- Design and Synthesis of 4-Alkylidene-β-lactams: Benzyl- and Phenethyl-carbamates as Key Fragments to Switch on Antibacterial Activity
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The emergence of multidrug-resistant bacterial strains is particularly important in chronic pathologies such as cystic fibrosis (CF), in which persistent colonization and selection of resistant strains is favored by the frequent and repeated use of antibacterial agents. Staphylococcus aureus is a common pathogen in CF patients that has an associated increased multidrug resistance. In previous studies we demonstrated that the presence of a 4-alkylidene side chain directly linked to a β-lactam appeared to strengthen the potency against S. aureus, especially against methicillin-resistant S. aureus (MRSA) strains. In the present study, 21 new 4-alkylidene-β-lactams were synthesized and evaluated for antibacterial activity. We designed the new compounds to have aryl, benzyl, or phenethyl-carbamate groups on the C3 hydroxyethyl side chain. We found a correlation between biological activity and the nitrogen substituent of the carbamate group, and two phenethyl-carbamate β-lactams were shown to be valuable antibacterial agents against selected linezolid-resistant strains, with a minimum inhibitory concentrations of 2–4 mg L?1.
- Giacomini, Daria,Martelli, Giulia,Piccichè, Miriam,Calaresu, Enrico,Cocuzza, Clementina Elvezia,Musumeci, Rosario
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p. 1525 - 1533
(2017/09/25)
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- Structure-based drug design and potent anti-cancer activity of tricyclic 5:7:5-fused diimidazo[4,5-d:4′,5′-f][1,3]diazepines
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Judicial structural modifications of 5:7-fused ring-expanded nucleosides (RENs), based on molecular modeling studies with one of its known targets, human RNA helicase (hDDX3), led to the lead, novel, 5:7-5-fused tricyclic heterocycle (1). The latter exhibited promising broad-spectrum in vitro anti-cancer activity against a number of cancer cell lines screened. This paper describes our systematic, albeit limited, structure-activity relationship (SAR) studies on this lead compound, which produced a number of analogs with broad-spectrum in vitro anti-cancer activities against lung, breast, prostate, and ovarian cancer cell lines, in particular compounds 15i, 15j, 15m and 15n which showed IC 50 values in submicromolar to micromolar range, and are worthy of further explorations. The SAR data also enabled us to propose a tentative SAR model for future SAR efforts for ultimate realization of optimally active and minimally toxic anti-cancer compounds based on the diimidazo[4,5-d:4′, 5′-f][1,3]diazepine structural skeleton of the lead compound 1.
- Kondaskar, Atul,Kondaskar, Shilpi,Fishbein, James C.,Carter-Cooper, Brandon A.,Lapidus, Rena G.,Sadowska, Mariola,Edelman, Martin J.,Hosmane, Ramachandra S.
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p. 618 - 631
(2013/02/25)
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- Synthesis and evaluation of novel compounds as potent dipeptidyl peptidase IV inhibitors
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A series of new 2-cyanopyrrolidine derivatives with constrained imidazolidin ring were synthesized, Their structures were confirmed by 1H NMR spectroscopy and/or mass spectrometry, and their activities were evaluated in vitro. They were proven to possess submicromolar inhibitory activities against dipeptidyl peptidase IV.
- Wang, Liutang,Zhang, Bin,Ji, Jianxin,Li, Bogang,Yan, Jufang,Zhang, Weiyu,Wu, Yong,Wang, Xuechao,Hou, Hui
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experimental part
p. 52 - 57
(2010/03/24)
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- (1-Nosyl-5-nitroindol-3-yl)methyl ester: A novel protective group for carboxylic acids
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(Chemical Equation Presented) The usefulness of (1-nosyl-5-nitroindol-3-yl) methyl esters as a novel protective group for carboxylic acid is fully demonstrated. The novel protective group is stable under a broad range of conditions and can easily be deprotected under the mild conditions used for removal of the nosyl (Ns) group. It is orthogonal to the existing protective groups for carboxylic acids such as t-butyl and allyl esters.
- Nishimura, Takuya,Yamada, Kouhei,Takebe, Tohru,Yokoshima, Satoshi,Fukuyama, Tohru
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supporting information; experimental part
p. 2601 - 2604
(2009/05/26)
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- Organosilicon synthesis of isocyanates: II. Synthesis of aliphatic, carbocyclic, and fatty-aromatic isocyanates
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Silylation of a series of aliphatic, carbocyclic, and fatty-aromatic amines gave the corresponding silyl derivatives whose yield depended on the electronic and steric structure of the substrate and the nature of the silylating agent. The yield of isocyanates obtained by phosgenation of the silyl derivatives under mild conditions decreased in going from aliphatic amines to benzylamines and rose as the length of the alkyl chain in fatty-aromatic amines extended. The most convenient procedure for the synthesis of low-boiling alkyl isocyanates was found to be based on the transformation of amines or ammonium salts into silyl or silyl silyl-carabamates, followed by pyrolysis of the latter in the presence of trichloro(phenyl)silane. Pleiades Publishing, Inc., 2006.
- Lebedev,Lebedeva,Sheludyakov,Ovcharuk,Kovaleva,Ustinova
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p. 469 - 477
(2008/02/07)
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- Piperidine-containing histamine H3 receptor antagonists of the carbamate series: The influence of the additional ether functionality
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Recently novel leads for histamine H3 receptor antagonists of the non-imidazole type have been described. As a continuation of this research eleven new carbamate derivatives possessing an additional ether functionality were prepared. The compounds were evaluated in vitro for their antagonist activity on isolated organs of guinea-pig (GP) H3 as well as H2, H1, and M3 receptors, respectively. All compounds investigated possessed moderate antagonist affinities at guinea-pig histamine H3 receptors (pA2 6.11-6.76). An ether functionality introduced in different places of the lipophilic part of carbamates differently influenced activity and selectivity toward H3, M3, and other histamine receptors tested.
- Lazewska,Kiec-Kononowicz, Katarzyna,Pertz,Elz,Stark,Schunack
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p. 791 - 795
(2007/10/03)
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