768-05-8Relevant articles and documents
A discrete dysprosium trigonal prism showing single-molecule magnet behaviour
Tian, Haiquan,Wang, Min,Zhao, Lang,Guo, Yun-Nan,Guo, Yang,Tang, Jinkui,Liu, Zhiliang
, p. 442 - 445 (2012)
A magnetic personality: A unique dysprosium trigonal prism with a new polydentate Schiff-base ligand behaves as a single molecule magnet (SMM), which may stimulate further investigations into the relaxation dynamics of SMMs with different topologies (see
Exchange Interactions Switch Tunneling: A Comparative Experimental and Theoretical Study on Relaxation Dynamics by Targeted Metal Ion Replacement
Tian, Haiquan,Ungur, Liviu,Zhao, Lang,Ding, Shuai,Tang, Jinkui,Chibotaru, Liviu F.
, p. 9928 - 9939 (2018)
The magnetic relaxation and magnetization blocking barriers of tailor-made homo- and heterodinuclear compounds [Dy2(opch)2(OAc)2(H2O)2]?MeOH (1) and [DyMn(opch)2(OAc)(MeOH)(H2O)
A chromone based Schiff base: An efficient colorimetric sensor for specific detection of Cu (II) ion in real water samples
Tomer, Nisha,Goel, Apurva,Ghule, Vikas D.,Malhotra, Rajesh
, (2021)
A new chromone based Schiff base ligand L was synthesized by the condensation of 3-formyl chromone and pyrazine-2-carbohydrazide as a colorimetric probe to detect Cu (II) ions selectively. An instant visual colour change from colourless to yellow was obtained on addition of Cu2+ ions to the probe L solution, while other metal ions found ineffective. The ligand L was characterized by 1H NMR, FTIR and HRMS spectral techniques. UV-Visible spectroscopic technique was used to study the sensing ability of probe L for copper ions above other metal ions. The Job's plot obtained from absorption studies and HRMS data confirmed that the Cu2+ ions bind with ligand L in 1:1 stoichiometric ratio. DFT computations were also supported the binding framework between L and Cu (II) ions. The LOD value and the association constant were obtained 3.9 × 10?7 M and 2.3 × 105 M?1 respectively, via Benesi-Hildebrand equation. Selectivity of L towards Cu2+ ions was also studied and it was found that the probe L worked specifically for copper ions without any considerable influence of other intruding metal ions. In addition, in real water samples, the ligand L was fully implemented for identification and quantification of Cu2+ ions.
1H-1,2,3-triazole embedded Isatin-Benzaldehyde-bis(heteronuclearhydrazones): design, synthesis, antimycobacterial, and cytotoxic evaluation
Sharma, Bharvi,Kumar, Sumit,Preeti,Johansen, Matt D.,Kremer, Laurent,Kumar, Vipan
, p. 301 - 307 (2021/12/09)
Rapid growth of global drug-resistant tuberculosis and urgent requirement for short treatment regimens is stimulating the need for discovery of new TB drugs. In this work, we report the design, synthesis and in vitro antimycobacterial evaluation of a library of isatin-derived bis(heteronuclear hydrazones). Evaluation results revealed that the inclusion of isoniazid core into 1H-1,2,3-triazole tethered isatin-benzaldehydes improved the antimycobacterial activity on tuberculosis mc26230 strain and significantly reduced the cytotoxicity against Vero cells. However, the introduction of semicarbazones/thiosemicarbazones or pyrazine-2-carbohydrazide produced the opposite effects. The compounds with isoniazid and polar-donating groups at the C-5 position of isatin emerged as the most promising conjugates with MIC99?=?0.36?μg/ml. The most active compounds were non-cytotoxic to Vero cells (IC50>100?μg/ml) with selectivity indices >277.
A chromone hydrazide Schiff base fluorescence probe with high selectivity and sensitivity for the detection and discrimination of human serum albumin (HSA) and bovine serum albumin (BSA)
Yan, Xiao-Jing,Li, Zhe,Liu, Hai-Bo,Wang, Zhi-Gang,Fan, Jing,Xie, Cheng-Zhi,Li, Qing-Zhong,Xu, Jing-Yuan
, (2021/10/12)
The discrimination and identification of human serum albumin (HSA) and bovine serum albumin (BSA) is very important, which is due to the vital roles of two SAs in biological and pharmaceutical research. Based on structural screening and docking calculation from a series of homologues, a coumarin Schiff base fluorescent probe 3-hydroxy-N′-((4-oxo-4H-chromen-3-yl)methylene)-2-naphthohydrazide (HCNH) has been designed and synthesized, which could effectively discriminate HSA and BSA. The probe HCNH exhibited superior sensitivity toward HSA and BSA with the detection limits of 10.62 nM and 16.03 nM in PBS solution, respectively. The binding mechanism of HCNH with SAs was studied by Job's plot analysis, SA destruction and displacement assay. Molecular docking and DFT methods were utilized to provide deep insight into the spatial conformation change of HCNH and binding sites in HSA/BSA. The conformation of HCNH was significantly influenced by the microenvironment provided by HSA and BSA, therefore its fluorescence emission was affected correspondingly. Non-toxic probe HCNH could be successfully used for fluorescence bio-imaging of HSA in cancer cells, which is significantly different from normal cells and favors the application in medical diagnosis.
New silver(I) phosphino complexes: Evaluation of their potential as prospective agents against Mycobacterium tuberculosis
Maldonado, Yndira Dolores,Scalese, Gonzalo,Manieri, Karyn Fernanda,Pavan, Fernando R.,Aguirre Méndez, Larry D.,Gambino, Dinorah
, (2021/12/14)
Despite being a preventable and curable disease, Tuberculosis (TB) is the world's top infectious killer. Development of new drugs is urgently needed. In this work, the synthesis and characterization of new silver(I) complexes, that include N′-[(E)-(pyridine-2-ylmethylene)pyrazine-2-carbohydrazide, HPCPH, as main ligand and substituted aryl-phosphines as auxiliary ligands, is reported. HPCPH was synthesized from pyrazinoic acid, the active metabolite of the first-line antimycobacterial drug pyrazinamide. Complexes [Ag(HPCPH)(PPh3)2]OTf (1), [Ag(HPCPH)((P(p-tolyl)3)2]OTf (2) and [Ag(HPCPH)(P(p-anisyl)3)2]OTf (3) were characterized in solid state and in solution by elemental analysis and FTIR and NMR spectroscopies (OTf[dbnd]triflate). Crystal structures of (1,2) were determined by XRD. The Ag atom is coordinated to azomethine and pyridine nitrogen atoms of HPCPH ligand and to the phosphorous atom of each aryl-phosphine co-ligand. Although HPCPH did not show activity, the Ag(I) compounds demonstrated activity against Mycobacterium tuberculosis (MTB), H37Rv strain, and multi-drug resistant clinical isolates (MDR-TB). Globally, results showed that the compounds are not only effective against the sensitive strain, but are more potent against MDR-TB than antimycobacterial drugs used in therapy. The compounds showed low to moderate selectivity index values (SI) towards the bacteria, using MRC-5 cells (ATCC CCL-171) as mammalian cell model. Interaction with DNA was explored to get insight into the potential mechanism of action against the pathogen. No significant interaction was detected, allowing to discard this biomolecule as a potential molecular target. Compound 1 was identified as a hit compound (MIC90 2.23 μM; SI 4.4) to develop further chemical modifications in the search for new drugs.
Pyrazinederived 1,2,3-triazole linked silanes and their magnetic nanoparticles for the colorimetric and fluorimetric dual sensing of Cu2+ ions
Devi, Anita,Diksha,Kaur, Jashandeep,Mohit,Priyanka,Saini, Anamika,Singh, Gurjaspreet,Suman,Sushma
, (2022/03/16)
In this article, pyrazinebased 1,2,3-triazole linked organosilanes have been synthesized and characterized with techniques like 1H, 13C NMR spectroscopy and mass spectrometry. The synthesized compound 6b (PTSR)could selectively and sensitively recognize Cu2+ ionswhereas the interference from other metal ions was negligible. The 6(b) behaves as reversible sensor for Cu2+ions. The fluorescence response of 6(b) toward Cu2+ions showed a significant fluorescence quenching. Further,the sensing application was enhanced by the immobilization of organic moiety on the magnetic silicasurface. The adsorption of organosilaneis confirmed by various techniques such as FT-IR, EDX, XRD, TGA, SEM, HR-TEM, DLS. The hybrid magnetic nanoparticles (HNPs)are found to be more sensitive for Cu2+ ions with low LOD as compare to 6(b)i.e. 2.7 × 10?6 M. In addition, the synthesized alkynes and silanes were examined fordrug-likeness profile by using online available toolkits like MOLINSPIRATION and ADMET.
Pleuromutilin derivative with 1, 3, 4-oxadiazole side chain and preparation and application thereof
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Paragraph 0055-0056; 0070; 0090; 0093; 0095; 0102, (2021/07/24)
The invention belongs to the field of medicinal chemistry, and particularly relates to a pleuromutilin derivative with a 1, 3, 4-oxadiazole side chain and preparation and application thereof The pleuromutilin derivative with the 1, 3, 4-oxadiazole side chain is a compound shown in a formula 2 or a pharmaceutically acceptable salt thereof, and a solvent compound, an enantiomer, a diastereoisomer and a tautomer of the compound shown in the formula 2 or the pharmaceutically acceptable salt thereof or a mixture of the solvent compound, the enantiomer, the diastereoisomer and the tautomer in any proportion, including a racemic mixture. The pleuromutilin derivative has good antibacterial activity, is especially suitable for being used as a novel antibacterial agent for systemic system infection of animals or human beings, and has good water solubility.
PIEZO1 AGONISTS FOR THE PROMOTION OF BONE FORMATION
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Page/Page column 30; 32, (2021/04/10)
Disclosed herein are Piezo 1 agonists. Also disclosed herein are methods of stimulating tissue anabolism in a subject comprising administering an effective amount of a Piezo 1 agonist and methods for chemically mimicking mechanical stimulation of a cell expressing Piezo 1 comprising contacting a cell expressing Piezo1 with an effective amount of a Piezo 1 agonist.
Evaluation and Docking Study of Pyrazine Containing 1, 3, 4-Oxadiazoles Clubbed with Substituted Azetidin-2-one: A New Class of Potential Antimicrobial and Antitubercular
Das, Rina,Mehta, Dinesh Kumar
, p. 26 - 35 (2020/10/21)
Background Tuberculosis (TB) caused by Mycobacterium tuberculosis is one of the main killers of people all over the world. The major hurdles with existing therapy are the lengthy regimen and appearance of multi drug resistant (MDR) and extensively drug resistant (XDR) strains of M.tuberculosis. Aims The present work was aimed to synthesize and determine antitubercular and antimicrobial potential of some novel 3-chloro-4-aryl-1-[4-(5-pyrazin-2-yl[1,3,4]oxadiazole-2-ylmethoxy)-phenyl]-azetidin-2-one derivatives 7 (a - h) from pyrazinoic acid as precursor, which is a well-established antitubercular agent. Here we report the synthesis of a new class of heterocyclic molecules in which pyrazine, 1, 3, 4-oxadiazole and azetidinone moieties were present in one frame work. Methods Pyrazinoic acid (1) was esterified first (2) followed by amination to produce hydrazide (3) which was refluxed with POCl3 to obtain 2-chloromethyl-5pyrazino-1, 3, 4-oxadiazole (4). This was then further reacted with 4-amino phenol to obtain 4-[5-pyrazino-1, 3, 4-oxadiazol-2-yl-methoxy]-phenyl amine (5) which on condensation with various aromatic aldehydes afforded a series Schiff's bases 6(a-h). Dehydrative annulations of 6(a-h) in the presence of chloroacetyl chloride and triethylamine yielded 3-chloro-4-aryl-1-[4-(5-pyrazin-2-yl-[1, 3, 4]oxadiazole-2-ylmethoxy)-phenyl]-azetidin-2-one derivatives 7(a-h). Antibacterial, antifungal and antitubercular potential of all the synthesized compounds were assessed. Docking study was performed using the software VLife Engine tools of Vlifemds 4.6 on the protein lumazine synthase of M. tuberculosis (PDB entry code 2C92). Results The present studies demonstrated that synthesized oxadiazole derivatives have good antimicrobial activity against the various microorganisms. Among the synthesized derivative, 7b and 7g were found to be prominent compounds which have potential antibacterial, antifungal and antitubercular activity (with MIC 3.12 μg/ml and high dock score ranging from -59.0 to -54.0) against Mycobacterium tuberculosis. Conclusions Derivatives 7b and 7g would be effective lead candidates for tuberculosis therapy.
