl)phenoxy)acetic acid, and the molecular formula is C13H8Cl2O4S, HPLC of Formula: 40180-04-9.

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Poli-Scaife, Sonia published the artcileThe Substrate Binding Site of Human Liver Cytochrome P450 2C9: An NMR Study, Quality Control of 40180-04-9, the main research area is substrate binding cytochrome P450 2C9 NMR; inhibitor binding cytochrome P450 2C9 NMR; sulfaphenazole binding cytochrome P450 2C9 NMR.

Purified recombinant human liver cytochrome P 450 2C9 was produced, from expression of the corresponding cDNA in yeast, in quantities large enough for UV-visible and 1H NMR experiments Its interaction with several substrates (tienilic acid and two derivatives, lauric acid and diclofenac) and with a specific inhibitor, sulfaphenazole, was studied by UV-visible and 1H NMR spectroscopy. At 27°, all those substrates led to an almost complete conversion of CYP 2C9 to high-spin (S = 5/2) CYP 2C9-substrate complexes characterized by a Soret peak at 390 nm; their KD values varied between 1 and 42 μM. On the contrary, sulfaphenazole led to a low-spin (S = 1/2) CYP 2C9 complex upon binding of its NH2 group to CYP 2C9 iron. Interactions of the five substrates with the enzyme were studied by paramagnetic relaxation effects of CYP 2C9-iron(III) on the 1H NMR spectrum of each substrate. Distances between the heme iron atom and substrate protons were calculated from the NMR data, and the orientation of the substrate relative to iron was determined from those distances. Finally, a model for substrate positioning in the CYP 2C9 active site was constructed by mol. modeling studies under the constraint of the iron-proton distances. It points out two structural characteristics for a compound to be selectively recognized by CYP 2C9: (i) the presence of an anionic site able to establish an ionic bond with a putative cationic residue of the protein and (ii) the presence of an hydrophobic zone between the substrate hydroxylation site and the anionic site. Sulfaphenazole was easily included in that model; its very high affinity for CYP 2C9 is due to a third structural feature, the presence of its NH2 function which binds to CYP 2C9 iron.

Biochemistry published new progress about Enzyme functional sites, active. 40180-04-9 belongs to class benzothiophene, name is 2-(2,3-Dichloro-4-(thiophene-2-carbonyl)phenoxy)acetic acid, and the molecular formula is C13H8Cl2O4S, Quality Control of 40180-04-9.

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Liu, Yuanhua published the artcileEfficient Access to Chiral 2-Oxazolidinones via Ni-Catalyzed Asymmetric Hydrogenation: Scope Study, Mechanistic Explanation, and Origin of Enantioselectivity, Recommanded Product: 3-Acetylthiophene, the main research area is oxazolidinone preparation enantioselective; oxazolone hydrogenation nickel catalyst.

Cheap transition metal Ni-catalyzed asym. hydrogenation of 2-oxazolones I (R = Me, Ph, thiophen-3-yl, etc.) was successfully developed, which provided an efficient synthetic strategy to prepare various chiral 2-oxazolidinones II with 95%-99% yields and 97%->99% ee. The gram-scale hydrogenation could be proceeded well with >99% ee in the presence of low catalyst loading (up to 3350 TON). This Ni-catalyzed hydrogenation protocol demonstrated great synthetic utility, and the chiral 2-oxazolidinone product II was easily converted to a variety of other important mols. in good yields and without loss of ee values, such as chiral dihydrothiophene-2(3H)-thione, amino alc., oxazoline ligand, and allenamide. Moreover, a series of deuterium labeling experiments, control experiments, and DFT calculations were conducted to illustrate a reasonable catalytic mechanism for this Ni-catalyzed asym. hydrogenation, which involved a tautomerization between the enamine and its isomer imine and then went through asym. 1,2-addition of Ni(II)-H to the preferred imine.

ACS Catalysis published new progress about Density functional theory, B3LYP. 1468-83-3 belongs to class benzothiophene, name is 3-Acetylthiophene, and the molecular formula is C6H6OS, Recommanded Product: 3-Acetylthiophene.

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Deng, Guobo published the artcileAssembly of Furazan-Fused Quinolines via an Expeditious Metal-Free [2+2+1] Radical Tandem Cyclization Process, Name: 3-Acetylthiophene, the main research area is oxadiazoloquinoline preparation; arylketimine benzonitrile tertbutyl nitrite radical tandem heteroannulation.

A [2+2+1]-NO-segment-incorporating heteroannulative cascade is described. This versatile method, particularly using modular cyanoarylated ketimine substrates 2-CN-3-R-4-R1-5-R2C6HN=C(Me)Ar (Ar = 3-methylphenyl, 4-bromophenyl, thiophen-2-yl, etc.; R = H, Br; R1 = H, Br; R2 = H, Me, F, Cl, Br, MeO, CF3), allows efficient access to structurally diversified quinolines embedded with an oxadiazole core I. This metal-free protocol proceeds smoothly at 30°C, offers easy manipulation of substituents on the quinoline moiety, and tolerates a spectrum of functional groups. D. functional theory calculation revealed that the cyano moiety is crucial to facilitate the early cyclization step in this heteroannulation process and is different from the previously established late cyclization mechanistic interpretation.

Organic Letters published new progress about Density functional theory, B3LYP. 1468-83-3 belongs to class benzothiophene, name is 3-Acetylthiophene, and the molecular formula is C6H6OS, Name: 3-Acetylthiophene.

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Nishida, K. published the artcileDyeing properties of disperse dyes derived from substituted 3-aminobenzo[b]thiophenes, Synthetic Route of 67189-92-8, the main research area is benzothiophene azo disperse dye; acetate fiber dye; polyamide fiber dye.

Six disperse azo dyes (I; R = CN, Ac, CO2Et, CO2H; R1 = H, Cl) λ 400-517 nm (EtOH) were prepared by coupling m-MeC6H4N(CH2CH2OH)CH2CH2CN [119-95-9] with diazotized 3-aminobenzo[b]thiophenes and their dyeing properties on acetate and nylon 6 fibers determined Most of the dyes showed good substantivity for both fibers, exhausting well to give bright dyeings of good general fastness; some showed higher lightfastness and brighter colors on acetate than on nylon 6.

Journal of the Society of Dyers and Colourists published new progress about Acetate fibers Role: USES (Uses). 67189-92-8 belongs to class benzothiophene, name is Ethyl 3-amino-4-chlorobenzo[b]thiophene-2-carboxylate, and the molecular formula is C11H10ClNO2S, Synthetic Route of 67189-92-8.

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Klammers, Florian published the artcileEstimation of fraction metabolized by cytochrome P450 enzymes using long-term cocultured human hepatocytes, Recommanded Product: 2-(2,3-Dichloro-4-(thiophene-2-carbonyl)phenoxy)acetic acid, the main research area is itraconazole antiinflammatory CYP450 enzyme hepatic metabolism.

Estimation of the fraction of a drug metabolized by individual hepatic CYP enzymes relative to hepatic metabolism (fm,CYP) or total clearance h as been challenging for low turnover compounds due to insufficient resolution of the intrinsic clearance (CLint) measurement in vitro and difficulties in quantifying the formation of low abundance metabolites. To overcome this gap, inhibition of drug depletion or selective metabolite formation for 7 marker CYP substrates was investigated using chem. inhibitors and a micro-patterned hepatocyte coculture system (HepatoPac). The use of 3μM itraconazole was successfully validated for estimation of fm,CYP3A4 by demonstration of fm values within a 2-fold of in vivo estimates for 10 out of 13 CYP3A4 substrates in a reference set of marketed drugs. Other CYP3A4 inhibitors (ketoconazole and posaconazole) were not optimal for estimation of fm,CYP3A4 for low turnover compounds due to their high CLint. The current study also demonstrated that selective inhibition sufficient for fm calculation was achieved by inhibitors of CYP1A2 (20μM furafylline), CYP2C8 (40μM montelukast), CYP2C9 (40μM sulfaphenazole), CYP2C19 [3μM (-)N-3-benzyl-phenobarbital], and CYP2D6 (5μM quinidine). Good estimation of fm,CYP2B6 was not possible in this study due to the poor selectivity of the tested inhibitor (20μM ticlopidine). The approach verified in this study can result in an improved fm estimation that is aligned with the regulatory agencies’ guidance and can support a victim drug-drug interaction risk assessment strategy for low clearance discovery and development drug candidates.

Drug Metabolism & Disposition published new progress about Cytochrome P450 CYP2B6 inhibitors. 40180-04-9 belongs to class benzothiophene, name is 2-(2,3-Dichloro-4-(thiophene-2-carbonyl)phenoxy)acetic acid, and the molecular formula is C13H8Cl2O4S, Recommanded Product: 2-(2,3-Dichloro-4-(thiophene-2-carbonyl)phenoxy)acetic acid.

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Schroeder, Sebastian published the artcileVinyl Triflimides-A Case of Assisted Vinyl Cation Formation, COA of Formula: C6H6OS, the main research area is vinyl triflimide preparation; alkyne lithium triflimide regioselective addition; alkynes; enzyme-mimicking synthesis; hydroaminosulfonation; triflimides; vinyl cations.

A new concept for selectivity control in carbocation-driven reactions was identified which allows for the chemo-, regio-, and stereoselective addition of nucleophiles to alkynes-assisted vinyl cation formation-enabled by a Li+-based supramol. framework. Mechanistic anal. of a model complex (Li2NTf2+.3H2O) confirms that solely the formation of a complex between the incoming nucleophile and the transition state of the alkyne protonation is responsible for the resulting selective N addition to the vinyl cation. Into the bargain, a general, operationally simple synthetic procedure to previously inaccessible vinyl triflimides is provided.

Angewandte Chemie, International Edition published new progress about Addition reaction, regioselective. 1468-83-3 belongs to class benzothiophene, name is 3-Acetylthiophene, and the molecular formula is C6H6OS, COA of Formula: C6H6OS.

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Bauman, Jonathon N. published the artcileCan In Vitro Metabolism-Dependent Covalent Binding Data Distinguish Hepatotoxic from Nonhepatotoxic Drugs? An Analysis Using Human Hepatocytes and Liver S-9 Fraction, Computed Properties of 40180-04-9, the main research area is hepatotoxic nonhepatotoxic drug liver covalent binding.

In vitro covalent binding studies in which xenobiotics are shown to undergo metabolism-dependent covalent binding to macromols. have been commonly used to shed light on the biochem. mechanisms of xenobiotic-induced toxicity. In this paper hepatotoxins and nonhepatotoxins were tested for their proclivity to demonstrate metabolism-dependent covalent binding to macromols. in human liver S-9 fraction (9000 g supernatant) or human hepatocytes, as an extension to previous work that used human liver microsomes published in this journal [Obachet al. (2008) Chem. Res. Toxicol.21, 1814-1822]. In the S-9 fraction, seven out of the nine drugs in each category demonstrated some level of metabolism-dependent covalent binding. Inclusion of reduced glutathione, cofactors needed by conjugating enzymes, and other parameters (total daily dose and fraction of total intrinsic clearance comprised by covalent binding) improved the ability of the system to sep. hepatotoxins from nonhepatotoxins to a limited extent. Covalent binding in human hepatocytes showed that six out of the nine hepatotoxins and four out of eight nonhepatotoxins demonstrated covalent binding. Taking into account estimates of total daily body burden of covalent binding from the hepatocyte data showed an improvement over other in vitro systems for distinguishing hepatotoxins from nonhepatotoxins; however, this metabolism system still displayed some false positives. Combined with the previous study using liver microsomes, these findings identify the limitations of in vitro covalent binding data for prospective prediction of hepatotoxicity for new drug candidates and highlight the need for a better understanding of the link between drug bioactivation, covalent adduct formation, and toxicity outcomes. Directly relating covalent binding to hepatotoxicity is likely an oversimplification of the process whereby adduct formation ultimately leads to toxicity. Understanding underlying complexities (e.g., which macromols. are important covalent binding targets, interindividual differences in susceptibility, etc.) will be essential to any understanding of the problem of metabolism-dependent hepatotoxicity and predicting toxicity from in vitro experiments

Chemical Research in Toxicology published new progress about Drug metabolism (covalent binding). 40180-04-9 belongs to class benzothiophene, name is 2-(2,3-Dichloro-4-(thiophene-2-carbonyl)phenoxy)acetic acid, and the molecular formula is C13H8Cl2O4S, Computed Properties of 40180-04-9.

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Bi, Yi-an published the artcileRole of Hepatic Organic Anion Transporter 2 in the Pharmacokinetics of R- and S-Warfarin: In Vitro Studies and Mechanistic Evaluation, Category: benzothiophene, the main research area is warfarin enantiomer liver clearance OAT2 pharmacokinetics pharmacogenomics; CYP2C9; organic anion transporter; pharmacokinetics; physiological based modeling; warfarin.

Interindividual variability in warfarin dose requirement demands personalized medicine approaches to balance its therapeutic benefits (anticoagulation) and bleeding risk. Cytochrome P 450 2C9 (CYP2C9) genotype-guided warfarin dosing is recommended in the clinic, given the more potent S-warfarin is primarily metabolized by CYP2C9. However, only about 20-30% of interpatient variability in S-warfarin clearance is associated with CYP2C9 genotype. We evaluated the role of hepatic uptake in the clearance of R- and S-warfarin. Using stably transfected HEK293 cells, both enantiomers were substrates of organic anion transporter (OAT)2 with a Michaelis-Menten constant (Km) of ∼7-12 μM but did not show substrate affinity for other major hepatic uptake transporters. Uptake of both enantiomers by primary human hepatocytes was saturable (Km ≈ 7-10 μM) and inhibitable by OAT2 inhibitors (e.g., ketoprofen) but not by OATP1B1/1B3 inhibitors (e.g., cyclosporine). To further evaluate the potential role of hepatic uptake in R- and S-warfarin pharmacokinetics, mechanistic modeling and simulations were conducted. A “”bottom-up”” PBPK model, developed assuming that OAT2-CYPs interplay, well recovered clin. pharmacokinetics, drug-drug interactions, and CYP2C9 pharmacogenomics of R- and S-warfarin. Clin. data were not available to directly verify the impact of OAT2 modulation on warfarin pharmacokinetics; however, the bottom-up PBPK model simulations suggested a proportional change in clearance of both warfarin enantiomers with inhibition of OAT2 activity. These results suggest that variable hepatic OAT2 function, in conjunction with CYP2C, may contribute to the high population variability in warfarin pharmacokinetics and possibly anticoagulation end points and thus warrant further clin. investigation.

Molecular Pharmaceutics published new progress about Drug interactions, pharmacokinetic. 40180-04-9 belongs to class benzothiophene, name is 2-(2,3-Dichloro-4-(thiophene-2-carbonyl)phenoxy)acetic acid, and the molecular formula is C13H8Cl2O4S, Category: benzothiophene.

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Methogo, Ruth Menque published the artcileIdentification of liver protein targets modified by tienilic acid metabolites using a two-dimensional Western blot-mass spectrometry approach, Product Details of C13H8Cl2O4S, the main research area is liver protein tienilic acid metabolite mass spectrometry electrophoresis immunoblotting.

A combined approach based on two-dimensional electrophoresis-immuno-blotting and nanoliquid chromatog. coupled online with electrospray ionization mass spectrometry (nLC-MS/MS) was used to identify proteins modified by a reactive intermediate of tienilic acid (TA). Liver homogenates from rats exposed to TA were fractionated using ultra centrifugation; four fractions were obtained and subjected to 2D electrophoresis. Following transfer to PVDF membranes, modified proteins were visualized after India ink staining, using an anti-serum raised against TA and ECL detection. Immuno-reactive spots were localized on the PVDF membrane by superposition of the ECL image, protein spots of interest were excised, digested on the membrane with trypsin followed by nLC-MS/MS anal. and protein identification. A total of 15 proteins were identified as likely targets modified by a TA reactive metabolite. These include selenium binding protein 2, senescence marker protein SMP-30, adenosine kinase, Acy1 protein, adenosyl-homocysteinase, capping protein (actin filament), protein disulfide isomerase, fumarylacetoacetase, arginase chain A, keto-hexokinase, proteasome endopeptidase complex, triosephosphate isomerase, superoxide dismutase, DNA-type mol. chaperone hsc73 and malate dehydrogenase.

International Journal of Mass Spectrometry published new progress about Autoimmune hepatitis (drug-induced). 40180-04-9 belongs to class benzothiophene, name is 2-(2,3-Dichloro-4-(thiophene-2-carbonyl)phenoxy)acetic acid, and the molecular formula is C13H8Cl2O4S, Product Details of C13H8Cl2O4S.

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem