- Analogues of 4-[(7-Bromo-2-methyl-4-oxo-3 H -quinazolin-6-yl)methylprop-2- ynylamino]- N -(3-pyridylmethyl)benzamide (CB-30865) as potent inhibitors of nicotinamide phosphoribosyltransferase (Nampt)
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We have shown previously that the target of the potent cytotoxic agent 4-[(7-bromo-2-methyl-4-oxo-3H-quinazolin-6-yl)methyl-prop-2-ynylamino] -N-(3-pyridylmethyl)benzamide (CB38065, 1) is nicotinamide phosphoribosyltransferase (Nampt). With its cellular target known we sought to optimize the biochemical and cellular Nampt activity of 1 as well as its cytotoxicity. It was found that a 3-pyridylmethylamide substituent in the A region was critical to cellular Nampt activity and cytotoxicity, although other aromatic substitution did yield compounds with submicromolar enzymatic inhibition. Small unsaturated groups worked best in the D-region of the molecule, with 3,3-dimethylallyl providing optimal potency. The E region required a quinazolin-4-one or 1,2,3-benzotriazin-4-one group for activity, and many substituents were tolerated at C2 of the quinazolin-4-one. The best compounds showed subnanomolar inhibition of Nampt and low nanomolar cytotoxicity in cellular assays.
- Lockman, Jeffrey W.,Murphy, Brett R.,Zigar, Daniel F.,Judd, Weston R.,Slattum, Paul M.,Gao, Zhong-Hua,Ostanin, Kirill,Green, Jeremy,McKinnon, Rena,Terry-Lorenzo, Ryan T.,Fleischer, Tracey C.,Boniface, J. Jay,Shenderovich, Mark,Willardsen, J. Adam
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experimental part
p. 8734 - 8746
(2011/02/23)
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- Quinazoline antifolates thymidylate synthase inhibitors: Lipophilic analogues with modification to the C2-methyl substituent
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Modification of the potent thymidylate synthase (TS) inhibitor 1-[[N-[4- [N-[(3,4-dihydro-2-methyl-4-oxo-6-quinazolinyl)methyl]-N-prop-2- ynylamino]benzoyl]amino]methyl]-3-nitrobenzene (4a) has led to the synthesis of quinazolinone antifolates bearing functionalized alkyl substituents at C2. A general synthetic route was developed which involved coupling the appropriate 1-[[N-[4-(alkylamino)benzoyl)amino]methyl]-3-nitrobenzene 20-22 with a 6-(bromomethyl)-2-(acetoxymethyl)-3,4-dihydro-4-oxoquinazoline 9 or 10. Replacement of the 2-acetoxy group by a chlorine atom followed by the displacement of the halogen of 25a-c by various nucleophiles led to compounds 26-40. Good TS (IC50 50 0.1-1 μM) were found with most of these new antifolates. TS inhibitors in this series do not apparently require the reduced folate carrier (RFC) for cell entry (they most likely penetrate the cell membrane by passive diffusion) and are not polyglutamated. N, O, S, Cl, and CN as well as large amino and mercapto substituents were tolerated by the enzyme. The simultaneous incorporation of 7-methyl and 2'-F substituents gave a series of highly potent agents inhibiting cell growth at concentrations 1 μM (24, 27bc; 30-32b, 35b). The incorporation of suitable C2 substituents has overcome the decrease in aqueous solubility observed with lipophilic quinazoline antifolates. This is best illustrated by compound 31a, where up to a 54-fold increase in solubility has been achieved by the incorporation of an N-methylpiperazine nucleus into the C2-methyl group of 4a.
- Hennequin, Laurent F.,Boyle, F. Thomas,Wardleworth, J. Michael,Marsham, Peter R.,Kimbell, Rosemary,Jackman, Ann L.
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p. 695 - 704
(2007/10/03)
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