- A new nonpolar N-hydroxy imidazoline lead compound with improved activity in a murine model of late-stage Trypanosoma brucei brucei infection is not cross-resistant with diamidines
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Treatment of late-stage sleeping sickness requires drugs that can cross the blood-brain barrier (BBB) to reach the parasites located in the brain. We report here the synthesis and evaluation of four new N-hydroxy and 12 new N-alkoxy derivatives of bisimidazoline leads as potential agents for the treatment of late-stage sleeping sickness. These compounds, which have reduced basicity compared to the parent leads (i.e., are less ionized at physiological pH), were evaluated in vitro against Trypanosoma brucei rhodesiense and in vivo in murine models of first- and second-stage sleeping sickness. Resistance profile, physicochemical parameters, in vitro BBB permeability, and microsomal stability also were determined. The N-hydroxy imidazoline analogues were the most effective in vivo, with 4-((1-hydroxy-4,5-dihydro-1H-imidazol-2-yl)amino)-N-(4-((1-hydroxy-4,5-dihydro-1H-imidazol-2-yl)amino)phenyl)benzamide (14d) showing 100% cures in the first-stage disease, while 15d, 16d, and 17d appeared to slightly improve survival. In addition, 14d showed weak activity in the chronic model of central nervous system infection in mice. No evidence of reduction of this compound with hepatic microsomes and mitochondria was found in vitro, suggesting that N-hydroxy imidazolines are metabolically stable and have intrinsic activity against T. brucei. In contrast to its unsubstituted parent compound, the uptake of 14d in T. brucei was independent of known drug transporters (i.e., T. brucei AT1/P2 and HAPT), indicating a lower predisposition to cross-resistance with other diamidines and arsenical drugs. Hence, the N-hydroxy bisimidazolines (14d in particular) represent a new class of promising antitrypanosomal agents.
- Ros Martnez, Carlos H.,Miller, Florence,Ganeshamoorthy, Kayathiri,Glacial, Fabienne,Kaiser, Marcel,De Koning, Harry P.,Eze, Anthonius A.,Lagartera, Laura,Herraiz, Toms,Dardonville, Christophe
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p. 890 - 904
(2015/03/05)
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- Discovery of 1-[4-(N-benzylamino)phenyl]-3-phenylurea derivatives as non-peptidic selective SUMO-sentrin specific protease (SENP)1 inhibitors
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We developed 1-[4-(N-benzylamino)phenyl]-3-phenylurea derivative 4 (GN6958) as a non-peptidic selective SUMO-sentrin specific protease (SENP)1 protease inhibitor based on the hypoxia inducible factor (HIF)-1α inhibitor 1 (GN6767). The direct interaction of compound 1 with SENP1 protein in cells was observed by the pull-down experiments using the biotin-tagged compound 2 coated on the streptavidin affinity column. Among the various 1-[4-(N-benzylamino) phenyl]-3-phenylurea derivatives tested, compounds 3 and 4 suppressed HIF-1α accumulation in a concentration-dependent manner without affecting the expression level of tubulin protein in HeLa cells. Both compounds inhibited SENP1 protease activity in a concentration-dependent manner, and compound 4 exhibited more potent inhibition than compound 3. Compound 4 exhibited selective inhibition against SENP1 protease activity without inhibiting other protease enzyme activities in vitro.
- Uno, Masaharu,Koma, Yosuke,Ban, Hyun Seung,Nakamura, Hiroyuki
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p. 5169 - 5173
(2012/09/07)
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- Eco-friendly synthesis of 4-4'S-diaminodiphenylurea, a Dye intermediate and direct dyes derived from it
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A rapid, environmental friendly and highly efficient method for the synthesis of 4-4'S-diaminodiphenylurea and direct dyes derived form it has been reported. The reported method is environmentally friendly, as it doesn't involve the usage of environmental
- Amjad, Rana,Munawar, Munawar Ali,Khan, Shahid Rehman,Naeem, Muhammad,Sohaib, Muhammad
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experimental part
p. 107 - 113
(2012/04/23)
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- An 'inside-out' approach to suramin analogues
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An approach to the synthesis of suramin analogues has been realised, which avoids synthetic problems associated with conventional routes. The use of isobutyl ester protecting groups for sulfonic acids was crucial to the success of the strategy, because these were able to be cleanly deprotected with sodium iodide, yielding the sodium salts of the corresponding sulfonic acids.
- McGeary, Ross P.,Bennett, Andrew J.,Tran, Quoc B.,Prins, Johannes,Ross, Benjamin P.
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experimental part
p. 3990 - 3997
(2009/10/09)
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- New bis(2-aminoimidazoline) and bisguanidine DNA minor groove binders with potent in vivo antitrypanosomal and antiplasmodial activity
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A series of 75 guanidine and 2-aminoimidazoline analogue molecules were assayed in vitro against Trypanosoma brucei rhodesiense STIB900 and Plasmodium falciparum K1. The dicationic diphenyl compounds exhibited the best activities with IC50 values against T. b. rhodesiense and P. falciparum in the nanomolar range. Five compounds (7b, 9a, 9b, 10b, and 14b) cured 100% of treated mice upon ip administration at 20 mg/kg in the difficult to cure T. b. rhodesiense STIB900 mouse model. Overall, the compounds that bear the 2-aminoimidazoline cations benefit from better safety profiles than the guanidine counterparts. The observation of a correlation between DNA binding affinity at AT sites and trypanocidal activity for three series of compounds supported the view of a mechanism of antitrypanosomal action due in part to the formation of a DNA complex. No correlation between antiplasmodial activity and in vitro inhibition of ferriprotoporphyrin IX biomineralisation was observed, suggesting that additional mechanism of action is likely to be involved.
- Rodríguez, Fernando,Rozas, Isabel,Kaiser, Marcel,Brun, Reto,Nguyen, Binh,Wilson, W. David,García, Rory Nelson,Dardonville, Christophe
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p. 909 - 923
(2008/12/22)
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- Studies on the laboratory scale synthesis of 4,4'-diaminodiphenylurea and preparation of direct dyes from the compound
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4,4′- Diaminodiphenyurea has been synthesized as a potential replacement for benzidine by reaction between p-phenylenediamine and urea under different catalytic and reaction conditions. Reaction conditions have been optimized to obtain maximum yield of in
- Khan, S. Rehman,Gilani,Inayat, Asma,Waheed, Shaheena
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p. 319 - 323
(2007/10/03)
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- Basic azo dyestuffs of the 3-cyano-2,4,6-triamino pyridine series
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The new basic azo dyestuffs of the formula STR1 wherein the symbols have the meaning given in the description, are suitable for dyeing synthetic and naturally occurring substrates which can be dyed with basic dyestuffs.
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- Novel Bis as Antitrypanosomal Agents
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A series of novel 1,1'-(4,1-phenylene)bis was prepared and evaluated for activity against Trypanosoma rhodesiense in mice.The importance of the bis structure and the nature of the spacer between the two phenyl rings for optimal activity have been revealed.The potent parenteral activity of several analogues within this series as well as preliminary indication of oral activity lends encouragement to further development of this structural class.
- Turner, William R.,Werbel, Leslie M.
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p. 1728 - 1740
(2007/10/02)
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