Search | SciELO

Need help?

Add field +

Search history

No documents were found for your search

Results: 18

au:RIVERO, IGNACIO A.

Filters

Collection + Options

All
Mexico

13
Brazil

5

Journal + Options

All
Journal of the Mexican Chemical Society

8
Journal of the Brazilian Chemical Society

4
Revista de la Sociedad Química de México

3
Acta universitaria

1
Brazilian Journal of Plant Physiology

1
Revista alergia México

1

Publication Year + Options

All
2004

2
2007

2
2010

2
2012

2
2019

2
2000

1
2006

1
2009

1
2011

1
2013

1
2016

1
2018

1
2021

1

SciELO Thematic Areas + Options

All
Biological Sciences

12
Exact and Earth Sciences

4
Health Sciences

1
Multidisciplinary

1

WoS Subject Categories + Options

All
Multidisciplinary

16
Chemistry

15
Sciences

2
Allergy

1
Humanities

1
Immunology

1
Issues

1
Plant

1
Social

1

WoS Citation Index + Options

All
Science Citation Index Expanded

8
Social Sciences Citation Index

4

Citables and non citables

All
Citable

18

Type of Literature + Options

All
Article

16
Brief report

1
Review article

1

Order by

Page of 2 Next

Select this page

Print | Send to email | Export |

Facebook
Twitter
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

0 Selected itens

List all
Erase all

Synthesis of Triazoles by Electro-Assisted Click Reaction Using a Copper Foil Electrode
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics
- Dimensions
- PlumX
- Altmetric

Carre-Rangel, Luceldi

; Espinoza, Karla A.

; Oropeza-Guzmán, Mercedes T.

; Rivero, Ignacio A.

Journal of the Brazilian Chemical Society

Journal Metrics
- Sobre o periódico
- SciELO Analytics

jul 2021, Volume 32 N. 7 Pages 1373 - 1380

Abstract: En | Text: En | PDF: En

This paper presents an innovative pathway for the synthesis of triazoles using the well-known “click chemistry” assisted by the electrochemical oxidation of metallic Cu0. The click reaction is used to couple a wide range of biological interest compounds. In this case, faster and less polluting methods for a biological environment was achived by in situ Cu0 electrooxidation, providing the suitable quantity of catalyst required by click reaction. The electrochemical cell was composed of a copper foil as the working electrode, a platinum wire serving as a counter electrode, and an Ag/AgCl wire as the reference electrode. Linear anodic sweep voltammetry in a tert-butanol-water medium (1:1), an electrolyte of tetrabutylammonium tetrafluoroborate (TBATFB), showed the onset potential of Cu0 electrooxidation. Using the same electrode configuration three different triazoles were prepared under constant electrode potential, in a short time (60 min), and splendid yields (78-90%). These results indicate that the in situ CuI formation occurs on the surface of the copper foil. A pulse potential program has also been implemented in which a yield of 92% was achieved, reducing electrode passivation and consequently increasing the process efficiency. The electro-assisted click reactions are highly efficient to produce triazoles by an innovative electrochemical reaction. The products were characterized by infrared (IR), nuclear magnetic resonance (1H and 13C NMR), and mass spectrometry (MS).

https://doi.org/10.21577/0103-5053.20210035 71 downloads

Resumen ejecutivo de ARIA 2019: vías integradas de atención para la rinitis alérgica en Argentina, España y México
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics
- Dimensions
- PlumX
- Altmetric

Ivancevich, Juan Carlos

; Cardona, Victoria

; Larenas Linnemann, Désirée

; Mullol, Joaquim

; Neffen, Hugo

; Zernotti, Mario

; Asayag, Estrella

; Blua, Ariel Eduardo

; Gómez, R. Maximiliano

; Jares, Edgardo

; Máspero, Jorge

; Anto, Josep M.

; Dedeu, Toni

; Rodríguez-González, Mónica

; Huerta-Villalobos, Yunuen Rocío

; Fuentes-Pérez, José Miguel

; Rodríguez-Zagal, Eréndira

; Valero, Antonio

; Bartra, Joan

; Alobid, Isam

; Castillo-Vizuete, José Antonio

; Dordal, Teresa

; Hijano, Rafael

; Picado, César

; Sastre, Joaquín

; Bedolla-Barajas, Martín

; Burguete-Cabañas, María Teresa

; Costa-Domínguez, María del Carmen

; Domínguez-Silva, Margarita

; Espinoza-Contreras, Jesús Guillermo

; Gálvez-Romero, José Luis

; García-Cobas, Cecilia Yvonne

; García-Cruz, María de la Luz Hortensia

; Hernández-Velázquez, Luiana

; Luna-Pech, Jorge A.

; Matta, Juan José

; Mogica-Martínez, María Dolores

; Rivero-Yeverino, Daniela

; Ruiz, Lucy Tania

; Río-Navarro, Blanca E. Del

; Gómez-Vera, Javier

; Macías-Weinmann, Alejandra

; Agache, Ionna

; Ansotegui, Ignacio

; Bachert, Claus

; Bedbrook, Anna

; Canonica, Giorgio Walter

; Casale, Thomas B.

; Cruz, Álvaro

; Fokkens, Wytske

; Hellings, Peter

; Samolinski, Bolesław

; Bousquet, Jean

Revista alergia México

Journal Metrics
- Sobre o periódico
- SciELO Analytics

dec 2019, Volume 66 N. 4 Pages 409 - 425

Abstract: En Es | Text: En Es | PDF: En | PDF: Es

Abstract The health and economic impact of allergic diseases are increasing rapidly, and changes in management strategies are required. Its influence reduces the capacity of work and school performance by at least a third. The ICPs of the airways (integrated care pathways for respiratory diseases) are structured multidisciplinary healthcare plans, promoting the recommendations of the guidelines in local protocols and their application to clinical practice. This document presents an executive summary for Argentina, Mexico, and Spain. Next-generation ARIA guidelines are being developed for the pharmacological treatment of allergic rhinitis (AR), using the GRADE-based guidelines for AR, tested with real-life evidence provided by mobile technology with visual analogue scales. It is concluded that in the AR treatment, H1-antihistamines are less effective than intranasal corticosteroids (INCS), in severe AR the INCS represent the first line of treatment, and intranasal combination INCS + anti-H1 is more effective than monotherapy. However, according to the MASK real-life observational study, patients have poor adherence to treatment and often self-medicate, according to their needs.

resumen está disponible en el texto completo

https://doi.org/10.29262/ram.v66i4.643 3239 downloads

Eco-Friendly Synthesis of 2,3-Dihydroquinazolin-4(1H)-ones Catalyzed by FeCl3/Al2O3 and Analysis of Large 1H NMR Diastereotopic Effect
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics
- Dimensions
- PlumX
- Altmetric

Monreal, Isabel

; Sánchez-Castellanos, Mariano

; Ramírez-Gualito, Karla

; Cuevas, Gabriel

; Espinoza, Karla A.

; Rivero, Ignacio A.

Journal of the Brazilian Chemical Society

Journal Metrics
- Sobre o periódico
- SciELO Analytics

jan 2019, Volume 30 N. 1 Pages 124 - 131

Abstract: En | Text: En | PDF: En

In the present study, we have carried out a condensation reaction for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones from 2-amino-N-benzylbenzamide and different aromatic aldehydes using FeCl3 catalyst supported on Al2O3. It was demonstrated that this material can be used successfully for the nucleation of quinazolinones with good to excellent yield; furthermore, the FeCl3/Al2O3 catalyst can be recovered and reused. This catalyst was used before in the synthesis of imidazole with very good yields. The synthesized quinazolinones showed a large range diastereotopic effect over the methylene group and, this anomalous difference was studied through nuclear magnetic resonance (NMR) and computational calculations.

https://doi.org/10.21577/0103-5053.20180161 674 downloads

Improved Method for Microwave-Assisted Synthesis of Benzodiazepine-2,5-diones from Isatoic Anhydrides Mediated by Glacial Acetic Acid
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics
- Dimensions
- PlumX
- Altmetric

Cruz, Armando De La

; Vega-Acevedo, Carlos Alejandro

; Rivero, Ignacio A.

; Chávez, Daniel

Journal of the Brazilian Chemical Society

Journal Metrics
- Sobre o periódico
- SciELO Analytics

aug 2018, Volume 29 N. 8 Pages 1607 - 1611

Abstract: En | Text: En | PDF: En

An improved and simpler method for the synthesis of benzodiazepin-2,5-diones and 7-iodobenzodiazepin-2,5-diones catalyzed by glacial acetic acid using isatoic anhydride and 6-iodoisatoic anhydride, respectively, as starting materials is reported. The target products were achieved in good yields (up to 71%) using microwave irradiation as the activating mode of reaction in the presence of acetic acid instead of the traditional polar aprotic solvents as dimethylformamide (DMF), dimethyl sulfoxide (DMSO) or dimethylacetamide (DMAC). Moreover, relatively simple purification workup is required. The optimal temperature to obtain the benzodiazepin-2,5-dione derivatives was 130 ºC, while the best irradiation time was 3 min. In addition, the methodology for the selective preparation of 6-iodoisatoic anhydride with an overall yield of 62% is presented.

https://doi.org/10.21577/0103-5053.20180031 777 downloads

Antioxidant activity and antimicrobial evaluation of 1-benzyl-1,2,3-triazole
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics
- Dimensions
- PlumX
- Altmetric

Montes-Ávila, Julio

; Sarmiento-Sánchez, Juan I.

; Delgado-Vargas, Francisco

; Rivero, Ignacio A.

; Díaz-Camacho, Sylvia P.

; Uribe-Beltrán, Magdalena

Acta universitaria

Journal Metrics
- Sobre o periódico
- SciELO Analytics

jun 2016, Volume 26 N. 3 Pages 63 - 67

Abstract: En Es | Text: En Es | PDF: En | PDF: Es

Abstract: This paper reports biological activities of 1-benzyl-1,2,3-triazoles: antimicrobial by broth microdilution method, antioxidant by DPPH (2,2-diphenyl-1-picrylhydrazyl)• inactivation assay and toxicity by brine shrimp (Artemia salina) assay. The compound 1-(1-Benzyl-1H-1,2,3-triazol-4-yl) cyclopentanol (50 µg/mL to 200 µg/mL) presented selective moderate inhibition of Staphylococcus aureus 3 growth whereas the same effect of 3-(1-Benzyl-1H-1,2,3-triazol-4-yl)propan-1-ol was registered against Escherichia coli AO11, E. coli AO15 and Salmonella enterica serovar Typhi. 5g-i compounds showed the highest DPPH• scanvenging. Synthetic 1,2,3-triazole evaluated compounds were classified in the range moderately toxic to non-toxic. Thus, based in the previously/actually published information, they could be a source of compounds with biological activities of importance for human health.

Resumen: Este artículo reporta las actividades biológicas de 1-bencil-1,2,3-triazoles: antibacteriana por el método de microdilución en caldo, antioxidante por el método de inactivación del DPPH (2,2-difenil-1-picrilhidrazil•) y la toxicidad en el ensayo de artemia (Artemia salina). El compuesto 1-(1-bencil-1H-1,2,3-triazol-4-il) ciclopentanol (50 µg/mL a 200 µg/mL) presentó inhibición selectiva y moderada contra el crecimiento de Staphylococcus aureus 3, mientras que el mismo efecto se registró para el 3-(1-bencil-1H-1,2,3-triazol-4-il)-1-propanol contra E. coli AO11, E. coli AO15 y Salmonella entérica serovar Typhi. Los compuestos 5g-i mostraron la más alta inactivación del DPPH•. Los compuestos sintéticos 1,2,3-triazoles evaluados se clasificaron en el intervalo de moderadamente tóxico a no tóxico. Así, basados en la información publicada actualmente, estos podrían ser una fuente de compuestos con actividades biológicas de importancia para la salud humana.

https://doi.org/10.15174/au.2016.937 747 downloads

Adsorption of Phenol and Chlorophenol Mixtures on Silicalite-1 Determined by GC-MS Method
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics

Ortiz-Arzate, Zareth

; Jiménez-Bravo, Thelma S

; Sánchez-Flores, Norma A.

; Pacheco-Malagón, Graciela

; Bulbulian, Silvia

; Rivero, Ignacio A.

Journal of the Mexican Chemical Society

Journal Metrics
- Sobre o periódico
- SciELO Analytics

jun 2013, Volume 57 N. 2 Pages 11 - 117

Abstract: En Es | Text: En Es | PDF: En | PDF: Es

A method is presented in which gas chromatography coupled with mass spectrometry (GC-MS) allows quantitative simultaneous detection of mixtures of phenol (Ph), 2-chlorophenol (2-CPh), 3-cholorphenol (3-CPh), and 4-cholorophenol (4-CPh) in aqueous mixtures after being adsorbed on silicalita-1, utilizing selected-ion monitoring (SIM) and full-scan modes mass selective detection. GC-MS with SIM at m/z = 64 and m/z = 128 showed good detection selectivity for mixtures of Ph, 2-CPh and 3-CPh (M1), and 2-CPh and 4-CPh (M2). Silicalita-1 was obtained from an amorphous organo-alumino-silicic gel from rice husk, an abundant and low cost agricultural waste residue that is readily available in large quantities. This product was used as a sorbent for solid phase extraction of organic analytes from aqueous solutions. The adsorption of the three chlorophenol isomers, ortho-, meta-, and para-, by silicalite-1 has been studied independently, showing that meta- and para-chlorophenol isomers are adsorbed more than ortho-chlorophenol. However the adsorption behavior of mixtures of these isomers was not reported. In this work, it was found that when the ortho-isomer is mixed either with meta-or para-chlorophenol, considerable differences were observed in the adsorption process; in the studied mixture, the ortho-isomer was adsorbed more than the meta-and para-chlorophenol.

En este trabajo se presenta un método cromatográfico acoplado a la espectrometría de masas (GC-MS) que permite la detección simultánea de fenol(Ph), 2-clorofenol (2-CPh), 3-clorofenol (3-CPh), y 4-clorofenol (4-CPh) en mezclas acuosas después de ser adsorbidas sobre silicalita-1, utilizando iones previamente seleccionados y el espectro completo de iones. Los iones en SIM de m/z = 64 y 128 mostraron una buena detección y selectividad para mezclas de Ph, 2-CPh, y 3CPh (M1) y 2-CPh y 4-Cph (M2). La silicalita-1 se obtuvo a partir de un gel órgano-alumino-silícico amorfo proveniente de cáscara de arroz, material abundante y de bajo costo, dado que proviene de residuos agrícolas disponibles fácilmente en grandes cantidades. Este producto se utilizó como un sorbente en la extracción en fase sólida de analitos orgánicos a partir de soluciones acuosas. La adsorción de los tres isómeros de clorofenol, orto, meta, y para, por la silicalita-1 ha sido estudiada de forma independiente, mostrando que los isómeros meta y para clorofenol se adsorben más que el orto-clorofenol. Sin embargo, el comportamiento de adsorción de mezclas de estos isómeros no se ha reportado. En este trabajo, se ha encontrado que cuando el isómero orto se encuentra en mezcla con el meta o para-clorofenol presentan diferencias considerables, como se observó en el proceso de adsorción; en la mezcla estudiada el isómero orto se adsorbe más que el meta y para-clorofenol.

1910 downloads

Reaction of o-Aminobenzamides with Dialkyl Carbonates and Ionic Liquids: A Novel one-pot, High-yield, Microwave-assisted Synthesis of 1-Alkylquinazoline-2,4-diones
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics

Guerrero R., Leticia

; Rivero, Ignacio A.

Journal of the Mexican Chemical Society

Journal Metrics
- Sobre o periódico
- SciELO Analytics

jun 2012, Volume 56 N. 2 Pages 201 - 206

Abstract: En Es | Text: En Es | PDF: En | PDF: Es

A simple and efficient methodology for the synthesis of 1-alkyl-2,4-(1H,3H)-quinazolinediones from o-aminobenzamides has been developed. The novel one-pot cyclization-alkylation reactions are easier and faster than any other reported protocols and resulted in excellent yields (96-98%) and high purities, making this methodology suitable for library synthesis in drug discovery efforts. By applying microwave irradiation at 130 °C and in the presence of ionic liquids, dimethyl or diethyl carbonates simultaneously act as carbonylating and alkylating agents.

Se ha desarrollado una metodología eficiente para la sÃntesis de 1-alquil-2,4-(1H,3H)-quinazolinedionas a partir de o-aminoben-zamidas. Es una reacción novedosa que realiza tanto la ciclación como la alquilación al mismo tiempo, es más fácil y rápida que cualquier otro protocolo, se obtienen con excelentes rendimientos (96-98%) y alta pureza. Esta metodología es adecuada para la síntesis de bibliote-cas que potencialmente promueven el desarrollo de nuevos fármacos. Mediante la irradiación por microondas a 130 °C y en presencia de líquidos iónicos, los carbonatos de dimetilo o de dietilo pueden actuar como agentes para la carbonilación y la alquilación.

1399 downloads

Study of the Influence of Microwave and Conventional Heating on the Lipase-Catalyzed Esterification of Lauric Acid with Different Alcohols
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics

Osuna, Velia

; Rivero, Ignacio A.

Journal of the Mexican Chemical Society

Journal Metrics
- Sobre o periódico
- SciELO Analytics

jun 2012, Volume 56 N. 2 Pages 176 - 182

Abstract: En Es | Text: En Es | PDF: En | PDF: Es

In a systematic study, three commercial lipases were used for the esterification of lauric acid with six different alcohols: methanol, ethanol, propanol, butanol, pentanol, and allyl alcohol, under conventional heating and microwave irradiation. Optimization of reaction conditions included reaction time and effect of temperature under microwave irradiation and conventional heating. The optimum reaction temperature was previously established in enzymatic esterification by conventional heating. Novozyme 435, lipase {Pseudomonas cepacia) immobilized in diatomite (PS-DI) and lipase (P. cepacia) immobilized in ceramic (PS-CI) were used in this study. The latter showed the highest activity, therefore, this enzyme was used to investigate the variation of reaction time under microwave heating. The stability of immobilized lipases under classical heating and under the microwave irradiation was studied by visual analysis of the immobilized matrix by scanning electron microscopy (SEM).

En este estudio sistemático, tres lipasas comerciales se utilizaron para la esterificación del acido láurico con seis diferentes alcoholes: metanol, etanol, propanol, butanol, pentanol, y alcohol alílico, utilizando calentamiento convencional y la radiación por microondas. Se optimizaron las condiciones de reactión; tiempo de reactión y la temperatura por calentamiento convencional y por radiación de microondas. Se estableció previamente la temperatura optima de reactión en la esterificación enzimática por calentamiento convencional. Las lipasas Novozyme 435, aislada de la Pseudomonas cepacia e inmovilizada en tierra de diatomeas (PS-DI) y la aislada de la P. cepacia inmovilizada en cerámica (PS-CI), fueron utilizadas en este estudio. La última presentó la mayor actividad, por lo tanto se utilizó para investigar el efecto del tiempo de reactión con calentamiento por microondas. La estabilidad de las lipasas inmovilizadas tanto por calentamiento convencional como con radiación por microondas fue monitoreada al estudiar la morfología de la matriz por microscopia electrónica de barrido (SEM).

1551 downloads

Sensitive single step fluorimetric method for monitoring solid-phase reactions on polystyrene resin-bound chloride groups
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics

Pina-Luis, Georgina E.

; Gómez, Marco A. Zazueta

; Espejel, Ignacio A. Rivero

; Díaz-García, Marta E.

Journal of the Brazilian Chemical Society

Journal Metrics
- Sobre o periódico
- SciELO Analytics

jun 2011, Volume 22 N. 6 Pages 1024 - 1032

Abstract: Pt En | Text: Pt En | PDF: Pt | PDF: En

Espectroscopia de fluorescência tem sido usada para monitorar a conversão química de resinas ligadas a grupos cloreto. Os perfis tempo-concentração de diferentes reações envolvendo a incorporação de derivados de hidroxifeniletanona (HPE) à resina Merrifield e 2-aminobencilalcool (ABA) à resina clorosulfonada são mostrados. A avaliação do progresso da reação foi feita usando-se um marcador fluorescente imobilizado (dansil hidrazina) e por medidas diretas de fluorescência da espécie formada em cada etapa das reações nos grãos da resina. Não foram observadas diferenças significativas entre estes dois métodos. Os resultados mostraram que medidas diretas na fase sólida sem o uso de marcadores fluorescentes representam uma análise simples, rápida, não destrutiva e de baixo custo para o monitoramento do progresso de reações em resinas cloradas, a qual permite não somente o estudo da cinética de reação, mas também proporciona uma ferramenta valiosa para a quantificação analítica de resina ligada a cloreto, sem nenhuma preparação da amostra, exceto a transferência do grão da resina de cada estágio reacional, do frasco reacional para a célula de fluxo, para a medida de fluorescência.

Fluorescence spectroscopy has been used to monitor the chemical conversion of resin-bound chloride groups. The time-concentration profiles of different reactions involving the incorporation of hydroxyphenylethanone (HPE) derivatives to Merrifield resin and 2-aminobencylalcohol (ABA) to a chlorosulphonate resin are shown. The evaluation of the reaction progress was made using an immobilized fluorescent tracer (dansyl hydrazine) and by direct fluorescence measurements of the species formed on each step of the reactions on resin beads. Significant differences between these two methods were not observed. The results demonstrate that direct measurements on solid phase without using fluorescent markers represent a single step, rapid, non destructive and low cost analysis by monitoring reaction progress on chlorinated resins, which allows not only the study of reaction kinetics but also provides a valuable tool for the analytical quantification of chloride resin bound, without any sample preparation, except the transfer of resin bead of each reaction stage from the reaction vessel to the flow cell for the fluorescent measurement.

2316 downloads

10.

Synthesis of Peptides Histamine H2 Receptors in Solid-Phase Assisted by Microwave
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics

Reynoso-Soto, Edgar A.

; Rivero, Ignacio A.

Journal of the Mexican Chemical Society

Journal Metrics
- Sobre o periódico
- SciELO Analytics

sep 2010, Volume 54 N. 3 Pages 160 - 163

Abstract: En Es | Text: En Es | PDF: En | PDF: Es

The synthesis of histamine H2 receptors peptides was conducted using the methodology of solid phase assisted by microwaves. Microwaves can reduce the reaction times during the coupling and deprotection steps to obtain the desired peptide sequence. The coupling reaction was carried out with a mixture of N, N'-diisopropyl-carbodiimide (DIC) and N,N,N'N'-tetramethyl-O-(1H-benzotriazol-1-yl)uronium hexafluorophosphate (HBTU). The purity and yield are improved in peptide synthesis assisted by microwaves. Coupling reactions and deprotection on Rink resin were carried out in 5 min depending on amino acid and the length of the peptide chain.

La síntesis de péptidos receptores de histamina H2 fue realizada empleando la metodología de síntesis en fase sólida asistida por microondas. Las microondas permitieron disminuir los tiempos de reacción durante las etapas acoplamiento y desprotección para obtener la secuencia deseada de péptido. La reacción de acoplamiento se llevó a cabo con una mezcla de N, N'-diisopripilcarbodimida y N,N,N',N'-tetrarnetil-O-(1H-benzotriazol-1-il)uronio hexafluorofosfato. La pureza y el rendimiento son mejorados en la síntesis de péptidos asistida por microondas. Las reacciones de acoplamiento y desprotección sobre la resina de Rink se llevaron a cabo en 5 min por protocolo y dependiendo del aminoácido son el número de protocolos empleados.

1097 downloads

11.

Special Issues of the J. Mex. Chem. Soc. in Honor of Dr. Silvia Bulbulian
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics

Rivero Espejel, Ignacio A.

Journal of the Mexican Chemical Society

Journal Metrics
- Sobre o periódico
- SciELO Analytics

mar 2010, Volume 54 N. 1

Abstract: En | Text: En | PDF: En

681 downloads

12.

Preparation and supporting on solid phase of chiral auxiliary (S)-4-(4-hydroxybenzyl)oxazolidin-2-one from L-tyrosinol assisted by Microwaves
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics

Cruz, Adriana

; Rivero, Ignacio A.

Journal of the Mexican Chemical Society

Journal Metrics
- Sobre o periódico
- SciELO Analytics

sep 2009, Volume 53 N. 3 Pages 120 - 125

Abstract: En Es | Text: En Es | PDF: En | PDF: Es

An oxazolidinone chiral auxiliary, (S)-(4-Hydroxybenzyl)-1,3-oxazolidin-2-one 4 was prepared in 23-80 % yield from L-tyrosinol using different methodologies. In solution, compound 4 was protected with a benzyl group on the phenolic hydroxyl 5a, which allowed the optimization of the solid phase synthesis of 5b-5d. Chiral auxiliaries 5a and 5b reacted in solution with an α, β-unsaturated system to give (S)-4-(4-(benzyloxy)benzyl)-1,3-oxazolidin-2-one 6a. By contrast, in solid phase the same reaction afforded 6b. Both reactions were carried out under microwave activation. New compounds were characterized by ¹H and 13C NMR, infrared spectroscopy and mass spectrometry.

En este trabajo se reporta la preparación del nuevo auxiliar quiral de tipo oxazolidinona, (S)-(4-hidroxibencil)-1,3-oxazolidin-2-ona 4 que fue preparado a partir del L-tirosinol utilizando diferentes metodologías, con rendimientos que fluctúan en un intervalo de 23-80 %, dependiendo del método. El compuesto 4 fue preparado en solución, protegidos con el grupo benciloxi en el hidroxilo fenólico 5a, para llevar a cabo la optimización de la síntesis en fase sólida de 5b-5d. Los auxiliares quirales 5a y 5b fueron adicionados en solución a un sistema α, β-insaturado, obteniéndose a la (S)-4-(4-(benciloxi)bencil)-1,3-oxazolidin-2-ona 6, mientras que en fase sólida se observó la formación del compuesto 6b. Estas reacciones fueron activadas con microondas. Todos los compuestos fueron caracterizados mediante RMN (¹H y 13C), IR y EM.

1172 downloads

13.

Physiology of citrus fruiting
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics

Iglesias, Domingo J.

; Cercós, Manuel

; Colmenero-Flores, José M.

; Naranjo, Miguel A.

; Ríos, Gabino

; Carrera, Esther

; Ruiz-Rivero, Omar

; Lliso, Ignacio

; Morillon, Raphael

; Tadeo, Francisco R.

; Talon, Manuel

Brazilian Journal of Plant Physiology

Journal Metrics
- Sobre o periódico
- SciELO Analytics

dec 2007, Volume 19 N. 4 Pages 333 - 362

Abstract: Pt En | Text: Pt En | PDF: Pt | PDF: En

Citrus é a principal fruteira no mundo, tendo, portanto, profundos impactos econômicos, sociais e culturais em nossa sociedade. Nos últimos anos, o conhecimento sobre a biologia reprodutiva de plantas tem aumentado consideravelmente, principalmente em função de trabalhos desenvolvidos com plantas-modelo. Todavia, a informação produzida nessas espécies nem sempre pode ser aplicada a citrus, fundamentalmente porque citrus é uma cultura arbórea perene com uma biologia reprodutiva muito peculiar e incomum. A regulação do crescimento e desenvolvimento do fruto em citrus é um fenômeno complexo e dependente de muitos fatores externos e internos que podem operar tanto seqüencialmente como simultaneamente. Os elementos e mecanismos pelos quais estímulos ambientes e endógenos afetam o crescimento do fruto vêm sendo interpretados, e esse conhecimento pode auxiliar a prover ferramentas que permitiriam otimizar a produção per se, além da obtenção de frutos com maior valor nutricional, o objetivo precípuo da Industria de Citrus. Neste artigo, revisam-se os avanços que vêm ocorrendo na fisiologia da frutificação de citrus durante os últimos anos; apresenta-se, também, o status atual de pesquisas mais relevantes nessa área.

Citrus is the main fruit tree crop in the world and therefore has a tremendous economical, social and cultural impact in our society. In recent years, our knowledge on plant reproductive biology has increased considerably mostly because of the work developed in model plants. However, the information generated in these species cannot always be applied to citrus, predominantly because citrus is a perennial tree crop that exhibits a very peculiar and unusual reproductive biology. Regulation of fruit growth and development in citrus is an intricate phenomenon depending upon many internal and external factors that may operate both sequentially and simultaneously. The elements and mechanisms whereby endogenous and environmental stimuli affect fruit growth are being interpreted and this knowledge may help to provide tools that allow optimizing production and fruit with enhanced nutritional value, the ultimate goal of the Citrus Industry. This article will review the progress that has taken place in the physiology of citrus fruiting during recent years and present the current status of major research topics in this area.

123407 downloads

14.

Parallel Synthesis of Polystyrene Anchored Imine Sulfide Materials: Sorption and Metal Sensing Studies
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics

Valdés, Aristides C.

; Pina-Luis, Georgina

; Rivero, Ignacio A.

Journal of the Mexican Chemical Society

Journal Metrics
- Sobre o periódico
- SciELO Analytics

jun 2007, Volume 51 N. 2 Pages 87 - 95

Abstract: En Es | Text: En Es | PDF: En | PDF: Es

In the present work we report the synthesis of a combinatorial library of 30 phenyl-ethyl based N-derivatives [nitro, amines and imines] bound to PS-thiophenol resin. The five step reaction sequence was characterized by ¹H NMR, MS and fluorescence spectroscopy of resin beads. The imines were screened for those that exhibited a large sorption capacity for Cu(II) and Pb(II) ions and those exhibiting a large fluorescence change upon the metal binding.

Se reporta la síntesis de una biblioteca combinatorial de 30 N-derivados fenil etilo (nitro, aminas e iminas) unidos a una resina PS-tiofenol. La secuencia de 5 pasos de reacción fue seguida por ¹H RMN, EM y espectroscopia de fluorescencia de la resina. Las iminas fueron monitoreadas para aquellas que mostraron gran capacidad de porción para iones Cu(II) y Pb(II) y aquellas que mostraron un gran cambio de fluorescencia por la unión al metal.

466 downloads

15.

Synthesis and Hydrolysis Monitoring of Sasrin-like Resin Bound Imines by Fluorescence Spectroscopy
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics

Madrigal, Domingo

; Pina-Luis, Georgina

; Rivero, Ignacio A.

Journal of the Mexican Chemical Society

Journal Metrics
- Sobre o periódico
- SciELO Analytics

dec 2006, Volume 50 N. 4 Pages 175 - 179

Abstract: En Es | Text: En Es | PDF: En | PDF: Es

Merrifield resin was converted to various dialkyl-trihy-droxybenzaldehyde resins and then to different bound imine resins. Fluorescence spectroscopy was used to continuously monitor the intermediates performed on the resins. Using fluorescent label (dansyl chloride) information on the kinetics of the amine cleavage was obtained. This study demonstrated that direct measures of fluorescence intensity on single-resin beads can be an effective method of monitoring solid phase organic reactions.

Se empleó resina de Merrifield para obtener varias resinas con grupos de trihidroxibenzaldehido dialquilados y posteriormente se obtuvieron las correspondientes iminas. Los intermediarios formados sobre las resinas fueron monitoreados usando espectroscopia de fluorescencia. Se obtuvo la cinética de liberación de la amina usando un indicador fluorescente (cloruro de dansilo). Este estudio sugiere que la intensidad de fluorescencia obtenida por medida directa desde una muestra de resina puede ser un método eficiente para monitorear reacciones en fase sólida.

364 downloads

Showing

itens per page

Page of 2 Next

Select one or more results

All Alphabetic

Results

Comparative chart Download CSV

Statistics of

Send result

To*

Use ; (semicolon) to insert more emails.

Send to email

This page

Selected records

All references (max. 300)

Your email

Subject

Comments

Export format:

RIS (for EndNote, ProCite, Reference Manager, RefWorks, Citavi, etc.)

BibTeX

Citation

CSV (for Excel, etc)

Export:

This page

Selected itens

All references (max. 2000)

Sem resultados

No documents were found for your search

Glossary and search help

You can enrich your search in a very simple way. Use the search indexes combined with the connectors (AND or OR) and specify more your search.

For example, if you want to search for articles about
cases of dengue in Brasil in 2015, use:
ti:dengue and publication_year:2015 and aff_country:Brasil

See below the complete list of search indexes that can be used:

Index code	Element
ti	article title
au	author
kw	article keywords
subject	subject (title words, abstract and keywords)
ab	abstract
ta	journal short title (e.g. Cad. Saúde Pública)
journal_title	journal full title (e.g. Cadernos de Saúde Pública)
la	publication language code (e.g. pt - Portuguese, es - Spanish)
type	document type
pid	publication identifier
publication_year	publication year of publication
sponsor	sponsor
aff_country	country code of the author's affiliation
aff_institution	author affiliation institution
volume	article volume
issue	article issue
elocation	elocation
doi	DOI number
issn	journal ISSN
in	SciELO colection code (e.g. scl - Brasil, col - Colômbia)
use_license	article usage license code

SciELO - Scientific Electronic Library Online
Rua Dr. Diogo de Faria, 1087 – 9º andar – Vila Clementino 04037-003 São Paulo/SP - Brasil
Email: scielo@scielo.org

All the contents of this site www.scielo.br, except where otherwise noted, is licensed under a Creative Commons Attribution License.
more »