Antitrypanosomal activities and cytotoxicity of 5-nitro-2-furancarbohydrazides
摘要:
A series of 5-nitro-2-furancarbohydrazides were synthesized. In vitro antitrypanosomal activities of these compounds were determined against the closely related protozoa Trypanosoma cruzi Trypanosoma brucei and discussed in relation to potential targets. (C) 2002 Elsevier Science Ltd. All rights reserved.
A series of 5-nitro-2-furancarbohydrazides were synthesized. In vitro antitrypanosomal activities of these compounds were determined against the closely related protozoa Trypanosoma cruzi Trypanosoma brucei and discussed in relation to potential targets. (C) 2002 Elsevier Science Ltd. All rights reserved.
Synthesis of 5-Nitro-2-furancarbohydrazides and Their <i>cis</i>-Diamminedichloroplatinum Complexes as Bitopic and Irreversible Human Thioredoxin Reductase Inhibitors
The human selenoprotein thioredoxin reductase is involved in antioxidant defense and DNA synthesis. As increased thioredoxin reductase levels are associated with drug sensitivity to cisplatin and drug resistance in tumor cells, this enzyme represents a promising target for the development of cytostatic agents. To optimize the potential of the widely used cisplatin to inhibit the human thioredoxin reductase and therefore to overcome cisplatin resistance, we developed and synthesized four cis-diamminedichloroplatinum complexes of the lead 5-nitro-2-furan-carbohydrazide 8 selected from high-throughput screening. Detailed kinetics revealed that the isolated fragments, 5-nitro-2-furancarbohydrazide and cisplatin itself, bind with micromolar affinities at two different subsites of the human enzyme. By tethering both fragments four nitrofuran-based cis-diamminedichloroplatinum complexes 13a-c and 20 were synthesized and identified as biligand irreversible inhibitors of the human enzyme with nanomolar affinities. Studies with mutant enzymes clearly demonstrate the penultimate selenocysteine residue as the prime target of the synthesized cis-diamminedichloroplatinum complexes.