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96 results on '"Calderón, José S."'

1. Editorial

Author

García-Macías, Pascual G., primary, Cueto-Calderón, José S., additional, García Zamora, Rodolfo, additional, Da Silva, Matheus Cardoso, additional, and García-Guerrero, Montserrat, additional

Published
2023
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2. Editorial

Author

García-Macías, Pascual G., Cueto-Calderón, José S., García Zamora, Rodolfo, Da Silva, Matheus Cardoso, García-Guerrero, Montserrat, García-Macías, Pascual G., Cueto-Calderón, José S., García Zamora, Rodolfo, Da Silva, Matheus Cardoso, and García-Guerrero, Montserrat

Published
2023

3. Editorial Note

Author

García-Macías, Pascual Gerardo, Cueto-Calderón, José S., Da Silva, Matheus Cardoso, Zamora, Rodolfo García, García-Macías, Pascual Gerardo, Cueto-Calderón, José S., Da Silva, Matheus Cardoso, and Zamora, Rodolfo García

Abstract

However, the question arises about the maneuvering room of these governments. While they share a critical stance against neoliberalism and seek to implement public policies that transform the socio-economic structures of the region, they face a series of challenges that we can summarize into three major ones: Adverse international context. The global economic crisis, the war in Ukraine, and the rise of the right in some countries around the world create a complex scenario for the implementation of progressive agendas. Existing power structures. Traditional economic and political elites still wield great power in the region, which can hinder the implementation of deep reforms. Institutional weaknesses. Corruption, lack of transparency, and the weakness of the rule of law are obstacles that limit the governments' ability to act. The debate on the future of the left in Latin America is complex and still open. While the current outlook is hopeful, it is important to consider the challenges faced by progressive governments. Their success will depend on their ability to build social consensus, strengthen institutions, and navigate in an adverse international context., Sin embargo, surge la pregunta sobre los márgenes de maniobra de estos gobiernos. Si bien comparten una postura crítica al neoliberalismo y buscan implementar políticas públicas que transformen las estructuras socioeconómicas de la región, se enfrentan a una serie que podemos resumir en tres grandes desafíos: Contexto internacional adverso. La crisis económica global, la guerra en Ucrania y el ascenso de la derecha en algunos países del mundo configuran un escenario complejo para la implementación de agendas progresistas. Estructuras de poder existentes. Las élites económicas y políticas tradicionales aún ostentan un gran poder en la región,lo que puede dificultar la implementación de reformas profundas. Debilidades institucionales.La corrupción, la falta de transparencia y la debilidad del Estado de derecho son obstáculos que limitan la capacidad de acción de los gobiernos. El debate sobre el futuro de la izquierda en América Latina es complejo y aún está abierto. Si bien el panorama actual es esperanzador, es importante tener en cuenta los desafíos que enfrentan los gobiernos progresistas. Su éxito dependerá de su capacidad para construir consensos sociales, fortalecer las instituciones y navegar en un contexto internacional adverso.

Published
2023

13. Antidiarrheal Thymol Derivatives from Ageratina glabrata. Structure and Absolute Configuration of 10-Benzoyloxy-8,9-epoxy-6-hydroxythymol Isobutyrate

Author

Bustos-Brito, Celia, primary, Vázquez-Heredia, Valeria J., additional, Calzada, Fernando, additional, Yépez-Mulia, Lilian, additional, Calderón, José S., additional, Hernández-Ortega, Simón, additional, Esquivel, Baldomero, additional, García-Hernández, Normand, additional, and Quijano, Leovigildo, additional

Published
2016
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14. Structure, Absolute Configuration, and Antidiarrheal Activity of a Thymol Derivative from Ageratina cylindrica

Author

Bustos-Brito, Celia, primary, Sánchez-Castellanos, Mariano, additional, Esquivel, Baldomero, additional, Calderón, José S., additional, Calzada, Fernando, additional, Yepez-Mulia, Lilian, additional, Hernández-Barragán, Angelina, additional, Joseph-Nathan, Pedro, additional, Cuevas, Gabriel, additional, and Quijano, Leovigildo, additional

Published
2014
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16. Antidiarrheal Thymol Derivatives from Ageratina glabrata. Structure and Absolute Configuration of 10-Benzoyloxy-8,9-epoxy-6- hydroxythymol Isobutyrate.

Author

Bustos-Brito, Celia, Vázquez-Heredia, Valeria J., Calzada, Fernando, Yépez-Mulia, Lilian, Calderón, José S., Hernández-Ortega, Simón, Esquivel, Baldomero, García-Hernández, Normand, and Quijano, Leovigildo

Subjects
THYMOL, PHENOL derivatives, ANTIDIARRHEALS, SHRUBS, ANTIPROTOZOAL agents, TRADITIONAL medicine
Abstract

Chemical investigation of the leaves from Ageratina glabrata yielded four new thymol derivatives, namely: 10-benzoyloxy-8,9-dehydro-6-hydroxythymol isobutyrate (4), 10-benzoyloxy-8, 9-dehydrothymol (5), 10-benzoyloxythymol (6) and 10-benzoyloxy-6,8-dihydroxy-9-isobutyryloxythymol (7). In addition, (8S)-10-benzoyloxy-8,9-epoxy-6-hydroxythymol isobutyrate (1), together with other two already known thymol derivatives identified as 10-benzoyloxy-8,9-epoxy- 6-methoxythymol isobutyrate (2) and 10-benzoyloxy-8,9-epoxythymol isobutyrate (3) were also obtained. In this paper, we report the structures and complete assignments of the 1H and 13C-NMR data of compounds 1-7, and the absolute configuration for compound 1, unambiguously established by single crystal X-ray diffraction, and evaluation of the Flack parameter. The in vitro antiprotozoal assay showed that compound 1 and its derivative 1a were the most potent antiamoebic and antigiardial compounds. Both compounds showed selectivity and good antiamoebic activity comparable to emetine and metronidazole, respectively, two antiprotozoal drugs used as positive controls. In relation to anti-propulsive effect, compound 1 and 1a showed inhibitory activity, with activities comparable to quercetin and compound 9, two natural antipropulsive compounds used as positive controls. These data suggest that compound 1 may play an important role in antidiarrheal properties of Ageratina glabrata. [ABSTRACT FROM AUTHOR]

Published
2016
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30. ent-Kaurene Glycosides from Ageratina cylindrica

Author

Bustos-Brito, Celia, Sánchez-Castellanos, Mariano, Esquivel, Baldomero, Calderón, José S., Calzada, Fernando, Yépez-Mulia, Lilian, Joseph-Nathan, Pedro, Cuevas, Gabriel, and Quijano, Leovigildo

Abstract

The aqueous extract of the leaves of Ageratina cylindricaafforded six new ent-kaurenoic acid glycosides together with the known diterpenoid paniculoside V, the flavonoid astragalin, chlorogenic acid, and l-chiro-inositol. The structures were elucidated mainly by NMR and MS methods, and the absolute configuration was established by vibrational circular dichroism spectroscopy. The new compounds showed moderate antiprotozoal activity against Entamoeba histolyticaand Giardia lambliatrophozoites.

Published
2015
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34. A C-Glycosylflavone from Piper ossanum, a Compound Conformationally Controlled by CH/π and Other Weak Intramolecular Interactions

Author

Larionova, María, Spengler, Iraida, Nogueiras, Clara, Quijano, Leovigildo, Ramírez-Gualito, Karla, Cortés-Guzmán, Fernando, Cuevas, Gabriel, and Calderón, José S.

Abstract

The structure of the known 2′′-O-α-rhamnosyl-4′′-O-methylvitexin (apigenin-8-C-α-rhamnosyl-(1→2)-β-4-O-methylglucopyranoside), isolated from the leaves of Piper ossanum, was revised to acacetin-8-C-neohesperidoside (acacetin-8-C-α-rhamnosyl-(1→2)-β-glucopyranoside or 2′′-O-α-rhamnosyl-4′-O-methylvitexin) (1). The NMR data and theoretical calculations established the preferred conformation of 1, which is controlled by CH/π interactions. This phenomenon explains the unusual chemical shifts of some protons in the molecule, besides other weak intramolecular interactions such as the anomeric effect, the Δ2 effect, and several hydrogen bonds.

Published
2010
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35. Flavonoids from Tephrosia major. A New Prenyl-ß-hydroxychalcone

Author

Gómez-Garibay, Federico, Téllez-Valdez, Oswaldo, Moreno-Torres, Gregorio, and Calderón, José S.

Abstract

The roots and aerial parts of Tephrosia major Micheli, afforded a new prenylated-ß-hydroxychalcone, characterized as 2',6'-dihydroxy-3'-prenyl-4'-methoxy-ß-hydroxychalcone. In addition, seven prenylated flavonoids, two rotenoids, ß-sitosterol, stigmasterol, lupeol and quercetin were isolated. The structure of the new ß-hydroxy chalcone was established by spectroscopic methods, including 2D NMR experiments.

Published
2002
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36. Inhibition of Photophosphorylation and Electron Transport by Flavonoids and Biflavonoids from Endemic Tephrosiaspp. of Mexico

Author

Céspedes, Carlos L., Achnine, Lahoucine, Lotina-Hennsen, Blas, Salazar, Juan R., Gómez-Garibay, Federico, and Calderón, José S.

Abstract

The biflavonoids tepicanol 1 and crassifolin 2 and the flavonoids elongatin 3, tephrobotin 4, tephroleocarpin 5, glabranin 6, and methylglabranin 7 were isolated from Tephrosia tepicana, T. crassifolia, T. viridiflora, T. abbottiae, T. leiocarpa,and T. madrensis,respectively, Leguminoseae-Papilionidae, a large tropical and subtropical genus, and their in vitroeffects on different photosynthetic activities were investigated. All the compounds isolated, except 1 and 3, induced a concentration-dependent inhibition of photophosphorylation. Compounds 2 and 4-7 interfered with the energetic metabolism of plants at the level of photosynthesis with different mechanisms of action. Compounds 2, 4, and 6 behave as Hill reaction inhibitors, and compounds 5 and 7 act as energy transfer inhibitors (H+-ATPase inhibitor).

Published
2001
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45. In Vivoand In Vitroα-Glucosidase Inhibitory Activity of Perfoliatin a from Melampodium Perfoliatum

Author

Flores-Bocanegra, Laura, Torres-Colín, Rafael, González-Andrade, Martin, Calderón, José S., and Mata, Rachel

Abstract

As part of our effort to discover new α-glucosidase inhibitors from natural sources, it was found that an aqueous extract from Melampodium perfoliatum(Cavanilles) Kunth (Asteraceae) inhibited the activity of rat-intestinal α-glucosidases in a concentration dependent manner (IC50= 958 μg/mL). Fractionation of the active extract led to the isolation of perfoliatin A (1), which was active against the mammal α-glucosidases and a recombinant α-glucosidase with maltase-glucoamylase activity obtained from Ruminococcus obeum.Kinetic analysis revealed that the interaction of 1with R. obeum-α-glucosidase was noncompetitive. The calculated Kiwas 0.68 ± 0.034 mM. In vivotesting using an oral sucrose tolerance test, in healthy and hyperglycemic mice, revealed that perfoliatin A (1) reduced significantly the postprandial peak, consistent with its α-glucosidase inhibitory activity. The effect was comparable or better to that of acarbose, a therapeutically used α-glucosidase inhibitor. Altogether, these findings clearly supported the α-glucosidase inhibitory activity of melampolide-type of sesquiterpene lactones.

Published
2019
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