Browsing by Author "Insuasty, Braulio"
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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 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.