Tag: 100-200

The author of 《Fluorescence Lifetime Imaging of p-tau Protein in Single Neuron with a Highly Selective Fluorescent Probe》 were Ge, Lihong; Tian, Yang. And the article was published in Analytical Chemistry (Washington, DC, United States) in 2019. HPLC of Formula: 1539-42-0 The author mentioned the following in the article:

Hyperphosphorylated tau (p-tau) protein is one of the key markers of Alzheimer’s disease (AD). However, a lack of anal. methods for p-tau protein with high selectivity and accuracy is the bottleneck to understand the pathol. processes of AD. In the present work, a highly selective fluorescence lifetime imaging microscopic (FLIM) probe (τ-p-tau) was rationally designed and developed for determination of p-tau protein, in which binuclear zinc units were designed as the recognition groups, and an improved cyanine was synthesized as the dye unit. The FLIM measurement is independent of the concentration of fluorescent probes, irradiation light sources, and measurement environments. Meanwhile, the developed τ-p-tau probe demonstrated strong affinity toward p-tau protein, thus enhancing the selectivity of determination of p-tau protein against Aβ, Aβ fibril, tau, protein kinases, ATP, and so on. The fluorescence lifetime of τ-p-tau probe showed a good linearity with the concentration of p-tau protein from 1.0 to 5.0 μM with a low detection limit of 85.15±0.03 nM. The response time of the present probe for p-tau protein was estimated to be less than 6.2 s. Furthermore, taking the advantages of low toxicity and good biocompatibility, the developed probe was successfully applied to monitor the fluctuation of concentration of p-tau protein by FLIM imaging at single neuron level. It was found that the concentration of p-tau protein inside live neurons obviously changed upon oxidative stress. In the experimental materials used by the author, we found Bis(pyridin-2-ylmethyl)amine(cas: 1539-42-0HPLC of Formula: 1539-42-0)

Bis(pyridin-2-ylmethyl)amine(cas: 1539-42-0) is a secondary amine with two picolyl substituents. As a tridentate ligand this compound provides three nitrogen donors that affords good selectivity for Zn2+ over biologically relevant metals such as Na+, K+, Mg2+ and Ca2+, and leaves coordination sites free for anion binding. HPLC of Formula: 1539-42-0

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2019,European Journal of Medicinal Chemistry included an article by Martin-Encinas, Endika; Rubiales, Gloria; Knudssen, Birgitta R.; Palacios, Francisco; Alonso, Concepcion. Synthetic Route of C5H5BrN2. The article was titled 《Straightforward synthesis and biological evaluation as topoisomerase I inhibitors and antiproliferative agents of hybrid chromeno[4,3-b][1,5]naphthyridines and chromeno[4,3-b][1,5]naphthyridin-6-ones》. The information in the text is summarized as follows:

Hybrid tetrahydrochromeno[4,3-b][1,5]naphthyridines I [R1 = H, F, Me; R2 = H, OMe; X = CH2], tetrahydrochromeno[4,3-b][1,5]naphthyridinones I [R1 = H, F; R2 = H, OMe, Br; X = C(O)], chromeno[4,3-b][1,5]naphthyridines II [X = CH2] and chromeno[4,3-b][1,5]naphthyridinones II [R3 = H, F, Me; R4 = H, OMe, Br; R5 = Ph, 4-MeOC6H4, 3,4-F2C6H3; Z = CH2, C(O)] were synthesized and evaluated as topoisomerase I inhibitors and antiproliferative agents. The synthetic route involved an intramol. Povarov [4 + 2]-cycloaddition of functionalized aldimines obtained by the condensation of 3-aminopyridine and aldehydes containing a double or triple carbon-carbon bond in ortho position and allowed the selective generation of three stereogenic centers. The subsequent dehydrogenation of the fused tetrahydrochromeno[4,3-b][1,5]naphthyridines I [X = CH2] and tetrahydrochromeno[4,3-b][1,5]naphthyridin-6-ones I [X = C=O] led to the formation of the corresponding tetracyclic chromeno[4,3-b][1,5]naphthyridine derivatives II [X = CH2] and chromeno[4,3-b][1,5]naphthyridin-6-ones II [X = C=O] in quant. yields. Some of the prepared products showed activity as inhibitors of topoisomerase I (TopI). Addnl., the cytotoxic behavior of these compounds was studied and the absence of cytotoxicity was observed against non-cancerous lung fibroblasts cell line (MRC5). Compound tetrahydrochromeno[4,3-b][1,5]naphthyridine I [R1 = R3 = H, R2 = Ph, X = CH2] showed excellent cytotoxic activity with a IC50 value of 1.03 ± 0.30 μM against the A549 cell line and a IC50 value of 1.75 ± 0.20 μM against the SKOV03 cell line. The obtained results point to these compounds as good antiproliferative candidates. Further, the physicochem. properties of these hybrid compounds were evaluated and could be considered as candidates for drugs with promising pharmacotherapeutic profiles similar to those of currently used drugs. In addition, docking experiments showed the possible mode of binding of these compounds and according to these studies the structural part corresponding to chromene or coumarin seems to play an important role in the interaction with the active site. The results came from multiple reactions, including the reaction of 6-Bromopyridin-3-amine(cas: 13534-97-9Synthetic Route of C5H5BrN2)

6-Bromopyridin-3-amine(cas: 13534-97-9) belongs to anime. Halogenation, in which one or more hydrogen atoms of an amine is replaced by a halogen atom, occurs with chlorine, bromine, and iodine, as well as with some other reagents, notably hypochlorous acid (HClO). With primary amines the reaction proceeds in two stages, producing N-chloro- and N,N-dichloro-amines, RNHCl and RNCl2, respectively. With tertiary amines, an alkyl group may be displaced by a halogen.Synthetic Route of C5H5BrN2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2019,Journal of the Brazilian Chemical Society included an article by de Mello, Murilo B. M.; de Oliveira, Antonio A. F.; de Oliveira, Caroline L.; Ultramari, Mariah A.; Gama, Fernando H. S.; Mascarello, Alessandra; Guimaraes, Cristiano R. W.; de Freitas, Miller N.; Cunha, Carlos E.; Lourenco, Tiago C.; Ferreira, Fernanda P.; Lopesa, Joao L. C.; Clososki, Giuliano C.. Category: pyridine-derivatives. The article was titled 《Characterization and in silico mutagenic assessment of a new betahistine degradation impurity》. The information in the text is summarized as follows:

Currently, the pharmaceutical industry devotes great attention to drug degradation products because these compounds can offer risks to patients. A previous degradation study of betahistine (N-α-methyl-2-pyridylethylamine) conducted under different stress conditions detected three main impurities named A, B and C. Degradation products were analyzed by high-resolution mass spectrometry in electrospray source and time of flight analyzer (ESI-TOF) and NMR (NMR). Impurity mutagenicity was evaluated by Derek Nexus and Sarah Nexus softwares. Liquid chromatog. hyphenate with tandem mass spectrometry (LC-MS/MS) anal. of the betahistine forced degradation sample indicated the presence of a new impurity, which was named impurity C1. 2D NMR experiments allowed the complete structural characterization of the new entity. The active pharmaceutical ingredient and degradation impurities were classified as inactive in the in silico mutagenic studies. Systematic investigation of a forced degradation sample led to the characterization of a new betahistine impurity. The in silico mutagenicity study of the betahistine degradation impurities may be useful in the risk assessment of the drug products. In the experimental materials used by the author, we found 2-(2-Hydroxyethyl)pyridine(cas: 103-74-2Category: pyridine-derivatives)

2-(2-Hydroxyethyl)pyridine(cas: 103-74-2) belongs to pyridine. Pyridine’s structure is isoelectronic with that of benzene, but its properties are quite different. Pyridine is completely miscible with water, whereas benzene is only slightly soluble. Like all hydrocarbons, benzene is neutral (in the acid–base sense), but because of its nitrogen atom, pyridine is a weak base.Category: pyridine-derivatives

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2019,Journal of the American Chemical Society included an article by Fernandez, Estefania; Rivero-Crespo, Miguel A.; Dominguez, Irene; Rubio-Marques, Paula; Oliver-Meseguer, Judit; Liu, Lichen; Cabrero-Antonino, Maria; Gavara, Rafael; Hernandez-Garrido, Juan C.; Boronat, Mercedes; Leyva-Perez, Antonio; Corma, Avelino. Category: pyridine-derivatives. The article was titled 《Base-Controlled Heck, Suzuki, and Sonogashira Reactions Catalyzed by Ligand-Free Platinum or Palladium Single Atom and Sub-Nanometer Clusters》. The information in the text is summarized as follows:

The assumption that oxidative addition is the key step during the cross-coupling reaction of aryl halides has led to the development of a plethora of increasingly complex metal catalysts, thereby obviating in many cases the exact influence of the base, which is a simple, inexpensive, and necessary reagent for this paramount transformation. Here, a combined exptl. and computational study shows that the oxidative addition is not the single kinetically relevant step in different cross-coupling reactions catalyzed by sub-nanometer Pt or Pd species, since the reactivity control is shifted toward subtle changes in the base. The exposed metal atoms in the cluster cooperate to enable an extremely easy oxidative addition of the aryl halide, even chlorides, and allow the base to bifurcate the coupling. With sub-nanometer Pd species, amines drive to the Heck reaction, carbonate drives to the Sonogashira reaction, and phosphate drives to the Suzuki reaction, while for Pt clusters and single atoms, good conversion is only achieved using acetate as a base. This base-controlled orthogonal reactivity with ligand-free catalysts opens new avenues in the design of cross-coupling reactions in organic synthesis.2-Pyridinylboronic acid(cas: 197958-29-5Category: pyridine-derivatives) was used in this study.

2-Pyridinylboronic acid(cas: 197958-29-5) belongs to pyridine. Pyridine’s structure is isoelectronic with that of benzene, but its properties are quite different. Pyridine is completely miscible with water, whereas benzene is only slightly soluble. Like all hydrocarbons, benzene is neutral (in the acid–base sense), but because of its nitrogen atom, pyridine is a weak base.Category: pyridine-derivatives

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2019,Chemical Communications (Cambridge, United Kingdom) included an article by Sang, Zitai; Lu, Yongping; Zhou, Yuanzheng; Ju, Yuan; An, Qi; Shen, Silan; Shi, Jianyou; He, Jun; Yang, Tao; Luo, Youfu. Related Products of 2510-22-7. The article was titled 《Efficient discovery of novel antimicrobials through integration of synthesis and testing in crude ribosome extract》. The information in the text is summarized as follows:

By coupling in situ [2+3] Huisgen cycloaddition with an in vitro transcription/translation luminescence assay in a crude ribosomal extract, a robust and accurate high-throughput platform was successfully developed and applied for efficient identification of novel structural types of ribosomal inhibitors with antimicrobial activity against drug-resistant bacteria. The experimental part of the paper was very detailed, including the reaction process of 4-Ethynylpyridine(cas: 2510-22-7Related Products of 2510-22-7)

4-Ethynylpyridine(cas: 2510-22-7) belongs to pyridine. In industry and in the lab, pyridine is used as a reaction solvent, particularly when its basicity is useful, and as a starting material for synthesizing some herbicides, fungicides, and antiseptics.Related Products of 2510-22-7

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《A validated UHPLC-MS method for tryptophan metabolites: Application in the diagnosis of multiple sclerosis》 was written by Tomosi, Ferenc; Kecskemeti, Gabor; Cseh, Edina Katalin; Szabo, Elza; Rajda, Cecilia; Kormany, Robert; Szabo, Zoltan; Vecsei, Laszlo; Janaky, Tamas. Application of 98-98-6This research focused onUHPLC mass spectrometry tryptophan metabolite diagnosis multiple sclerosis; Derivatization; DryLab®4; Liquid chromatography-mass spectrometry; Multiple sclerosis; Tryptophan metabolism; Validation. The article conveys some information:

The simultaneous quant. estimation of tryptophan (TRP) and its metabolites represents a great challenge because of their diverse chem. properties, e.g., presence of acidic, basic, and nonpolar functional groups and their immensely different concentrations in biol. matrixes. A short ultra high-performance liquid chromatog. (UHPLC)-tandem mass spectrometry (MS/MS) method was validated for targeted anal. of TRP and its 11 most important metabolites derived via both kynurenine (KYN) and serotonin (SERO) pathways in human serum and cerebrospinal fluid (CSF): SERO, KYN, 3-hydroxyanthranilic acid, 5-hydroxyindoleacetic acid, anthranilic acid, kynurenic acid (KYNA), 3-hydroxykynurenine (3-HK), xanthurenic acid, melatonin, picolinic acid (PICA), and quinolinic acid (QUIN). After selecting the “”best”” reversed-phase column and organic modifier, DryLab4 was used to optimize the gradient time and temperature in chromatog. separation To achieve absolute quantification, deuterium-labeled internal standards were used. Among all compounds, 3 were analyzed in derivatized (Bu ester) forms (3-HK, PICA, and QUIN) and the remaining 9 in underivatized forms. Validation was performed in accordance with the ICH and FDA guidelines to determine the intraday and interday precision, accuracy, sensitivity, and recovery. To demonstrate the applicability of the developed UHPLC-MS/MS method, the aforementioned metabolites were analyzed in serum and CSF samples from patients with multiple sclerosis (multiple sclerosis group) and those with symptomatic or noninflammatory neurol. diseases (control group). The concentration of QUIN dramatically increased, whereas that of KYNA slightly decreased in the multiple sclerosis group, resulting in a significantly increased QUIN/KYNA ratio and significantly decreased PICA/QUIN ratio. In the part of experimental materials, we found many familiar compounds, such as Picolinic acid(cas: 98-98-6Application of 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.Application of 98-98-6

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Recommanded Product: Bis(pyridin-2-ylmethyl)amineIn 2021 ,《Design of 99mTc-labeled zinc-chelating imaging probe for SPECT imaging of the pancreas》 was published in Bioorganic & Medicinal Chemistry Letters. The article was written by Eeda, Venkateswararao; Hedrick, Andria; Awasthi, Vibhudutta. The article contains the following contents:

Early and sensitive diagnosis of pancreatic diseases is a contemporary clin. challenge. Zinc level in pancreatic tissue and its secretion in pancreatic juice has long been considered a surrogate marker of pancreatic function. The objective of this study was to design a Zn-chelating imaging probe (ZCIP) which could be labeled with 99mTc radionuclide for imaging of pancreas using single photon emission tomog. (SPECT). We synthesized ZCIP as a bifunctional chelate consisting of diethylene triamine pentaacetic acid for 99mTc-chelation at one end and bispicolylethylamine for Zn-complexation at the other end. ZCIP was labeled with 99mTc by standard Sn2+-based reduction method. The 99mTc-labeled ZCIP was studied in normal mice (0.3 mCi) for SPECT imaging. We found that ZCIP consistently labeled with 99mTc radionuclide with over 95% efficiency. Addition of ZCIP altered the spectrum of standard dithizone-Zn complex, indicating its ability to chelate Zn. SPECT data demonstrated the ability of 99mTc-ZCIP to image pancreas with high sensitivity in a non-invasive manner; liver and spleen were the other major organs of 99mTc-ZCIP uptake. Based on these results, we conclude that 99mTc-ZCIP presents as a novel radiotracer for pancreas imaging for diagnosis of diseases such as pancreatitis. After reading the article, we found that the author used Bis(pyridin-2-ylmethyl)amine(cas: 1539-42-0Recommanded Product: Bis(pyridin-2-ylmethyl)amine)

Bis(pyridin-2-ylmethyl)amine(cas: 1539-42-0) is a secondary amine with two picolyl substituents. The compound is a tridentate ligand in coordination chemistry and commonly used to produce Zn-based chemosensors/probes, such as Zinpry.Recommanded Product: Bis(pyridin-2-ylmethyl)amine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Formula: C5H7N3In 2020 ,《Synthesis and characterization of nanocollector for removal of nickel ions from synthetic wastewater using ion flotation》 was published in Separation and Purification Technology. The article was written by Hoseinian, Fatemeh Sadat; Rezai, Bahram; Kowsari, Elaheh; Chinnappan, Amutha; Ramakrishna, Seeram. The article contains the following contents:

Amino functionalized graphene oxide was synthesized (AFGO) using a chem. method in order to apply in ion flotation process as a novel nanocollector for nickel ion removal with the aim of reducing collector consumption during the process. The synthesized AFGO was investigated using various anal. anal. To create the neg. charge onto the amino functionalized graphene oxide, 2,6-diaminopyridine was used to improve the properties of amino functionalized graphene oxide for removal of nickel ions with pos. charge from synthetic wastewater using ion flotation. This study introduced a new collector for ion flotation to reduce the required collector concentration during the process which had simple synthesis, economical, high efficiency and stability in a wastewater. The nickel removal percentage of approx. 100% was achieved using the nanocollector. In the part of experimental materials, we found many familiar compounds, such as 2,6-Diaminopyridine(cas: 141-86-6Formula: C5H7N3)

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.Formula: C5H7N3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Name: 4-EthynylpyridineIn 2022 ,《Discovery of the First Highly Selective Antagonist of the GluK3 Kainate Receptor Subtype》 appeared in International Journal of Molecular Sciences. The author of the article were Chalupnik, Paulina; Vialko, Alina; Pickering, Darryl S.; Hinkkanen, Markus; Donbosco, Stephanie; Moeller, Thor C.; Jensen, Anders A.; Nielsen, Birgitte; Bay, Yasmin; Kristensen, Anders S.; Johansen, Tommy N.; Latka, Kamil; Bajda, Marek; Szymanska, Ewa. The article conveys some information:

In search of selective ligands for the GluK3 kainate receptor subtype, a series of I [R = 3-Me Ph, 4-Me Ph, 4-Et Ph, etc] analogs was synthesized and pharmacol. characterized at selected recombinant ionotropic glutamate receptors. Among them, compound I [R = imidazo[1,2-b]pyridazin-3-ylmethyl] was found to be a competitive GluK3 antagonist with submicromolar affinity and unprecedented high binding selectivity, showing a 400-fold preference for GluK3 over other homomeric receptors GluK1, GluK2, GluK5 and GluA2. Furthermore, in functional assays performed for selected metabotropic glutamate receptor subtypes, I [R = imidazo[1,2-b]pyridazin-3-ylmethyl] did not show agonist or antagonist activity. The mol. determinants underlying the observed affinity profile of I [R = imidazo[1,2-b]pyridazin-3-ylmethyl] were analyzed using mol. docking and mol. dynamics simulations performed for individual GluK1 and GluK3 ligand-binding domains.4-Ethynylpyridine(cas: 2510-22-7Name: 4-Ethynylpyridine) was used in this study.

4-Ethynylpyridine(cas: 2510-22-7) 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. Name: 4-Ethynylpyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《Exploiting the umpolung reactivity of diazo groups: direct access to triazolyl-azaarenes from azaarenes》 was written by Devi, Lalita; Kumar, Prashant; Kant, Ruchir; Rastogi, Namrata. Name: 4-AcetylpyridineThis research focused ontriazolyl isoquinoline pyridine phenanthridine preparation; azaarene diazo iodonium triflate tandem electrophilic substitution dipolar cycloaddition. The article conveys some information:

The present work documents electrophilic substitution of azaarenes, mainly isoquinolines, with hypervalent iodine diazo reagents (HIDR) followed by formal [3+2]-dipolar cycloaddition in a tandem fashion. Other azaarenes viz. pyridines and phenanthridines too could be successfully used in the reaction. The methodol. capitalizes on the umpolung nature of α-aryliodonio diazo compounds for installing a nucleophile, i.e. azaarene, at their α-position. Subsequent ylide formation and intramol. 1,5-cyclization furnished 4,3-fused 1,2,4-triazolyl-azaarenes in good yields. The reaction is notable for its mild conditions, operational simplicity and fairly general scope. In the experiment, the researchers used many compounds, for example, 4-Acetylpyridine(cas: 1122-54-9Name: 4-Acetylpyridine)

4-Acetylpyridine(cas: 1122-54-9) belongs to pyridine. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. Additionally, pyridine-based natural products continue to be discovered and studied for their properties and to understand their biosynthesis.Name: 4-Acetylpyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem