Day: October 21, 2022

HPLC of Formula: 98-98-6In 2021 ,《Serum protein-hyaluronic acid complex nanocarriers: Structural characterisation and encapsulation possibilities》 appeared in Carbohydrate Polymers. The author of the article were Kovacs, Alexandra N.; Varga, Norbert; Juhasz, Adam; Csapo, Edit. The article conveys some information:

A protein-polysaccharide-based potential nanocarrier system have been developed via a simple, one-step preparation protocol without the use of long-term heating and the utilization of hardly removable crosslinking agents, surfactants, and toxic organic solvents. To the best of our knowledge, this article is the first which summarizes in detail the pH-dependent quant. relationship between the bovine serum albumin (BSA) and hyaluronic acid (HyA) confirmed by several physico-chem. techniques. The formation of colloidal complex nanoconjugates with average diameter of ca. 210-240 nm is strongly depend on the pH and the applied BSA:HyA mass ratio. Particle charge titrations studies strongly support the core-shell type structure, where the BSA core is covered by a thick HyA shell. Besides the optimization of these conditions, the drug encapsulation capacity and the dissolution profiles have been also studied for ibuprofen (IBU) and 2-picolinic acid (2-PA) as model drugs. In the experimental materials used by the author, we found Picolinic acid(cas: 98-98-6HPLC of Formula: 98-98-6)

Picolinic acid(cas: 98-98-6) is used as a chelate for alkaline earth metals. Used to prepare picolinato ligated transition metal complexes. In synthetic organic chemistry, has been used as a substrate in the Mitsunobu reaction and in the Hammick reaction.HPLC of Formula: 98-98-6

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Related Products of 29682-15-3In 1997 ,《Regiospecific carboalkoxylation of 2,5-dibromopyridine》 appeared in Synthetic Communications. The author of the article were Chambers, R.J.; Marfat, A.. The article conveys some information:

Carboalkoxylation of 2,5-dibromopyridine with carbon monoxide and an alc. in the presence of palladium acetate and 1,1′-bis(diphenylphosphino)ferrocene (dppf) occurs regiospecifically to afford esters of 5-bromopyridine-2-carboxylic acid in good yield. In the part of experimental materials, we found many familiar compounds, such as Methyl 5-bromopicolinate(cas: 29682-15-3Related Products of 29682-15-3)

Methyl 5-bromopicolinate(cas: 29682-15-3) belongs to pyridine. The basicity and metallophilic high donor number of these π-deficient systems has long favored them as ligands in metal catalysis. The last decade saw pyridine assume a stronger role as functional group for directed C–H oxidation/activation.Related Products of 29682-15-3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Application In Synthesis of 5-Bromo-2-chloropyridineIn 2021 ,《Directing Group Enables Electrochemical Selectively Meta-Bromination of Pyridines under Mild Conditions》 appeared in Journal of Organic Chemistry. The author of the article were Wu, Yanwei; Xu, Shanghui; Wang, Hong; Shao, Dongxu; Qi, Qiqi; Lu, Yi; Ma, Li; Zhou, Jianhua; Hu, Wei; Gao, Wei; Chen, Jianbin. The article conveys some information:

Without the use of catalysts and oxidants, a facile and sustainable electrochem. bromination protocol was developed. By introducing the directing groups, the regioselectivity of pyridine derivatives could be controlled at the meta-position utilizing the inexpensive and safe bromine salts at room temperature A variety of brominated pyridine derivatives were obtained in 28-95% yields, and the reaction could be readily performed at a gram scale. By combining the installation and removing the directing group, the concept of meta-bromination of pyridines could be verified. After reading the article, we found that the author used 5-Bromo-2-chloropyridine(cas: 53939-30-3Application In Synthesis of 5-Bromo-2-chloropyridine)

5-Bromo-2-chloropyridine(cas: 53939-30-3) belongs to pyridine. The basicity and metallophilic high donor number of these π-deficient systems has long favored them as ligands in metal catalysis. The last decade saw pyridine assume a stronger role as functional group for directed C–H oxidation/activation.Application In Synthesis of 5-Bromo-2-chloropyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Recommanded Product: 3510-66-5In 2019 ,《A greener approach toward N-1 heteroarylation of indoles: Synthesis and in vitro evaluation of potential anti-proliferative agents》 appeared in Arabian Journal of Chemistry. The author of the article were Sailaja, E.; Bhavani, S.; Rambabu, D.; Basaveswara Rao, M. V.; Pal, Manojit. The article conveys some information:

A greener approach was developed to synthesize N-pyridyl indoles e.g., I [R1 = R2 = H, R3 = 2-pyridyl] and N-pyrimidinyl indoles e.g., I [R1 = R2 = H, R3 = 2-pyrimidinyl] via an ultrasound assisted selective N-1 heteroarylation of indoles. This methodol. involved reaction of indoles with heteroaryl halides in PEG-400 under ultrasound irradiation Compound I [R1 = R2 = H, R3 = 2-pyrimidinyl] was benzoylated at C-2 position via palladium-mediated C-H bond activation. All the synthesized N-1 heteroarylindoles were tested for their in vitro anti-proliferative properties against cancer (leukemia) and non-cancerous cell lines. Among the tested compounds, compounds I [R1 = H; R2 = 5-OMe; R3 = 2-pyridyl, 5-Me-2-pyridyl, 2-pyrimidinyl] showed promising activity against K562 leukemia cells whereas compound I [R1 = H, R2 = 5-OMe, R3 = 2-pyrimidinyl] showed significant activity against Colo-205 cells. Addnl., none of these N-heteroaryl indoles showed any effect against noncancerous HEK293 cell lines, indicating their selectivity toward cancer cells specifically leukemia. In addition to this study using 2-Bromo-5-methylpyridine, there are many other studies that have used 2-Bromo-5-methylpyridine(cas: 3510-66-5Recommanded Product: 3510-66-5) was used in this study.

2-Bromo-5-methylpyridine(cas: 3510-66-5) belongs to pyridine. Pyridine and pyridine-derived structures are privileged pharmacophores in medicinal chemistry and an essential functionality for organic chemists. As the prototypical π-deficient heterocycle, pyridine illustrates distinctive chemistry as both substrate and reagent. Recommanded Product: 3510-66-5

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Category: pyridine-derivativesIn 2021 ,《Visible-Light-Mediated Nitrogen-Centered Radical Strategy: Preparation of 3-Acylated Spiro[4,5]trienones》 was published in Advanced Synthesis & Catalysis. The article was written by Chen, Pu; Xie, Jun; Chen, Zan; Xiong, Bi-Quan; Liu, Yu; Yang, Chang-An; Tang, Ke-Wen. The article contains the following contents:

A nitrogen-centered radical strategy for the preparation of 3-acylated spiro[4,5]trienones I [R1 = H, 6-Me, 7-I, etc.; R2 = Me, Bn, allyl, etc.; R3 = Ph, 2-MeC6H4, 2-naphthyl, etc.; R4 = Me, Et, iPr, etc.] via visible-light-mediated acylation/ipso-cyclization of alkynes with acyl oxime esters was reported. This method provided a way for the construction of compounds I, which could introduced aryl- or alkyl-substituted acyl into spiro[4,5]trienone skeletons. In addition to this study using fac-Tris(2-phenylpyridine)iridium, there are many other studies that have used fac-Tris(2-phenylpyridine)iridium(cas: 94928-86-6Category: pyridine-derivatives) was used in this study.

fac-Tris(2-phenylpyridine)iridium(cas: 94928-86-6) belongs to pyridine. Pyridines, quinolines, and isoquinolines have found a function in almost all aspects of organic chemistry. Pyridine has found use as a solvent, base, ligand, functional group, and molecular scaffold. As structural elements, these moieties are potent electron-deficient groups, metal-directing functionalities, fluorophores, and medicinally important pharmacophores. Category: pyridine-derivatives

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Formula: C5H3Br2NIn 2021 ,《Synthesis and Studies of Stable Nonaromatic Dithia Pyribenzihexaphyrins》 was published in Journal of Organic Chemistry. The article was written by Rawat, Nisha; Sinha, Avisikta; Prasannan, Dijo; Ravikanth, Mangalampalli. The article contains the following contents:

We report here one of the rare examples of expanded hexaphyrins named as dithia pyribenzihexaphyrin macrocycles containing six-membered rings such as pyridine and p-phenylene along with five-membered heterocycles such as pyrrole and thiophene as a part of a macrocyclic frame. Trifluoroacetic acid catalyzed [3+3] condensation of equimolar mixture of [10,10′-bis(p-tert-Bu phenyl)hydroxymethyl]-1,3-bis(2-thienyl)pyridine diol (2,6-pyri diol) and 1,4-bis(phenyl(1H-pyrrol-2-yl)methyl)benzene (p-benzidipyrrane) in CH2Cl2 followed by oxidation with DDQ afforded stable nonaromatic dithia 2,6-pyri-para-benzihexapyrins and in 6-8% yields. The macrocycles were characterized by high-resolution mass spectroscopy and 1D and 2D NMR spectroscopy. NMR studies revealed the nonaromatic nature of dithia 2,6-pyri-p-benzihexaphyrins and indicated that the para-phenylene ring prefers to be in quininoid form rather than in benzenoid form. The macrocycles displayed sharp absorption bands in the region of ~380-500 nm and a broad band at ~700 nm, reflecting their nonaromatic nature. Upon protonation, these macrocycles showed NIR absorption properties. The redox studies of macrocycles indicated their electron-deficient nature. The DFT/TD-DFT studies are in line with the exptl. observations. The experimental part of the paper was very detailed, including the reaction process of 2,6-Dibromopyridine(cas: 626-05-1Formula: C5H3Br2N)

2,6-Dibromopyridine(cas: 626-05-1) belongs to pyridine. Pyridines, quinolines, and isoquinolines have found a function in almost all aspects of organic chemistry. Pyridine has found use as a solvent, base, ligand, functional group, and molecular scaffold. As structural elements, these moieties are potent electron-deficient groups, metal-directing functionalities, fluorophores, and medicinally important pharmacophores. Formula: C5H3Br2N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Safety of Picolinic acidIn 2019 ,《Red Blood Cell Metabolic Responses to Torpor and Arousal in the Hibernator Arctic Ground Squirrel》 was published in Journal of Proteome Research. The article was written by Gehrke, Sarah; Rice, Sarah; Stefanoni, Davide; Wilkerson, Rebecca B.; Nemkov, Travis; Reisz, Julie A.; Hansen, Kirk C.; Lucas, Alfredo; Cabrales, Pedro; Drew, Kelly; D’Alessandro, Angelo. The article contains the following contents:

Arctic ground squirrels provide a unique model to investigate metabolic responses to hibernation in mammals. During winter months these rodents are exposed to severe hypothermia, prolonged fasting, and hypoxemia. In the light of their role in oxygen transport/off-loading and owing to the absence of nuclei and organelles (and thus de novo protein synthesis capacity), mature red blood cells have evolved metabolic programs to counteract physiol. or pathol. hypoxemia. However, red blood cell metabolism in hibernation has not yet been investigated. Here we employed targeted and untargeted metabolomics approaches to investigate erythrocyte metabolism during entrance to torpor to arousal, with a high resolution of the intermediate time points. We report that torpor and arousal promote metabolism through glycolysis and pentose phosphate pathway, resp., consistent with previous models of oxygen-dependent metabolic modulation in mature erythrocytes. Erythrocytes from hibernating squirrels showed up to 100-fold lower levels of biomarkers of reperfusion injury, such as the pro-inflammatory dicarboxylate succinate. Altered tryptophan metabolism during torpor was here correlated to the accumulation of potentially neurotoxic catabolites kynurenine, quinolinate, and picolinate. Arousal was accompanied by alterations of sulfur metabolism, including sudden spikes in a metabolite putatively identified as thiorphan (level 1 confidence)-a potent inhibitor of several metalloproteases that play a crucial role in nociception and inflammatory complication to reperfusion secondary to ischemia or hemorrhage. Preliminary studies in rats showed that i.v. injection of thiorphan prior to resuscitation mitigates metabolic and cytokine markers of reperfusion injury, etiol. contributors to inflammatory complications after shock. In addition to this study using Picolinic acid, there are many other studies that have used Picolinic acid(cas: 98-98-6Safety of Picolinic acid) was used in this study.

Picolinic acid(cas: 98-98-6) is used as a chelate for alkaline earth metals. Used to prepare picolinato ligated transition metal complexes. In synthetic organic chemistry, has been used as a substrate in the Mitsunobu reaction and in the Hammick reaction.Safety of Picolinic acid

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Formula: C7H5NIn 2019 ,《Screening of Three Transition Metal-Mediated Reactions Compatible with DNA-Encoded Chemical Libraries》 was published in Helvetica Chimica Acta. The article was written by Favalli, Nicholas; Bassi, Gabriele; Zanetti, Tania; Scheuermann, Joerg; Neri, Dario. The article contains the following contents:

The construction of DNA-encoded chem. libraries (DECLs) crucially relies on the availability of chem. reactions, which are DNA-compatible and which exhibit high conversion rates for a large number of diverse substrates. In this work, we present our optimization and validation procedures for three copper and palladium-catalyzed reactions (Suzuki cross-coupling, Sonogashira cross-coupling, and copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC)), which have been successfully used by our group for the construction of large encoded libraries. The results came from multiple reactions, including the reaction of 4-Ethynylpyridine(cas: 2510-22-7Formula: C7H5N)

4-Ethynylpyridine(cas: 2510-22-7) belongs to pyridine. Pyridines, quinolines, and isoquinolines have found a function in almost all aspects of organic chemistry. Pyridine has found use as a solvent, base, ligand, functional group, and molecular scaffold. As structural elements, these moieties are potent electron-deficient groups, metal-directing functionalities, fluorophores, and medicinally important pharmacophores. Formula: C7H5N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Recommanded Product: 626-05-1In 2022 ,《Synthesis and Structural Properties of NIR-Absorbing Pyridine-Containing Heptaphyrins》 was published in Chemistry – An Asian Journal. The article was written by Rawat, Nisha; Sinha, Avisikta; Ravikanth, Mangalampalli. The article contains the following contents:

Four examples of stable nonaromatic pyridine containing heteroheptaphyrins (pyrithiaheptaphyrins) 2-5 were synthesized in 8-13% yields by [5+2] condensation of newly synthesized pyridine-based pentapyrrane 8 and bithiophene diol 9 a-d. The X-ray crystallog. anal. of macrocycle 2 proved that the macrocycle assumes a highly planar structure with two inverted thiophene rings. The heteroheptaphyrins 2-5 are asym. and showed a greater number of resonances in 1H NMR spectra compared to our previously reported sym. heterohexaphyrin (pyrithiahexaphyrin) 1 c. Most of the macrocyclic core protons in pyrithiahepaphyrins 2-5 experienced upfield/downfield shifts compared to pyrithiahexaphyrin 1 c indicating the alteration of π-conjugation in the macrocycles. The absorption bands were significantly red-shifted and located in the NIR region in macrocycles 2-5 compared to 1 c supporting the increase of π-delocalization. The theor. studies support the exptl. findings and NICS(0) value supports the non-aromaticity of the macrocycles. In the experimental materials used by the author, we found 2,6-Dibromopyridine(cas: 626-05-1Recommanded Product: 626-05-1)

2,6-Dibromopyridine(cas: 626-05-1) belongs to pyridine. Pyridines, quinolines, and isoquinolines have found a function in almost all aspects of organic chemistry. Pyridine has found use as a solvent, base, ligand, functional group, and molecular scaffold. As structural elements, these moieties are potent electron-deficient groups, metal-directing functionalities, fluorophores, and medicinally important pharmacophores. Recommanded Product: 626-05-1

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Application of 141-86-6In 2019 ,《Excellent toughening of 2,6-diaminopyridine derived poly (urethane urea) via dynamic cross-linkages and interfering with hydrogen bonding of urea groups from partially coordinated ligands》 was published in Polymers (Basel, Switzerland). The article was written by Sun, Ailing; Guo, Wenjuan; Zhang, Jinping; Li, Wenjuan; Liu, Xin; Zhu, Hao; Li, Yuhan; Wei, Liuhe. The article contains the following contents:

Conventional approaches to synthesize thermoplastic polyurethane (TPU) with excellent robustness are limited by a competing relationship between soft and hard segments for tuning mech. properties in terms of chain flexibility and micro-phase separation Herein, we present a facile and effective way of simultaneously improving the tensile strength, elongation, and toughness by constructing dynamic cross-linkages from metal-ligand interaction between Zn2+ and pyridine moiety in backbone of poly(urethane urea) (PUU) derived from 2,6-diaminopyridine and poly(propylene glycol). It was found that a Zn2+/pyridine ratio of 1:4 is the most effective for improving robustness. Specifically, tensile strength, elongation, and toughness could be remarkably increased to 16.0 MPa, 1286%, and 89.3 MJ/m3 with 226%, 29%, and 185% increments compared to uncomplexed PUU, resp. Results from UV-vis, Fourier transform IR spectroscopy (FTIR), cyclic tensile tests, and stress relaxation reveal that metal-ligand interaction significantly interferes with the hydrogen bonding of urea groups, thus leading to weakening of stiffness. Furthermore, half of vacant ligands enable dynamic complexation during stretching, which consequently ensures constant noncovalent cross-linkages for constraining mutual chain sliding, contributing to simultaneous improvement of tensile strength, elongation, and toughness. This work provides a promising approach for designing TPU with excellent robustness. In the experiment, the researchers used 2,6-Diaminopyridine(cas: 141-86-6Application of 141-86-6)

2,6-Diaminopyridine(cas: 141-86-6) belongs to pyridine. Pyridine and its simple derivatives are stable and relatively unreactive liquids, with strong penetrating odours that are unpleasant.Application of 141-86-6

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem