Browsing by Author "Abonia, Rodrigo"
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Item A facile synthesis of stable β-amino-N-/O-hemiacetals through a catalyst-free three-component Mannich-type reaction(Elsevier Ltd, 2017-03-02) Abonia, Rodrigo; Castillo, Juan C.; Garay, Alexander; Insuasty, Braulio; Quiroga, Jairo; Nogueras, Manuel; Cobo, Justo; D'Vries, Richard F.A practical, straightforward and one-step procedure for the synthesis of novel and stable b-amino-N-/Ohemiacetals (i.e. c-aminoalcohols) is provided. The title compounds were obtained in good to excellent yields through an uncatalyzed three-component reaction by treatment of secondary amines with polyformaldehyde and electron-rich alkenes in acetonitrile as solvent at ambient temperature. The reactions proceeded with the formation of iminium ions, through a Mannich-type reaction, as the key intermediates for the generation of the target products. Single crystal X-ray analysis of derivative 4l confirmed unequivocally the structure and stability of the obtained compounds.Item A facile synthesis of stable β-amino-N-/O-hemiacetals through a catalyst-free three-component Mannich-type reaction(Tetrahedron Letters, 2017) Abonia, Rodrigo; Castillo, Juan C.; Garay, Alexander; Insuasty, Braulio; Quiroga, Jairo; Nogueras, Manuel; Cobo, Justo; D’Vries, Richard F.A practical, straightforward and one-step procedure for the synthesis of novel and stable β-amino-N-/O-hemiacetals (i.e γ-aminoalcohols) is provided. The title compounds were obtained in good to excellent yields through an uncatalyzed three-component reaction by treatment of secondary amines with polyformaldehyde and electron-rich alkenes in acetonitrile as solvent at ambient temperature. The reactions proceeded with the formation of iminium ions, through a Mannich-type reaction, as the key intermediates for the generation of the target products. Single crystal X-ray analysis of derivative 4l confirmed unequivocally the structure and stability of the obtained compounds.Item Methoxyquinolone–Benzothiazole Hybrids as New Aggregation-Induced Emission Luminogens and Efficient Fluorescent Chemosensors for Cyanide Ions(MDPI, 2024) Mutis Ayala, Mario; Trilleras, Jorge; D’Vries, Richard; Macías, Mario A.; Insuasty, Alberto; Abonia, Rodrigo; Quiroga, Jairo; Illicachi, Luis A.; Márquez, Edgar; Insuasty, DanielThis work describes the synthesis and characterization of new quinolone–benzothiazole hybrids, the study of their aggregation-induced emission (AIE) properties, and the use of these systems as efficient fluorescent probes for cyanide ions. These conjugated derivatives are linked through a double bond favoring electronic communication, and together with their planar geometry, can strongly aggregate under solvophobic environments, leading to aggregation and exhibiting significant AIE behavior. The double bond between electroactive units is prone to nucleophilic addition reactions by cyanide ions, selectively, conducive to turning off the fluorescence properties, making this hybrid system an efficient probe for cyanide ions. These studies were theoretically explained using DFT and TD-DFT calculations.Item Synthesis and antifungal activity of nitrophenyl-pyrazole substituted Schiff bases(Elsevier B.V., 2022-04-05) Restrepo Acevedo, Andrés; Osorio, Nicolas; Giraldo López, Luis E.; D'Vries, Richard F.; Zacchino, Susana; Abonia, Rodrigo; Le Lagadec, Ronan; Cuenú Cabezas, FernandoThree new pyrazole-based azomethine isomers (2a-c) bearing a 2-, 3- or 4-nitrophenyl substituent were prepared in almost quantitative yields using environmentally friendly techniques such as solvent-free and microwave-assisted procedures. The compounds were fully characterized by standard analytical methods, including single-crystal X-ray diffraction crystallography for two of the three synthesized compounds. The calculated molecular orbitals distributions of the HOMO and LUMO show that the band gap energy can be tuned by the addition of a nitrophenyl group on the pyrazole moiety and therefore the electrophilic character and the reactivity of the Schiff bases. The relative position of the nitro group plays an important role on the antifungal activity against C. albicans as compound bearing the 2-nitrophenyl substituent (2a) was considerably more active than the other derivatives. In contrast, all three isomers presented a similar, limited, activity against C. neoformans. Molecular docking simulations showed that the most active compound 2a presented the lowest binding energy with 3PVK model protein. © 2021 Elsevier B.V.Item Synthesis of novel quinoline–based 4,5–dihydro–1H–pyrazoles as potential anticancer, antifungal, antibacterial and antiprotozoal agents(Elsevier Masson SAS, 2017-03-16) Ramírez Prada, Jonathan; Robledo, Sara M.; Velez, Ivan D.; Crespo, María del Pilar; Quiroga, Jairo; Abonia, Rodrigo; Montoya, Alba; Svetaz, Laura; Zacchino, Susana; Insuasty, BraulioA new series of Nesubstituted 2epyrazolines 9aef, 10aef, 11aef, 12aef and 13aef were obtained from the cyclocondensation reaction of [(7echloroquinoline4eyl)amino]chalcones 8aef with hydrazine hydrate and its derivatives. Fourteen of the synthesized compounds including the starting chalcones were selected by US National Cancer Institute (NCI) for testing their anticancer activity against 60 different human cancer cell lines, with the most important GI50 values ranging from 0.28 to 11.7 mM (0.13e6.05 mg/ mL) and LC50 values ranging from 2.6 to > 100 mM (1.2 to > 51.7 mg/mL), for chalcones 8a,d and pyrazolines 10c,d. All compounds were assessed for antibacterial activity against wild type and multidrug resistant gram negative and gram positive bacteria, with MIC values ranging from 31.25 to 500 mg/mL. Additionally, the novel compounds were tested for antifungal and antiparasitic properties. Although these compounds showed mild activity against Candida albicans, chalcones 8a and 8e showed high activity against Cryptococcus neoformans with MIC50 ¼ 7.8 mg/mL. For antiePlasmodium falciparum activity the 2epyrazoline 11b was the most active with EC50 ¼ 5.54 mg/mL. Regarding the activity against Trypanosoma cruzi, compound 10a was highly active with EC50 ¼ 0.70 mg/mL. Chalcone 8a had good activity against Leishmania panamensis amastigotes with EC50 ¼ 0.79 mg/mL.Item Synthesis of Novel Triazine-Based Chalcones and 8,9-dihydro-7H-pyrimido[4,5-b][1,4]diazepines as Potential Leads in the Search of Anticancer, Antibacterial and Antifungal Agents(MDPI, 2024) Moreno, Leydi M.; Quiroga, Jairo; Abonia, Rodrigo; Crespo, María del P.; Aranaga, Carlos; Martínez Martínez, Luis; Sortino, Maximiliano; Barreto, Mauricio; Burbano, María E.; Insuasty, BraulioThis study presents the synthesis of four series of novel hybrid chalcones (20,21)a–g and (23,24)a–g and six series of 1,3,5-triazine-based pyrimido[4,5-b][1,4]diazepines (28–33)a–g and the evaluation of their anticancer, antibacterial, antifungal, and cytotoxic properties. Chalcones 20b,d, 21a,b,d, 23a,d–g, 24a–g and the pyrimido[4,5-b][1,4]diazepines 29e,g, 30g, 31a,b,e–g, 33a,b,e–g exhibited outstanding anticancer activity against a panel of 60 cancer cell lines with GI50 values between 0.01 and 100 μM and LC50 values in the range of 4.09 μM to >100 μM, several of such derivatives showing higher activity than the standard drug 5-fluorouracil (5-FU). On the other hand, among the synthesized compounds, the best antibacterial properties against N. gonorrhoeae, S. aureus (ATCC 43300), and M. tuberculosis were exhibited by the pyrimido[4,5-b][1,4]diazepines (MICs: 0.25–62.5 µg/mL). The antifungal activity studies showed that triazinylamino-chalcone 29e and triazinyloxy-chalcone 31g were the most active compounds against T. rubrum and T. mentagrophytes and A. fumigatus, respectively (MICs = 62.5 μg/mL). Hemolytic activity studies and in silico toxicity analysis demonstrated that most of the compounds are safe.Item Synthesis, structural characterization and theoretical studies of a new Schiff base 4-(((3-(tert-Butyl)-(1-phenyl)pyrazol-5-yl) imino)methyl)phenol(Elsevier B.V., 2017-09) Cuenú, Fernando; Londono Salazar, Jennifer; Torres, John Eduard; Abonia, Rodrigo; D'Vries, Richard F.4-(((3-(tert-Butyl)-(1-phenyl)pyrazol-5-yl)imino)methyl)phenol (4-OHFPz) was synthesized and characterized by FT-IR, MS, NMR, and single-crystal X-ray diffraction. Optimization of molecular geometry, vibrational frequencies, and chemical shifts were calculated by using the methods of density functional theory (DFT) with B3LYP and B3PW91 as functionals and Hartree-Fock with 6-311G++(d,p) as basis set using the GAUSSIAN 09 program package. With the VEDA 4 software, the vibrational frequencies were assigned in terms of the potential energy distribution (PED). The equilibrium geometries calculated by all methods were compared with X-ray diffraction results, indicating that the theoretical results matches well with the experimental ones. The data obtained from the vibrational analysis and the calculated NMR are consistent with the experimental spectra.