Document Report Card

ID: ALA1156268

Journal: J Med Chem

Title: Michael acceptor based antiplasmodial and antitrypanosomal cysteine protease inhibitors with unusual amino acids.

Authors: Breuning A, Degel B, Schulz F, Büchold C, Stempka M, Machon U, Heppner S, Gelhaus C, Leippe M, Leyh M, Kisker C, Rath J, Stich A, Gut J, Rosenthal PJ, Schmuck C, Schirmeister T.

Abstract: New peptidic Michael acceptor based cysteine protease inhibitors displaying antiparasitic activity were identified by testing a broad series of 45 compounds in total, containing Asn, Gln, or Phe. As target enzymes, falcipain-2 and -3 from P. falciparum and rhodesain from T. b. rhodesiense were used. In the case of the Asn/Gln containing compounds, the trityl-protected, diastereomeric E-configured vinylogous dipeptide esters 16 (Boc-(S)-Phg-(R/S)-vGln(Trt)-OEt) were discovered as most active inhibitors concerning both protease inhibition and antiparasitic acitivity, with inhibition constants in the submicromolar range. The compounds were shown to display time-dependent and competitive inhibition. In the case of the Phe containing compounds, the maleic acid derivatives 42 and 43 (BnO-Phe<--Mal-Phe-OBn, BnO-Phe<--Mal-Phe-Ala-OBn, Mal = maleic acid) displayed good inhibition of rhodesain as well as good antitrypanosomal activity, while the fumaric acid derived E-analogue 14 (BnO-Phe<--Fum-Phe-OBn) only displayed inhibition of the target enzymes but no antiparasitic activity. Inhibition by these Phe derivatives was shown to be time-independent and competitive.

CiteXplore: 20131843

DOI: 10.1021/jm900946n