Tag: 100-200

《Simultaneous determination of phenazopyridine HCl and trimethoprim in presence of phenazopyridine HCl impurity by univariate and multivariate spectrophotometric methods – Quantification of phenazopyridine HCl impurity by univariate methods》 was written by Soudi, Aya T.; Hussein, Ola G.; Elzanfaly, Eman S.; Zaazaa, Hala E.; Abdelkawy, Mohamed. Synthetic Route of C5H7N3 And the article was included in Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy in 2020. The article conveys some information:

Three univariate and two multivariate spectrophotometric methods were developed and subsequently validated to determine phenazopyridine HCl (PHZ) and trimethoprim (TMP) in the presence of 2,6-Diaminopyridine (2,6-DAP). The first univariate method depends on direct determination of phenazopyridine by measuring its absorbance at 412 nm and performed in concentration range of 1.00-10.00μg/mL. Then the contribution of phenazopyridine is removed by dividing the mixture spectrum with PHZ divisor (5μg/mL) after that the constant is math. subtracted and finally the generated spectrum is multiplied with the PHZ divisor. These steps eliminate PHZ contribution and the recovered spectrum is that of TMP and 2,6-DAP only where different methods can be applied to determine TMP and 2,6-DAP through this binary mixture spectrum. The first method to determine both components depends on measuring both TMP and 2,6-DAP through their first derivative (1DD) spectra at 244.70 and 259.60 nm for TMP and 2,6-DAP, resp. with concentration ranges of 4.00-24.00μg/mL TMP and 4.00-26.00μg/mL 2,6-DAP. The second method depends on application of the isoabsorptive method which was used for TMP determination at its isoabsorptive point with 2,6-DAP at 242.64 nm with concentration range 1.00-20.00μg/mL for TMP. The developed univariate methods were successfully applied to determine PHZ, TMP and PHZ impurity (2,6-DAP). Two multivariate methods were applied for determination of PHZ and TMP in presence of 2,6-DAP namely, Principle Component Regression (PCR) and Partial Least Squares (PLS). The results of the two models show that simultaneous determination of PHZ and TMP in presence of PHZ impurity can be performed in the concentration ranges of 6.00-14.00μg/mL PHZ and 24.00-56.00μg/mL TMP. All the proposed methods were successfully applied to analyze PHZ and TMP in pharmaceutical formulations without interference from the dosage form additives and the results were statistically compared with the reported method.,. In the experimental materials used by the author, we found 2,6-Diaminopyridine(cas: 141-86-6Synthetic Route of 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.Synthetic Route of C5H7N3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2022,Fischer, Kim; Krahmer, Jan; Tuczek, Felix published an article in Zeitschrift fuer Naturforschung, B: A Journal of Chemical Sciences. The title of the article was 《Chemically and Light-Driven Coordination-Induced Spin State Switching (CISSS) of a nonheme-iron complex》.Synthetic Route of C12H13N3 The author mentioned the following in the article:

The new Fe(II) complex [Fe(trident)(bmik)](ClO4)2 (1) (trident = bis(2-pyridylmethyl)benzylamine and bmik = bis(1-methylimidazole)ketone) exhibits a change of magnetic moment in dichloromethane (DCM) solution upon addition of pyridine which is attributed to the Coordination-Induced Spin State Switching effect (CISSS). By attaching a photoisomerizable azopyridine sidegroup to the tridentate ligand the complex [Fe(azpy-trident)(bmik)](ClO4)2 (2; azpy-trident = [N,N-bis(2-pyridylmethyl)]-3-(3-pyridylazo)benzylamine) is obtained. As detected by Evans NMR spectroscopy, 2 reversibly changes its magnetic moment in homogeneous solution upon photoirradiation which is attributed to intermol. Light-Driven Coordination-Induced Spin State Switching (LD-CISSS). Further support for this interpretation is inferred from concentration-dependent Evans NMR measurements. In the experimental materials used by the author, we found Bis(pyridin-2-ylmethyl)amine(cas: 1539-42-0Synthetic Route of C12H13N3)

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. Synthetic Route of C12H13N3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《Chromogenic hydrazide Schiff base reagent: Spectrophotometric determination of CN- ion》 was published in Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy in 2020. These research results belong to Dey, Sunanda; Sen, Chandana; Sinha, Chittaranjan. Name: Picolinic acid The article mentions the following:

A Schiff base reagent, Picolinohydrazide-naphthol (HL), was used for trace level detection of toxic CN- selectively in presence of eighteen other anions (SCN-, OCN-, S2O2-3, HPO2-4, H2PO-4, I-, ClO-4, HSO-4, SO2-4, AsO3-4, NO-2, AsO-2, Cl-, F-, HF-2, NO-3, Br-, N-3) by visual color change, colorless to yellow, in DMSO/H2O (9:1, volume/volume) at pH, 7.2 (HEPES buffer) medium. The sensitivity of the probe shows that the limit of detection (LOD) is 7.08μM. The probable mechanism for the sensing behavior involves the deprotonation of naphthol-OH by CN- that was authenticated by 1H NMR titration and Mass spectra. The composition (1:1 mol ratio) is supported by Job’s plot and binding constant (Ka, 1.5 × 104 M-1) is reported by Benesi-Hildebrand plot. Also, a simple paper strip device is fabricated for the determination of CN- ion in water. DFT computation is carried out to explain the electronic spectral feature of the sensor.Picolinic acid(cas: 98-98-6Name: Picolinic acid) was used in this study.

Picolinic acid(cas: 98-98-6) is used in the preparation of 2-Aminodihydro[1,3]thiazines as BACE 2 inhibitors and their preparation and use in the treatment of diabetes.Name: Picolinic acid

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

The author of 《Impact of Pyridyl Moieties on the Inhibitory Properties of Prominent Acyclic Metal Chelators Against Metallo-β-Lactamase-Producing Enterobacteriaceae: Investigating the Molecular Basis of Acyclic Metal Chelators’ Activity》 were Sosibo, Sphelele C.; Somboro, Anou M.; Amoako, Daniel G.; Osei Sekyere, John; Bester, Linda A.; Ngila, Jane C.; Sun, Darren D.; Kumalo, Hezekiel M.. And the article was published in Microbial Drug Resistance (New Rochelle, NY, United States) in 2019. Computed Properties of C12H13N3 The author mentioned the following in the article:

Carbapenem-resistant Enterobacteriaceae (CREs)-mediated infections remain a huge public health concern. CREs produce enzymes such as metallo-β-lactamases (MBLs), which inactivate β-lactam antibiotics. Hence, developing efficient mols. capable of inhibiting these enzymes remains a way forward to overcoming this phenomenon. In this study, we demonstrate that pyridyl moieties favor the inhibitory activity of cyclic metal-chelating agents through in vitro screening, mol. modeling, and docking assays. Di-(2-picolyl) amine and tris-(2-picolyl) amine exhibited great efficacy against different types of MBLs and strong binding affinity for NDM-1, whereas 2-picolyl amine did not show activity at a concentration of 64 mg/L in combination with meropenem; it further showed the lowest binding affinity from computational mol. anal., commensurating with the in vitro screening assays. The findings revealed that the pyridyl group plays a vital role in the inhibitory activity of the tested mols. against CREs and should be exploited as potential MBL inhibitors. After reading the article, we found that the author used Bis(pyridin-2-ylmethyl)amine(cas: 1539-42-0Computed Properties of C12H13N3)

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. Computed Properties of C12H13N3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《A cocrystal of L-ascorbic acid with picolinic acid: the role of O-H···O, N-H···O and C-H···O hydrogen bonds and L-ascorbic acid conformation in structure stabilization》 was written by Evtushenko, Diana N.; Arkhipov, Sergey G.; Fateev, Alexander V.; Izaak, Tatyana I.; Egorova, Lidia A.; Skorik, Nina A.; Vodyankina, Olga V.; Boldyreva, Elena V.. Category: pyridine-derivatives And the article was included in Acta Crystallographica, Section B: Structural Science, Crystal Engineering and Materials in 2020. The article conveys some information:

A new 1:1 cocrystal (L-Asc-Pic) of L-ascorbic acid (vitamin C) with picolinic acid was prepared as a powder and as single crystals. The crystal structure was solved and refined from single-crystal X-ray diffraction (SCXRD) data collected at 293 (2) and 100 (2) K. The samples of the L-Asc-Pic cocrystal were characterized by elemental (HCNS) anal. and titrimetric methods, TG/DTG/DSC, and IR and Raman spectroscopy. The asym. unit comprises a picolinic acid zwitterion and an L-ascorbic acid mol. The stabilization energy of intermol. interactions involving hydrogen bonds, the vibrational spectrum and the energies of the frontier MOs were calculated using the GAUSSIAN09 and the CrystalExplorer17 programs. The charge distribution on the atoms of the L-Asc-Pic cocrystal, L-ascorbic acid itself and its 12 known cocrystals (structures from Version 5.40 of the Cambridge Structural Database) were calculated by the methods of Mulliken, Voronoi and Hirshfeld charge analyses (ADF) at the bp86/TZ2P+ level of theory. The total effective charges and conformations of the L-ascorbic acid mols. in the new and previously reported cocrystals were compared with those of the two symmetry-independent mols. in the crystals of L-ascorbic acid. A correlation between mol. conformation and its effective charge is discussed. In the experiment, the researchers used many compounds, for example, Picolinic acid(cas: 98-98-6Category: pyridine-derivatives)

Picolinic acid(cas: 98-98-6) is used in the preparation of 2-Aminodihydro[1,3]thiazines as BACE 2 inhibitors and their preparation and use in the treatment of diabetes.Category: pyridine-derivatives

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

The author of 《Synthesis and spectroscopic study of some 3-nitropyridines》 were Youssef, Adel F.; Farag, Hassan H.; Youssef, H.. And the article was published in Indian Journal of Chemistry, Section B: Organic Chemistry Including Medicinal Chemistry in 1977. Name: 2-Methyl-3-nitropyridine hydrochloride The author mentioned the following in the article:

6-Methyl-5-nitropyridine-2-carboxylic acid (I), and 3-(2-methyl-3-nitro-6-pyridyl)acrylic acid (II) were prepared The IR, mass and NMR spectra of 2,6-dimethyl-3-nitropyridine, 2-methyl-3-nitropyridine (III) and II were discussed. The structures of I and II were confirmed indirectly via conformation of the structure of their precursor III. II was a mixture of cis-(38%) and trans-(62%) isomers as revealed by its NMR. In the experiment, the researchers used 2-Methyl-3-nitropyridine hydrochloride(cas: 63585-69-3Name: 2-Methyl-3-nitropyridine hydrochloride)

2-Methyl-3-nitropyridine hydrochloride(cas: 63585-69-3) belongs to pyridine. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. As ligands, solvents, and catalysts they facilitate reactions; thus descriptions of these new ligands and their applications abound each year.Name: 2-Methyl-3-nitropyridine hydrochloride

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《A novel multidentate pyridyl ligand: A turn-on fluorescent chemosensor for Hg2+ and its potential application in real sample analysis》 was written by Ngororabanga, Jean Marie Vianney; Moyo, Cyprian B.; Tshentu, Zenixole R.. Application In Synthesis of 2,6-Diaminopyridine And the article was included in Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy in 2020. The article conveys some information:

A novel pyridyl-based ligand with multiple binding sites was developed as potential turn on fluorescent probe for mercuric ion. In comparison with other transition metal ions, the ligand displayed a significant optical selectivity and sensitivity for Hg2+ in aqueous solution with a remarkable fluorescence enhancement. The obtained spectroscopic response was related to the inhibition of the photo-chem. mechanism known as photo-induced electron transfer (PET) in the ligand and C=N isomerization by Hg2+ binding. A good linearity between fluorescence responses and Hg2+ concentration was obtained in the range 3.3 x 10-9 M-1.6 x 10-8 M and a nanomolar level limit of detection (LOD) (1.4 x 10-9 M ∼ 0.28 ppb) and limit of quantification (LOQ) (4.8 x 10-9 M ∼ 0.93 ppb) were obtained. Both LOD and LOQ values are very low compared to the reported permissible Hg2+ level in drinking water (2 ppb) by US Environmental Protection Agency (EPA). The possible binding mode between ligand and Hg2+ were determined using Job′s plot anal. and d. functional theory (DFT) calculations and a complex with 1:1 stoichiometric ratio was suggested. The response of the pyridyl ligand upon Hg2+ addition was noted to be fast without any time delay and reversible. The performance of the ligand at nanomolar level of Hg2+ and real sample application of the proposed method was investigated and satisfactory results were obtained. In the part of experimental materials, we found many familiar compounds, such as 2,6-Diaminopyridine(cas: 141-86-6Application In Synthesis of 2,6-Diaminopyridine)

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 In Synthesis of 2,6-Diaminopyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Shafikov, Marsel Z.; Suleymanova, Alfiya F.; Kutta, Roger J.; Brandl, Fabian; Gorski, Aleksander; Czerwieniec, Rafal published an article in 2021. The article was titled 《Dual emissive dinuclear Pt(II) complexes and application to singlet oxygen generation》, and you may find the article in Journal of Materials Chemistry C: Materials for Optical and Electronic Devices.Recommanded Product: 2-Bromo-5-methylpyridine The information in the text is summarized as follows:

Room-temperature dual emission consisting of spectrally separated fluorescence and phosphorescence is highly attractive as a design principle for ratiometric sensing materials, for example, for detection of dioxygen. Compounds susceptible to emission quenching by dioxygen, producing dioxygen in electronically excited states, are also used as photosensitizers for singlet O generation. Combination of the dual emission behavior and efficient energy transfer from one of the emitting states (triplet state) of the dual emissive compound to mol. dioxygen can result in potent photosensitizers easily traceable by fluorescence spectroscopy, which may be advantageous for instance in biol. studies. Herein, the authors present two Pt(II) complexes 1 and 2 of dinuclear structure which exhibit green fluorescence with sub-nanosecond lifetimes and near IR (NIR) phosphorescence with microsecond lifetimes. Such properties are achieved via the design of a strongly π-excessive ditopic ligand with a NĈ-CN̂ coordinating mode that bridges the metal centers. The ligand centered character of the lowest excited singlet (S1) and triplet (T1) states leads to strong exchange interaction of the unpaired electrons and hence to large energy separation ΔE(S1-T1) amounting to 0.6 eV for 1 and 0.7 eV for 2, resp. The large energy gap ΔE(S1-T1) and weak metal contribution to the states S1 and T1 results in unusually long intersystem crossing (ISC) times τISC(S1 → T1) of 27.5 ps (1) and 65.2 ps (2), resp., as determined by transient absorption spectroscopy. Owing to the slow ISC, the T1 → S0 phosphorescence of both 1 and 2 is accompanied by S1 → S0 fluorescence of comparable intensity. The large gap ΔE(S1-T1) provides also a good optical separation of the two emissions. The phosphorescence signal is efficiently quenched in the presence of dioxygen, which is manifested in both the lower relative intensity and shorter decay time of phosphorescence. Thus, the compounds show high potential as ratiometric dioxygen sensing materials. The singlet O photogeneration efficiencies of complexes 1 and 2, measured in air saturated CH2Cl2, are as high as φΔ ≈ 0.77 ± 0.1 and 0.57 ± 0.1, resp. Thus, the compounds represent efficient singlet O photosensitizers.2-Bromo-5-methylpyridine(cas: 3510-66-5Recommanded Product: 2-Bromo-5-methylpyridine) was used in this study.

2-Bromo-5-methylpyridine(cas: 3510-66-5) belongs to pyridine. Pyridine derivatives lend themselves to many roles in the spirited field of supramolecular chemistry – whether as the ligand backbone of metal-organic polymers or presiding over the key electronic stations of nanodevices. In biochemistry, pyridine-containing cofactors are necessary nutrients on which our lives depend. Recommanded Product: 2-Bromo-5-methylpyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《Iridium motif linked porphyrins for efficient light-driven hydrogen evolution via triplet state stabilization of porphyrin》 was written by Tritton, Daniel Nnaemaka; Bodedla, Govardhana Babu; Tang, Geliang; Zhao, Jianzhang; Kwan, Chak-Shing; Leung, Ken Cham-Fai; Wong, Wai-Yeung; Zhu, Xunjin. Computed Properties of C12H12N2 And the article was included in Journal of Materials Chemistry A: Materials for Energy and Sustainability in 2020. The article conveys some information:

Two new iridium motif linked porphyrins, MBPyZnP-Ir and TBPyZnP-Ir are developed for photocatalytic hydrogen evolution (PHE). The tetra-iridium linked one, TBPyZnP-Ir, displayed the highest H2 production rate (ηH2) of 16.12 mmol g-1 h-1 within 5 h of irradiation, which is over 2.73-fold higher than MBPyZnP-Ir (5.90 mmol g-1 h-1) and much higher than their precursors TBPyZnP (0.12 mmol g-1 h-1) and MBPyZnP (0.06 mmol g-1 h-1) without iridium. The superior ηH2 of TBPyZnP-Ir could be explained by the iridium motifs linked to the porphyrin, stabilizing the triplet states of the porphyrin through intramol. energy transfer; thus enhancing electron transfer from the triplet photo-excited porphyrin moiety to the cobaloxime co-catalyst and consequently proton reduction The experimental process involved the reaction of 4,4′-Dimethyl-2,2′-bipyridine(cas: 1134-35-6Computed Properties of C12H12N2)

4,4′-Dimethyl-2,2′-bipyridine(cas: 1134-35-6) is used as a chemical Intermediate. It can be used for the determination of ferrous and cyanide compounds.Computed Properties of C12H12N2 Furthermore, 4,4′-Dimethyl-2,2′-bipyridine is used in the synthesis of a series of o-phenanthroline-substituted ruthenium(II) complexes.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Formula: C8H9NO3On November 30, 1998 ,《Additive effect of substituents and heterocyclic nitrogen on the alkaline hydrolysis rate of methyl esters of the substituted pyridinecarboxylic acids》 appeared in Russian Journal of Organic Chemistry (Translation of Zhurnal Organicheskoi Khimii). The author of the article were Sedova, V. F.; Skurko, O. P.. The article conveys some information:

Rate constants of alk. hydrolysis of Me esters in 6 series of substituted pyridinecarboxylates additively correlate with σ-constants of the N atom in the pyridine ring and of substituents, taking into account the transmission factors of their inductive and resonance effects.Methyl 5-methoxypicolinate(cas: 29681-39-8Formula: C8H9NO3) was used in this study.

Methyl 5-methoxypicolinate(cas: 29681-39-8) belongs to pyridine. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. As ligands, solvents, and catalysts they facilitate reactions; thus descriptions of these new ligands and their applications abound each year.Formula: C8H9NO3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem