Esteban Ravaschino - Academia.edu (original) (raw)
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Papers by Esteban Ravaschino
Arkivoc, 2003
Glutathionylspermidine synthase (GSS) is a crucial enzyme in the trypanothione biosynthetic pathw... more Glutathionylspermidine synthase (GSS) is a crucial enzyme in the trypanothione biosynthetic pathway and is also an interesting molecular target for drug design. We synthesized a series of amides of a glutathione analogue (L-γ-Glu-L-Leu-Gly-NHR) where R are linear alkyl groups. All of these drugs exhibited marginal biological activity against the responsible agent of Chagas' disease, the protozoan Trypanosoma cruzi.
Journal of Medicinal Chemistry, 2006
As a part of our project aimed at the search for new safe chemotherapeutic and chemoprophylactic ... more As a part of our project aimed at the search for new safe chemotherapeutic and chemoprophylactic agents against American trypanosomiasis (Chagas's disease), a series of phosphinopeptides structurally related to glutathione was designed, synthesized, and evaluated as antiproliferative agents against the parasite responsible for this disease, the hemoflagellated protozoan Trypanosoma cruzi. The rationale for the synthesis of these compounds was supported on the basis that the presence of the phosphinic acid moiety would mimic the tetrahedral transition state of trypanothione synthase (TryS), a typical C:N ligase, and the molecular target of these drugs. Of the designed compounds, 53 and 54 were potent growth inhibitors against the clinically more relevant form of T. cruzi (amastigotes) growing in myoblasts. The efficacy for these drugs was comparable to that exhibited by the well-known antiparasitic agent WC-9. The simple phosphinopeptide structure found as a pharmacophore in the present study constitutes a starting point for the development of straightforward optimized drugs.
Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto
Resumen es: Como toda ciencia basica, la quimica, en su antiguedad y amplitud, nos inhibe de iden... more Resumen es: Como toda ciencia basica, la quimica, en su antiguedad y amplitud, nos inhibe de identificar su origen exacto, tanto asociado a una civilizacion en parti...
Quimica Viva, 2011
Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto
Quimica Viva, 2007
Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto
Journal of Medicinal Chemistry, 2006
Cheminform, 2006
For Abstract see ChemInform Abstract in Full Text.
Current Medicinal Chemistry, 2006
The progresses made in the field of drug design to combat tropical protozoan parasitic diseases, ... more The progresses made in the field of drug design to combat tropical protozoan parasitic diseases, such as Chagas' disease, leishmaniasis, and sleeping sickness are discussed. This article is focused on different approaches based on unique aspects of parasites biochemistry and physiology, selecting the more promising molecular targets for drug design. In spite of the enormous amount of work on the above features, the chemotherapy for all of these diseases remains unsolved. It is based on old and fairly not specific drugs associated, in several cases, with long-term treatments and severe side effects. Drug resistance and different strains susceptibility are further drawbacks of the existing chemotherapy. In this review article, a thorough analysis of selected molecular targets, mainly those that are significantly different compared with the mammalian host or, even, are not present in mammals would be described in terms of their potencial usefulness for drug design. Therefore, this article covers rational approaches to the chemotherapeutic control of these parasitic infections, such as the progresses in the search for novel metabolic pathways in parasites that may be essential for parasites survival but with no counterpart in the host. Ergosterol biosynthesis is a very interesting example. There are many enzymes involved in this biosynthetic pathway such us squalene synthase, farnesylpyrophosphate synthase, and other enzymes that are able to deplete endogenous sterols will be treated in this article. The enzymes involved in trypanothione biosynthesis, glutathionyl spermidine synthetase and trypanothione synthetase do not have an equivalent in mammals, and therefore it can be predicted low toxicity for compounds that are able to produce highly selective inhibition. Trypanothione reductase (TR), glyceraldehyde-3-phosphate dehydrogenase, dihydrofolate reductase, prenyltransferases, ornithine decarboxylase, etc, will be thoroughly analyzed. The design of specific inhibitors of such metabolic activities as possible means of controlling the parasites without damaging the hosts will be presented. The recent advances in the biochemistry of pathogenic parasites including the discovery of novel organelles will be discussed.
Journal of Medicinal Chemistry, 2006
Bioorganic & Medicinal Chemistry Letters, 2005
We have investigated the effect of a series of 1-amino-1,1-bisphosphonates derived from fatty aci... more We have investigated the effect of a series of 1-amino-1,1-bisphosphonates derived from fatty acids against proliferation of the clinically more relevant form of Trypanosoma cruzi, the causative agent of American trypanosomiasis (Chagas' disease). Some of these drugs were potent inhibitors against the intracellular form of the parasite, exhibiting IC50 values at low micromolar level. Cellular activity was associated with the inhibition of enzymatic activity of T. cruzi farnesyl pyrophosphate synthase. As bisphosphonate-containing drugs are FDA-approved for the treatment of bone resorption disorders, their potential innocuousness makes them good candidates to control tropical diseases.
Bioorganic & Medicinal Chemistry Letters, 2002
Glutathionylspermidine synthetase/amidase (GspS) is an essential enzyme in the biosynthesis and t... more Glutathionylspermidine synthetase/amidase (GspS) is an essential enzyme in the biosynthesis and turnover of trypanothione and represents an attractive target for the design of selective anti-parasitic drugs. We synthesised a series of analogues of glutathione (l-g-Glu-l-Leu-Gly-X) where the glycine carboxylic acid group (X) has been substituted for other acidic groups such as tetrazole, hydroxamic acid, acylsulphonamide and boronic acid. The boronic acid appears the most promising lead compound (IC 50 of 17.2 mM). #
Arkivoc, 2003
Glutathionylspermidine synthase (GSS) is a crucial enzyme in the trypanothione biosynthetic pathw... more Glutathionylspermidine synthase (GSS) is a crucial enzyme in the trypanothione biosynthetic pathway and is also an interesting molecular target for drug design. We synthesized a series of amides of a glutathione analogue (L-γ-Glu-L-Leu-Gly-NHR) where R are linear alkyl groups. All of these drugs exhibited marginal biological activity against the responsible agent of Chagas' disease, the protozoan Trypanosoma cruzi.
Journal of Medicinal Chemistry, 2006
As a part of our project aimed at the search for new safe chemotherapeutic and chemoprophylactic ... more As a part of our project aimed at the search for new safe chemotherapeutic and chemoprophylactic agents against American trypanosomiasis (Chagas's disease), a series of phosphinopeptides structurally related to glutathione was designed, synthesized, and evaluated as antiproliferative agents against the parasite responsible for this disease, the hemoflagellated protozoan Trypanosoma cruzi. The rationale for the synthesis of these compounds was supported on the basis that the presence of the phosphinic acid moiety would mimic the tetrahedral transition state of trypanothione synthase (TryS), a typical C:N ligase, and the molecular target of these drugs. Of the designed compounds, 53 and 54 were potent growth inhibitors against the clinically more relevant form of T. cruzi (amastigotes) growing in myoblasts. The efficacy for these drugs was comparable to that exhibited by the well-known antiparasitic agent WC-9. The simple phosphinopeptide structure found as a pharmacophore in the present study constitutes a starting point for the development of straightforward optimized drugs.
Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto
Resumen es: Como toda ciencia basica, la quimica, en su antiguedad y amplitud, nos inhibe de iden... more Resumen es: Como toda ciencia basica, la quimica, en su antiguedad y amplitud, nos inhibe de identificar su origen exacto, tanto asociado a una civilizacion en parti...
Quimica Viva, 2011
Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto
Quimica Viva, 2007
Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto
Journal of Medicinal Chemistry, 2006
Cheminform, 2006
For Abstract see ChemInform Abstract in Full Text.
Current Medicinal Chemistry, 2006
The progresses made in the field of drug design to combat tropical protozoan parasitic diseases, ... more The progresses made in the field of drug design to combat tropical protozoan parasitic diseases, such as Chagas' disease, leishmaniasis, and sleeping sickness are discussed. This article is focused on different approaches based on unique aspects of parasites biochemistry and physiology, selecting the more promising molecular targets for drug design. In spite of the enormous amount of work on the above features, the chemotherapy for all of these diseases remains unsolved. It is based on old and fairly not specific drugs associated, in several cases, with long-term treatments and severe side effects. Drug resistance and different strains susceptibility are further drawbacks of the existing chemotherapy. In this review article, a thorough analysis of selected molecular targets, mainly those that are significantly different compared with the mammalian host or, even, are not present in mammals would be described in terms of their potencial usefulness for drug design. Therefore, this article covers rational approaches to the chemotherapeutic control of these parasitic infections, such as the progresses in the search for novel metabolic pathways in parasites that may be essential for parasites survival but with no counterpart in the host. Ergosterol biosynthesis is a very interesting example. There are many enzymes involved in this biosynthetic pathway such us squalene synthase, farnesylpyrophosphate synthase, and other enzymes that are able to deplete endogenous sterols will be treated in this article. The enzymes involved in trypanothione biosynthesis, glutathionyl spermidine synthetase and trypanothione synthetase do not have an equivalent in mammals, and therefore it can be predicted low toxicity for compounds that are able to produce highly selective inhibition. Trypanothione reductase (TR), glyceraldehyde-3-phosphate dehydrogenase, dihydrofolate reductase, prenyltransferases, ornithine decarboxylase, etc, will be thoroughly analyzed. The design of specific inhibitors of such metabolic activities as possible means of controlling the parasites without damaging the hosts will be presented. The recent advances in the biochemistry of pathogenic parasites including the discovery of novel organelles will be discussed.
Journal of Medicinal Chemistry, 2006
Bioorganic & Medicinal Chemistry Letters, 2005
We have investigated the effect of a series of 1-amino-1,1-bisphosphonates derived from fatty aci... more We have investigated the effect of a series of 1-amino-1,1-bisphosphonates derived from fatty acids against proliferation of the clinically more relevant form of Trypanosoma cruzi, the causative agent of American trypanosomiasis (Chagas' disease). Some of these drugs were potent inhibitors against the intracellular form of the parasite, exhibiting IC50 values at low micromolar level. Cellular activity was associated with the inhibition of enzymatic activity of T. cruzi farnesyl pyrophosphate synthase. As bisphosphonate-containing drugs are FDA-approved for the treatment of bone resorption disorders, their potential innocuousness makes them good candidates to control tropical diseases.
Bioorganic & Medicinal Chemistry Letters, 2002
Glutathionylspermidine synthetase/amidase (GspS) is an essential enzyme in the biosynthesis and t... more Glutathionylspermidine synthetase/amidase (GspS) is an essential enzyme in the biosynthesis and turnover of trypanothione and represents an attractive target for the design of selective anti-parasitic drugs. We synthesised a series of analogues of glutathione (l-g-Glu-l-Leu-Gly-X) where the glycine carboxylic acid group (X) has been substituted for other acidic groups such as tetrazole, hydroxamic acid, acylsulphonamide and boronic acid. The boronic acid appears the most promising lead compound (IC 50 of 17.2 mM). #