In Vitro and In Silico Analysis of New n-Butyl and Isobutyl Quinoxaline-7-carboxylate 1,4-di-N-oxide Derivatives against Trypanosoma cruzi as Trypanothione Reductase Inhibitors

American trypanosomiasis is a worldwide health problem that requires attention due to ineffective treatment options. We evaluated n-butyl and isobutyl quinoxaline-7-carboxylate 1,4-di-N-oxide derivatives against trypomastigotes of the Trypanosoma cruzi strains NINOA and INC-5. An in silico analysis of the interactions of 1,4-di-N-oxide on the active site of trypanothione reductase (TR) and an enzyme inhibition study was carried out. The n-butyl series compound identified as T-150 had the best trypanocidal activity against T. cruzi trypomastigotes, with a 13% TR inhibition at 44 μM. The derivative T-147 behaved as a mixed inhibitor with Ki and Ki' inhibition constants of 11.4 and 60.8 µM, respectively. This finding is comparable to the TR inhibitor mepacrine (Ki = 19 µM)

Evaluación biológica in vitro e in silico de derivados de ftalamida como agentes antiproliferativos

Phthalimide is considered a scaffold for the development of new anticancer agents. In this work, the antiproliferative activity of forty-three phthalimide derivatives was evaluated against cervical (HeLa), liver (HepG2), breast (4T1) cancer cell lines, and a normal cell line of murine fibroblasts (3T3). Finally, a molecular docking analysis of phthalimide derivatives on the active site of the enzymes DNA methyltransferase 1 (DNMT1) and vascular endothelial growth factor receptor 2 (VEGR2) as potential drug targets was performed. The compounds, C16, E11, and E16 showed the best antiproliferative activity against the cell lines HeLa and 4T1. Only, the compound H16 decreased 32% cell proliferation against HepG2 cell line. The compounds H5, H16, E2, E16, and C1 did not affect the proliferation of the 3T3 cell line. The molecular docking analysis showed that phthalimide derivatives have a greater affinity for DNMT1 than S-adenosyl-l-homocysteine, a potent DNMT1 inhibitor. However, molecular docking results do not correlate with their antiproliferative effects, suggesting another potential mechanism of action for the active compounds.La estructura de la ftalimida es considerada un bloque de construcción para el desarrollo de nuevos agentes anticancerígenos. En este trabajo, se evaluó la actividad antiproliferativa de cuarenta y tres derivados de ftalimida contra las líneas celulares cancerígenas de cérvix (HeLa), hígado (HepG2), mama (4T1), y la línea celular normal de fibroblastos murinos (3T3). Por último, se realizó un análisis de acoplamiento molecular de los derivados de la ftalimida en el sitio activo de la enzima metiltransferasa 1 de DNA (DNMT1, por sus siglas en inglés) y el receptor del factor de crecimiento endotelial vascular 2 (VEGR2, por sus siglas en inglés) como posibles blancos farmacológicos. Los compuestos C16, E11 y E16 mostraron la mejor actividad antiproliferativa contra las líneas celulares HeLa y 4T1. Solamente, el compuesto H16 disminuyó 32% la proliferación celular de la línea HepG2. Los compuestos H5, H16, E2, E16 y C1 no afectaron la proliferación celular de la línea 3T3. El análisis de acoplamiento molecular demostró que los derivados de la ftalimida tienen una mayor afinidad que la S-adenosil-l-homocisteína, un potente inhibidor de la metiltransferasa 1 de DNA. Sin embargo, los resultados del acoplamiento molecular no se correlacionan con los efectos antiproliferativos; lo cual sugiere que los compuestos activos tienen otro mecanismo de acción

Molecular docking and dynamic simulations of quinoxaline 1,4-di-N-oxide as inhibitors for targets from Trypanosoma cruzi, Trichomonas vaginalis, and Fasciola hepatica

Context Quinoxaline 1,4-di-N-oxide is a scaffold with a wide array of biological activities, particularly its use to develop new antiparasitic agents. Recently, these compounds have been described as trypanothione reductase (TR), triosephosphate isomerase (TIM), and cathepsin-L (CatL) inhibitors from Trypanosoma cruzi, Trichomonas vaginalis, and Fasciola hepatica, respectively. Methods Therefore, the main objective of this work was to analyze quinoxaline 1,4-di-N-oxide derivatives of two databases (ZINC15 and PubChem) and literature by molecular docking, dynamic simulation and complemented by MMPBSA, and contact analysis of molecular dynamics’ trajectory on the active site of the enzymes to know their potential effect inhibitory. Interestingly, compounds Lit_C777 and Zn_C38 show preference as potential TcTR inhibitors over HsGR, with favorable energy contributions from residues including Pro398 and Leu399 from Z-site, Glu467 from γ-Glu site, and His461, part of the catalytic triad. Compound Lit_C208 shows potential selective inhibition against TvTIM over HsTIM, with favorable energy contributions toward TvTIM catalytic dyad, but away from HsTIM catalytic dyad. Compound Lit_C388 was most stable in FhCatL with a higher calculated binding energy by MMPBSA analysis than HsCatL, though not interacting with catalytic dyad, holding favorable energy contribution from residues oriented at FhCatL catalytic dyad. Therefore, these kinds of compounds are good candidates to continue researching and confirming their activity through in vitro studies as new selective antiparasitic agents

Triose Phosphate Isomerase Structure-Based Virtual Screening and In Vitro Biological Activity of Natural Products as <i>Leishmania mexicana</i> Inhibitors

Cutaneous leishmaniasis (CL) is a public health problem affecting more than 98 countries worldwide. No vaccine is available to prevent the disease, and available medical treatments cause serious side effects. Additionally, treatment failure and parasite resistance have made the development of new drugs against CL necessary. In this work, a virtual screening of natural products from the BIOFACQUIM and Selleckchem databases was performed using the method of molecular docking at the triosephosphate isomerase (TIM) enzyme interface of Leishmania mexicana (L. mexicana). Finally, the in vitro leishmanicidal activity of selected compounds against two strains of L. mexicana, their cytotoxicity, and selectivity index were determined. The top ten compounds were obtained based on the docking results. Four were selected for further in silico analysis. The ADME-Tox analysis of the selected compounds predicted favorable physicochemical and toxicological properties. Among these four compounds, S-8 (IC50 = 55 µM) demonstrated a two-fold higher activity against the promastigote of both L. mexicana strains than the reference drug glucantime (IC50 = 133 µM). This finding encourages the screening of natural products as new anti-leishmania agents