T,
NRelevant articles and documents
All total 65 Articles be found
All total 65 Articles be found-
Sisler,H.H. et al.
, p. 1819 - 1821 (1961)
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Synthesis of 1H-indazole: A combination of experimental and theoretical studies
Chen, Xinzhi,Zhou, Shaodong,Qian, Chao,He, Chaohong
, p. 1619 - 1628 (2012)
A new practical synthesis of 1H-indazole is presented. A previous mechanism for the cyclization step is proved to be nonfeasible and a hydrogen bond propelled mechanism is proposed. The new mechanism is suitable for similar cyclization, and a new reaction is predicted. Springer Science+Business Media B.V. 2012.
A novel potent metal-binding NDM-1 inhibitor was identified by fragment virtual, SPR and NMR screening
Bai, Weiqi,Cheng, Kai,Gao, Yan,Guo, Huifang,He, Wei,Li, Conggang,Li, Zhuorong,Wu, Cai
, (2020)
NDM-1 can hydrolyze nearly all available β-lactam antibiotics, including carbapenems. NDM-1 producing bacterial strains are worldwide threats. It is still very challenging to find a potent NDM-1 inhibitor for clinical use. In our study, we used a metal-binding pharmacophore (MBP) enriched virtual fragment library to screen NDM-1 hits. SPR screening helped to verify the MBP virtual hits and identified a new NDM-1 binder and weak inhibitor A1. A solution NMR study of 15N-labeled NDM-1 showed that A1 disturbed all three residues coordinating the second zinc ion (Zn2) in the active pocket of NDM-1. The perturbation only happened in the presence of zinc ion, indicating that A1 bound to Zn2. Based on the scaffold of A1, we designed and synthesized a series of NDM-1 inhibitors. Several compounds showed synergistic antibacterial activity with meropenem against NDM-1 producing K. pneumoniae.
Forster,Withers
, p. 266 (1913)
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Fichter,Willi
, p. 1416,1418 (1934)
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Indole-3-carbinol and 1,3,4-oxadiazole hybrids: Synthesis and study of anti-proliferative and anti-microbial activity
Gokhale, Nikhila,Panathur, Naveen,Dalimba, Udayakumar,Kumsi, Manjunatha
, p. 1603 - 1613 (2015)
In the present study, molecular hybrids of indole-3-carbinol and 1,3,4-oxadiazole-2-thiols have been designed and synthesized. The thiol analogues consisted of diversely substituted benzyl and alkyl groups with different electronic properties. The structures of all the newly synthesized scaffolds and target compounds were ascertained using 1H NMR, 13C NMR, mass spectrometry, and elemental analyses. All the final compounds were screened in vitro for their anti-proliferative and anti-microbial activity. Three compounds showed excellent anti-proliferative activity with more than 70% cell growth inhibition against three cancer cell lines, HepG2 (human liver hepatocellular carcinoma), HeLa (human cervix carcinoma), and MCF-7 (human breast carcinoma). In the anti-microbial studies, compounds with electron-withdrawing fluoro or nitro substituent displayed appreciable activity similar to that of standard drugs. Also, the final compounds are non-toxic to non-cancerous Vero cell line.
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Clusius,Hoch
, (1958)
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Hydrolysis mechanisms for the acetylpyridinephenylhydrazone ligand in sulfuric acid
Garcia, Begona,Munoz, Maria S.,Ibeas, Saturnino,Leal, Jose M.
, p. 3781 - 3786 (2000)
The excess acidity method was applied to rate data obtained for 2-acetylpyridinephenylhydrazone hydrolysis in strong acid media using various aqueous/organic solvents, and it was observed that the reaction rate decreases with increasing permittivity of the medium. Two hydrolysis mechanisms are indicated. Below 0.6 M H2SO4, no hydrolysis was observed; between 0.6 and 6.0 M H2SO4, the substrate hydrolyzes by an A-SE2 mechanism and switches to an A-2 mechanism at higher acidity. This change of mechanism was justified on the basis of the syn and anti rotational conformers of the diene -N(1)D=C-C=N(2)- group; the greater stability of the former can be explained by the formation of hydrogen bonds between the proton and the N(1) and N(2) nitrogen atoms, giving rise to a very stable five-membered ring. If the syn conformer is predominant, then no hydrolysis is observed; above 0.6 M, the attack of a second proton gives rise to a balance between the syn and anti forms, the latter being responsible for the hydrolysis of the hydrazone group.
Synthesis and Characterization of Telmisartan-Derived Cell Death Modulators to Circumvent Imatinib Resistance in Chronic Myeloid Leukemia
Schoepf, Anna M.,Salcher, Stefan,Hohn, Verena,Veider, Florina,Obexer, Petra,Gust, Ronald
, p. 1067 - 1077 (2020)
New strategies to eradicate cancer stem cells in chronic myeloid leukemia (CML) include a combination of imatinib with peroxisome proliferator-activated receptor gamma (PPARγ) ligands. Recently, we identified the partial PPARγ agonist telmisartan as effective sensitizer of resistant K562 CML cells to imatinib treatment. Here, the importance of the heterocyclic core on the cell death-modulating effects of the telmisartan-derived lead 4′-((2-propyl-1H-benzo[d]imidazol-1-yl)methyl)-[1,1′-biphenyl]-2-carboxylic acid (3 b) was investigated. Inspired by the pharmacodynamics of HYL-6d and the selective PPARγ ligand VSP-51, the benzimidazole was replaced by a carbazole or an indole core. The results indicate no correlation between PPARγ activation and sensitization of resistant CML cells to imatinib. The 2-COOH derivatives of the carbazoles or indoles achieved low activity at PPARγ, while the benzimidazoles showed 60-100 % activation. Among the 2-CO2CH3 derivatives, only the ester of the lead (2 b) slightly activated PPARγ. Sensitizing effects were further observed for this non-cytotoxic 2 b (80 % cell death), and to a lesser extent for the lead 3 b or the 5-Br-substituted ester of the benzimidazoles (5 b).
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Reisenegger
, p. 662 (1883)
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Clusius,Huerzeler
, p. 1831 (1955)
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Visible-light-mediated phosphonylation reaction: formation of phosphonates from alkyl/arylhydrazines and trialkylphosphites using zinc phthalocyanine
Hosseini-Sarvari, Mona,Koohgard, Mehdi
supporting information, p. 5905 - 5911 (2021/07/12)
In this work, we developed a ligand- and base-free visible-light-mediated protocol for the photoredox syntheses of arylphosphonates and, for the first time, alkyl phosphonates. Zinc phthalocyanine-photocatalyzed Csp2-P and Csp3-P bond formations were efficiently achieved by reacting aryl/alkylhydrazines with trialkylphosphites in the presence of air serving as an abundant oxidant. The reaction conditions tolerated a wide variety of functional groups.
Discovery of novel inhibitors of human phosphoglycerate dehydrogenase by activity-directed combinatorial chemical synthesis strategy
Gou, Kun,Luo, Youfu,Luo, Yuan,Sun, Qingxiang,Tan, Yuping,Tao, Lei,Zhao, Yinglan,Zhou, Xia,Zhou, Yue,Zuo, Zeping
, (2021/07/26)
Serine, the source of the one-carbon units essential for de novo purine and deoxythymidine synthesis plays a crucial role in the growth of cancer cells. Phosphoglycerate dehydrogenase (PHGDH) which catalyzes the first, rate-limiting step in de novo serine biosynthesis has become a promising target for the cancer treatment. Here we identified H-G6 as a potential PHGDH inhibitor from the screening of an in-house small molecule library based on the enzymatic assay. We adopted activity-directed combinatorial chemical synthesis strategy to optimize this hit compound. Compound b36 was found to be the noncompetitive and the most promising one with IC50 values of 5.96 ± 0.61 μM against PHGDH. Compound b36 inhibited the proliferation of human breast cancer and ovarian cancer cells, reduced intracellular serine synthesis, damaged DNA synthesis, and induced cell cycle arrest. Collectively, our results suggest that b36 is a novel PHGDH inhibitor, which could be a promising modulator to reprogram the serine synthesis pathway and might be a potential anticancer lead worth further exploration.
Synthesis and biological activity of conformationally restricted indole-based inhibitors of neurotropic alphavirus replication: Generation of a three-dimensional pharmacophore
Barraza, Scott J.,Sindac, Janice A.,Dobry, Craig J.,Delekta, Philip C.,Lee, Pil H.,Miller, David J.,Larsen, Scott D.
supporting information, (2021/06/18)
We have previously reported the development of indole-based CNS-active antivirals for the treatment of neurotropic alphavirus infection, but further optimization is impeded by a lack of knowledge of the molecular target and binding site. Herein we describe the design, synthesis and evaluation of a series of conformationally restricted analogues with the dual objectives of improving potency/selectivity and identifying the most bioactive conformation. Although this campaign was only modestly successful at improving potency, the sharply defined SAR of the rigid analogs enabled the definition of a three-dimensional pharmacophore, which we believe will be of value in further analog design and virtual screening for alternative antiviral leads.
Cross-Coupling between Hydrazine and Aryl Halides with Hydroxide Base at Low Loadings of Palladium by Rate-Determining Deprotonation of Bound Hydrazine
Borate, Kailaskumar,Choi, Kyoungmin,Goetz, Roland,Hartwig, John F.,Shinde, Harish,Wang, Justin Y.,Zuend, Stephan J.
supporting information, p. 399 - 408 (2020/10/29)
Reported here is the Pd-catalyzed C–N coupling of hydrazine with (hetero)aryl chlorides and bromides to form aryl hydrazines with catalyst loadings as low as 100 ppm of Pd and KOH as base. Mechanistic studies revealed two catalyst resting states: an arylpalladium(II) hydroxide and arylpalladium(II) chloride. These compounds are present in two interconnected catalytic cycles and react with hydrazine and base or hydrazine alone to give the product. The selectivity of the hydroxide complex with hydrazine to form aryl over diaryl hydrazine was lower than that of the chloride complex, as well as the catalytic reaction. In contrast, the selectivity of the chloride complex closely matched that of the catalytic reaction, indicating that the aryl hydrazine is derived from this complex. Kinetic studies showed that the coupling process occurs by rate-limiting deprotonation of a hydrazine-bound arylpalladium(II) chloride complex to give an arylpalladium(II) hydrazido complex.
Synthesis of and characterization of some Heterocyclic Compounds derived from Thiophenol
AL-Khazraji, Shaima Ibraheem Chyad
, p. 5655 - 5662 (2021/09/11)
This research work involved preparation of heterogeneous pent lateral cyclic compounds (thiazolidine -4- one, benzothiazole, triazole, 4-oxothiazolidin) using thiophenol as raw materials: Thiophenol was reacted with mono chloroacetic acid in the presence of potassium hydroxide to prepare (sh1) followed by ortho amino aniline results the (sh2). The reaction of thiophenol with ethylchloroacetate afforded (sh3) and the reaction of (sh3) with thiosemicarbazide and 4% NaOH leads to ring closure giving 1,2,4- triazole (sh5). A treatment of thiophenol with hydrazine hydrate to obtain the intermediate (sh6) with aromatic aldehyde synthesized azomethines (sh7- sh9) then treated with mercaptoacetic acid to obtained (sh10-sh12). A treatment of thiophenol with chloroacetyl chloride produced (sh13) compound then treated with hydrazine hydrate to obtain (sh14) compound followed by bromobenzaldehyde synthesized azomethine (sh15) compound then treated with mercaptoacetic acid to obtained (sh16) compound. Characterization results for the prepared compounds using IR spectroscopy, NMR and melting points confirmed their chemical structures.
