Day: October 17, 2022

Santos, Jose L. F.; de Souza, Gabriel L. C. published the artcile< Water hydrogen-bonding effects on the ground and low-lying excited states of dipyridyl isomers>, Computed Properties of 581-47-5, the main research area is dipyridyl water excited state hydrogen bond mol structure.

In this work, we examined the ground and low-lying excited states of six dipyridyl isomers (2,2′-dipyridyl, 2,3′-dipyridyl, 2,4′-dipyridyl, 3,3′-dipyridyl, 3,4′-dipyridyl, and 4,4′-dipyridyl), emphasizing the effects that solvation (water) mols. have on properties such as ground state equilibrium structures, relative energies in terms of conformations and transition states (regarding possible cis-trans interconversions), vertical excitation energies (VEs), generalized oscillator strengths (GOS), and excited state structures. D. functional theory (DFT) and its time-dependent formalism (TD-DFT) were used for determining all the ground state and excited state properties, resp., both being employed with the CAM-B3LYP exchange-correlation functional and the cc-pVTZ basis set. In addition, effects caused by interactions with the solvent environment were probed by means of using two different approaches: (i) the integral equation formalism polarizable continuum model (IEF-PCM) and (ii) a composite solvation model (CSM) through the incorporation of explicit water mols. in combination with the IEF-PCM. In general, a decrease in the relative energies regarding a given cis/trans counterpart is noticed when solvation is considered independently from the model used; all the dipyridyl cis/trans isomers became (practically) isoenergetical due to dipyridyl-H2O hydrogen-bonding interactions. Moreover, the interconversion barriers were also found to be lowered due to solvation effects. For instance, the energy barrier in terms of interconversion of the trans 2,2′-dipyridyl to the cis 2,2′-dipyridyl was determined as (approx.) 67% of the corresponding value obtained in the gas-phase. Although no major differences regarding the values of the VEs associated to a bright state are suggested from the comparison between the results obtained for a given isomer through the consideration of solvation and those corresponding determined in the gas-phase, the GOS are all increased when solvation is considered, suggesting an enhancement in the photoabsorption of all the isomers when in presence of solvent. In addition and in contrast to what was seen previously in the case of the gas-phase, 4,4′-dipyridyl presented a bright state among the five lowest-lying excited singlets (accessible at the UVC energy region), which is located at 5.49 eV (with GOS = 0.4465) at the TD-DFT/CAM-B3LYP/cc-pVTZ level of theory in water (IEF-PCM) and at 5.47 eV (with GOS = 0.5331) at the same level of theory with the CSM. Given that no significant change was noticed in the optimized structures for the excited states, it is possible to infer that all the compounds will decompose through photo decomposition (chem. reaction occurring in the excited state) rather than direct photolysis when in solution

Journal of Molecular Liquids published new progress about Conformation. 581-47-5 belongs to class pyridine-derivatives, and the molecular formula is C10H8N2, Computed Properties of 581-47-5.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

He, Qidi; Cai, Shuangshuang; Wu, Jinghao; Hu, Ou; Liang, Lushan; Chen, Zuanguang published the artcile< Determination of tuberculosis-related volatile organic biomarker methyl nicotinate in vapor using fluorescent assay based on quantum dots and cobalt-containing porphyrin nanosheets>, Application In Synthesis of 93-60-7, the main research area is methyl nicotinate vapor fluorescent assay tuberculosis Mycobacterium; Fluorescent assay; Methyl nicotinate; Nanoporphyrin; Quantum dots; Tuberculosis; Volatile organic biomarker.

Me nicotinate (MN) is a representative and typical volatile organic marker of Mycobacterium tuberculosis, and the specific detection of MN in human breath facilitates non-invasive, rapid, and accurate epidemic screening of tuberculosis infection. Herein, we constructed a fluorescent assay consisted of CdTe quantum dots (QD) and cobalt-metalized tetrakis(4-carboxyphenyl) porphyrin (CoTCPP) nanosheets to determine Me nicotinate (MN) in vapor samples. Red-emission QD (λex=370 nm, λem=658 nm) acts as signal switches whose fluorescence signals can be effectively quenched by CoTCPP nanosheets but restored in the presence of MN. The strategy relied on the distinct binding affinity of cobalt ion and MN. MN restored the fluorescence of QD quenched by CoTCPP in a concentration-dependent manner, which exhibited a well-linear relationship in the range 1-100 μM, and a limit of detection of 0.59 μM. The proposed platform showed sensitivity and selectivity to detect MN in vapor samples with satisfactory RSD below 3.33%. The method is cheap, simple, and relatively rapid (detected within 4 min), which suggests a potential in tuberculosis diagnosis in resource- and professional-lacked areas.

Microchimica Acta published new progress about Fluorescence immunoassay. 93-60-7 belongs to class pyridine-derivatives, and the molecular formula is C7H7NO2, Application In Synthesis of 93-60-7.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Race, Nicholas J.; Yuan, Qianjia; Sigman, Matthew S. published the artcile< Enantioselective C2-Alkylation of Indoles through a Redox-Relay Heck Reaction of 2-Indole Triflates>, Related Products of 1416819-91-4, the main research area is enantioselective alkylation indole Heck triflate; Heck reaction; asymmetric catalysis; enantioselective catalysis; indole; palladium.

A palladium-catalyzed enantioselective redox-relay Heck reaction of 2-indole triflates and disubstituted alkenes is reported. This process combines readily available indole triflates with a variety of alkenes to afford a range of indole derivatives bearing a stereocenter adjacent to C2. Enantioselectivity is achieved through use of a simple pyridine-oxazoline ligand. Tuning the electronics of the indole, through judicious choice of N-protecting group, is required to ensure selective β-hydride elimination away from the indole core. Utility of this method is highlighted in a modular formal synthesis of an S1P1 agonist precursor developed by Merck.

Chemistry – A European Journal published new progress about Alkylation. 1416819-91-4 belongs to class pyridine-derivatives, and the molecular formula is C13H15F3N2O, Related Products of 1416819-91-4.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Demakov, Pavel A.; Ryadun, Alexey A.; Dorovatovskii, Pavel V.; Lazarenko, Vladimir A.; Samsonenko, Denis G.; Brylev, Konstantin A.; Fedin, Vladimir P.; Dybtsev, Danil N. published the artcile< Intense multi-colored luminescence in a series of rare-earth metal-organic frameworks with aliphatic linkers>, Application of C10H8N2, the main research area is rare metal organic framework aliphatic linker multicolored luminescence.

Two series of highly luminescent yttrium(III), europium(III) and terbium(III) metal-organic frameworks containing diimine aromatic ligands and the dicarboxylate linker trans-1,4-cyclohexanedicarboxylate (chdc2-) which can be described by the general formulas [M2(bpy)2(chdc)3], where M = Y3+ (1), Eu3+ (2), and Tb3+ (3) and bpy = 2,2′-bipyridyl, and [M2(phen)2(chdc)3], where M = Y3+ (4), Eu3+ (5), and Tb3+ (6) and phen = 1,10-phenanthroline, were synthesized and characterized. All compounds are based on the same dinuclear {M2(L)2(OOCR)6} building blocks and possess a similar topol. of the 3D framework with narrow pores. The chelate aromatic ligands act as efficient light-harvesting antennas for subsequent energy transfer to the emitting metal center (M = Eu3+, Tb3+) or intraligand photoemission (M = Y3+). As a result, the reported compounds display intense emission in the red (Eu3+), green (Tb3+) or blue (Y3+) regions representing three basic colors (RGB) of visible light. The measured quantum yields (QYs) of the solid-state luminescence for individual compounds were found to be 63% (1), 46% (2), 59% (3), 2.3% (4), 55% (5) and 49% (6). The drastic reduction of the luminescence efficiency for 4 is explained by the strong disorder of phen ligands. The high thermal stability (up to 300 °C) and exceptional moisture resistance of the bpy-based frameworks 1-3 were confirmed by TG and PXRD measurements. Various bimetal or trimetal compositions were also prepared for the bpy-series. The luminescence properties of these mixed-metal compounds depend on both the chem. composition and excitation wavelength (λex). Remarkably, pure white emission with color temperature = 6126 K was achieved for [Y1.68Eu0.08Tb0.24(bpy)2(chdc)3] at λex = 360 nm with QY = 20%. The reported results suggest that the obtained coordination framework series is a convenient platform for the design of highly efficient light emitting materials with tunable properties.

Dalton Transactions published new progress about Crystal structure. 366-18-7 belongs to class pyridine-derivatives, and the molecular formula is C10H8N2, Application of C10H8N2.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Jiao, Chen; Obst, Franziska; Geisler, Martin; Che, Yunjiao; Richter, Andreas; Appelhans, Dietmar; Gaitzsch, Jens; Voit, Brigitte published the artcile< Reversible Protein Capture and Release by Redox-Responsive Hydrogel in Microfluidics>, Product Details of C10H8N2S2, the main research area is protein capture redox responsive hydrogel microfluidics; disulfide bonds; hydrogels; mechanical properties; microfluidics; protein capture and release; redox-responsive; swelling behaviors.

Stimuli-responsive hydrogels have a wide range of potential applications in microfluidics, which has drawn great attention. Double crosslinked hydrogels are very well suited for this application as they offer both stability and the required responsive behavior. Here, we report the integration of poly(N-isopropylacrylamide) (PNiPAAm) hydrogel with a permanent crosslinker (N,N′-methylenebisacrylamide, BIS) and a redox responsive reversible crosslinker (N,N′-bis(acryloyl)cystamine, BAC) into a microfluidic device through photopolymerization Cleavage and re-formation of disulfide bonds introduced by BAC changed the crosslinking densities of the hydrogel dots, making them swell or shrink. Rheol. measurements allowed for selecting hydrogels that withstand long-term shear forces present in microfluidic devices under continuous flow. Once implemented, the thiol-disulfide exchange allowed the hydrogel dots to successfully capture and release the protein bovine serum albumin (BSA). BSA was labeled with rhodamine B and functionalized with 2-(2-pyridyldithio)-ethylamine (PDA) to introduce disulfide bonds. The reversible capture and release of the protein reached an efficiency of 83.6% in release rate and could be repeated over 3 cycles within the microfluidic device. These results demonstrate that our redox-responsive hydrogel dots enable the dynamic capture and release of various different functionalized (macro)mols. (e.g., proteins and drugs) and have a great potential to be integrated into a lab-on-a-chip device for detection and/or delivery.

Polymers (Basel, Switzerland) published new progress about Bovine serum albumin Role: PEP (Physical, Engineering or Chemical Process), PUR (Purification or Recovery), PROC (Process), PREP (Preparation) (rhodamine B and PDA-labeled). 2127-03-9 belongs to class pyridine-derivatives, and the molecular formula is C10H8N2S2, Product Details of C10H8N2S2.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Kizu, Tomohito; Uraguchi, Daisuke; Ooi, Takashi published the artcile< Independence from the Sequence of Single-Electron Transfer of Photoredox Process in Redox-Neutral Asymmetric Bond-Forming Reaction>, Name: Ir(p-F-ppy)3, the main research area is enantioselective coupling arylaminomethane methanesulfonylaldimine iridium photosensitizer.

A catalytic cycle initiated by the oxidative quenching of the excited photosensitizer (Ir*(ppy)3) is established for the enantioselective coupling between (N-arylamino)methanes and (N-methanesulfonyl)aldimines catalyzed by Ir-based photosensitizer and a chiral (arylamino)phosphonium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate under visible light irradiation This achievement clearly demonstrates the insensitivity of this redox-neutral asym. reaction to the sequence of the key redox events involved in the synergistic catalysis.

Journal of Organic Chemistry published new progress about Aldimines Role: RCT (Reactant), RACT (Reactant or Reagent). 370878-69-6 belongs to class pyridine-derivatives, and the molecular formula is C33H21F3IrN3, Name: Ir(p-F-ppy)3.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Bonardd, Sebastian; Angel, Alejandro; Norambuena, Angel; Coll, Deysma; Tundidor-Camba, Alain; Ortiz, Pablo A. published the artcile< Novel polyelectrolytes obtained by direct alkylation and ion replacement of a new aromatic polyamide copolymer bearing pyridinyl pendant groups>, SDS of cas: 3731-53-1, the main research area is aromatic polyamide copolymer pyridinyl pendant bearing polyelectrolyte alkylation; polyamide; polyelectrolyte; pyridinyl groups; quaternisation.

The following work shows, for the first time, the synthesis and characterization of a new family of polyelectrolytes, along with their preliminary assessments in terms of desalin water treatment. These materials fall into the category of aromatic co-polyamides, which are obtained by the direct condensation of monomers 4,4′-oxydianiline (ODA), isophthaloyl chloride, and 3,5-diamino-N-(pyridin-4-ylmethyl)benzamide (PyMDA). Thereby, the charged nature exhibited by these materials was achieved through the quaternization of PyMDA moieties using linear iodoalkanes of different lengths (CnI with n = 1, 2, 4, and 6). After completing the quaternization process, polyelectrolytes were subjected to a one-step anion substitution process, where iodide counterions were replaced by bis(trifluoromethane)sulfonamide entities. For all the obtained materials, solubility tests were carried out, showing that those alkylated with Me and Et chains exhibit high solubility in rutinary aprotic polar solvents, while those containing Bu and n-hexyl units resulted in the formation of insoluble gels. Due to the above, the latest were discarded from this study early on. The structural characterization of the initial neutral co-polyamide was carried out by means of IR spectroscopy (FT-IR), NMR (1H, 13C-NMR), and size-exclusion chromatog. (SEC), while the structure of methylated and ethylated polyelectrolytes was successfully confirmed through FT-IR, 1H, 13C, and 19F-NMR. Addnl., the thermal behavior of these materials was analyzed in terms of thermogravimetric anal. (TGA) and differential scanning calorimetry (DSC), showing thermal degradation temperatures above 300°C and glass transition temperatures (Tg) above 200°C, resulting in polymers with outstanding thermal properties for water treatment applications. On the other hand, through the solvent-casting method, both neutral and charged polymers were found to be easily prepared into films, exhibiting a remarkably flexibility. The mech. properties of the films were analyzed using the traction test, from which tensile strength values ranging between 83.5 and 87.9 Mpa, along with Young’s modulus values between 2.4 and 2.5 Gpa were obtained. Moreover, through contact angle measurements and absorption anal. by immersion, polyelectrolytes showed important changes in terms of affinity against polar and polar substances (water, n-heptane, and benzene), exhibiting a higher rejection regarding the neutral polymer. Finally, as a preliminary test against the seepage of saline waters, thin polymer films (from 11.4 to 17.1μm) were deposited on top of com. filter disks and tested as filters of saline solutions ([NaCl] = 1000 and 2000 ppm). These tests revealed a decrease of the salt concentration in the obtained filtrates, with retention values ranging between 6.2 and 20.3%, depending on the concentration of the former solution and the polymer used.

Polymers (Basel, Switzerland) published new progress about Absorption. 3731-53-1 belongs to class pyridine-derivatives, and the molecular formula is C6H8N2, SDS of cas: 3731-53-1.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Bregman, Howard; Simard, Jeffrey R.; Andrews, Kristin L.; Ayube, Shawn; Chen, Hao; Gunaydin, Hakan; Guzman-Perez, Angel; Hu, Jiali; Huang, Liyue; Huang, Xin; Krolikowski, Paul H.; Lehto, Sonya G.; Lewis, Richard T.; Michelsen, Klaus; Pegman, Pamela; Plant, Matthew H.; Shaffer, Paul L.; Teffera, Yohannes; Yi, Shuyan; Zhang, Maosheng; Gingras, Jacinthe; DiMauro, Erin F. published the artcile< The Discovery and Hit-to-Lead Optimization of Tricyclic Sulfonamides as Potent and Efficacious Potentiators of Glycine Receptors>, HPLC of Formula: 55279-29-3, the main research area is sulfonamide glycine receptor analgesic pain.

Current pain therapeutics suffer from undesirable psychotropic and sedative side-effects, as well as abuse potential. Glycine receptors (GlyRs) are inhibitory ligand-gated ion channels expressed in nerves of the spinal dorsal horn, where their activation is believed to reduce transmission of painful stimuli. Herein, the authors describe the identification and hit-to-lead optimization of a novel class of tricyclic sulfonamides as allosteric GlyR potentiators. Initial optimization of high-throughput screening (HTS) hit led to the identification of a compound, which demonstrated ex vivo potentiation of glycine-activated current in mouse dorsal horn neurons from spinal cord slices. Further improvement of potency and pharmacokinetics produced in vivo proof-of-concept tool mol. I (AM-1488) which reversed tactile allodynia in a mouse spared-nerve injury (SNI) model. Addnl. structural optimization provided highly potent potentiator II (AM-3607), which was cocrystd. with human GlyRα3cryst to afford the first described potentiator-bound x-ray cocrystal structure within this class of ligand-gated ion channels (LGICs).

Journal of Medicinal Chemistry published new progress about Analgesics. 55279-29-3 belongs to class pyridine-derivatives, and the molecular formula is C6H6N2O, HPLC of Formula: 55279-29-3.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Cheda, Aneta; Nowosielska, Ewa M.; Gebicki, Jerzy; Marcinek, Andrzej; Chlopicki, Stefan; Janiak, Marek K. published the artcile< A derivative of vitamin B3 applied several days after exposure reduces lethality of severely irradiated mice>, Reference of 350-03-8, the main research area is vitamin B3 lethality anti inflammatory agent.

Most, if not all, of the hitherto tested substances exert more or less pronounced pro-survival effects when applied before or immediately after the exposure to high doses of ionizing radiation. In the present study we demonstrate for the first time that 1-Me nicotinamide (MNA), a derivative of vitamin B3, significantly (1.6 to 1.9 times) prolonged survival of BALB/c mice irradiated at LD30/30 (6.5 Gy), LD50/30 (7.0 Gy) or LD80/30 (7.5 Gy) of γ-rays when the MNA administration started as late as 7 days post irradiation A slightly less efficient and only after the highest dose (7.5 Gy) of γ-rays was another vitamin B3 derivative, 1-methyl-3-acetylpyridine (1,3-MAP) (1.4-fold prolonged survival). These pro-survival effects did not seem to be mediated by stimulation of haematopoiesis, but might be related to anti-inflammatory and/or anti-thrombotic properties of the vitamin B3 derivatives Our results show that MNA may represent a prototype of a radioremedial agent capable of mitigating the severity and/or progression of radiation-induced injuries when applied several hours or days after exposure to high doses of ionizing radiation.

Scientific Reports published new progress about Anti-inflammatory agents. 350-03-8 belongs to class pyridine-derivatives, and the molecular formula is C7H7NO, Reference of 350-03-8.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem