RESUMO
BACKGROUND: IgA nephropathy is the most common primary glomerulonephritis worldwide, and there is emerging evidence linking galactose-deficient IgA1 (Gd-IgA1) to the pathogenesis of the disease. However, mouse models that can be used to study Gd-IgA1's origin of production, biochemical characteristics, and immune reactivity are lacking. METHODS: We generated a humanized IgA1 mouse model with transgenic expression of the human IGHA1 gene from the mouse chromosomal locus of IgA heavy chain. The IGHA1+/+ mice were crossed with complement factor H heterozygous mutant (FHW/R) to generate IGHA1+/+FHW/R mice. IGHA1+/+ mice were exposed to different levels of environmental pathogens in the first 4 months, as housed in either germ-free, specific pathogen-free, or conventional environments. In addition, wild-type C57BL/6J mice, IGHA1+/+ mice, and IGHA1+/+FHW/R mice were inoculated with Lactobacillus casei cell bacterial wall extract (LCWE) mixed with complete Freund's adjuvant (CFA) at two months of age to develop a mouse model of IgA nephropathy. RESULTS: Elevated levels of human IgA1 in blood circulation and mucosal sites were observed in IGHA1+/+ mice from exposure to pathogens. Compared to buffer-treated control mice, LCWE plus CFA-treated mice had moderately elevated levels of circulating human IgA1 (by one fold) and human IgA1 immune complexes (by two folds). Serum Gd-IgA1 levels increased fourfold following LCWE treatments. Analyses of the O-glycopeptides of the IgA1 hinge region confirmed hypo-galactosylation of IgA1, with the variety of the glycoforms matching those seen in clinical samples. Furthermore, LCWE induced persistent IgA1 and C3 deposition in the glomerular mesangial areas in association with mesangial expansion and hypercellularity, which are frequently observed in IgA nephropathy biopsies. The IGHA1+/+FHW/R mice stimulated with LCWE and CFA developed albuminuria and hematuria. CONCLUSIONS: We observed elevated plasma Gd-IgA1 levels with kidney deposition of IgA1 in the IGHA1+/+ mice following LCWE and CFA. In conjunction with factor H mutation, the mice exhibited severe glomerular alterations, associated with hematuria and albuminuria in resemblance of clinical IgA nephropathy.
RESUMO
Velagliflozin is the active ingredient of the first oral liquid medication approved by the Food and Drug Administration for the treatment of diabetes in cats. This compound belongs to the known class of sodium-glucose cotransporter 2 inhibitors approved to treat diabetes in human. Here, we report the detailed synthesis of velagliflozin labeled with carbon 14 and carbon 13.
Assuntos
Isótopos de Carbono , Radioisótopos de Carbono , Radioisótopos de Carbono/química , Isótopos de Carbono/química , Técnicas de Química Sintética , Glucosídeos/síntese química , Glucosídeos/química , Glucosídeos/farmacologia , Inibidores do Transportador 2 de Sódio-Glicose/síntese química , Inibidores do Transportador 2 de Sódio-Glicose/química , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Compostos BenzidrílicosRESUMO
A specific and sensitive method was firstly developed using high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) to simultaneously quantify imigliptin (KBP-3853) and its three metabolites (KBP-3926, KBP-3902, KBP-5493) in human plasma and urine. Solid-phase extraction (SPE) and direct dilution were used to extract imigliptin and its three metabolites from plasma and urine, respectively. The extracts were injected onto a SymmetryShield RP8 column with a gradient elution of acetonitrile and water containing 5mM ammonium acetate (pH 7). Ionization of KBP-3853, KBP-3926, KBP-3902, KBP-5493, and XZP-3244 (internal standard, IS) was performed using an electrospray ionization (ESI) source in positive mode and detection was carried out with multiple reaction monitoring (MRM) mode. The lower limits of quantitation (LLOQ) of KBP-3853/KBP-3926/KBP-3902/KBP-5493 in human plasma and urine were 0.500/0.500/0.500/0.500ng/mL and 20.0/20.0/10.0/10.0ng/mL, respectively. Inter- and intra-batch precision of imigliptin and its three metabolites were less than 15% and the accuracy was within 85-115% for both plasma and urine. The extraction recoveries of all analytes at three concentration levels were consistent. The specificity, matrix effect, linearity and stabilities under various conditions were validated for imigliptin and its three metabolites in human plasma and urine. In conclusion, the validation results showed that this method was robust, specific, and sensitive and it can successfully fulfill the requirement of clinical pharmacokinetic study of imigliptin hydrochloride in Chinese healthy subjects.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Hipoglicemiantes/sangue , Hipoglicemiantes/urina , Imidazóis/sangue , Imidazóis/urina , Piridinas/sangue , Piridinas/urina , Espectrometria de Massas em Tandem/métodos , Humanos , Hipoglicemiantes/farmacocinética , Imidazóis/farmacocinética , Piridinas/farmacocinética , Reprodutibilidade dos TestesRESUMO
We report our discovery of a novel series of potent and selective dipeptidyl peptidase IV (DPP-4) inhibitors. Starting from a lead identified by scaffold-hopping approach, our discovery and development efforts were focused on exploring structure-activity relationships, optimizing pharmacokinetic profile, improving in vitro and in vivo efficacy, and evaluating safety profile. The selected candidate, Imigliptin, is now undergoing clinical trial.
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A highly convergent large scale synthesis of a 15-membered macrocyclic hepatitis C virus (HCV) protease inhibitor BI 201302 was achieved, in which the key features are the practical macrocyclization by Ru-catalyzed ring-closing metathesis (0.1 mol % Grela catalyst, 0.1-0.2 M concentration) and the efficient sulfone-mediated SNAr reaction.
Assuntos
Antivirais/síntese química , Antivirais/farmacologia , Hepacivirus/efeitos dos fármacos , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/farmacologia , Inibidores de Proteases/síntese química , Inibidores de Proteases/farmacologia , Antivirais/química , Catálise , Ciclização , Estrutura Molecular , Peptídeos Cíclicos/química , Inibidores de Proteases/químicaRESUMO
The key Pd-catalyzed cross-coupling of aryl bromides or triflates and cyclopropylmagnesium bromide in the presence of substoichiometric amounts of zinc bromide produces cyclopropyl arenes in good to excellent yields. The cross-coupling of other alkyl, cycloalkyl, and aryl Grignard reagents with aryl bromides under the same conditions gives the corresponding substituted arenes in good yields.
Assuntos
Brometos/química , Calixarenos/síntese química , Hidrocarbonetos Bromados/química , Compostos Organometálicos/química , Paládio/química , Compostos de Zinco/química , Calixarenos/química , Catálise , Estrutura Molecular , EstereoisomerismoRESUMO
We report here that dramatic improvement of the key RCM reaction in the synthesis of HCV protease inhibitor BILN2061 can be achieved by N-substitution of the diene substrate with an electron-withdrawing group. Mechanistic studies using 1H NMR spectroscopy showed an unprecedented switch of the initiation sites and the correlation between such switch and the results of RCM, from the unmodified to the modified substrates. We also provided theoretical evidence that such modification may also increase the thermodynamic preference of the macrocyclic product over the diene substrate.
Assuntos
Carbamatos/química , Hepacivirus/enzimologia , Compostos Macrocíclicos/química , Inibidores de Proteases/química , Quinolinas/química , Tiazóis/química , CiclizaçãoRESUMO
[reaction: see text] The yields, enantioselectivities, and regioselectivities of the reactions of amines and phenoxides with allylic carbonates in the presence of a metallacyclic iridium catalyst were compared. These data show that both preactivation of the catalyst and the size of the ligand affect the yield, enantioselectivity, and regioselectivity. With the activated catalyst containing a bis-naphthethylamino group, the allylic amination and etherification of a broad range of allylic carbonates occurred in high yields and with high regioselectivities and enantioselectivities.
Assuntos
Aminas/síntese química , Irídio/química , Aminação , Catálise , Conformação Molecular , EstereoisomerismoRESUMO
Individual diastereomeric phosphoramidites and mixtures of diastereomeric phosphoramidites were evaluated in the iridium-catalyzed amination of allylic carbonates. The original process was conducted with a phosphoramidite ligand containing a resolved 2,2-dihydroxy-1,1-binaphthyl (BINOL) group and a diastereomerically and enantiomerically pure bis(phenethyl)amino group. Evaluation of the structure of the active catalyst and relative rates for reactions in the presence of catalysts containing diastereomeric ligands led to the identification of a phosphoramidite that provided the amination product with enantiomeric excess similar to the original, more structurally and stereochemically complex ligand and that contains a racemic BINOLate and an N-benzylphenethylamino group on phosphorus.
RESUMO
Studies were conducted to determine possible intermediates in the highly enantioselective, iridium-catalyzed amination and etherification of allylic carbonates, and these studies revealed that cyclometalation of the phosphoramidite ligand is likely to generate the active catalyst. The square-planar [Ir(COD)(L1)Cl] (L1 = P(BINOL)(bisphenethylamine)) did not react with cinnamyl carbonate, but did react with amine to generate an Ir(I) trigonal bipyramidal complex coordinated by COD, a cyclometalated kappa2-phosphoramidite, and a kappa1-phosphoramidite. This complex reacted with phosphines to generate products from replacement of the kappa1-phosphoramidite. These cyclometalated complexes were highly active catalysts for allylic amination and etherification and retained the high selectivity of the original catalyst system. In addition, these complexes combined with [Ir(cod)Cl]2 catalyzed reactions of amines with lower loadings, catalyzed reactions of alkylamines and aromatic amines that did not react with the original catalyst system, and catalyzed reactions of phenoxides under milder conditions.
Assuntos
Compostos Alílicos/síntese química , Aminas/síntese química , Éteres/síntese química , Irídio/química , Compostos Organometálicos/química , Aminação , Catálise , Cinética , Compostos Organometálicos/síntese químicaRESUMO
A conceptually new approach to the enantiocontrolled synthesis of 2,6-disubstituted piperidines was achieved by desymmetrization of meso-2,6-dimethoxy-eta-(3,4,5)-dihydropyridinylmolybdenum complexes. After protection of the piperidine nitrogen as a urethane derived from (+)- or (-)-trans-2-(alpha-cumyl)cyclohexyl (TCC), a sequential, one-pot methoxide abstraction/nucleophilic addition/methoxide abstraction/nucleophilic addition generated good yields of 2,6-disubstituted-eta-(3,4,5)-dihydropyridinylmolybdenum complexes. This sequence proceeds by way of a highly diastereoselective methoxide abstraction (>40:1). High yielding protodemetalation and N-deprotection provided a simple and enantiocontrolled synthetic entry to a variety of 2,6-disubstituted piperidines. This new method was used for the total synthesis of (-)-dihydropinidine and (-)-andrachcinidine.