- Investigations of luminescent behavior and intramolecular energy transfer mechanism of europium(III) complexes with fluorinated β-ketoester ligand
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A fluorinated β-ketoester ligand, ethyl-(2-fluorobenzoyl) acetate (EFBA) has been employed to synthesized new europium binary and ternary complexes with ancillary ligands neocuproine (neo), bathophenanthroline (batho), 1,10-phenanthroline (phen) and 2,2-bipyridyl (bipy) in high yield by the solution precipitation method. The ligand (EFBA) and the synthesized complexes Eu(EFBA)3·(H2O)2 (C1), Eu(EFBA)3·neo (C2), Eu(EFBA)3·batho (C3), Eu(EFBA)3·phen (C4), Eu(EFBA)3·bipy (C5) were characterized by elemental analysis, 1H NMR, IR, UV-vis, thermal analysis (TG/DTG) and luminescence spectroscopy. The thermal analysis results show that the complex is stable up to 231 °C temperature which is sufficient for the normal working of OLEDs. The luminescence measurements indicate that π electron rich organic ligand ethyl-(2-fluorobenzoyl) acetate possessing high absorption coefficient acts as a suitable chromophoric moiety for the transfer of energy to the central Eu3+ ion by the process of sensitization, this results in strong emissions band in red spectral region attributed to electric dipole 5D0 → 7F2 transition of europium ion. The luminescence intensity further enhanced by the introduction of N-containing ancillary ligands neocuproine, bathophenanthroline, 1,10-phenanthroline, and 2,2-bipyridyl in the ternary complexes C2-C5 because these ligands replace the solvent molecule in the coordination sphere and satisfy the coordination number around central europium ion. The sensitization process in europium complexes is investigated through the proposed energy transfer mechanism. The decay curves observations show the similar chemical environment around the europium ion in all the complexes.
- Devi, Rekha,Bala, Manju,Khatkar, S. P.,Taxak, V. B.,Boora, Priti
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- Amide/Ester Cross-Coupling via C-N/C-H Bond Cleavage: Synthesis of β-Ketoesters
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Activated primary, secondary, and tertiary amides were coupled with enolizable esters in the presence of LiHMDS to obtain good yields of β-ketoesters at room temperature. Notably, this protocol provides an efficient, mild, and high chemoselectivity method
- Chen, Jiajia,Joseph, Devaneyan,Xia, Yuanzhi,Lee, Sunwoo
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p. 5943 - 5953
(2021/04/02)
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- Construction of isoxazolone-fused phenanthridinesviaRh-catalyzed cascade C-H activation/cyclization of 3-arylisoxazolones with cyclic 2-diazo-1,3-diketones
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A Rh(iii)-catalyzed cascade C-H activation/intramolecular cyclization of 3-aryl-5-isoxazolones with cyclic 2-diazo-1,3-diketones was described, leading to the formation of isoxazolo[2,3-f]phenanthridine skeletons. The protocol features the simultaneous one-pot formation of two new C-C/C-N bonds and one heterocycle in moderate-to-good yields with good functional group compatibility. It is amenable to large-scale synthesis and further transformation.
- Hu, Wangcheng,He, Xinwei,Zhou, Tongtong,Zuo, Youpeng,Zhang, Shiwen,Yang, Tingting,Shang, Yongjia
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supporting information
p. 552 - 556
(2021/02/06)
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- Iridium-Catalyzed Enantioselective and Diastereoselective Hydrogenation of Racemic β’-Keto-β-Amino Esters via Dynamic Kinetic Resolution
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An iridium/f-diaphos catalytic system for the enantioselective hydrogenation of α-substituted β-ketoesters via dynamic kinetic resolution is reported. The desired anti β’-hydroxy-β-amino esters were obtained in moderate to good yields (60–95%) with 72–99% ees and 91:9 to 99:1 drs. This protocol tolerates various functional groups and could be easily conducted on gram scale with lower catalyst loading (TON up to 9100). (Figure presented.).
- He, Jiayin,Huang, An,Ling, Fei,Wang, Shiliang,Wang, Yifan,Wang, Ze,Zhao, Xianghua,Zhong, Weihui
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supporting information
p. 4714 - 4719
(2021/09/02)
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- 3-pyridinesulfonyl-1-N-heteropyrrole derivatives capable of treating peptic ulcer as well as preparation method and application thereof
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The invention discloses 3-pyridinesulfonyl-1-N-heteropyrrole derivatives capable of treating peptic ulcer as well as a preparation method and application of the derivative, and particularly provides compounds as shown in a formula I, or pharmaceutically a
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Paragraph 0083-0087
(2020/11/26)
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- Synthesis of Dithiolethiones and Identification of Potential Neuroprotective Agents via Activation of Nrf2-Driven Antioxidant Enzymes
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Oxidative stress is implicated in the pathogenesis of a wide variety of neurodegenerative disorders, and accordingly, dietary supplement of exogenous antioxidants or/and upregulation of the endogenous antioxidant defense system are promising for therapeutic intervention or chemoprevention of neurodegenerative diseases. Nrf2, a master regulator of the cellular antioxidant machinery, cardinally participates in the transcription of cytoprotective genes against oxidative/electrophilic stresses. Herein, we report the synthesis of 59 structurally diverse dithiolethiones and evaluation of their neuroprotection against 6-hydroxydopamine-or H2O2-induced oxidative damages in PC12 cells, a neuron-like rat pheochromocytoma cell line. Initial screening identified compounds 10 and 11 having low cytotoxicity but conferring remarkable protection on PC12 cells from oxidative-mediated damages. Further studies demonstrated that both compounds upregulated a battery of antioxidant genes as well as corresponding genes' products. Significantly, silence of Nrf2 expression abolishes cytoprotection of 10 and 11, indicating targeting Nrf2 activation is pivotal for their cellular functions. Taken together, the two lead compounds discovered here with potent neuroprotective functions against oxidative stress via Nrf2 activation merit further development as therapeutic or chemopreventive candidates for neurodegenerative disorders.
- Bai, Feifei,Fang, Jianguo,Song, Zi-Long,Zhang, Baoxin
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p. 2214 - 2231
(2020/03/06)
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- Design, Synthesis, and Biochemical Characterization of Non-Native Antagonists of the Pseudomonas aeruginosa Quorum Sensing Receptor LasR with Nanomolar IC50 Values
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Quorum sensing (QS), a bacterial cell-to-cell communication system mediated by small molecules and peptides, has received significant interest as a potential target to block infection. The common pathogen Pseudomonas aeruginosa uses QS to regulate many of its virulence phenotypes at high cell densities, and the LasR QS receptor plays a critical role in this process. Small molecule tools that inhibit LasR activity would serve to illuminate its role in P. aeruginosa virulence, but we currently lack highly potent and selective LasR antagonists, despite considerable research in this area. V-06-018, an abiotic small molecule discovered in a high-throughput screen, represents one of the most potent known LasR antagonists but has seen little study since its initial report. Herein, we report a systematic study of the structure-activity relationships (SARs) that govern LasR antagonism by V-06-018. We synthesized a focused library of V-06-018 derivatives and evaluated the library for bioactivity using a variety of cell-based LasR reporter systems. The SAR trends revealed by these experiments allowed us to design probes with 10-fold greater potency than that of V-06-018 and 100-fold greater potency than other commonly used N-acyl-l-homoserine lactone (AHL)-based LasR antagonists, along with high selectivities for LasR. Biochemical experiments to probe the mechanism of antagonism by V-06-018 and its analogues support these compounds interacting with the native ligand-binding site in LasR and, at least in part, stabilizing an inactive form of the protein. The compounds described herein are the most potent and efficacious antagonists of LasR known and represent robust probes both for characterizing the mechanisms of LuxR-type QS and for chemical biology research in general in the growing QS field.
- Blackwell, Helen E.,Manson, Daniel E.,Nyffeler, Kayleigh E.,O'Reilly, Matthew C.
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- Desymmetrization of meso-dicarbonatecyclohexene with β-Hydrazino carboxylic esters via a Pd-catalyzed allylic substitution cascade
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The desymmetrization of meso-dicarbonatecyclohexene with β-hydrazino carboxylic esters has been achieved via a RuPHOX/Pd-catalyzed allylic substitution cascade for the construction of chiral hexahydrocinnoline derivatives with high performance. Mechanistic studies reveal that the reaction exploits a pathway different from that of our previous work and that the first nitrogen nucleophilic process is the rate-determining step. The protocol could be conducted on a gram scale without any loss of catalytic behavior, and the corresponding chiral hexahydrocinnolines can undergo diverse transformations.
- Xu, Kai,Zheng, Yan,Ye, Yong,Liu, Delong,Zhang, Wanbin
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supporting information
p. 8836 - 8841
(2020/11/30)
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- Development of 2-arylbenzo[: H] quinolone analogs as selective CYP1B1 inhibitors
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The CYP1B1 enzyme is regarded as a potential target for cancer prevention and therapy. Based on the structure of α-naphthoflavone (ANF), diverse 2-arylbenzo[h]quinolone derivatives were designed, synthesized and evaluated as selective CYP1B1 inhibitors. Compared with ANF, although few of the title compounds possessed comparable or slightly higher CYP1B1 inhibitory activity, these compounds displayed a significantly increased selectivity toward CYP1B1 over CYP1A2. Among them compounds 5e, 5g and 5h potently inhibited the activity of CYP1B1 with IC50 values of 3.6, 3.9 and 4.1 nM respectively, paralleled by an excellent selectivity profile. On the basis of predicted clogP values, these target compounds may exhibit improved water-solubility compared to ANF. In particular, 5h showed a great superiority in the reversal of CYP1B1-mediated docetaxel resistance in vitro. The current study may serve as a good starting point for the further development of more potent as well as specific CYP1B1 inhibitors capable of reversing CYP1B1-mediated anticancer-drug resistance.
- Dong, Jinyun,Wang, Zengtao,Meng, Qingqing,Zhang, Qijing,Huang, Guang,Cui, Jiahua,Li, Shaoshun
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p. 15009 - 15020
(2018/04/30)
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- PROCESSES FOR THE PREPARATION OF IVACAFTOR
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The present invention provides processes for the preparation of ivacaftor using novel intermediates and a process for its preparation.
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Page/Page column 49; 50
(2017/03/21)
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- The synthesis and evaluation of triazolopyrimidines as anti-tubercular agents
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We identified a di-substituted triazolopyrimidine with anti-tubercular activity against Mycobacterium tuberculosis. Three segments of the scaffold were examined rationally to establish a structure-activity relationship with the goal of improving potency and maintaining good physicochemical properties. A number of compounds displayed sub-micromolar activity against Mycobacterium tuberculosis with no cytotoxicity against eukaryotic cells. Non-substituted aromatic rings at C5 and a two-carbon chain connecting a terminal aromatic at C7 were preferred features; the presence of NH at C7 and a lack of substituent at C2 were essential for potency. We identified compounds with acceptable metabolic stability in rodent and human liver microsomes. Our findings suggest that the easily-synthesized triazolopyrimidines are a promising class of potent anti-tubercular agents and warrant further investigation in our search for new drugs to fight tuberculosis.
- Zuniga, Edison S.,Korkegian, Aaron,Mullen, Steven,Hembre, Erik J.,Ornstein, Paul L.,Cortez, Guillermo,Biswas, Kallolmay,Kumar, Naresh,Cramer, Jeffrey,Masquelin, Thierry,Hipskind, Philip A.,Odingo, Joshua,Parish, Tanya
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p. 3922 - 3946
(2017/07/05)
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- Rhodium-catalyzed asymmetric hydrogenation of tetrasubstituted β-acetoxy-α-enamido esters and efficient synthesis of droxidopa
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A rhodium-catalyzed asymmetric hydrogenation of challenging tetrasubstituted β-acetoxy-α-enamido esters was developed, giving chiral β-acetoxy-α-amido esters in high yields with excellent enantioselectivities (up to >99% ee). The products could be easily transformed to β-hydroxy-α-amino acid derivatives which are valuable chiral building blocks and a novel route for the synthesis of droxidopa was also developed.
- Guan, Yu-Qing,Gao, Min,Deng, Xu,Lv, Hui,Zhang, Xumu
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supporting information
p. 8136 - 8139
(2017/07/24)
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- Application and preparation method of Morusignin L and derivatives thereof
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The invention discloses application and preparation method of Morusignin L and derivatives thereof. According to the invention, by employing a Morusignin L total synthesis technological route, or in a process of Morusignin L total synthesis, structure modification is carried out on Morusignin L by replacing a substituent of a reaction substrate, and then Morusignin L and a series of derivatives can be synthesized. The Morusignin L is a kind of important anti-tumor activity lead compounds, a compound source can be provided for anti-tumor activity screening by synthesis of the derivatives, and Morusignin L and a series of derivatives have important meaning for searching the novel anti-tumor activity lead compounds. The preparation method of Morusignin L and the derivatives thereof has the advantages that operation is simple, raw material synthesis is low in cost and easy to perform and can be carried out in various organic solvents, the stability in air is good, the application is wide, and compatibility for various substituents is good. The derivatives have certain inhibition capability for the tumor cells growth activity, and can be used as an antitumor drug or an antitumor drug lead compound.
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Page/Page column 15
(2016/10/09)
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- A one-pot copper(II)-catalyzed tandem synthesis of 2-substituted pyrrolo[1,2-b]pyridazin-4(1H)-ones
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A one-pot copper(II)-catalyzed tandem synthesis of 2-substituted pyrrolo[1,2-b]pyridazin-4(1H)-ones from N-aminopyrroles was developed. This tandem reaction involves a Conrad-Limpach-type reaction, including the thermal condensation of N-aminopyrroles with the carbonyl group of β-oxo esters followed by the cyclization of Schiff base intermediates. Compared to the traditional Conrad-Limpach quinoline synthesis, we herein successfully applied copper(II) as a catalyst in this transformation to furnish 2-substituted pyrrolo[1,2-b]pyridazin-4(1H)-ones for the first time. Most of the substrates bearing electron-donating (EDG) and electron-withdrawing (EWG) groups worked well with this procedure. The corresponding products could be converted directly into diverse pyrrolo[1,2-b]pyridazine for drug discovery and materials science. A copper(II)-catalyzed tandem synthesis of 2-substituted pyrrolo[1,2-b]pyridazin-4(1H)-ones from N-aminopyrroles was developed, and the corresponding products could be converted directly into diverse pyrrolo[1,2-b]pyridazine for drug discovery and materials science.
- Tan, Cun,Xiang, Haoyue,He, Qian,Yang, Chunhao
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supporting information
p. 3656 - 3660
(2015/06/16)
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- QUINOLINE AND CINNOLINE COMPOUNDS AND USE THEREOF
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The present invention relates to a series of quinoline and cinnoline derivatives of general formula I, pharmaceutically acceptable salts, hydrates, solvates or prodrugs thereof. And the compounds of general formula I show potent inhibitory activity gainst c-Met kinase. The present invention further relates to the uses of the compounds, pharmaceutically acceptable salts and hydrates for the preparation of medicaments for the treatment and/or prevention of diseases caused by abnormal expression of c-Met kinase, especially for treatment and/or prevention of cancer.
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Paragraph 0057
(2014/11/13)
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- Quinoline and cinnoline derivatives and their applications
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The present invention relates to a series of quinoline and cinnoline derivatives of general formula I, pharmaceutically acceptable salts, hydrates, solvates or prodrugs thereof. And the compounds of general formula I show potent inhibitory activity gainst c-Met kinase. The present invention further relates to the uses of the compounds, pharmaceutically acceptable salts and hydrates for the preparation of medicaments for the treatment and/or prevention of diseases caused by abnormal expression of c-Met kinase, especially for treatment and/or prevention of cancer.
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Paragraph 0188
(2015/01/06)
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- Tert-BuOK-Catalyzed condensation of ethyl diazoacetate to aldehydes and palladium-catalyzed 1,2-hydrogen migration for the synthesis of β-ketoesters under solvent-free conditions
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A mild and convenient method for the condensation of ethyl diazoacetate (EDA) with aldehydes catalyzed by tert-BuOK under solvent-free conditions was developed. The corresponding α-diazo-β-hydroxy esters were further converted into β-ketoesters through palladium-catalyzed 1,2-hydrogen migration under neat conditions. The two-step transformation exemplifies a simple method for the efficient and green synthesis of β-ketoesters. The Royal Society of Chemistry 2013.
- Chen, Shufeng,Yuan, Fang,Zhao, Haiying,Li, Baoguo
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p. 12616 - 12620
(2013/08/23)
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- Discovery of novel 4-(2-fluorophenoxy)quinoline derivatives bearing 4-oxo-1,4-dihydrocinnoline-3-carboxamide moiety as c-Met kinase inhibitors
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A series of novel 4-(2-fluorophenoxy)quinoline derivatives containing 4-oxo-1,4-dihydrocinnoline-3-carboxamide moiety were designed, synthesized and evaluated for their in vitro biological activities against c-Met kinase and six typical cancer cell lines (A549, H460, HT-29, MKN-45, U87MG and SMMC-7721). All the prepared compounds showed moderate to excellent antiproliferative activity, and the analysis of their structure-activity relationships indicated that 2-chloro or 2-trifluoromethyl substituted phenyl group on the 1-position of cinnoline ring was more favorable for antitumor activity. In this study, a promising compound 33, with a c-Met IC50 value of 0.59 nM, was identified as a multitargeted receptor tyrosine kinase inhibitor.
- Li, Sai,Zhao, Yanfang,Wang, Kewen,Gao, Yali,Han, Jianming,Cui, Bingbing,Gong, Ping
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p. 2843 - 2855
(2013/06/27)
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- Synthesis and antitumor activity of novel 4-(2-fluorophenoxy)quinoline derivatives bearing the 4-Oxo-1,4-dihydroquinoline-3-carboxamide moiety
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A series of 4-(2-fluorophenoxy)quinoline derivatives bearing the 4-oxo-1,4-dihydroquinoline-3-carboxamide moiety were designed, synthesized, and evaluated for their in vitro antitumor activity against the H460, HT-29, MKN-45, U87MG, and SMMC-7721 cancer cell lines. Most of the tested compounds showed potent activity and high selectivity toward the HT-29 and MKN-45 cell lines. Furthermore, compounds 21b, 21c, and 21i were further examined for their c-Met kinase activity and exhibited strong efficacy with IC50 values in the single-digit nanomolar range, which was comparable with the positive control foretinib. The most promising compound 21c showed excellent cytostatic activity with IC50 values from 0.01 to 0.53 μM against all tested cell lines, thus being 1.7-2.2 times more active than foretinib. Novel 4-(2-fluorophenoxy)quinoline derivatives bearing the 4-oxo-1,4-dihydroquinoline- 3-carboxamide moiety were evaluated for their in vitro antitumor activity against several cancer cell lines. Compounds 21b, 21c, and 21i were also examined for their c-Met kinase activity in comparison to foretinib. Compound 21c showed excellent cytostatic activity with IC50 values from 0.01 to 0.53 μM against all tested cell lines and higher activity than foretinib.
- Li, Sai,Jiang, Rui,Qin, Mingze,Liu, Haicheng,Zhang, Guangyan,Gong, Ping
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p. 521 - 533
(2013/07/26)
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- Design and synthesis of 6,7-methylenedioxy-4-substituted phenylquinolin-2(1H)-one derivatives as novel anticancer agents that induce apoptosis with cell cycle arrest at G2/M phase
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Novel 6,7-methylenedioxy-4-substituted phenylquinolin-2(1H)-one derivatives 12a-n were designed and prepared through an intramolecular cyclization reaction and evaluated for in vitro anticancer activity. Among the synthesized compounds, 6,7-methylenedioxy-4-(2,4-dimethoxyphenyl)quinolin-2(1H)-one (12e) displayed potent cytotoxicity against several different tumor cell lines at a sub-micromolar level. Furthermore, results of fluorescence-activated cell sorting (FACS) analysis suggested that 12e induced cell cycle arrest in the G2/M phase accompanied by apoptosis in HL-60 and H460 cells. This action was confirmed by Hoechst staining and caspase-3 activation. Due to their easy synthesis and remarkable biological activities, 4-phenylquinolin-2(1H)-one analogs (4-PQs) are promising new anticancer leads based on the quinoline scaffold. Accordingly, compound 12e was identified as a new lead compound that merits further optimization and development as an anticancer candidate.
- Chen, Yi-Fong,Lin, Yi-Chien,Huang, Po-Kai,Chan, Hsu-Chin,Kuo, Sheng-Chu,Lee, Kuo-Hsiung,Huang, Li-Jiau
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p. 5064 - 5075
(2013/09/02)
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- Ethyl 1,4-dihydro-4-oxo-3-quinolinecarboxylates by a tandem addition-elimination-SNAr reaction
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The ethyl 1,4-dihydro-4-oxo-3-quinolinecarboxylate ring structure, important in several drug compounds, has been prepared in two steps from ethyl 2-(2-fluorobenzoyl)acetate. Treatment of this β-ketoester with N,N-dimethylformamide dimethyl acetal gives a
- Bunce, Richard A.,Lee, Eric J.,Grant, Matthew T.
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experimental part
p. 620 - 625
(2011/07/30)
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- Structure-activity relationships of 1,4-dihydropyridines that act as enhancers of the vanilloid receptor 1 (TRPV1)
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Vanilloid agonists such as capsaicin activate ion flux through the TRPV1 channel, a heat- and ligand-gated cation channel that transduces painful chemical or thermal stimuli applied to peripheral nerve endings in skin or deep tissues. We have probed the SAR of a variety of 1,4-dihydropyridine (DHP) derivatives as novel 'enhancers' of TRPV1 activity by examining changes in capsaicin-induced elevations in 45Ca2+-uptake in either cells ectopically expressing TRPV1 or in cultured dorsal root ganglion (DRG) neurons. The enhancers increased the maximal capsaicin effect on 45Ca2+-uptake by typically 2- to 3-fold without producing an action when used alone. The DHP enhancers contained 6-aryl substitution and small alkyl groups at the 1 and 4 positions, and a 3-phenylalkylthioester was tolerated. Levels of free intracellular Ca2+, as measured by calcium imaging, were also increased in DRG neurons when exposed to the combination of capsaicin and the most efficacious enhancer 23 compared to capsaicin alone. Thus, DHPs can modulate TRPV1 channels in a positive fashion.
- Roh, Eun Joo,Keller, Jason M.,Olah, Zoltan,Iadarola, Michael J.,Jacobson, Kenneth A.
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experimental part
p. 9349 - 9358
(2009/04/06)
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- PROCESS FOR PRODUCING FUSED IMIDAZOLE COMPOUND, REFORMATSKY REAGENT IN STABLE FORM, AND PROCESS FOR PRODUCING THE SAME
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The present invention provides an industrially advantageous process for producing a steroid C17,20 lyase inhibitor represented by the general formula (I): and a Reformatsky reagent in a stable form suitable for the process.In the present invention, a compound represented by the general formula (I) is produced by reducing a specific β-hydroxy ester compound derivative or a salt thereof obtained from a specific carbonyl compound in a Reformatsky reaction in the presence of a metal hydride complex and a metal halide, and then subjecting it to a ring-closing reaction. In the above Reformatsky reaction, it is useful to use a stable solution of a compound represented by the general formula BrZnCH2COOC2H5 or a crystal of the compound which is represented by the formula (BrZnCH2COOC2H5·THF)2.
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