Abstract Functionalised N ‐heterocyclic pyridinium N ‐aminides have been designed and synthesised to evaluate a nitrenoid‐based annulation strategy into imidazole‐fused oxo‐substituted frameworks of importance to medicinal and agrochemical discovery programmes. Sulfenyl substituted ynamides were identified as privileged reactants affording productive gold‐catalysed annulation reactions with these and other nitrenoids. This annulation method provides selective and efficient access into geminally amino‐sulfenyl substituted nitrogen heterocycles under mild reaction conditions. magnified image

Annulation

Imidazole

Michael reaction

10.1002/adsc.202000134

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Citations (19)

Electrocatalytic Activity of Nano-Crystalline Ni-Co-Mo-Fe Alloys on the Oxygen Evolution Reaction (OER)

ECS Transactions (2006)

Miguel Domínguez Magdalena Plata A.M. Torres–Huerta Claudia Ramírez Elsa M. Arce

Abstract The electrocatalytic behavior of nanocrystalline Co30Ni70, Co40Mo60, Ni40Mo60, Co15Ni30Mo55, Fe10Co35Ni55 and Co15Fe30Ni55 mol-% alloys on the oxygen evolution reaction [OER ] in a 30 wt-% KOH aqueous solution at 298, 323 and 343 K has been assessed in this work. Appreciable currents for oxygen evolution reactions were measured at Ni-Co-Mo-Fe electrodes produce by this technique. It was also found that iron increased the electrocatalytic activity for oxygen evolution reaction, but it was not as good as obtained on hydrogen evolution reaction [HER]. Tafel plots of preoxidized and prolonged cycled Co30Ni70, Co40Mo60, Ni40Mo60, Co15Ni30Mo55, Fe10Co35Ni55 and Co15Fe30Ni55 crystalline electrodes were very different, which might be related to changes in the surface enrichment of one or two of the alloy constituents. The electrocatalytic effects Mo seem to be more important on the OER at high temperatures than those showed previously for HER. Nickel and Molybdenum rich alloys showed particularly high activity towards the OER in comparison with their nanocrystalline counterparts.

Oxygen evolution

Nanocrystalline material

10.1149/1.2357105

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The protein aggregation inhibitor YAT2150 has potent antimalarial activity in Plasmodium falciparum in vitro cultures

BMC Biology (2022)

Inés Bouzón‐Arnáiz Yunuen Ávalos-Padilla Arnau Biosca Omar Caño-Prades Lucía Román-Álamo

Abstract Background By 2016, signs of emergence of Plasmodium falciparum resistance to artemisinin and partner drugs were detected in the Greater Mekong Subregion. Recently, the independent evolution of artemisinin resistance has also been reported in Africa and South America. This alarming scenario calls for the urgent development of new antimalarials with novel modes of action. We investigated the interference with protein aggregation, which is potentially toxic for the cell and occurs abundantly in all Plasmodium stages, as a hitherto unexplored drug target in the pathogen. Results Attempts to exacerbate the P. falciparum proteome’s propensity to aggregation by delivering endogenous aggregative peptides to in vitro cultures of this parasite did not significantly affect their growth. In contrast, protein aggregation inhibitors clearly reduced the pathogen’s viability. One such compound, the bis(styrylpyridinium) salt YAT2150, exhibited potent antiplasmodial activity with an in vitro IC 50 of 90 nM for chloroquine- and artemisinin-resistant lines, arresting asexual blood parasites at the trophozoite stage, as well as interfering with the development of both sexual and hepatic forms of Plasmodium . At its IC 50 , this compound is a powerful inhibitor of the aggregation of the model amyloid β peptide fragment 1-40, and it reduces the amount of aggregated proteins in P. falciparum cultures, suggesting that the underlying antimalarial mechanism consists in a generalized impairment of proteostasis in the pathogen. YAT2150 has an easy, rapid, and inexpensive synthesis, and because it fluoresces when it accumulates in its main localization in the Plasmodium cytosol, it is a theranostic agent. Conclusions Inhibiting protein aggregation in Plasmodium significantly reduces the parasite’s viability in vitro. Since YAT2150 belongs to a novel structural class of antiplasmodials with a mode of action that potentially targets multiple gene products, rapid evolution of resistance to this drug is unlikely to occur, making it a promising compound for the post-artemisinin era.

Proteostasis

Proteome

10.1186/s12915-022-01374-4

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Citations (9)

Photodecomposition of NO by sol–gel TiO2 catalysts under atmospheric conditions: Effect of the method on the textural and morphologic properties

Journal of Alloys and Compounds (2006)

Rafael Montesinos Carrera Aimé Vázquez Elsa M. Arce M. Morán-Pineda S. Castillo

10.1016/j.jallcom.2006.08.334

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Citations (10)

The ph and the trypsin or chymotrypsin kinetic reaction with amino acil esters

Elsa M. Arce Zoyla Nieto Armando Castañeda

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