- 2-Arylamino-6-ethynylpurines are cysteine-targeting irreversible inhibitors of Nek2 kinase
-
Renewed interest in covalent inhibitors of enzymes implicated in disease states has afforded several agents targeted at protein kinases of relevance to cancers. We now report the design, synthesis and biological evaluation of 6-ethynylpurines that act as covalent inhibitors of Nek2 by capturing a cysteine residue (Cys22) close to the catalytic domain of this protein kinase. Examination of the crystal structure of the non-covalent inhibitor 3-((6-cyclohexylmethoxy-7H-purin-2-yl)amino)benzamide in complex with Nek2 indicated that replacing the alkoxy with an ethynyl group places the terminus of the alkyne close to Cys22 and in a position compatible with the stereoelectronic requirements of a Michael addition. A series of 6-ethynylpurines was prepared and a structure activity relationship (SAR) established for inhibition of Nek2. 6-Ethynyl-N-phenyl-7H-purin-2-amine [IC50 0.15 μM (Nek2)] and 4-((6-ethynyl-7H-purin-2-yl)amino)benzenesulfonamide (IC50 0.14 μM) were selected for determination of the mode of inhibition of Nek2, which was shown to be time-dependent, not reversed by addition of ATP and negated by site directed mutagenesis of Cys22 to alanine. Replacement of the ethynyl group by ethyl or cyano abrogated activity. Variation of substituents on the N-phenyl moiety for 6-ethynylpurines gave further SAR data for Nek2 inhibition. The data showed little correlation of activity with the nature of the substituent, indicating that after sufficient initial competitive binding to Nek2 subsequent covalent modification of Cys22 occurs in all cases. A typical activity profile was that for 2-(3-((6-ethynyl-9H-purin-2-yl)amino)phenyl)acetamide [IC50 0.06 μM (Nek2); GI50 (SKBR3) 2.2 μM] which exhibited >5-10-fold selectivity for Nek2 over other kinases; it also showed > 50% growth inhibition at 10 μM concentration against selected breast and leukaemia cell lines. X-ray crystallographic analysis confirmed that binding of the compound to the Nek2 ATP-binding site resulted in covalent modification of Cys22. Further studies confirmed that 2-(3-((6-ethynyl-9H-purin-2-yl)amino)phenyl)acetamide has the attributes of a drug-like compound with good aqueous solubility, no inhibition of hERG at 25 μM and a good stability profile in human liver microsomes. It is concluded that 6-ethynylpurines are promising agents for cancer treatment by virtue of their selective inhibition of Nek2. This journal is
- Bayliss, Richard,Boxall, Kathy,Carbain, Benoit,Coxon, Christopher R.,Fry, Andrew M.,Golding, Bernard T.,Griffin, Roger J.,Hardcastle, Ian R.,Harnor, Suzannah J.,Mas-Droux, Corine,Matheson, Christopher J.,Newell, David R.,Richards, Mark W.,Sivaprakasam, Mangaleswaran,Turner, David,Cano, Céline
-
supporting information
p. 707 - 731
(2020/08/24)
-
- Rhodium-catalyzed oxygenative [2 + 2] cycloaddition of terminal alkynes and imines for the synthesis of β-lactams
-
A rhodium-catalyzed oxygenative [2 + 2] cycloaddition of terminal alkynes and imines has been developed, which gives β-lactams as products with high trans diastereoselectivity. In the presence of a Rh(I) catalyst and 4-picoline N-oxide, a terminal alkyne is converted to a rhodium ketene species via oxidation of a vinylidene complex and subsequently undergoes a [2 + 2] cycloaddition with an imine to give rise to the 2-azetidinone ring system. Mechanistic studies suggest that the reaction proceeds through a metalloketene rather than free ketene intermediate. The new method taking advantage of catalytic generation of a ketene species directly from a terminal alkyne provides a novel and efficient entry to the Staudinger synthesis of β-lactams under mild conditions.
- Kim, Insu,Roh, Sang Weon,Lee, Dong Gil,Lee, Chulbom
-
supporting information
p. 2482 - 2485
(2014/05/20)
-
- Initial process development and scale-up of the synthesis of a triple reuptake inhibitor ALB 109780
-
Early process development toward a triple reuptake inhibitor is described. Three different routes were evaluated; one of them was optimized and scaled up to generate 470 g of API as this route minimized the formation of undesired side products. The select
- Yang, Qiang,Ulysse, Luckner G.,McLaws, Mark D.,Keefe, Daniel K.,Haney, Brian P.,Zha, Congxiang,Guzzo, Peter R.,Liu, Shuang
-
scheme or table
p. 499 - 506
(2012/08/08)
-
- METHODS OF USING SEMI-SYNTHETIC GLYCOPEPTIDES AS ANTIBACTERIAL AGENTS
-
Methods of using semi-synthetic glycopeptides of formula I-XIV having antibacterial activity are described.
- -
-
Page/Page column 99; 100
(2011/11/30)
-
- Process development and pilot-scale synthesis of new cyclization conditions of substituted phenylacetamides to tetrahydroisoquinoline-2-ones using Eaton's reagent
-
Tetrahydroisoquinoline is a ubiquitous structural framework presented in numerous pharmacologically relevant molecules. Although accessible by the Pictet-Spengler cyclization, conditions commonly used for such cyclizations are often difficult to implement on scale. Herein, we report the development of a scaleable approach utilizing Eaton's reagent for the cyclization of substituted phenylacetamide analogues to tetrahydroisoquinoline-2-one. The development, optimization, and safety hazard evaluations, which outline the benefits and ease of workup of this new process, are discussed.
- Ulysse, Luckner G.,Yang, Qiang,McLaws, Mark D.,Keefe, Daniel K.,Guzzo, Peter R.,Haney, Brian P.
-
experimental part
p. 225 - 228
(2010/04/29)
-
- Anticonvulsant activity of some 4-aminophenylacetamides
-
A series of 4-aminophenylacetamides was prepared and evaluated for anticonsulvant activity. These compounds were prepared during studies designed to determine the relationship between benzamide-like compounds and anticonsulvant effects. Unlike benzamides, these phenylacetamides have a methylene group between the aromatic ring and the amide carbonyl. Consequently, formal conjugation is lost, and the number of conformational degrees of freedom has increased. The compounds were tested in mice against seizures induced by electroshock and pentylenetetrazol, and in the rotorod assay for neurologic deficit. The more active and selective anticonsulvants prepared in this study were those having an additional aromatic ring as part of the substituent on the amide nitrogen. Compound 16, the 4-aminophenylacetamide derived from 2,6-dimethylaniline, was the most potent compound observed (ED50 = 50.50 mg/kg against electroshock-induced convulsions and ED50 = 93.20 mg/kg against pentylenetetrazol-induced convulsions).
- Clark,Davenport
-
-