Month: December 2022

Morimoto, Nobuyuki published the artcileThe Design of Sulfobetaine Polymers with Thermoresponsiveness under Physiological Salt Conditions, Name: 4-Amino-2-picoline, the publication is Macromolecular Chemistry and Physics (2020), 221(5), 1900429, database is CAplus.

Thermoresponsive polymers are attractive in terms of basics and applications because of the phase separation in aqueous solution Some sulfobetaine polymers are known for their antifouling biocompatibility and upper critical solution temperature (UCST) type thermoresponsiveness; however, thermoresponsiveness disappears in aliphatic sulfobetaine polymers in physiol. salt conditions. Aromatic cation-containing sulfobetaine polymers are not responded because of the strong intermol. interactions. In this study, new sulfobetaine methacrylamides with a pyridinium cation, 3-(4-(2-methacrylamido)alkyl pyridinio-1-yl)propane-1-sulfonates, (PySMAAm)s, are designed and then prepared the homopolymers using aqueous reversible addition-fragmentation chain transfer polymerization The P(PySMAAm)s exhibited UCST-type thermoresponsiveness that is induced by substitution of the dipole-dipole interaction between the interpolymer side chain to an ion-dipole interaction in physiol. salt conditions. The thermoresponsiveness is affected by the mol. weight and structure of the side chains. Such sulfobetaine polymers can be promising tools as biomaterials especially for drug delivery and regenerative medicine.

Macromolecular Chemistry and Physics published new progress about 18437-58-6. 18437-58-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 4-Amino-2-picoline, and the molecular formula is C6H8N2, Name: 4-Amino-2-picoline.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Taya, Toshiki published the artcileKinetic study of solvent extraction of nickel(II) from aqueous solution by some heterocyclic substituted-hydrazones, Application In Synthesis of 2215-33-0, the publication is Analytical Sciences (1991), 7(Suppl.), 21-4, database is CAplus.

Solvent extraction of nickel(II) complexes with five heterocyclic hydrazones (containing pyridine- or/ and quinoline-nitrogen atoms as the coordinating sites) into chloroform or benzene was studied kinetically at 25°C and μ = 0.1 by means of a spectrophotometric method. The kinetics of extraction of nickel(II) ion is first order in each of the aqueous nickel(II) concentration and the hydrazone concentration in the organic phase. The observed second-order rate constant, k_obs, -pH profiles suggest three rate-determining steps to be considered in the aqueous phase: Ni²⁺ + H₂L⁺ â†? Ni²⁺ + HL â†?and Ni(OH)⁺ + HL â†? The rate constant for the formation of 1:1 complexes with 2-pyridylmethanone 2-pyridylhydrazone (PAPH) was consistent with those for bipyridine and terpyridine. Replacement of pyridyl group by quinolyl group affects the distribution constant (K_d) of the ligand between the two phases rather than the rate constants The influence of the structure of ligands on the rate constants is also discussed.

Analytical Sciences published new progress about 2215-33-0. 2215-33-0 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, and the molecular formula is C18H34N4O5S, Application In Synthesis of 2215-33-0.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Taya, Toshiki published the artcileExtraction equilibria of nickel(II) with several heterocyclic substituted hydrazones, Quality Control of 2215-33-0, the publication is Analytical Sciences (1993), 9(6), 835-41, database is CAplus.

The extraction of nickel(II) with seven N,N,N-tridentate heterocyclic hydrazones, a neutral form of which is abbreviated as HL, using chloroform or benzene as an extraction solvent has been studied, the extraction equilibrium being analyzed on the basis of the data for the proton dissociation of H₃L²⁺, the formation of Ni(HL)²⁺ and Ni(HL)₂²⁺ complexes and the proton dissociation of Ni(HL)₂²⁺ complexes in aqueous solution Nickel(II) is extracted as NiL₂ although it forms such complexing ions an Ni(HL)²⁺ or Ni(HL)₂²⁺ in the aqueous phase. The distribution constants of HL and NiL₂ (the abbreviations of which are K_d and K_dm, resp.) have been determined under the same condition as in aqueous solution The logarithmic plots of Kdm vs. K_d displayed two straight lines with slopes of 1.9; one is for hydrazones bearing one pyridyl or one quinolyl ring in the aldehyde moiety and the other for hydrazones bearing another pyridyl ring introduced to the aldehyde moiety. This is attributed to an intramol. hydrogen bond between the imino hydrogen and the nitrogen of pyridine of the latter hydrazones.

Analytical Sciences published new progress about 2215-33-0. 2215-33-0 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, and the molecular formula is C13H16BFO4, Quality Control of 2215-33-0.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Ogino, Yoshio published the artcileSyntheses and structure-activity relationships of novel, potent, and selective trans-2-[3-oxospiro[isobenzofuran-1(3H),1′-cyclohexan]-4′-yl]benzimidazole NPY Y5 receptor antagonists, Category: pyridine-derivatives, the publication is Bioorganic & Medicinal Chemistry Letters (2008), 18(18), 4997-5001, database is CAplus and MEDLINE.

Syntheses and structure-activity relationships of a novel class of 2-[3-oxospiro[isobenzofuran-1(3H),1′-cyclohexan]-4′-yl]benzimidazole NPY Y5 receptor antagonists are described. Optimization of the lead compound (I) by incorporating substituents into the 5-position or into both the 5- and 6-positions of the benzimidazole core part led to the identification of two potent, selective, and orally bioavailable Y5 receptor antagonists (II (IC₅₀ = 3.3 nM) and III (IC₅₀ = 5.9 nM)).

Bioorganic & Medicinal Chemistry Letters published new progress about 197958-29-5. 197958-29-5 belongs to pyridine-derivatives, auxiliary class Pyridine,Boronic acid and ester, name is 2-Pyridinylboronic acid, and the molecular formula is C5H6BNO2, Category: pyridine-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Adachi, Kenji published the artcileElectrophilic fluorination with N,N’-difluoro-2,2′-bipyridinium salt and elemental fluorine, Category: pyridine-derivatives, the publication is Journal of Fluorine Chemistry (2003), 120(2), 173-183, database is CAplus.

N,N’-Difluoro-2,2′-bipyridinium bis(tetrafluoroborate) (MEC-31) was shown to be a highly reactive electrophilic fluorinating agent with the highest effective fluorine content in its class. We have developed the perfect recycled fluorination system with MEC-31 for the lower-cost industrial fluorination and for an environment. MEC-31 can be completely recycled including the counter-anion. We found the fluorination of 2-naphthol in liquid CO₂ with MEC-31 in the presence of catalytic amount of NaOTf proceeded quant. without the generation of byproduct. In the fluorination of 1,3-dicarbonyl compounds with elemental fluorine, we found the introduction method of fluorine gas would be very important in order to make a reaction efficient. As fluorination goes on, the quantity of 1,3-dicarbonyl compounds of the starting material is reduced gradually, and therefore the quantity of fluorine must be reduced by the method to control the flow rate or the concentration of fluorine gas diluted with nitrogen, together the fluorination to proceed efficiently.

Journal of Fluorine Chemistry published new progress about 107263-95-6. 107263-95-6 belongs to pyridine-derivatives, auxiliary class Fluorination reagent, name is 1-Fluoropyridiniumtriflate, and the molecular formula is C6H5F4NO3S, Category: pyridine-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Oda, Mitsunori published the artcileSynthesis and properties of 2-(2-pyridyl)-1-azaazulene, Formula: C5H6BNO2, the publication is Tetrahedron Letters (2007), 48(26), 4471-4475, database is CAplus.

The title azaazulene (I) was synthesized either by reaction of tropone with N-[(2-pyridyl)acetyl]pyridinium iodide in the presence of ammonium acetate or by palladium-catalyzed cross-coupling between 2-halo-1-azaazulene and 2-substituted pyridine. The compound shows relatively stronger basicity compared with 2,2′-bipyridyl. While I showed no emission from the S₁ state but from the S₂ state like azulene does, the protonated species of I exhibited emission from the S₁ state. Cationic metal-dependent absorption and emission relating to complexation were also studied.

Tetrahedron Letters published new progress about 197958-29-5. 197958-29-5 belongs to pyridine-derivatives, auxiliary class Pyridine,Boronic acid and ester, name is 2-Pyridinylboronic acid, and the molecular formula is C5H6BNO2, Formula: C5H6BNO2.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Kim, Jong Hyun published the artcileAnticancer gold(III)-bisphosphine complex alters the mitochondrial electron transport chain to induce in vivo tumor inhibition, Application In Synthesis of 91-02-1, the publication is Chemical Science (2021), 12(21), 7467-7479, database is CAplus and MEDLINE.

Expanding the chem. diversity of metal complexes provides a robust platform to generate functional bioactive reagents. To access an excellent repository of metal-based compounds for probe/drug discovery, we capitalized on the rich chem. of gold to create organometallic gold(III) compounds by ligand tuning. We obtained novel organogold(III) compounds bearing a 1,2-bis(diphenylphosphino)benzene ligand, providing structural diversity with optimal physiol. stability. Biol. evaluation of the lead compound AuPhos-89 demonstrates mitochondrial complex I-mediated alteration of the mitochondrial electron transport chain (ETC) to drive respiration and diminish cellular energy in the form of ATP (ATP). Mechanism-of-action efforts, RNA-Seq, quant. proteomics, and NCI-60 screening reveal a highly potent anticancer agent that modulates mitochondrial ETC. AuPhos-89 inhibits the tumor growth of metastatic triple neg. breast cancer and represents a new strategy to study the modulation of mitochondrial respiration for the treatment of aggressive cancer and other disease states where mitochondria play a pivotal role in the pathobiol.

Chemical Science published new progress about 91-02-1. 91-02-1 belongs to pyridine-derivatives, auxiliary class Pyridine,Benzene,Ketone, name is Phenyl(pyridin-2-yl)methanone, and the molecular formula is C12H9NO, Application In Synthesis of 91-02-1.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Ishii, Hajime published the artcileEquilibria and kinetics of the extraction of nickel with 2-pyridinecarbaldehyde 2-(5-substituted)pyridylhydrazones, Formula: C11H10N4, the publication is Analytical Sciences (1988), 4(1), 73-6, database is CAplus.

The equilibrium and kinetics of the extraction of Ni with benzene solutions of 2-pyridinecarbaldehyde 2-(5-substituted)pyridylhydrazones were studied at 25 ± 0.1° and an ionic strength of 0.2. The extracted species was found too be NiL₂ for each hydrazone, where L denotes the undissociable part of the hydrazone. Partition constants of the hydrazones and extraction constants of their Ni complexes between an aqueous and a benzene phase were determined The rate of extraction was best described by a two-term expression, both terms being 1st order in Ni ion and HL concentrations The first term has zero dependence on H⁺ concentration, whereas the 2nd is inversely first order with respect to H⁺ concentration These results support the hypothesis that the rate-determining steps involve 2 concurrent reactions of Ni with neutral and anionic forms of the hydrazones. Kinetic data and activation parameters for the first reaction were determined, but those for the second one involving the anion could not be obtained.

Analytical Sciences published new progress about 2215-33-0. 2215-33-0 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, and the molecular formula is C11H10N4, Formula: C11H10N4.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Ishii, Hajime published the artcileSynthesis of sensitive pyridylhydrazone reagents and extraction-spectrophotometric determination of trace nickel with 2-pyridinecarboxaldehyde 2-(5-nitro)pyridylhydrazone, Name: 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, the publication is Analytical Sciences (1987), 3(4), 347-52, database is CAplus.

Three new hydrazones, in which the hydrogen at the 5-position of the pyridine ring in the hydrazine moiety of 2-pyridinecarboxaldehyde 2-pyridylhydrazone was substituted by a Me, chloro, or nitro group, have been synthesized and their chromogenic properties, reactivities with metal ions, and extractabilities of the metal complexes were studied. The acid dissociation constants (K_a) of the synthesized hydrazones were determined spectrophotometrically. These values obeyed Hammett’s law, the inductive effect of the substituents being found to reflect the pK_a values. Of the synthesized hydrazones, 2-pyridinecarboxaldehyde 2-(5-nitro)pyridylhydrazone (PANPH), in which an electron-withdrawing nitro group was introduced, was most sensitive for metal ions. Its copper and nickel complexes showed molar absorptivities of the order of 10⁵. A highly sensitive and selective extraction-spectrophotometric method for the determination of nickel with PANPH is proposed and has been successfully applied to the determination of nickel in steel samples. The method has been further sensitized by employing analog derivative spectrophotometry.

Analytical Sciences published new progress about 2215-33-0. 2215-33-0 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, and the molecular formula is C11H10N4, Name: 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Kikuchi, Daisuke published the artcileAntihypertensive drug prescription trends for pregnant women with hypertension in acute hospitals in Japan, Name: Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, the publication is Hypertension Research (2022), 45(9), 1441-1446, database is CAplus and MEDLINE.

Abstract: Hypertensive disorders of pregnancy cause maternal organ damage. Therefore, appropriate management with antihypertensive medication is required from the first trimester. We aimed to clarify the antihypertensive drug prescription trends in pregnant women with hypertension in Japan. The administrative data of pregnant outpatients aged 16-49 years who visited acute hospitals between 2013 and 2020 were included. The annual antihypertensive drug prescription trends were evaluated based on their prescription proportions. The most prescribed drug in 2020 was nifedipine, followed by methyldopa and amlodipine. The proportion of nifedipine prescriptions significantly increased from 33.5 to 40.8% during the study period, whereas that of methyldopa significantly decreased from 16.6 to 11.6%. There was no change in the prescription trend of amlodipine. Dihydropyridine calcium channel blockers were the most commonly prescribed drug for pregnant women with hypertension.

Hypertension Research published new progress about 21829-25-4. 21829-25-4 belongs to pyridine-derivatives, auxiliary class Membrane Transporter/Ion Channel,Calcium Channel, name is Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C17H18N2O6, Name: Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem