DNA-Dependent Protein Kinase (DNA-PK) Inhibitors. Synthesis and Biological Activity of Quinolin-4-one and Pyridopyrimidin-4-one Surrogates for the Chromen-4-one Chemotype

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• 作者：Cline Cano ; Olivier R. Barbeau ; Christine Bailey ; Xiao-Ling Cockcroft ; Nicola J. Curtin ; Heather Duggan ; Mark Frigerio ; Bernard T. Golding ; Ian R. Hardcastle ; Marc G. Hummersone ; Charlotte Knights ; Ke
• 刊名：Journal of Medicinal Chemistry
• 出版年：2010
• 出版时间：December 23, 2010
• 年：2010
• 卷：53
• 期：24
• 页码：8498-8507
• 全文大小：962K
• 年卷期：v.53,no.24(December 23, 2010)
• ISSN：1520-4804

文摘

Following the discovery of dibenzo[b,d]thiophen-4-yl)-2-morpholino-4H-chromen-4-one (NU7441) (Leahy, J. J. J.; Golding, B. T.; Griffin, R. J.; Hardcastle, I. R.; Richardson, C.; Rigoreau, L.; Smith, G. C. M. e>Bioorg. Med. Chem. Lett.e> 2004, <em>14em>, 6083−6087) as a potent inhibitor (IC₅₀ = 30 nM) of DNA-dependent protein kinase (DNA-PK), we have investigated analogues in which the chromen-4-one core template has been replaced by aza-heterocyclic systems: 9-substituted 2-morpholin-4-ylpyrido[1,2-a]pyrimidin-4-ones and 8-substituted 2-morpholin-4-yl-1H-quinolin-4-ones. The 8- and 9-substituents were either dibenzothiophen-4-yl or dibenzofuran-4-yl, which were each further substituted at the 1-position with water-solubilizing groups [NHCO(CH₂)_nNR¹R², where n = 1 or 2 and the moiety R¹R²N was derived from a library of primary and secondary amines (e.g., morpholine)]. The inhibitors were synthesized by employing a multiple-parallel approach in which the two heterocyclic components were assembled by Suzuki−Miyaura cross-coupling. Potent DNA-PK inhibitory activity was generally observed across the compound series, with structure−activity studies indicating that optimal potency resided in pyridopyrimidin-4-ones bearing a substituted dibenzothiophen-4-yl group. Several of the newly synthesized compounds (e.g., 2-morpholin-4-yl-N-[4-(2-morpholin-4-yl-4-oxo-4H-pyrido[1,2-a]pyrimidin-9-yl)dibenzothiophen-1-yl]acetamide) combined high potency against the target enzyme (DNA-PK IC₅₀ = 8 nM) with promising activity as potentiators of ionizing radiation-induced cytotoxicity in vitro.