ATP competitive inhibitors of d-alanine–d-alanine ligase based on protein kinase inhibitor scaffolds
作者:Gemma Triola、Stefan Wetzel、Bernhard Ellinger、Marcus A. Koch、Katja Hübel、Daniel Rauh、Herbert Waldmann
DOI:10.1016/j.bmc.2008.02.046
日期:2009.2
D-Alanine-D-alanine ligase (DDl) is an essential enzyme in bacterial cell wall biosynthesis and an important target for developing new antibiotics. Here, we describe a new approach to identify new inhibitor scaffolds for DDl based on similarity in the ATP binding region of different kinases and DDl. After an initial screening of several protein kinase inhibitors, we found that the Brutons's tyrosine kinase inhibitor LFM-A13, an analog of the Leflunomide metabolite A771726, inhibits DDl with a K-i of 185 mu M. A series of malononitrilamide and salicylamide derivatives of LFM-A13 has been synthesized to confirm the validity of this scaffold as an inhibitor of DDl. (C) 2008 Elsevier Ltd. All rights reserved.
The title compound, C11H8Br2N2O2 (LFM-A13), is the first reported BTK-specific tyrosine kinase inhibitor and the first antileukemic agent targeting BTK (Bruton's tyrosine kinase). The crystal structure showed that the molecule adopts an approximately planar conformation aided by an intramolecular hydrogen bond formed between the hydroxyl group and the amide carbonyl group. The dihedral angle between the phenyl ring and the plane defined by the N-C-C=C-CH3 group is 8.2(6)degrees. The crystal packing shows an additional weak intermolecular hydrogen bond between the hydroxyl group and the amide carbonyl-O atom of the centrosymmetrically related molecule.