- Oxadiazole-isopropylamides as potent and noncovalent proteasome inhibitors
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Screening of the 50 000 ChemBridge compound library led to the identification of the oxadiazole-isopropylamide 1 (PI-1833) which inhibited chymotrypsin-like (CT-L) activity (IC50 = 0.60 μM) with little effects on the other two major proteasome proteolytic activities, trypsin-like (T-L) and postglutamyl-peptide-hydrolysis-like (PGPH-L). LC-MS/MS and dialysis show that 1 is a noncovalent and rapidly reversible CT-L inhibitor. Focused library synthesis provided 11ad (PI-1840) with CT-L activity (IC50 = 27 nM). Detailed SAR studies indicate that the amide moiety and the two phenyl rings are sensitive toward modifications. Hydrophobic residues, such as propyl or butyl in the para position (not ortho or meta) of the A-ring and a m-pyridyl group as B-ring, significantly improve activity. Compound 11ad (IC50 = 0.37 μM) is more potent than 1 (IC50 = 3.5 μM) at inhibiting CT-L activity in intact MDA-MB-468 human breast cancer cells and inhibiting their survival. The activity of 11ad warrants further preclinical investigation of this class as noncovalent proteasome inhibitors.
- Ozcan, Sevil,Kazi, Aslamuzzaman,Marsilio, Frank,Fang, Bin,Guida, Wayne C.,Koomen, John,Lawrence, Harshani R.,Sebti, Sa?d M.
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p. 3783 - 3805
(2013/06/27)
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- The discovery of a selective, high affinity A2B adenosine receptor antagonist for the potential treatment of asthma
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Adenosine has been suggested to play a role in asthma, possibly via activation of A2B adenosine receptors on mast cells and other pulmonary cells. We describe our initial efforts to discover a xanthine based selective A2B AdoR antagonist that resulted in the discovery of CVT-5440, a high affinity A2B AdoR antagonist with good selectivity (A2B AdoR Ki = 50 nM, selectivity A1 > 200: A2A > 200: A3 > 167).
- Zablocki, Jeff,Kalla, Rao,Perry, Thao,Palle, Venkata,Varkhedkar, Vaibhav,Xiao, Dengming,Piscopio, Anthony,Maa, Tenning,Gimbel, Art,Hao, Jia,Chu, Nancy,Leung, Kwan,Zeng, Dewan
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p. 609 - 612
(2007/10/03)
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- Antikinetoplastid activity of 3-aryl-5-thiocyanatomethyl-1,2,4-oxadiazoles
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A series of 5-thiocyanatomethyl- and 5-alkyl-3-aryl-1,2,4-oxadiazoles were synthesized and evaluated for their activity against kinetoplastid parasites. Formation of the oxadiazole ring was accomplished through the reaction of benzamidoximes with acyl chlorides, while the thiocyanate group was inserted by reacting the appropriate 5-halomethyl oxadiazole with ammonium thiocyanate. The thiocyanate-containing compounds possessed low micromolar activity against Leishmania donovani and Trypanosoma brucei, while the 5-alkyl oxadiazoles were less active against these parasites. 3-(4-Chlorophenyl)-5-(thiocyanatomethyl)-1, 2,4-oxadiazole (compound 4b) displayed modest selectivity for L. donovani axenic amastigote-like parasites over J774 macrophages, PC3 prostate cancer cells, and Vero cells (6.4-fold, 3.8-fold, and 9.1-fold, respectively), while 3-(3,4-dichlorophenyl)-5-(thiocyanatomethyl)-1,2,4-oxadiazole (compound 4h) showed 30-fold selectivity against Vero cells but was not selective against PC3 cells. In a murine model of visceral leishmaniasis, compound 4b decreased liver parasitemia caused by L. donovani by 48% when given in five daily i.v. doses at 5mg/kg and by 61% when administered orally for 5days at 50mg/kg. These results indicate that aromatic thiocyanates hold promise for the treatment of leishmanial infections if the selectivity of these compounds can be improved.
- Cottrell, Denise M.,Capers, Jeffrey,Salem, Manar M.,DeLuca-Fradley, Kate,Croft, Simon L.,Werbovetz, Karl A.
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p. 2815 - 2824
(2007/10/03)
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- CVT-4325: A potent fatty acid oxidation inhibitor with favorable oral bioavailability
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New inhibitors of palmitoyl-CoA oxidation are based on the introduction of nitrogen heterocycles in the 'Western Portion' of the molecule. SAR studies led to the discovery of CVT-4325, a potent FOXi (IC50 = 380 nM, rat mitochondria) with favorable PK properties (F = 93%, t1/2 = 13.6 h, dog). New inhibitors of palmitoyl-CoA oxidation are based on the introduction of nitrogen heterocycles in the 'Western Portion' of the molecule. SAR studies led to the discovery of CVT-4325 (shown), a potent FOXi (IC50 = 380 nM rat mitochondria) with favorable PK properties (F = 93%, t1/2 = 13.6 h, dog).
- Elzein, Elfatih,Ibrahim, Prabha,Koltun, Dmitry O.,Rehder, Ken,Shenk, Kevin D.,Marquart, Timothy A.,Jiang, Bob,Li, Xiaofen,Natero, Reina,Li, Yuan,Nguyen, Marie,Kerwar, Suresh,Chu, Nancy,Soohoo, Daniel,Hao, Jia,Maydanik, Victoria Y.,Lustig, David A.,Zeng, Dewan,Leung, Kwan,Zablocki, Jeff A.
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p. 6017 - 6021
(2007/10/03)
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