Category: pyridine-derivatives

Lu, Yao published the artcileDevelopment of a two-layer transwell co-culture model for the in vitro investigation of pyrrolizidine alkaloid-induced hepatic sinusoidal damage, SDS of cas: 21829-25-4, the main research area is pyrrolizidine alkaloid hepatic sinusoidal damage transwell culture; HepaRG hepatocytes; Hepatic sinusoidal damage; In vitro cell model; Pyrrolizidine alkaloid; Transwell co-culture model.

Pyrrolizidine alkaloids (PAs) are hepatotoxic and specifically damage hepatic sinusoidal endothelial cells (HSECs) via cytochrome P 450 enzymes (CYPs)-mediated metabolic activation. Due to the lack of CYPs in HSECs, currently there is no suitable cell model for investigating PA-induced HSEC injury. This study aimed to establish a two-layer transwell co-culture model that mimics hepatic environment by including HepaRG hepatocytes and HSECs to evaluate cytotoxicity of PAs on their major target HSECs. In this model, PAs were metabolically activated by CYPs in HepaRG hepatocytes to generate reactive pyrrolic metabolites, which react with co-cultured HSECs leading to HSEC damage. Three representative PAs, namely retrorsine, monocrotaline, and clivorine, induced significant concentration-dependent cytotoxicity in HSECs in the co-culture model, but did no cause obvious cytotoxicity directly in HSECs. Using the developed co-cultured model, further mechanism studies of retrorsine-induced HSEC damage demonstrated that the reactive pyrrolic metabolite generated by CYP-mediated bioactivation in HepaRG hepatocytes caused formation of pyrrole-protein adducts, reduction of GSH content, and generation of reactive oxygen species in HSECs, leading to cell apoptosis. The established co-culture model is reliable and applicable for cytotoxic assessment of PA-induced HSEC damage and offers a novel platform for screening toxicity of different PAs on their target cells.

Food and Chemical Toxicology published new progress about Apoptosis. 21829-25-4 belongs to class pyridine-derivatives, name is Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C17H18N2O6, SDS of cas: 21829-25-4.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Laryushkin, Denis P. published the artcileRole of L-Type Voltage-Gated Calcium Channels in Epileptiform Activity of Neurons, Related Products of pyridine-derivatives, the main research area is voltage gated calcium channel neuron epileptiform activity; diltiazem; epileptiform activity; isradipine; neurons; nifedipine; paroxysmal depolarization shift; verapamil; voltage-gated calcium channels.

Epileptic discharges manifest in individual neurons as abnormal membrane potential fluctuations called paroxysmal depolarization shift (PDS). PDSs can combine into clusters that are accompanied by synchronous oscillations of the intracellular Ca2+ concentration ([Ca2+]i) in neurons. Here, we investigate the contribution of L-type voltage-gated calcium channels (VGCC) to epileptiform activity induced in cultured hippocampal neurons by GABA(A)R antagonist, bicuculline. Using KCl-induced depolarization, we determined the optimal EDs of the blockers. Dihydropyridines (nifedipine and isradipine) at concentrations â‰?10μM demonstrate greater selectivity than the blockers from other groups (phenylalkylamines and benzothiazepines). However, high doses of dihydropyridines evoke an irreversible increase in [Ca2+]i in neurons and astrocytes. In turn, verapamil and diltiazem selectively block L-type VGCC in the range of 1-10μM, whereas high doses of these drugs block other types of VGCC. We show that L-type VGCC blockade decreases the half-width and amplitude of bicuculline-induced [Ca2+]i oscillations. We also observe a decrease in the number of PDSs in a cluster and cluster duration. However, the pattern of individual PDSs and the frequency of the cluster occurrence change insignificantly. Thus, our results demonstrate that L-type VGCC contributes to maintaining the required [Ca2+]i level during oscillations, which appears to determine the number of PDSs in the cluster.

International Journal of Molecular Sciences published new progress about Astrocyte. 21829-25-4 belongs to class pyridine-derivatives, name is Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C17H18N2O6, Related Products of pyridine-derivatives.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Kim, Seul Gi published the artcileNifedipine-induced AMPK activation alleviates senescence by increasing autophagy and suppressing of Ca2+ levels in vascular smooth muscle cells, Application of Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, the main research area is vascular smooth muscle cell senescence autophagy calcium AMPK nifedipine; AMPK; Autophagy; Ca(2+); Nifedipine; Senescence; Vascular smooth muscle cell.

Calcium (Ca2+) homeostasis is disrupted during aging in several cell types and this disruption leads to autophagy impairment. The mechanisms regarding Ca2+, senescence, and autophagy need to be elucidated. Therefore, we hypothesized that cellular senescence can be improved by regulating Ca2+ level and autophagy activity. We identified that hydrogen peroxide (H2O2)-induced senescence was accompanied by Ca2+ elevation, impairment of autophagic flux and increase of mammalian target of rapamycin (mTOR) phosphorylation in VSMCs. The treatment of nifedipine dose-dependently suppressed H2O2-induced senescence by reducing Ca2+ entry, autophagy impairment and mTOR signaling, and this suppression was found to be related to senescence-associated β-galactosidase (SA-β-gal) activity and the expressions of senescence marker protein 30 (SMP30), p53, and p21. Furthermore, H2O2-induced autophagy impairment also accelerated senescence and accumulations of ubiquitinated proteins. AMPK inhibition or transfection with AMPK siRNA showed that the anti-senescence effect of nifedipine involved AMPK activation. These results suggest nifedipine-inducted AMPK activation suppresses VSMC senescence by regulating autophagic flux and Ca2+ levels.

Mechanisms of Ageing and Development published new progress about Autophagy. 21829-25-4 belongs to class pyridine-derivatives, name is Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C17H18N2O6, Application of Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Croitoru, M. D. published the artcileDirect HPLC-UV determination of cyclemate, saccharine and aspartame from soft drinks, Recommanded Product: Ethyl 4-hydroxy-6-oxo-6,7-dihydrothieno[2,3-b]pyridine-5-carboxylate, the main research area is cyclamate saccharine aspartame soft drink HPLC UV detection.

Artificial sweeteners were introduced in therapy as sugar substitutes for diabetic patients. Nowadays these substances are widely used for sugar substitution in low calorie drinks and sweets. Most commonly used products to date are saccharine, cyclamate, aspartame, and acesulfam; maximum accepted daily intakes are stated for each one. A simple reverse phase (RP18) HPLC-UV method with direct detection (196 nm) was developed by us in order to measure the concentrations of the three sweeteners. No sample preparation is required, other than dilution Limits of detection are 12 mg l-1, 0.5 mg l-1 and lower than 0.25 mg l-1 for cyclamate, aspartame and saccharine, resp. Concentrations ranged between 113.14-280.07 mg l-1 in the case of cyclamate, 17.96-50.94 mg l-1 for saccharine, and 9.94-296.82 mg l-1 for aspartame.

Acta Alimentaria published new progress about Beverages. 99429-68-2 belongs to class pyridine-derivatives, name is Ethyl 4-hydroxy-6-oxo-6,7-dihydrothieno[2,3-b]pyridine-5-carboxylate, and the molecular formula is C10H9NO4S, Recommanded Product: Ethyl 4-hydroxy-6-oxo-6,7-dihydrothieno[2,3-b]pyridine-5-carboxylate.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Liu, Xiaoxi published the artcileRegulating Molecular Recognition with C-Shaped Strips Attained by Chirality-Assisted Synthesis, Safety of 1,1-Di-n-octyl-4,4-bipyridinium Dibromide, the main research area is chirality assisted synthesis mol recognition mol shape strip; chirality-assisted synthesis; cooperative effects; host-guest interactions; shape control; supramolecular chemistry.

Chirality-assisted synthesis (CAS) is a general approach to control the shapes of large mol. strips. CAS is based on enantiomerically pure building blocks that are designed to strictly couple in a single geometric orientation. Fully shape-persistent structures can thus be created, even in the form of linear chains. With CAS, selective recognition between large host and guest mols. can reliably be designed de novo. To demonstrate this concept, three C-shaped strips that can embrace a pillar[5]arene macrocycle were synthesized. The pillar[5]arene bound to the strips was a better host for electron-deficient guests than the free macrocycle. Exptl. and computational evidence is provided for these unique cooperative interactions to illustrate how CAS could open the door towards the precise positioning of functional groups for regulated supramol. recognition and catalysis.

Angewandte Chemie, International Edition published new progress about Chirality. 36437-30-6 belongs to class pyridine-derivatives, name is 1,1-Di-n-octyl-4,4-bipyridinium Dibromide, and the molecular formula is C26H42Br2N2, Safety of 1,1-Di-n-octyl-4,4-bipyridinium Dibromide.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Cobine, Caroline A. published the artcileRhythmic calcium transients in smooth muscle cells of the mouse internal anal sphincter, Application In Synthesis of 21829-25-4, the main research area is calcium transient smooth muscle cell internal analysis sphincter; gastrointestinal; interstitial cells of Cajal; pacemaker; slow wave; tone.

Ca2+ transients displayed ongoing rhythmic firings at both lengths and were abolished by nifedipine and the KATP channel activator pinacidil indicating their dependence upon CavL. Like SWs, CTs were greatest in frequency and amplitude at the distal extremity and conducted proximally. Removal of the distal IAS reduced but did not abolish CTs. The time constant for clearing cytoplasmic Ca2+ averaged 0.46 s and basal Ca2+ levels were significantly elevated. The similarities in spatiotemporal and pharmacol. properties of CTs and SWs suggest that SW gives rise to CTs while muscle stretch is not required. Elevated relative basal Ca2+ in the IAS is likely due to the inability of cells to clear or sequester Ca2+ between rapid frequency voltage-dependent Ca2+ entry events, i.e., conditions that will lead to tone development. The conduction of CTs from distal to proximal IAS will lead to orally directed contractions and likely contribute to the maintenance of fecal continence.

Neurogastroenterology & Motility published new progress about Cytoplasm. 21829-25-4 belongs to class pyridine-derivatives, name is Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C17H18N2O6, Application In Synthesis of 21829-25-4.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Udumyan, Ruzan published the artcileBeta-blocker use and lung cancer mortality in a nationwide cohort study of patients with primary non-small cell lung cancer, Category: pyridine-derivatives, the main research area is non small cell lung cancer mortality beta blocker.

β-Adrenergic receptor blockers have been associated with improved survival among patients with different types of malignancies, but available data for patients with non-small cell lung cancer are contradictory and limited to small hospital-based studies. We aimed to investigate whether β-blocker use at time of cancer diagnosis is associated with lung cancer mortality in largest general population-based cohort of patients with NSCLC to date. For this retrospectively defined nationwide cohort study, we used prospectively collected data from Swedish population and health registers. Through Swedish Cancer Register, we identified 18,429 patients diagnosed with primary NSCLC between 2006 and 2014 with follow-up to 2015. Cox regression was used to estimate the association between β-blocker use at time of cancer diagnosis ascertained from the Prescribed Drug Register and cancer-specific mortality identified from the Cause of Death Register. Over a median follow-up of 10.2 mo, 14,994 patients died. Compared with nonuse, β-blocker use was not associated with lung cancer mortality [HR (95% confidence interval): 1.01 (0.97-1.06)]. However, the possibility that diverging associations for specific β-blockers and some histopathol. subtypes exist cannot be excluded. In this nationwide cohort of patients with NSCLC, β-blocker use was not associated with lung cancer mortality when assessed in aggregate in the total cohort, but evidence for some β-blockers is less conclusive.

Cancer Epidemiology, Biomarkers & Prevention published new progress about Diagnosis. 72509-76-3 belongs to class pyridine-derivatives, name is 3-Ethyl 5-methyl 4-(2,3-dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C18H19Cl2NO4, Category: pyridine-derivatives.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Makara, Gergely M. published the artcileSynthesis of Bicyclic Pyrimidine Derivatives as ATP Analogues, Formula: C26H42Br2N2, the main research area is pyrimidine bicyclic derivative solid phase synthesis reduction; ATP analog solid phase synthesis reduction.

A highly efficient and general solid-phase synthesis of bicyclic pyrimidine derivatives that target purine dependent proteins is reported. The synthesis of the key intermediate, 4,6-disubstituted-5-amino-pyrimidine, involved reduction of the corresponding nitro derivatives using 1,1′-dioctyl-viologen in a triphasic milieu. The mild reduction conditions enable the use of any acid labile solid support as well as a wide range of combinatorial substituents, thus enabling the synthesis of large libraries of highly diverse bicyclic pyrimidines. Alternative reduction conditions with tin(II) chloride and structure-reactivity studies are discussed as well.

Journal of Organic Chemistry published new progress about Reduction. 36437-30-6 belongs to class pyridine-derivatives, name is 1,1-Di-n-octyl-4,4-bipyridinium Dibromide, and the molecular formula is C26H42Br2N2, Formula: C26H42Br2N2.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Shen, Hsuan-Shu published the artcileChinese herbal medicines have potentially beneficial effects on the perinatal outcomes of pregnant women, HPLC of Formula: 21829-25-4, the main research area is chinese herbal medicine premature birth miscarriage population; Chinese herbal products; National health insurance research database; preterm labor; threatened miscarriage; tocolytic treatment.

Tocolytic treatment is beneficial to pregnant women with a risk of premature labor or miscarriage. However, previous reports have shown that progestogen might not be effective and ritodrine may increase the risk of maternal vascular-related diseases. Chinese herbal products (CHP) are used as alternative therapies for pregnant women. The goal was to evaluate the efficacy of combined tocolytic therapy and CHP therapy in pregnancy outcomes for pregnant women in Taiwan. We conducted a retrospective cohort study based on the National Health Insurance Research Database. A total of 47,153 pregnantwomen treatedwith tocolytics aged 18-50 years from 2001 to 2015 were selected from two million random samples. According to the medical use of tocolytics and CHP, we divided the users into two groups: westernmedicine (WM) only (n = 40,961) andWM/CHP (n = 6,192) groups. A propensity score (PS)-matched cohort (6,192 pairs) was established based on baseline confounders. All participants were followed up to perinatal outcomes. Conditional logistic regression anal. was used to examine the effects of CHP use on the odds of miscarriage and preterm birth. The adjusted odds ratio (OR) for premature birth in the WM/CHP group (n = 411, 6.64%) was significantly lower than in the WM group (n = 471, 7,61%) (0,86, 95% confidence interval [CI], 0.74-0.99). Further subgroup anal. based on the usage of formulas that activate blood and remove stasis or purgative formulas, the adjusted OR of preterm birth of those using these formulas was significantly lower in theWM/CHP group (n = 215, 6.32%) than that in theWM group (n = 265, 7.77%) (OR: 0.79, 95% CI: 0.65-0.96). We found that the combination of CHP and tocolytics can be beneficial to pregnant women in the prevention of premature birth. Further research is required to investigate causal relationships.

Frontiers in Pharmacology published new progress about Abortion. 21829-25-4 belongs to class pyridine-derivatives, name is Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C17H18N2O6, HPLC of Formula: 21829-25-4.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Hong, Ji Young published the artcileAntenatal magnesium sulfate treatment and risk of necrotizing enterocolitis in preterm infants born at less than 32 weeks of gestation, Product Details of C17H18N2O6, the main research area is necrotizing enterocolitis gestation magnesium sulfate.

Abstract: Antenatal magnesium sulfate (MgSO4) treatment is widely used for fetal neuroprotection in women at risk of preterm delivery. However, some studies have recently suggested that in utero MgSO4 exposure is associated with an increased risk of necrotizing enterocolitis (NEC). This study aimed to investigate the association between antenatal MgSO4 treatment and risk of NEC. This retrospective cohort study included 756 infants born at 24-31 wk gestation. Subjects were classified into three groups: period 1, when MgSO4 treatment protocol for fetal neuroprotection was not adopted (n = 267); period 2, when the protocol was adopted (n = 261); and period 3, when the protocol was withdrawn because of concern of risk of NEC (n = 228). Rates of NEC (�stage 2b) were analyzed according to time period and exposure to antenatal MgSO4. Significant difference in the rate of NEC was not found across the three time periods (2.6% vs. 6.5% vs. 4.8% in periods 1, 2 and 3, resp., p = 0.103). The rate of NEC was comparable between the infants exposed and unexposed to antenatal MgSO4 (5.1% vs. 3.6%, p = 0.369). These results showed that antenatal MgSO4 treatment was not associated with risk of NEC in our study population.

Scientific Reports published new progress about Acidosis. 21829-25-4 belongs to class pyridine-derivatives, name is Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C17H18N2O6, Product Details of C17H18N2O6.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem