Synthesis of Fluorogenic Arylureas and Amides and Their Interaction with Amines: A Competition between Turn-on Fluorescence and Organic Radicals on the Way to a Smart Label for Fish Freshness

We describe the synthesis of fluorogenic arylureas and amides and their interaction with primary or secondary amines under air and light in organic-aqueous mixtures to give rise to a new class of persistent organic radicals, described on the basis of their electron paramagnetic resonance (EPR), as well as UV–vis, fluorescence, NMR, and quantum mechanics calculations, and their prospective use as multi-signal reporters in a smart label for fish freshness.Funded by the NATO Science for Peace and Security Programme (Grant SPS G5536), the Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (Grant BU263P18), and the Ministerio de Ciencia e Innovación (Grant PID2019-111215RB-100

Synthesis of Pyrrolidine-Fused 1,3-Dithiolane Oligomers by the Cycloaddition of Polycyclic Dithiolethiones to Maleimides and Evaluation as Mercury(II) Indicators

The scandium triflate-catalyzed cycloaddition reaction of polycyclic 1,2-dithiolethiones to maleimides is described. The reaction constitutes an easy approach to linear as well as branched oligomeric cis-fused dihydro[1,3]dithiolo[4,5-c]pyrrole-4,6-dione rings interconnected by 3,5-diylidenethiomorpholine-2,6-dithione or ylidene-6-thioxo[1,2]dithiolo[3,4-b][1,4]thiazin-3-one groups. The presence of highly colored, highly polarized push−pull α,β- unsaturated thione groups in their structures make these compounds sensitive to the presence of mercury(II) cation in organic or mixed organic/aqueous solvents.Ministerio de Economía y Competitividad, Spain (Project CTQ2012- 31611), Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (Project BU246A12-1), and the European Commission Seventh Framework Programme (Project SNIFFER FP7-SEC-2012-312411)

Porous aromatic polyamides the easy and green way

We prepared microporous aramid films through a simple, inexpensive and green way, using ionic liquids (IL) as porosity promoters. Commercial poly(m-phenylene isophthalamide) (MPIA) films with different IL proportions were prepared, and then microporous films were obtained by removing the IL in distilled water. Microporous films presented density values between 0.34 and 0.71 g⋅cm−3 (around five times lower to commercial MPIA), with a homogeneous and controlled cellular morphology dependent on the proportion of the IL, showing cell sizes in the microcellular range (radii between 1 and 8 µm). Thermal, mechanical and electrical properties (specifically ionic conductivity) of the aramid films were analyzed to evaluate the influence of the IL proportion. Finally, it was observed that the MPIA/IL system presented a reversible thermally induced phase-separation process around 60 °C, which was characterized through AFM-Raman images and spectra, together with the variation of the ionic conductivity.FEDER (Fondo Europeo de Desarrollo Regional) and both the Spanish Agencia Estatal de Investigación (MAT2017-84501-R) and the Consejería de Educación-Junta de Castilla y León (BU306P18

Self-Assembly Hydrosoluble Coronenes: A Rich Source of Supramolecular Turn-On Fluorogenic Sensing Materials in Aqueous Media

Water-soluble coronenes, that form nanoparticles by self-association, work as new fluorescent materials by complexation with cucurbit[7]uril, as well as selective turn-on fluorogenic sensors for nitroaromatic explosives with remarkable selectivity, by using only water as solvent.NATO Science for Peace and Security Programme (SPS G5536), Ministerio de Ciencia, Innovación y Universidades-FEDER (PID2019-111215RB-100 and RTI2018-102040-B-100), Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (BU263P18) and “la Caixa” Foundation (LCF/PR/PR12/11070003) for financial support. A.R.C. thanks Secretaría General de Universidades (FPU18/03225)

Synthesis of water-soluble hemicoronenediimides by photocyclization of perylenediimides: Turn-on fluorescent probes in water by complexation with Cucurbit[7]uril or binding to G-quadruplex Motifs

A new series of perylene and hemicoronene diimides, obtained by visible light photocyclization, are presented, between them some remarkable examples that are soluble in only water, and give nanoparticles by selfassociation. Those compounds work as new fluorescent materials in water by complexation with cucurbit[7] uril, as well as selective G-quadruplex binding ligands with remarkable cytotoxic activity when the interaction with G4 was sufficiently strong.We acknowledge the Ministerio de Ciencia, Innovación y Universidades-FEDER (Grants PID2019-111215RB-100 and RTI2018- 102040-B-100), the Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (Grants BU263P18 and BU305P18), “la Caixa” Foundation (LCF/PR/PR12/11070003) for financial support. A. R.C. thanks Secretaría General de Universidades for a FPU18/03225 Grant. This research has made use of the high-performance computing resources of the Castilla y León Supercomputing Center (SCAYLE, htt ps://www.scayle.es), financed by FEDER (Fondo Europeo de Desarrollo Regional). We thank Ms. Ma del Pilar Castroviejo-Fernández, from PCT, UBU, for assistance in AFM studies and Mr. Javier Gutierrez-Reguera from LTI, UVA, for assistance in DLS studies

Effect of the aniline fragment in Pt(II) and Pt(IV) complexes as anti-proliferative agents. Standard reduction potential as a more reliable parameter for Pt(IV) compounds than peak reduction potential

The problems of resistance and side effects associated with cisplatin and other chemotherapeutic drugs have boosted research aimed at finding new compounds with improved properties. The use of platinum(IV) prodrugs is one alternative, although there is some controversy regarding the predictive ability of the peak reduction potentials. In the work described here a series of fourteen chloride Pt(II) and Pt(IV) compounds was synthesised and fully characterised. The compounds contain different bidentate arylazole heterocyclic ligands. Their cytotoxic properties against human lung carcinoma (A549), human breast carcinoma (MCF7) and human colon carcinoma (HCT116 and HT29) cell lines were studied. A clear relationship between the type of ligand and the anti-proliferative properties was found, with the best results obtained for the Pt(II) compound that contains an aniline fragment, (13), thus evidencing a positive effect of the NH2 group. Stability and aquation studies in DMSO, DMF and DMSO/water mixtures were carried out on the active complexes and an in-depth analysis of the two aquation processes, including DFT analysis, of 13 was undertaken. It was verified that DNA was the target and that cell death occurred by apoptosis in the case of 13. Furthermore, the cytotoxic derivatives did not exhibit haemolytic activity. The reduction of the Pt(IV) compounds whose Pt(II) congeners were active was studied by several techniques. It was concluded that the peak reduction potential was not useful to predict the ability for reduction. However, a correlation between the cytotoxic activity and the standard reduction potential was found.This work has been funded by the Spanish Ministerio de Ciencia, Innovación y Universidades (MCIU), Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER) (RTI2018-100709-B-C21 to BRM, RTI2018-100709-B-C22 to AM, RTI2018-094093-B-I00 to RSP), Junta de Comunidades de Castilla-La Mancha-FEDER (JCCM) (grant SBPLY/19/180501/000260 to BRM), Ministerio de Economía y Competitividad (Project PID2019-104381GB-I00 to GC), Fundación Leticia Castillejo Castillo to MJRH, Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (Projects BU263P18 and BU087G19 to JVC) as well as UCLM-FEDER (grants 2019-GRIN-27183 and 2019-GRIN-27209 to BRM) and University of Girona (MPCUdG2016/076 to AM)

Dye-modified silica–anatase nanoparticles for the ultrasensitive fluorogenic detection of the improvised explosive TATP in an air microfluidic device

We describe the proof of concept of a portable testing setup for the detection of triacetone triperoxide (TATP), a common component in improvised explosive devices. The system will allow field-testing and generation of real-time results to test for TATP vapor traces in a number of different environments. It will work by recirculating the gas samples in connection to the sensing mechanism in a suitable microfluidic portable device. In this way, the system will allow controlled trapping of the analyte in the chemical sensor to afford reliable results at very low concentrations in air.This research was funded by the NATO Science for Peace and Security Programme (Grant SPS G5536), the Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (Grant BU263P18) and the Ministerio de Ciencia e Innovación (Grant PID2019-111215RB-100). Financial support from Latvian Institute of Organic Synthesis is gratefully acknowledged (internal grant: IG-2021-01). This research has made use of the high performance computing resources of the Castilla y León Supercomputing Center (SCAYLE, https://www. scayle.es), financed by FEDER (Fondo Europeo de Desarrollo Regional)

Influence of core extension and side chain nature in targeting G-quadruplex structures with perylene monoimide derivatives

A structure–activity relationship (SAR) study in terms of G-quadruplex binding ability and antiproliferative activity of six fluorescent perylenemonoimide (PMIs) derivatives is reported. A positive charge seems to be the key to target G4. This study also reveals the importance of the element substitution in the potential biological activity of PMIs, being the polyethylene glycol (PEG) chains in the peri position responsible for their antiproliferative activity. Among them, the cationic PMI6 with two PEG chains is the most promising compound since its fluorescence is enhanced in the presence of G-quadruplex structures. Moreover, PMI6 binds to the human telomeric G-quadruplex hTelo with high affinity and displays a high antiproliferative potential towards HeLa (cervical adenocarcinoma), A549 (lung adenocarcinoma) and A2780 (ovarian adenocarcinoma) cells. Its fate can be followed inside cells thanks to its fluorescent properties: the compound is found to accumulate in the mitochondria.“la Caixa” Foundation (LCF/PR/PR12/11070003), Ministerio de Ciencia, Innovación y Universidades-FEDER (RTI2018-102040-B-100), Junta de Castilla y León-FEDER (BU305P18 and BU263P18) is gratefully acknowledged. N.B. is grateful to Aurore Guédin of the ARNA Laboratory for technical support and also to the financial support of the José Castillejo Program by the Spanish Ministry of Education, Culture and Sports (JC2015-00403). A.H. was funded by a Juan de la Cierva fellowship (FJCI-2015-26175) from the Ministerio de Economía y Competitividad. This research has made use of the high-performance computing resources of the Castilla y León Supercomputing Center (SCAYLE, https://www.scayle.es), financed by FEDER (Fondo Europeo de Desarrollo Regional). Networking support of NECTAR COST Action CA18202 is fully acknowledged. This work was supported by the SYMBIT project (reg. no. CZ.02.1.01/0.0/0.0/15_003/0000477) financed by the ERDF

Raman spectroelectrochemical determination of clopyralid in tap water

Clopyralid is a common herbicide used all around the world that can be dissolved in the rain stream and accumulate in underground water with the potential threat of reaching drinking water. Many methodologies have been proposed to perform quantitative analysis of this compound but, to this day, no Raman detection of clopyralid has been carried out. Here, a novel methodology to quantify clopyralid, based on Electrochemical Surface Oxidation-Enhanced Raman Scattering (EC-SOERS), is developed, using disposable silver screen-printed electrodes as substrate. The optimization of the electrolytic media is carried out, searching for the conditions where a maximum Raman enhancement is obtained. Moreover, a study about the effect of various interfering compounds, which could be present in water, on the clopyralid Raman response is performed. The results demonstrate that the presented methodology allows the determination of clopyralid in the micromolar range in tap water without any purification or preconcentration step, requiring few minutes to perform the measurement of each sample.Authors acknowledge Ministerio de Ciencia e Innovación and Agencia Estatal de Investigación (MCIN/AEI/10.13039/501100011033, PID2020-113154RB-C21), Junta de Castilla y León (Grant BU297P18) and Ministerio de Ciencia, Innovación y Universidades (RED2018–102412-T) for the support of this work. Martín Perez and Sheila Hernández acknowledge Junta de Castilla y Leon for their predoctoral contracts

Dataset of the work “Raman spectroelectrochemical determination of clopyralid in tap water”

Clopyralid is a common herbicide used all around the world that can be dissolved in the rain stream and accumulate in underground water with the potential threat of reaching drinking water. Many methodologies have been proposed to perform quantitative analysis of this compound but, to this day, no Raman detection of clopyralid has been carried out. Here, a novel methodology to quantify clopyralid, based on Electrochemical Surface Oxidation-Enhanced Raman Scattering (EC-SOERS), is developed, using disposable silver screen-printed electrodes as substrate. The optimization of the electrolytic media is carried out, searching for the conditions where a maximum Raman enhancement is obtained. Moreover, a study about the effect of various interfering compounds, which could be present in water, on the clopyralid Raman response is performed. The results demonstrate that the presented methodology allows the determination of clopyralid in the micromolar range in tap water without any purification or preconcentration step, requiring few minutes to perform the measurement of each sample.Authors acknowledge Ministerio de Ciencia e Innovacion and Agencia Estatal de Investigacion (MCIN/AEI/10.13039/501100011033, PID2020-113154RB-C21), Junta de Castilla y Leon (Grant BU297P18) and Ministerio de Ciencia, Innovacion y Universidades (RED2018–102412-T) for the support of this work. Martín Perez and Sheila Hernandez acknowledge Junta de Castilla y Leon for their predoctoral contracts