Pergamon Bioorganic & Medicinal Chemistry Letters, Vol. 7, No. 17, pp. 2181-2186, 1997 © 1997 ElsevierScienceLtd All rights reserved. Printed in Great Britain 0960-894X/97 $17,00 + 0.00 PII: S0960-894X(97)00394-6 STRUCTURE-BASED DESIGN OF NON-PEPTIDIC PYRIDONE ALDEHYDES AS 1NHIBITORS OF INTERLEUKIN-113 CONVERTING ENZYME. Julian M. C. Golec,* §, Michael D. Mullican,*t Mark A. Murcko, t Keith P. Wilson, t David P. Kay, § Stuart D. Jones, § Robert Murdoch, § Guy W. Bemis, t Scott A. Raybuck, t Yu-Ping Luong, t and David J. Livingstont Vertex Pharmaceuticals Inc., 130 Waverly Street, Cambridge MA, USA 02139-4211 § Roussel Laboratories Ltd., Kingfisher Drive, Swindon, UK SN3 5BZ a Abstract. Pyridone derivatives, especially with 6-aryl substituents, have been shown to be useful P2-P3 peptidomimetic scaffolds for the design of potent inhibitors of ICE. © 1997 Elsevier Science Ltd. lnterleukin-1 [3 (IL-1 ~) is an important mediator in inflammatory and infectious diseases. 1 Interleukin- 113 converting enzyme (ICE; caspase-1), which cleaves its substrates at aspartic acid, converts the inactive form of IL- 1 ~ to its mature form.2, 3 Thus, ICE offers an opportunity for the development of small molecules able to disrupt specifically the production of this cytokine as novel antiinflammatory agents. Prototype ICE inhibitors have been shown to block type lI collagen induced arthritis in mice, acute inflammation and pyrexia.4, 5 ICE- deficient mice are resistant to endotoxic shock, showing reduced secretion of IL-I~ as well as IL-I ~.6 Recently, ICE has been shown to activate IGIF, a potent inducer of interferon-? (IFN-?).7 Mice lac ng IFN-? or its receptor are also resisitant to endotoxic shock indicating that ICE may have additional mechanisms by which it may exert proinflammatory effects.7, 8 Although, a number of peptide-based ICE inhibitors have been reported, these compounds are likely to suffer from poor oral bioavailability and rapid clearance. 9 The results of N-methyl scans 10 and X-ray crystallography data of ICE complexed with inhibitors 1 l revealed that ICE binds substrates and active site inhibitors through hydrogen bonds between the enzyme backbone and P1-NH, P3-NH, and P3 C=O in a manner similar to serine proteases of the chymotrypsin superfamily. By substituting the P3 amino acid with a pyridone or pyrimidone containing lipophilic groups at the 6-position to access the S 2 pocket, researchers at Zeneca converted a peptide-based inhibitor of elastase into a series of potent inhibitors with little peptidic character. 12 In direct analogy to the elastase inhibitors 1 and 2, a series of pyrimidone and pyridone based ICE inhibitors 3 has been reported. 13 We report the results of our exploration of the S 2 pocket in ICE from the 6-position of the 3-aminopyrid-2-ones. o ,sX"-r~R20 1 X=C 2X=N x.. R2 CO2H o ,c'\y o 3 X = N, R = 2,6-dichlorobenzoyl 4 × = CH, R = phenyl aCurrent addresses: Julian M. C. Golec, Xenova Ltd., 240 Bath Road, Slough, Berkshire, SLI 4EF UK. David P. Kay, Biocompatibles Ltd., Frensham House, Farnham Business Park, Weydon Lane, Farnham, Surrey, GU9 8QL, UK. Robert Murdoch, Receptor Research Ltd., Unit 5 Cory Close, Wainhouse Corner, Bude, Cornwall, EX23 OAR,UK Stuart D. Jones, Proteus Molecular Design Ltd.. Proteus House, Lyme Green, Business Park, Macclesfield,Cheshire, SKI 1 0JL, UK. 2181