Structure-based organic synthesis of unnatural aeruginosin hybrids as potent inhibitors of thrombin

Based on X-ray crystallographic data of complexes of chlorodysinosin A with the enzyme thrombin, a series of analogs were synthesized varying the nature of the P-1, P-2, and P-3 pharmacophoric sites and the central octahydroindole carboxyamide core. In general, introduction of a hydrophobic substituent on the D-leucine amide residue dramatically improved the inhibition of the enzyme. This is rationalized based on a better fit of the P-3 subunit in the hydrophobic S-3 enzyme site. Single digit nanomolar inhibition expressed as IC50 was observed for several analogs. (c) 2007 Elsevier Ltd. All rights reserved.