Twelve compounds (100 mu M) had a predicted log P between -0.5 and -3.0 and inhibited AHAS activity by >40%. CE, IQ, and SMM showed dose-dependent inhibition of Bacillus anthracis AHAS (BAntx AHAS) with IC50 values of 7.01 +/- 0.81, 6.97 +/- 0.44, and 10.02 +/- 11.42 mu M, respectively. CE and IQ were noncompetitive and uncompetitive inhibitors of BAntx AHAS with K-u values of 3.77 and 2.02, respectively. The order of potency towards BAntx AHAS was CE > PSE > MSM > TSM > SIAM for sulfonylureas and IQ> Imazapic > IP for imidazolinones. The most active compound, CE, showed the lowest total interaction energy and highest MolDock score of -140.054 kcal/mol and -141.52, respectively. Three hydrogen bonds were identified between BAntxAHAS and CE. AHAS appears to be a promising potential target for new anti-anthracis drugs. (C) 2008 Elsevier Inc. All rights reserved.