The development of new compounds to treat Chagas disease is imperative due to the adverse effects of current drugs and their low efficacy in the chronic phase. This study aims to investigate nitroisoxazole derivatives that produce oxidative stress while modifying the compounds’ lipophilicity, affecting their ability to fight trypanosomes. The results indicate that these compounds are more effective against the epimastigote form of T. cruzi, with a 52 ± 4% trypanocidal effect for compound 9. However, they are less effective against the trypomastigote form, with a 15 ± 3% trypanocidal effect. Additionally, compound 11 interacts with a higher number of amino acid residues within the active site of the enzyme cruzipain. Furthermore, it was also found that the presence of a nitro group allows for the generation of free radicals; likewise, the large size of the compound enables increased interaction with aminoacidic residues in the active site of cruzipain, contributing to trypanocidal activity. This activity depends on the size and lipophilicity of the compounds. The study recommends exploring new compounds based on the nitroisoxazole skeleton, with larger substituents and lipophilicity to enhance their trypanocidal activity.

3-formyl-2-quinolones have attracted the scientific community’s attention because they are used as versatile building blocks in the synthesis of more complex compounds showing different and attractive biological activities. Using copper-catalyzed Chan–Lam coupling, we synthesized 32 new N-aryl-3-formyl-2-quinolone derivatives at 80 °C, in air and using inexpensive phenylboronic acids as arylating agents. 3-formyl-2-quinolones and substituted 3-formyl-2-quinolones can act as substrates, and among the products, the p-methyl derivative 9a was used as a substrate to obtain different derivatives such as alcohol, amine, nitrile, and chalcone.

A series of N-phenyl-3-(thiophen-2-yl)acrylamide derivatives were designed and synthesized to investigate the influence of electronic and steric modifications on cytotoxic activity. Although related thiophene-containing acrylamides have been reported, the specific compounds studied in this study have not been previously described. Structural variations were introduced at the para position of the N-phenyl ring (H, CF₃, and OCF₃) and at the 5-position of the thiophene ring (H and CH₃) to enable preliminary structure–activity relationship (SAR) analysis. The target compounds were synthesized via Knoevenagel–Doebner condensation, followed by carbodiimide-mediated amide coupling. The compounds were characterized using nuclear magnetic resonance (NMR) spectroscopy, high-resolution mass spectrometry (HRMS), Fourier-transform infrared (FTIR) spectroscopy, and high-performance liquid chromatography (HPLC). Computational evaluation indicated compliance with Lipinski’s rule of five and the absence of predicted mutagenic, tumorigenic, irritant, and reproductive risks. Cytotoxic activity was determined using the sulforhodamine B (SRB) assay against human breast adenocarcinoma (MCF-7), gastric adenocarcinoma (AGS), colorectal adenocarcinoma (Caco-2), oral squamous cell carcinoma (HSC-3), hepatocellular carcinoma (HepG2) cell lines and non-cancerous human dermal fibroblasts (HDF). Compounds 11 and 16 displayed the most consistent activity, with half-maximal inhibitory concentration (IC₅₀) values of 379, 420, and 265 μM and 272, 256, and 242 μM against AGS, Caco-2, and MCF-7 cells, respectively. MCF-7 cells were the most sensitive model. The most active derivative was compound 16, suggesting that the combination of a 5-methylthiophene moiety and a para-CF₃ substituent may be beneficial within this limited compound series. These findings provide a preliminary evaluation of this scaffold and will help guide future studies on structural modifications.