Lead compound 1 was successfully redesigned to provide compounds with improved pharmacokinetic profiles for this series of human urotensin-II antagonists. Replacement of the 2-pyrrolidinylmethyl-3-phenyl-piperidine core of 1 with a substituted N-methyl-2-(1-pyrrolidinyl)ethanamine core as in compound 7 resulted in compounds with improved oral bioavailability in rats. The relationship between stereochemistry and selectivity for hUT over the kappa-opioid receptor was also explored.

This work describes the development of potent and selective human Urotensin-II receptor antagonists starting from lead compound 1, (3,4-dichlorophenyl)methyl{2-oxo-2-[3-phenyl-2-(1-pyrrolidinylmethyl)-1-piperidinyl]ethyl}amine. Several problems relating to oral bioavailability, cytochrome P450 inhibition, and off-target activity at the kappa opioid receptor and cardiac sodium channel were addressed during lead development. hUT binding affinity relative to compound 1 was improved by more than 40-fold in some analogs, and a structural modification was identified which significantly attenuated both off-target activities.

In our continuing efforts to identify small molecule vitronectin receptor antagonists, we have discovered a series of phenylbutyrate derivatives, exemplified by 16, which have good potency and excellent oral bioavailability (approximately 100% in rats). This new series is derived conceptually from opening of the seven-membered ring of SB-265123.

ABSTRACT Bacterial enoyl-acyl carrier protein (ACP) reductase (FabI) catalyzes the final step in each elongation cycle of bacterial fatty acid biosynthesis and is an attractive target for the development of new antibacterial agents. High-throughput screening of the Staphylococcus aureus FabI enzyme identified a novel, weak inhibitor with no detectable antibacterial activity against S. aureus. Iterative medicinal chemistry and X-ray crystal structure-based design led to the identification of compound 4 [(E)-N-methyl-N-(2-methyl-1H-indol-3-ylmethyl)-3-(7-oxo-5,6,7,8-tetrahydro-1,8-naphthyridin-3-yl)acrylamide], which is 350-fold more potent than the original lead compound obtained by high-throughput screening in the FabI inhibition assay. Compound 4 has exquisite antistaphylococci activity, achieving MICs at which 90% of isolates are inhibited more than 500 times lower than those of nine currently available antibiotics against a panel of multidrug-resistant strains of S. aureus and Staphylococcus epidermidis. Furthermore, compound 4 exhibits excellent in vivo efficacy in an S. aureus infection model in rats. Biochemical and genetic approaches have confirmed that the mode of antibacterial action of compound 4 and related compounds is via inhibition of FabI. Compound 4 also exhibits weak FabK inhibitory activity, which may explain its antibacterial activity against Streptococcus pneumoniae and Enterococcus faecalis, which depend on FabK and both FabK and FabI, respectively, for their enoyl-ACP reductase function. These results show that compound 4 is representative of a new, totally synthetic series of antibacterial agents that has the potential to provide novel alternatives for the treatment of S. aureus infections that are resistant to our present armory of antibiotics.

Bacterial enoyl-ACP reductase (FabI) catalyzes the final step in each cycle of bacterial fatty acid biosynthesis and is an attractive target for the development of new antibacterial agents. Our efforts to identify potent, selective FabI inhibitors began with screening of the GlaxoSmithKline proprietary compound collection, which identified several small-molecule inhibitors of Staphylococcus aureus FabI. Through a combination of iterative medicinal chemistry and X-ray crystal structure based design, one of these leads was developed into the novel aminopyridine derivative 9, a low micromolar inhibitor of FabI from S. aureus (IC(50) = 2.4 microM) and Haemophilus influenzae (IC(50) = 4.2 microM). Compound 9 has good in vitro antibacterial activity against several organisms, including S. aureus (MIC = 0.5 microg/mL), and is effective in vivo in a S. aureus groin abscess infection model in rats. Through FabI overexpressor and macromolecular synthesis studies, the mode of action of 9 has been confirmed to be inhibition of fatty acid biosynthesis via inhibition of FabI. Taken together, these results support FabI as a valid antibacterial target and demonstrate the potential of small-molecule FabI inhibitors for the treatment of bacterial infections.

1,4-Disubstituted imidazole inhibitors of Staphylococcus aureus and Escherichia coli enoyl acyl carrier protein reductase (FabI) have been identified. Crystal structure data shows the inhibitor 1 bound in the enzyme active site of E. coli FabI.

ADVERTISEMENT RETURN TO ISSUEPREVLetterNEXTDiscovery of Orally Active Nonpeptide Vitronectin Receptor Antagonists Based on a 2-Benzazepine Gly-Asp MimeticWilliam H. Miller, Doreen P. Alberts, Pradip K. Bhatnagar, William E. Bondinell, James F. Callahan, Raul R. Calvo, Russell D. Cousins, Karl F. Erhard, Dirk A. Heerding, Richard M. Keenan, Chet Kwon, Peter J. Manley, Kenneth A. Newlander, Stephen T. Ross, James M. Samanen, Irene N. Uzinskas, Joseph W. Venslavsky, Catherine C.-K. Yuan, R. Curtis Haltiwanger, Maxine Gowen, Shing-Mei Hwang, Ian E. James, Michael W. Lark, David J. Rieman, George B. Stroup, Leonard M. Azzarano, Kevin L. Salyers, Brian R. Smith, Keith W. Ward, Kyung O. Johanson, and William F. HuffmanView Author Information Research & Development Division, SmithKline Beecham Pharmaceuticals, 1250 South Collegeville Road, P.O. Box 5089, Collegeville, Pennsylvania 19426-0989, and 709 Swedeland Road, P.O. Box 1539, King of Prussia, Pennsylvania 19406-0939 Cite this: J. Med. Chem. 2000, 43, 1, 22–26Publication Date (Web):December 23, 1999Publication History Received30 August 1999Published online23 December 1999Published inissue 1 January 2000https://pubs.acs.org/doi/10.1021/jm990446uhttps://doi.org/10.1021/jm990446urapid-communicationACS PublicationsCopyright © 2000 American Chemical SocietyRequest reuse permissionsArticle Views1485Altmetric-Citations102LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Amides,Antagonists,Assays,Bioavailability,Rodent models Get e-Alerts

An efficient solid phase regioselective alkylation at the N4 positionof a 3-oxo-1,4-benzodiazepine template exemplified by 4-H-2,3,4,5-tetrahydro-7-iodo-3-oxo-1H-1,4-benzodiazepine-2-acetate-polymerester is described. Further chemical elaboration atposition 7, utilizing a modified Heck reaction, allows the incorporationof amides from primary or secondary amines. The two diversity points atpositions 4 and 7 were utilized tosynthesize a 28-membered, combinatorial array on Sasrin® resin in moderate yields and >80% purity. Having validated the chemistry on solid support, acombine and splitapproach to prepare a bead-bound combinatorial library is achievableutilizing similar experimental practices and procedures as in thearray synthesis.

A peptide RGD analog containing a novel 2-aminopyridine arginine mimetic was discovered to have good affinity and selectivity for the vitronectin receptor. Incorporation of the 2-aminopyridine arginine mimetic into the 3-oxo-1,4-benzodiazepine-2-acetic acid integrin antagonist series led to novel and potent nonpeptide vitronectin receptor antagonists with promising levels of oral bioavailability.

In a 3-oxo-1,4-benzodiazepine-2-acetic acid series of vitronectin receptor (alpha v beta 3) antagonists containing a benzimidazole as a novel arginine mimetic, we examined the effects of benzimidazole modifications and amide substitutions on both activity and pharmacokinetics.

In the 3-oxo-1,4-benzodiazepine-2-acetic acid series of vitronectin receptor (αvβ3) antagonists, a compound containing an imidazopyridine arginine mimetic was discovered which had sufficient potency and iv pharmacokinetics for demonstration of efficacy in a rat restenosis model.

An alternate enantiospecific synthesis of methyl (S)-7-tert-butoxycarbonyl-2,3,4,5-tetrahydro-4-methyl-3-oxo-1H-1,4-benzodiazepine-2-acetate (5) is reported. The key step, which involves an intermolecular displacement of the activated aryl fluoride (9) by L-aspartic acid β-methyl ester, proceeds without racemization.

In an investigation of the contribution of N-1 to the binding, antiaggregatory, and oral activity in 3-oxo-1,4-benzodiazepine-2-acetic acid based GPIIb/IIIa antagonists, a series of 2-benzazepine analogs, wherein N-1 of the 1,4-benzodiazepine nucleus has been replaced by a methylene group, was examined.