David Briones

Curcumin-loaded silica-based mesoporous materials: Synthesis, characterization and cytotoxic properties against cancer cells

Two different silica based (MSU-2 and MCM-41) curcumin loaded mesoporous materials V3 and V6 were synthesized and characterized by several physico-chemical techniques. Release kinetic study revealed the slow and sustained release of curcumin from those materials in blood simulated fluid (pH: 7.4). The materials V3 and V6 were found to be biocompatible in non-cancerous CHO cell line while exhibiting significant cytotoxicity in different cancer cells (human lung carcinoma cells: A549, human breast cancer cells: MCF-7, mouse melanoma cells: B16F10) compared to pristine curcumin indicating the efficacy of the mesoporous silica materials based drug delivery systems (DDSs). The generation of intracellular reactive oxygen species (ROS) and down regulation of anti-apoptotic protein leading to the induction of apoptosis were found to be the plausible mechanisms behind the anti-cancer activity of these DDSs. These results suggest that curcumin-loaded drug delivery system may be successfully employed as an alternative treatment strategy for cancer therapeutics through a nanomedicine approach in near future.

A Recyclable Cu-MOF-74 Catalyst for the Ligand-Free O-Arylation Reaction of 4-Nitrobenzaldehyde and Phenol

The activity and recyclability of Cu-MOF-74 as a catalyst was studied for the ligand-free C–O cross-coupling reaction of 4-nitrobenzaldehyde (NB) with phenol (Ph) to form 4-formyldiphenyl ether (FDE). Cu-MOF-74 is characterized by having unsaturated copper sites in a highly porous metal-organic framework. The influence of solvent, reaction temperature, NB/Ph ratio, catalyst concentration, and basic agent (type and concentration) were evaluated. High conversions were achieved at 120 °C, 5 mol % of catalyst, NB/Ph ratio of 1:2, DMF as solvent, and 1 equivalent of K2CO3 base. The activity of Cu-MOF-74 material was higher than other ligand-free copper catalytic systems tested in this study. This catalyst was easily separated and reused in five successive runs, achieving a remarkable performance without significant porous framework degradation. The leaching of copper species in the reaction medium was negligible. The O-arylation between NB and Ph took place only in the presence of Cu-MOF-74 material, being negligible without the solid catalyst. The catalytic advantages of using nanostructured Cu-MOF-74 catalyst were also proven.

New URJC-1 Material with Remarkable Stability and Acid-Base Catalytic Properties

Emerging new metal-organic structures with tunable physicochemical properties is an exciting research field for diverse applications. In this work, a novel metal-organic framework Cu(HIT)(DMF)0.5, named URJC-1, with a three-dimensional non-interpenetrated utp topological network, has been synthesized. This material exhibits a microporous structure with unsaturated copper centers and imidazole–tetrazole linkages that provide accessible Lewis acid/base sites. These features make URJC-1 an exceptional candidate for catalytic application in acid and base reactions of interest in fine chemistry. The URJC-1 material also displays a noteworthy thermal and chemical stability in different organic solvents of different polarity and boiling water. Its catalytic activity was evaluated in acid-catalyzed Friedel–Crafts acylation of anisole with acetyl chloride and base-catalyzed Knoevenagel condensation of benzaldehyde with malononitrile. In both cases, URJC-1 material showed very good performance, better than other metal organic frameworks and conventional catalysts. In addition, a remarkable structural stability was proven after several consecutive reaction cycles.

CCDC 1543459: Experimental Crystal Structure Determination

Related Article: Jose M. Seco, Sonia Perez-Yanez, David Briones, Jose Angel Garcia, Javier Cepeda, Antonio Rodriguez-Dieguez|2017|Cryst.Growth Des.|17|3893|doi:10.1021/acs.cgd.7b00522

CCDC 1543461: Experimental Crystal Structure Determination

Related Article: Jose M. Seco, Sonia Perez-Yanez, David Briones, Jose Angel Garcia, Javier Cepeda, Antonio Rodriguez-Dieguez|2017|Cryst.Growth Des.|17|3893|doi:10.1021/acs.cgd.7b00522

CCDC 1543460: Experimental Crystal Structure Determination

Related Article: Jose M. Seco, Sonia Perez-Yanez, David Briones, Jose Angel Garcia, Javier Cepeda, Antonio Rodriguez-Dieguez|2017|Cryst.Growth Des.|17|3893|doi:10.1021/acs.cgd.7b00522

CCDC 1543458: Experimental Crystal Structure Determination

Related Article: Jose M. Seco, Sonia Perez-Yanez, David Briones, Jose Angel Garcia, Javier Cepeda, Antonio Rodriguez-Dieguez|2017|Cryst.Growth Des.|17|3893|doi:10.1021/acs.cgd.7b00522

2D-cadmium MOF and gismondine-like zinc coordination network based on the N-(2-tetrazolethyl)-4′-glycine linker

This work was supported by the MEC of Spain (Project CTQ2011-24478) and the Junta de Andalucia (FQM-1484). D. F.-J. thanks the Royal Society for a University Research Fellowship.