Drug to Genome to Drug: Discovery of New Antiplasmodial Compounds
摘要:
The dominant strategy for discovery of new antimalarial drugs relies on cell-free assays on specific biochemical pathways of Plasmodium falciparum . However, it appears that screening directly on the parasite is a more rewarding approach. The "drug to genome to drug" approach consists of testing a small set of structural analogues of a drug acting on human proteins that have plasmodial orthologues. Both man and plasmodium possess cyclic nucleotide phosphodiesterases (PDEs) that are key players of cell homeostasis. We synthesized and tested 40 analogues of tadalafil, a human PDE5 inhibitor, on P. falciparum in culture and obtained potent inhibitors of parasite growth. We discuss the structure-activity relationships, which support the hypothesis that our compounds kill the parasite via inhibition of plasmodial PDE activity. We also prove that antiplasmodial derivatives inhibit the hydrolysis of cyclic nucleotides of the parasite, validating the cAMP/cGMP pathways as therapeutic targets against Plasmodium falciparum .
5,5-Dimethylproline dipeptides: an acid-stable class of pseudoproline
摘要:
Commercially available Fmoc-protected L-amino acids were employed and coupled to L-allylglycine. Cross metathesis with 2-methyl-2-butene using second generation Grubbs' catalyst gave L-prenylglycine-containing dipeptides. Treatment with trifluoromethanesulfonic acid resulted in cyclisation and subsequent formation of acid-stable 5,5-dimethyl-L-proline dipeptides for direct insertion into linear peptide sequences. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.
Synthesis of 1,2,4-oxadiazole-linked orthogonally urethane-protected dipeptide mimetics
作者:Vommina V. Sureshbabu、Hosahalli P. Hemantha、Shankar A. Naik
DOI:10.1016/j.tetlet.2008.06.091
日期:2008.8
The synthesis of a new class of 1,2,4-oxadiazole-linked orthogonally urethane-protected dipeptide mimetics is described. The protocol employs a reaction between an N-protected amino acyl fluoride and an amino acid-derived amidoxime. All the three commonly employed urethanes have been used in this protocol for N-protection. The course of the reaction was found to be high yielding and all new compounds were well characterized by NMR and mass spectroscopy. The C-acyl amidoxime intermediate has also been isolated as a stable solid. (C) 2008 Elsevier Ltd. All rights reserved.