Analogues of (dibenzo[b,d]thiophen-4-yl)-2-morpholino-4H-chromen-4-one (NU7441), a potent inhibitor of DNA-dependent protein kinase (DNA-PK; IC50 = 42 ± 2 nM), have been synthesized in which 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] were placed at the 1-position.
View Article and Find Full Text PDFDNA double-strand breaks (DSB) are the most cytotoxic lesions induced by topoisomerase II poisons. Nonhomologous end joining (NHEJ) is a major pathway for DSB repair and requires DNA-dependent protein kinase (DNA-PK) activity. DNA-PK catalytic subunit (DNA-PKcs) is structurally similar to PI-3K, which promotes cell survival and proliferation and is upregulated in many cancers.
View Article and Find Full Text PDFIntroduction of an O-alkoxyphenyl substituent at the 8-position of the 2-morpholino-4H-chromen-4-one pharmacophore enabled regions of the ATP-binding site of DNA-dependent protein kinase (DNA-PK) to be probed further. Structure-activity relationships have been elucidated for inhibition of DNA-PK and PI3K (p110α), with N-(2-(cyclopropylmethoxy)-4-(2-morpholino-4-oxo-4H-chromen-8-yl)phenyl)-2-morpholinoacetamide 11a being identified as a potent and selective DNA-PK inhibitor (IC(50)=8 nM).
View Article and Find Full Text PDFFollowing the discovery of dibenzo[b,d]thiophen-4-yl)-2-morpholino-4H-chromen-4-one (NU7441) ( Leahy , J. J. J.
View Article and Find Full Text PDFThe mammalian target of rapamycin (mTOR) kinase forms two multiprotein complexes, mTORC1 and mTORC2, which regulate cell growth, cell survival, and autophagy. Allosteric inhibitors of mTORC1, such as rapamycin, have been extensively used to study tumor cell growth, proliferation, and autophagy but have shown only limited clinical utility. Here, we describe AZD8055, a novel ATP-competitive inhibitor of mTOR kinase activity, with an IC50 of 0.
View Article and Find Full Text PDFWe describe a novel series of potent inhibitors of the kinase activity of mTOR. The compounds display good selectivity relative to other PI3K-related kinase family members and, in cellular assays, inhibit both mTORC1 and mTORC2 complexes and exhibit good antiproliferative activity.
View Article and Find Full Text PDFA pharmacophore mapping approach, derived from previous experience of PIKK family enzymes, was used to identify a hit series of selective inhibitors of the mammalian target of rapamycin (mTOR). Subsequent refinement of the SAR around this hit series based on a tri-substituted triazine scaffold has led to the discovery of potent and selective inhibitors of mTOR.
View Article and Find Full Text PDFNovel nonpeptide small molecule renin inhibitors bearing an N-isopropyl P(1) motif were designed based on initial lead structures 1 and aliskiren (2). (P(3)-P(1))-Benzamide derivatives such as 9a and 34, as well as the corresponding P(1) basic tertiary amine derivatives 10 and 35 were found to display low nanomolar inhibition against human renin in vitro.
View Article and Find Full Text PDFPoly(ADP-ribose) polymerase activation is an immediate cellular response to metabolic-, chemical-, or ionizing radiation-induced DNA damage and represents a new target for cancer therapy. In this article, we disclose a novel series of substituted 4-benzyl-2 H-phthalazin-1-ones that possess high inhibitory enzyme and cellular potency for both PARP-1 and PARP-2. Optimized compounds from the series also demonstrate good pharmacokinetic profiles, oral bioavailability, and activity in vivo in an SW620 colorectal cancer xenograft model.
View Article and Find Full Text PDFThe synthesis and biological evaluation of libraries of 8-biarylchromen-4-ones enabled the elucidation of structure-activity relationships for inhibition of the DNA-dependent protein kinase (DNA-PK), with 8-(3-(thiophen-2-yl)phenyl)chromen-4-one and 8-(3-(thiophen-3-yl)phenyl)chromen-4-one being especially potent inhibitors.
View Article and Find Full Text PDFWe have previously described poly(ADP-ribose) polymerase-1 (PARP-1) inhibitors based on a substituted benzyl-phthalazinone scaffold. As an alternative chemical template, a novel series of alkoxybenzamides were developed with restricted conformation through intramolecular hydrogen bond formation; the compounds exhibit low nM enzyme and cellular activity as PARP-1 inhibitors.
View Article and Find Full Text PDFJ Med Chem
April 2007
Structure-activity relationships have been investigated for inhibition of DNA-dependent protein kinase (DNA-PK) and ATM kinase by a series of pyran-2-ones, pyran-4-ones, thiopyran-4-ones, and pyridin-4-ones. A wide range of IC50 values were observed for pyranones and thiopyranones substituted at the 6-position, with the 3- and 5-positions proving intolerant to substitution. Related pyran-2-ones, pyran-4-ones, and thiopyran-4-ones showed similar IC50 values against DNA-PK, whereas the pyridin-4-one system proved, in general, ineffective at inhibiting DNA-PK.
View Article and Find Full Text PDFWe have previously described the discovery of poly(ADP-ribose)polymerase-1 (PARP-1) inhibitors based on a phthalazinone scaffold. Subsequent optimisation of inhibitory activity, metabolic stability and pharmacokinetic parameters has led to a novel series of meta-substituted 4-benzyl-2H-phthalazin-1-one PARP-1 inhibitors which retain low nM cellular activity and show good stability in vivo and efficacy in cell based models.
View Article and Find Full Text PDFScreening of the Maybridge compound collection identified 4-arylphthalazinones as micromolar inhibitors of PARP-1 catalytic activity. Subsequent optimisation of both inhibitory activity and metabolic stability led to a novel series of meta-substituted 4-benzyl-2H-phthalazin-1-ones with low nanomolar, cellular activity as PARP-1 inhibitors and promising metabolic stability in vitro.
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