Estudio de la polimerización de algunas aldo y cetohexosas en medios ácidos / Alberto Tárraga Tomás ; director Pedro Antonio García Ruiz

Tesis-Universidad de Murcia.Consulte la tesis en: BCA. GENERAL. ARCHIVO UNIVERSITARIO. T.M.-148

Nuevo método de preparación de soforosa y kojibiosa a partir de 1,6-anhidrok-- D-glucopiranosa

Se describe un nuevo método para la preparación de os disackridos soforosa y koji,biosa por tratamiento en condiciones suaves de 1,ó-anhidro-& D-glucopiranosa en DMF-HCI 0.03 N

Oligomerización dé aldohexosas en DMF-HCl. Estudio del mecanismo

Basándose en los datos obtenidos en reacciones de oligomerización catalizadas por ácidos de D-glucosa, D-galactosa, D-manosa y L-rhamnosa en DMF-HGl se proponen esquemas mecanísticos para cada caso

Tratamiento ácido de cetohexosas.

Se estudia el comportamiento de D-fructosa y L-sorbosa frente a medios ácidos, empleando como disolventes agua y NN-dimetilformamida. Las cetohexosas fueron sometidas a idénticas condiciones de acidez, concentración, temperatura y tiempo de reacción que las aldohexosas estudiadas en trabajos anteriores (1), con objeto de comparar los resultados, no sólo en cuanto a posibles reacciones de glicosidación, con formación de disacáridos, sino también frente a posibles reacciones secundarias

Structure−property correlation behind the high mobility of carbazolocarbazole

A comparative study of carbazolocarbazole isomers and their respective N-alkyl derivatives confirms the good performance of carbazolo[2,1-a]carbazole as hole transporting material in organic field effect transistors. The azaphenacene structure of this molecule forms a dense packing promoted by particularly short longitudinal shifts between molecules establishing face-to-face and edge-to-face interactions. Computational calculations have determined an almost isotropic 2D transport environment within a lamellar structure. This favorable solid state arrangement, in combination with appropriate interfacial layers, has led to a high mobility (1.3 cm2V-1s-1) that validates the aptitude of this molecular material as organic semiconductor

Reactividad del catión 4,6-dif enil-2-metiltiopiridinio N-sustituido frente a reactivos nucleófilos

Se describen las reacciones del catión 4,6-difenil-2-nietiltiopiridinio (III) frente a diferentes reactivos nucleófilos. El compuesto (III), reacciona con trifenilfosfina para dar los correspondientes yoduros de arilmetil trifenil fosfonio. Similarmente, (III) reacciona con trietilamina, azida de sodio y acetato de sodio para dar los correspondientes yoduros de arilmetil trietil amonio, arilmetil azidas y acetados de arilmetilo. El compuesto (III) reacciona con cloruro de mercurio (II) para dardos correspondientes dicloroyodomercuriatos de piridinio

Melanoma Activation of 3-O-(3,4,5-Trimethoxybenzoyl)-(-)-Epicatechin to a Potent Irreversible Inhibitor of Dihydrofolate Reductase

This is an Accepted Manuscript version of the following article, accepted for publication in [Molecular Pharmaceutics]. [Sánchez-del-Campo L, Tárraga A, Montenegro MF, Cabezas-Herrera J, Rodríguez-López JN. Melanoma activation of 3-o-(3,4,5-trimethoxybenzoyl)-(-)-epicatechin to a potent irreversible inhibitor of dihydrofolate reductase. Mol Pharm. 2009 May-Jun;6(3):883-94. doi: 10.1021/mp800259k]. It is deposited under the terms of the Creative Commons Attribution-Non Commercial License (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is properly cited.©2009. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Accepted version of a Published Work that appeared in final form in Molecular Pharmaceutics. To access the final edited and published work see https://doi.org/10.1021/mp800259kHuman melanoma is a significant clinical problem because it is resistant to treatment by most chemotherapeutic agents, including antifolates. It is therefore a desirable goal to develop a second generation of low-toxicity antifolate drugs to overcome acquired resistance to the prevention and treatment of this skin pathology. In our efforts to improve the stability and bioavailability of green tea polyphenols for cancer therapy, we synthesized a trimethoxy derivative of epicatechin-3-gallate, which showed high anti proliferative and proapoptotic activity against melanoma. This derivative, 3-O-(3,4,5-trimethoxybenzoyl)-(-)-epicatechin (TMECG), is a prodrug that is selectively activated by the specific melanocyte enzyme tyrosinase. Upon activation, TMECG generates a stable quinone methide product that strongly inhibits dihydrofolate reductase in an irreversible manner. The treatment of melanoma cells with TMECG also affected cellular folate transport and the gene expression of DHFR, which supported the antifolate nature of this compound. In addition, its pharmacological efficacy has been confirmed in a mouse melanoma model, in which tumor growth and metastasis were inhibited, significantly enhancing the mean survival of the treated groups. TMECG, therefore, shows a potential for clinical use in melanoma therapy

Synthesis and characterization of carbazolo[2,1-a]carbazole in thin film and single crystal field-effect transistors

The synthesis of a hexacyclic fused polyheteroaromatic system, namely carbazolo[2,1-a]carbazole, using a simple two-step route is reported. Additionally, the characterization of its electronic structure is described, corresponding to a very stable molecule that is also transparent to the visible light. The solid state packing is determined by X-ray diffraction analysis which, in combination with the computational calculation of the charge transfer parameters, reveals an adequate molecular arrangement to achieve a low anisotropic environment for charge transport. This π-conjugated system is used as organic semiconductor for the fabrication of thin film and single crystal organic field-effect transistors (OFETs). Furthermore, the evaluation of different gate dielectrics results in transistors with very good hole mobilities and low operating voltages. In agreement with these results, carbazolo[2,1-a]carbazole becomes some of the best organic semiconductors belonging to the family of carbazole-based azaphenacenes

Hydrogen-bonded azaphenacene: a strategy for the organization of π-conjugated materials

A centrosymmetric fused polyheteroaromatic system, namely 7-azaindolo[2,3-h]α-carboline has been synthesized. The pentacyclic structure includes rationally located hydrogen bond donor and hydrogen bond acceptor sites to induce its self-assembly. The molecular units associate forming an extended monodimensional arrangement that further self-organizes through π-stacking. The optical, electrochemical, X-ray diffraction, computational and electronic characterization in organic field effect transistors proves the utility of hydrogen bond-directed self-assembly as strategy to enhance edge-to-edge interactions and orbital overlap that contribute to the charge transport properties in π-conjugated systems