ABSTRACT
Herein we describe the development of an efficient one-pot regioselective synthesis protocol to obtain N-protected or N-deprotected 1,5-diaryl-3-amino-1,2,4-triazoles from N-acyl-N-Boc-carbamidothioates. This improved protocol using microwave irradiation and low reaction times (up to 1 h) furnished desired compounds in yields ranging from 50 to 84%. This chemistry is useful for a variety of aromatic groups with electronically diverse substituents. The design and correct derivation of the amino group led to compounds able to inhibit cholinesterases with good IC50 of up to 1 µM. Also, the mode of action (mixed-type) and SAR analysis for this series of compounds was described by means of kinetic and molecular modelling evaluations, showing potential for this class of compounds as new scaffolds for this biological activity.
ABSTRACT
Trypanothione disulfide (T[S]2), an unusual form of glutathione found in parasitic protozoa, plays a crucial role in the regulation of the intracellular thiol redox balance and in the defense against oxidative stress. Trypanothione reductase (TR) is central to the thiol metabolism in all trypanosomatids, including the human pathogens Trypanosoma cruzi, Trypanosoma brucei and Leishmania. Here we report the cloning, sequencing and expression of the TR encoding gene from L. (L.) amazonensis. Multiple protein sequence alignment of all known trypanosomatid TRs highlights the high degree of conservation and illustrates the phylogenetic relationships. A 3D homology model for L. amazonensis TR was constructed based on the previously reported Crithidia fasciculata structure. The purified recombinant TR shows enzyme activity and in vivo expression of the native enzyme could be detected in infective promastigotes, both by Western blotting and by immunofluorescence.
