Six polyheterocycles were studied in vitro against human SARS-CoV-2 finding that one of them exhibited significant activity at initial infection stages, showing prophylactic potential. A second one showed both, prophylactic and therapeutic activity.

An Ugi–Zhu three-component reaction (UZ-3CR) coupled in a one-pot manner to a cascade process (N-acylation/aza Diels–Alder cycloaddition/decarboxylation/dehydration) was performed to synthesize a series of pyrrolo[3,4-b]pyridin-5-ones in 20% to 92% overall yields using ytterbium triflate as a catalyst, toluene as a solvent, and microwaves as a heat source. The synthesized molecules were evaluated in vitro against breast cancer cell lines MDA-MB-231 and MCF-7, finding that compound 1f, at a concentration of 6.25 μM, exhibited a potential cytotoxic effect. Then, to understand the interactions between synthesized compounds and the main proteins related to the cancer cell lines, docking studies were performed on the serine/threonine kinase 1 (AKT₁) and Orexetine type 2 receptor (Ox₂R), finding moderate to strong binding energies, which matched accurately with the in vitro results. Additionally, molecular dynamics were performed between proteins related to the studied cell lines and the three best ligands.

A series of six bis-furyl-pyrrolo[3,4-b]pyridin-5-ones synthesized via an Ugi-Zhu reaction coupled to a cascade process [aza Diels-Alder cycloaddition/N-acylation/aromatization] were evaluated in vitro against Dengue virus serotype 4 infection, and the Dengue virus replicon system encoding a Renilla luciferase gen reporter. Also, in silico studies on the non-structural protein 3 (NS3), a flavivirus protease comprising an attractive target for development of therapeutic antivirals bound to non-structural protein 2B (NS3-NS2B) were performed. The in vitro results showed that compounds 1a and 1b reduced the expression of Renilla luciferase in 44.2 and 31.6%, respectively. Additionally, the same compounds decreased viral load, thus revealing their potential activity against Dengue virus serotype 4. From in silico simulations, it was developed a NS3-NS2B model, which was used as a target for the studied molecules. Computational results agree with experimental data, showing that 1a is the best ligand. Finally, a pharmacophoric model was computed for NS3-NS2B, which shows that the ligands need two hydrophobic and one hydrophilic fragment. Such results suggest that two out of the six synthesized bis-furyl-pyrrolo[3,4-b]pyridin-5-ones derivatives presents potential antiviral activity against Dengue virus in vitro. Resumen. Una serie de seis bis-furil-pirrolo[3,4-b]piridin-5-onas sintetizadas vía una reacción Ugi-Zhu acoplada a un proceso en cascada [cicloadición aza Diels-Alder/N-acilación/aromatización] fueron evaluadas in vitro contra infección por el serotipo 4 del virus del dengue y el sistema de replicón del virus del Dengue que codifica un gen reportero de la luciferasa de la Renilla. Además, se realizaron estudios in silico sobre la proteína no estructural 3 (NS3), una proteasa de flavivirus que comprende un blanco atractivo para el desarrollo de antivirales terapéuticos unidos a la proteína no estructural 2B (NS3-NS2B). Los estudios in vitro revelaron que los compuestos 1a y 1b reducen la expresión de Renilla luciferasa en un 44.2 y 31.6%, respectivamente. Adicionalmente, estos compuestos redujeron la carga viral, revelando así su actividad potencial contra el virus del Dengue serotipo 4. Derivado de las simulaciones in silico, se obtuvo un modelo homólogo para NS3-NS2B, el cual fue considerado como blanco de las moléculas estudiadas. Los resultados computacionales correlacionan con los experimentales, mostrando que 1a es el mejor ligando. Finalmente, se generó un modelo farmacofórico para NS3-NS2B, el cual muestra que los ligandos necesitan dos fragmentos hidrofóbicos y uno hidrofílico. Estos resultados demuestran que dos de los seis compuestos que se estudiaron presentan actividad antiviral in vitro.