Browsing by Author "Paulino, Margot"

Now showing 1 - 6 of 6
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    Combined molecular modelling and 3D-QSAR study for understanding the inhibition of NQO1 by heterocyclic quinone derivatives
    (2018) Lopez-Lira, Claudia; Alzate-Morales, Jans H.; Paulino, Margot; Mella-Raipan, Jaime; Salas, Cristian O.; Tapia Apati, Ricardo; Soto-Delgado, Jorge
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    Expanding the chemical space of aryloxy-naphthoquinones as potential anti-Chagasic agents: synthesis and trypanosomicidal activity
    (SPRINGER BIRKHAUSER, 2021) Becerra, Nohemi A.; Espinosa Bustos, Christian; Vazquez, Karina; Rivera, Gildardo; Paulino, Margot; Cantero, Jorge; Nogueda, Benjamin; Chacon Vargas, Fabiola; Castillo Velazquez, Uziel; Elizondo Rodriguez, Ana F.; Toledo, Sofia; Moreno Rodriguez, Adriana; Aranda, Mario; Salas, Cristian O.
    In continuation our effort to research the chemical space of aryloxy-naphthoquinones as potential anti-Chagas agents, we synthesized nine derivatives and these compounds were evaluated in vitro against the epimastigote and trypomastigote forms of Mexican strains of Trypanosoma cruzi (T. cruzi). Most of these derivatives are highly active against epimastigote forms (IC50 < 1.0 mu M) compared to the reference drug benznidazole (Bzn). Then these were evaluated on trypomastigotes, which is showing better potency results than Bzn for compounds 3b and 3g. In addition, the cytotoxicity of these compounds was determined on the murine macrophage cell line J774. 3b and 3i were the most selective compounds against NINOA trypomastigote and INC-5 epimastigote forms, respectively. Further these compounds also have good oral bioavailability according to theoretical predictions. Finally, we were able to determine optimal substitution patterns using pharmacophoric models. All these results are provided very useful structural information to continue our designing of naphthoquinone derivatives against T. cruzi.
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    Mode of action of p-quinone derivatives with trypanocidal activity studied by experimental and in silico models
    (2023) Ballesteros-Casallas, Andres; Quiroga, Cristina; Ortiz, Cecilia; Benitez, Diego; Denis, Pablo A.; Figueroa, David; Salas, Cristian O.; Bertrand, Jeanluc; Tapia, Ricardo A.; Sanchez, Patricio; Miscione, Gian Pietro; Comini, Marcelo A.; Paulino, Margot
    Quinones are attractive pharmacological scaffolds for developing new agents for the treatment of different transmissible and non-transmissible human diseases due to their capacity to alter the cell redox homeostasis.The bioactivity and potential mode of action of 19 p-quinone derivatives fused to different aromatic rings (carbo or heterocycles) and harboring distinct substituents were investigated in infective Trypanosoma brucei brucei. All the compounds, except for a furanequinone (EC50=38 mu M), proved to be similarly or even more potent (EC50 = 0.5-5.5 mu M) than the clinical drug nifurtimox (EC50 = 5.3 mu M). Three furanequinones and one thia-zolequinone displayed a higher selectivity than nifurtimox. Two of these selective hits resulted potent inhibitors of T. cruzi proliferation (EC50=0.8-1.1 mu M) but proved inactive against Leishmania infantum amastigotes.Most of the p-quinones induced a rapid and marked intracellular oxidation in T. b. brucei. DFT calculations on the oxidized quinone (Q), semiquinone (Q center dot-) and hydroquinone (QH2) suggest that all quinones have negative Delta G for the formation of Q center dot-. Qualitative and quantitative structure-activity relationship analyses in two or three dimensions of different electronic and biophysical descriptors of quinones and their corresponding bioactivities (killing potency and oxidative capacity) were performed.Charge distribution over the quinone ring carbons of Q and Q.-and the frontier orbitals energies of SUMO (Q.-) and LUMO (Q) correlate with their oxidative and trypanocidal activity. QSAR analysis also highlighted that both bromine substitution in the p-quinone ring and a bulky phenyl group attached to the furane and thiazole rings (which generates a negative charge due to the 7C electron system polarized by the nearby heteroatoms) are favorable for activity.By combining experimental and in silico procedures, this study disclosed important information about p-qui-nones that may help to rationally tune their electronic properties and biological activities.
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    New Smoothened ligands based on the purine scaffold as potential agents for treating pancreatic cancer
    (2024) Espinosa-Bustos, Christian; Bertrand, Jeanluc; Villegas-Menares, Alondra; Guerrero, Simon; Di Marcotullio, Lucia; Navacci, Shirin; Schulte, Gunnar; Kozielewicz, Pawel; Bloch, Nicolas; Villela, Valentina; Paulino, Margot; Kogan, Marcelo J.; Cantero, Jorge; Salas, Cristian O.
    Aberrant activation of the Hedgehog (Hh) signalling pathway has been associated with the development and progression of pancreatic cancer. For this reason, blockade of Hh pathway by inhibitors targeting the G proteincoupled receptor Smoothened (SMO) has been considered as a therapeutic target for the treatment of this cancer. In our previous work, we obtained a new SMO ligand based on a purine scaffold (compound I), which showed interesting antitumor activity in several cancer cell lines. In this work, we report the design and synthesis of 17 new purine derivatives, some of which showed high cytotoxic effect on Mia-PaCa-2 (Hh-dependent pancreatic cancer cell lines) and low toxicity on non-neoplastic HEK-293 cells compared with gemcitabine, such as 8f, 8g and 8h (IC50 = 4.56, 4.11 and 3.08 mu M, respectively). Two of these purines also showed their ability to bind to SMO through NanoBRET assays (pKi = 5.17 for 8f and 5.01 for 8h), with higher affinities to compound I (pKi = 1.51). In addition, docking studies provided insight the purine substitution pattern is related to the affinity on SMO. Finally, studies of Hh inhibition for selected purines, using a transcriptional functional assay based on luciferase activity in NIH3T3 Shh-Light II cells, demonstrated that 8g reduced GLI activity with a IC50 = 6.4 mu M as well as diminished the expression of Hh target genes in two specific Hh-dependent cell models, Med1 cells and Ptch1- /- mouse embryonic fibroblasts. Therefore, our results provide a platform for the design of SMO ligands that could be potential selective cytotoxic agents for the treatment of pancreatic cancer.
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    Structural analysis and molecular docking of trypanocidal aryloxy-quinones in trypanothione and glutathione reductases: a comparison with biochemical data
    (2017) Vera, Brenda; Vázquez, Karina; Mascayano, Carolina; Tapia Apati, Ricardo; Espinosa, Victoria; Soto, Jorge Delgado; Salas Sánchez, Cristián Osvaldo; Paulino, Margot
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    Synthesis and Pharmacophore Modelling of 2.6.9-Trisubstituted Purine Derivatives and Their Potential Role as Apoptosis-Inducing Agents in Cancer Cell Lines
    (2015) Calderón Arancibia, Jeannette; Espinosa Bustos, Christian Marcelo; Cañete Molina, Álvaro; Tapia Apati, Ricardo; Faúndez Cáceres, Mario; Torres Torres, María José; Aguirre, Adam; Paulino, Margot; Salas Sánchez, Cristián Osvaldo