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In current work, we prepared a series of nine 4-benzyloxy-5-benzylidene-1,3-thiazolidine-2,4-diones using a two-step pathway. Compounds 1–9 were tested in vitro using a set of three ...proteins recognized as important targets in diabetes and related diseases: PPARα, PPARγ, and GLUT-4. Compounds 1–3, 5, and 7 showed significant increases in the mRNA expression of PPARγ and GLUT-4, whereas compounds 1–3 did it over PPARα. Compounds 1–3 were identified as a dual PPAR α/γ modulators and were selected for evaluating the in vivo antidiabetic action at 100 mg/kg dose, being orally actives and decreasing blood glucose concentration in a hyperglycemic mice model, as well as reducing the triacylglycerides levels in normolipidemic rats. Docking and molecular dynamics studies were conducted to clarify the dual effect and binding mode of compounds 1–3 on both PPARs. Compounds 2 and 3 exhibited robust in vitro and in vivo efficacy and could be considered dual PPAR modulators with antidiabetic and antidyslipidemic effects.
In this work, a new set of quinazolin‐2,4,6‐triamine derivatives were synthesized to explore their potential biological activity as xanthine oxidase (XO) inhibitors, superoxide scavengers and ...screening of their toxicological profile. Among all the synthesized compounds, B1 exhibited better inhibitory activity against bovine xanthine oxidase (bXO) than allopurinol (IC50=1.56 μM and IC50=6.99 μM, respectively). As superoxide scavengers, B1, B2 and B13 exhibited a better effect than allopurinol (97.3 %, 82.1 %, 87.4 % and 69.4 %, respectively). Regarding the toxicological profile, B1 was less cytotoxic than methotrexate on HCT‐15 cancer cells. Apoptosis results obtained in cells of female and male mice, showed that B1 and B2 presented a similar behaviour to CrO3 (positive control) with respect to the average frequency to induce apoptosis; while B13 apoptosis induced effect was similar to DMSO and control group. Finally, B1, B2, B13 did not induce genotoxicity in a micronuclei murine model compared to CrO3.
One quinazolin‐2,4,6‐triamine derivative was found to be a better bovine xanthine oxidase (bXO) inhibitor than allopurinol. Three quinazoline derivatives were not micronuclei inducers in a murine model. Three quinazolin‐2,4,6‐triamine derivatives acted as superoxide scavengers, and one 5,6‐dihydro‐3H‐pirimidin‐4‐one showed bXO inhibitory activity.
DAPT is a potent γ-secretase (GS) inhibitor that blocks the production of short amyloid-β (Aβ) peptides. Aggregation and oligomerization of Aβ peptides have been associated with the development and ...progression of Alzheimer's disease. A recent cryo-electron microscopy density map disclosed DAPT binding at the GS active site. In this study, we employed the density map data to assign a possible binding pose of DAPT to characterize its dynamic behavior through different molecular dynamics simulation approaches. Our simulations showed a high preference of DAPT for the intramembrane region of the protein and that its entry site is located between TM2 and TM3 of PS1. DAPT interaction with the active site led to a decreased flexibility of key PS1 regions related to the recognition and internalization of GS substrates. Moreover, our study showed that the proximity of DAPT to the catalytic aspartic acids should be able to modify its protonation states, preventing the enzyme from reaching its active form. These results provide valuable information toward understanding the molecular mechanism of a GS inhibitor for the development of novel Alzheimer's disease treatments.
Sarcoendoplasmic reticulum calcium ATPase (SERCA), a member of the P-type ATPase family of ion and lipid pumps, is responsible for the active transport of Ca
from the cytoplasm into the sarcoplasmic ...reticulum lumen of muscle cells, into the endoplasmic reticulum (ER) of non-muscle cells. X-ray crystallography has proven to be an invaluable tool in understanding the structural changes of SERCA, and more than 70 SERCA crystal structures representing major biochemical states (defined by bound ligand) have been deposited in the Protein Data Bank. Consequently, SERCA is one of the best characterized components of the calcium transport machinery in the cell. Emerging approaches in the field, including spectroscopy and molecular simulation, now help integrate and interpret this rich structural information to understand the conformational transitions of SERCA that occur during activation, inhibition, and regulation. In this review, we provide an overview of the crystal structures of SERCA, focusing on identifying metrics that facilitate structure-based categorization of major steps along the catalytic cycle. We examine the integration of crystallographic data with different biophysical approaches and computational methods to link biochemical and structural states of SERCA that are populated in the cell. Finally, we discuss the challenges and new opportunities in the field, including structural elucidation of functionally important and novel regulatory complexes of SERCA, understanding the structural basis of functional divergence among homologous SERCA regulators, and bridging the gap between basic and translational research directed toward therapeutic modulation of SERCA.
Helicobacter pylori (H. pylori) is a pathogen that can remain in the stomach of an infected person for their entire life. As a result, this leads to the development of severe gastric diseases such as ...gastric cancer. In addition, current therapies have several problems including antibiotics resistance. Therefore, new practical options to eliminate this bacterium, and its induced affections, are required to avoid morbidity and mortality worldwide. One strategy in the search for new drugs is to detect compounds that inhibit a limiting step in a central metabolic pathway of the pathogen of interest. In this work, we tested 55 compounds to gain insights into their possible use as new inhibitory drugs of H. pylori glucose-6-phosphate dehydrogenase (HpG6PD) activity. The compounds YGC-1; MGD-1, MGD-2; TDA-1; and JMM-3 with their respective scaffold 1,3-thiazolidine-2,4-dione; 1H-benzimidazole; 1,3-benzoxazole, morpholine, and biphenylcarbonitrile showed the best inhibitory activity (IC50 = 310, 465, 340, 204 and 304 μM, respectively). We then modeled the HpG6PD protein by homology modeling to conduct an in silico study of the chemical compounds and discovers its possible interactions with the HpG6PD enzyme. We found that compounds can be internalized at the NADP+ catalytic binding site. Hence, they probably exert a competitive inhibitory effect with NADP+ and a non-competitive or uncompetitive effect with G6P, that of the compounds binding far from the enzyme’s active site. Based on these findings, the tested compounds inhibiting HpG6PD represent promising novel drug candidates against H. pylori.
Based on our previous research on cysticidal drugs, we report the synthesis and evaluation of three new benzimidazole derivatives. In these compounds, the amido group was used as a bioisosteric ...replacement of the ester group. The molecular docking on β-tubulin revealed that the derivatives interacted through hydrogen bonding with N165, E198 and V236. All compounds showed in vitro activity against Taenia crassiceps cysts. Among them, benzimidazole 3 was found to be the most potent of the series (EC50 0.86 µM). This compound also exhibited the highest probability of binding and the lowest binding free energy score and was therefore selected for in vivo evaluation. Results indicated that the efficacy of compound 3 was comparable to that of the reference drug, albendazole (50.39 vs. 47.16% parasite reduction). Animals treated with compound 3 seemed to tolerate this benzimidazole well, with no changes in behavior, or food and water consumption. These findings are consistent with the in silico prediction results, which indicated low toxicity risks. The pharmacokinetic study showed that the half-life and mean residence time (6.06 and 11.9 h, respectively) were long after oral administration. Together, these results indicate that this new benzimidazole derivative represents a promising structure with cysticidal activity.
γ‐Secretase is a four‐component membrane‐embedded aspartyl protease involved in the final cleavage step of the amyloid precursor protein (APP) to generate the amyloid‐β (Aβ) peptide. Different ...amino‐acid lengths of Aβ peptide can be produced by this enzyme, of which the oligomerization and aberrant accumulation of the product containing 42 amino acids (Aβ42) has been associated with the development and formation of amyloid‐β plaques in the brain of Alzheimer's disease (AD) patients. Herein, we review some of the most important topics associated with the structure and activity of γ‐secretase and the factors that alter the substrate cleavage pattern, critical to the formation of the different isoforms of the amyloid‐β peptides.
Microtubules are highly dynamic assemblies of α/β‐tubulin heterodimers whose polymerization inhibition is among one of the most successful approaches for anticancer drug development. Overexpression ...of the class I (βI) and class III (βIII) β‐tubulin isotypes in breast and lung cancers and the highly expressed class VI (βVI) β‐tubulin isotype in normal blood cells have increased the interest for designing specific tubulin‐binding anticancer therapies. To this end, we employed our previously proposed model of the β‐tubulin–nocodazole complex, supported by the recently determined X‐ray structure, to identify the fundamental structural differences between β‐tubulin isotypes. Moreover, we employed docking and molecular dynamics (MD) simulations to determine the binding mode of a series of benzimidazole‐2‐carbamete (BzC) derivatives in the βI‐, βIII‐, and βVI‐tubulin isotypes. Our results demonstrate that Ala198 in the βVI isotype reduces the affinity of BzCs, explaining the low bone marrow toxicity for nocodazole. Additionally, no significant differences in the binding modes between βI‐ and βIII‐BzC complexes were observed; however, Ser239 in the βIII isotype might be associated with the low affinity of BzCs to this isotype. Finally, our study provides insight into the β‐tubulin–BzC interaction features essential for the development of more selective and less toxic anticancer therapeutics.
β‐Tubulin isotypes are attractive therapeutic targets for the design of specific anticancer treatments. Herein, we carried out docking and molecular dynamics simulations to determine the binding mode of a series of benzimidazole‐2‐carbamete derivatives in the βI‐, βIII‐, and βVI‐tubulin isotypes. Finally, we propose novel approaches in the design of BzCs as microtubule polymerization inhibitors with a potential higher affinity to βI and βIII isotypes compared to that to the βVI isotype.
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