Inhibitors of N α-acetyl-l-ornithine deacetylase: synthesis, characterization and analysis of their inhibitory potency

• DOI: 10.1007/s00726-009-0326-8
• Publication Date: 2009-08-01T15:35:37Z
• Authors: J. Hlaváček; J. Pícha; V. Vaněk; J. Jiráček; J. Slaninová; V. Fučík; M. Buděšínský; D. Gilner; R. C. Holz
• Keywords: Ornithine; Spectrometry, Mass, Electrospray Ionization; Magnetic Resonance Spectroscopy; synthesis; 572; Microbial Sensitivity Tests; Amidohydrolases; 03 medical and health sciences; acetylornithine derivatives; Enzyme Inhibitors; Phosgene; Chromatography, High Pressure Liquid; 0303 health sciences; Molecular Structure; Escherichia coli Proteins; inhibitory and antibacterial activity; Anti-Bacterial Agents; Molecular Weight; Chemistry; Kinetics; ArgE inhibitors; Drug Design; Polystyrenes; Bacillus subtilis

A series of N (alpha)-acyl (alkyl)- and N (alpha)-alkoxycarbonyl-derivatives of L- and D-ornithine were prepared, characterized, and analyzed for their potency toward the bacterial enzyme N (alpha)-acetyl-L-ornithine deacetylase (ArgE). ArgE catalyzes the conversion of N (alpha)-acetyl-L-ornithine to L-ornithine in the fifth step of the biosynthetic pathway for arginine, a necessary step for bacterial growth. Most of the compounds tested provided IC(50) values in the muM range toward ArgE, indicating that they are moderately strong inhibitors. N (alpha)-chloroacetyl-L-ornithine (1g) was the best inhibitor tested toward ArgE providing an IC(50) value of 85 microM while N (alpha)-trifluoroacetyl-L-ornithine (1f), N (alpha)-ethoxycarbonyl-L-ornithine (2b), and N (alpha)-acetyl-D-ornithine (1a) weakly inhibited ArgE activity providing IC(50) values between 200 and 410 microM. Weak inhibitory potency toward Bacillus subtilis-168 for N (alpha)-acetyl-D-ornithine (1a) and N (alpha)-fluoro- (1f), N (alpha)-chloro- (1g), N (alpha)-dichloro- (1h), and N (alpha)-trichloroacetyl-ornithine (1i) was also observed. These data correlate well with the IC(50) values determined for ArgE, suggesting that these compounds might be capable of getting across the cell membrane and that ArgE is likely the bacterial enzymatic target.