Biostimulant Nanoencapsulation: The New Keystone To Fight Hunger

Jiménez-Arias, David; Morales-Sierra, Sarai; Borges, Andrés A.; Díaz Díaz, David

Journal of Agricultural and Food Chemistry 68(27): 7083–7085 (2020)
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Enantiodivergent cyclization by inversion of the reactivity inambiphilic molecules

Inverting the reactivity of the functional groups in ambiphilic molecules provides a new synthetic strategy to carry out late‐stage enantiodivergence. Both enantiomers of the final compound can be obtained from a common chiral precursor. As a proof of concept, the synthesis of substituted five‐ and six‐membered oxacycles is described. The key step is the cyclization of an ambiphilic linear precursor bearing a propargylic alcohol and an epoxide linked through an alkyl chain. Through a slight modification of these linear precursors and employing different reaction conditions, these functional groups can inverse their chemical reactivity, producing one enantiomer or another of the final product. This enantiodivergent cyclization involves three stereogenic centers that can undergo fully controlled retention or inversion of their configuration depending on the cyclization pathway that is activated. The cyclization provides late‐stage enantiodivergence, enabling the synthesis of either enantiomers of the oxacycles from a common chiral substrate with total transfer of the enantiomeric purity.

Rodríguez-López, Julio; Brovetto, Margartia; Martín, Víctor, S.; Martín, Tomás

Angewandte Chemie - International Edition (2020)
DOIDigital.CSIC

Rejected brine recycling in hydroponic and thermo-solar evaporation systems for leisure and tourist facilities. Changing waste into raw material

For >50 years the Canary Islands have been using seawater desalinization facilities in order to satisfy the freshwater demand of their main economic activity –tourism, which continues to contribute to the economic and social progress of the archipelago. However, this desalinization process involves the production of a “waste” product known as rejected brine, which is discharged from coastal regions and islands, whether it originates from public or private facilities. Rejected brines are potentially a serious threat to marine ecosystems. However, here we demonstrate that this “waste” can be processed and reused as a nutrient mineral solution for a hydroponic production system and also a source of freshwater. The efficiency of this management process in terms of fresh-water production and water recycling economy is also discussed. The aim of this paper is to change the attitude towards rejected brines, which should be treated as potential raw material to permit high savings in the running costs of leisure and tourist facilities around the archipelago. In addition, this will also have a positive effect on the environment, making desalinization more sustainable and environmentally friendly, which is nowadays an added value in customer and user satisfaction.
 

 

Jiménez-Arias, David; Morales-Sierra, Sarai; García-Machado, Francisco J.; García-García, Ana L.; Luis, Juan C.; Valdés, Francisco; Sandalio, Luisa M.; Hernández-Suárez, Manuel; Borges, Andrés A.

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Desalination 114443: 1-24 (2020)
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First report of the invasive alien species Caenoplana coerulea Moseley, 1877 (Platyhelminthes, Tricladida, Geoplanidae) in the subterranean environment of the Canary Islands

The blue land planarian Caenoplana coerulea Moseley, 1877 is reported for the first time in the hypogean environment. Seven individuals of C. coerulea were collected in the most humid branch of an abandoned water mine in Gran Canaria (Canary Islands). Due to its character of generalist predator, it should be considered a threat for the endemic subterranean fauna.

Suárez, Daniel; Martín, Sonia; Naranjo, Manuel

Subterranean Biology 26: 67-74 (2018)
DOIDigital.CSIC

Opto-chemical and laser properties of FLTX1, a novel fluorescent tamoxifen derivative, and its potential applications in breast cancer photodynamic chemotherapy

Tamoxifen is the most common antiestrogen used in the chronic treatment of breast cancer. In these cells, it mainly binds to intracellular receptors (estrogen receptor alpha, ERα) and antagonizes the binding of its cognate ligand, 17β-estradiol, thereby preventing uncontrolled hormone-dependent cellular proliferation and growth. In the last decade, in our laboratories we have developed and characterized different tamoxifen derivatives, including a novel fluorescent tamoxifen conjugate: FLTX1. FLTX1 is formed by the covalent binding of tamoxifen to a common fluorescent biomarker NBD. This new prodrug was originally designed as a fluorescent biomarker to localize intracellular targets, which not only keeps the pharmacological activity of tamoxifen but also adds a luminescent functionality. Strikingly, the quantum efficiency of FLTX1 is so high that laser emission has been obtained as an emerging property. In this review, we will show its laser properties under three different configurations. First, as amplified spontaneous emission or mirrorless laser; second, through the evanescent field of WGMs of a ring resonator around an optical fiber; and finally as random laser in uterine tissues impregnated with the prodrug. Further, we observed another emergent property for FLTX1: this molecule, but not tamoxifen alone or NBD, was able to generate reactive oxygen species (ROS) upon irradiation. This property is extremely interesting as FLTX1 might be used for photodynamic therapy. Under this paradigm, FLTX1 would act as a sensitizer in ERα-overexpressing cells (which feature the most prevalent form of hormone-dependent breast cancer), causing cell death in ERα+ cells but reducing damage to other non-cancer (healthy) cells or surrounding tissues. We show here time resolved fluorescence results that suggest molecular aggregations, which could explain the subsequent generation of ROS. This is an original cancer therapy strategy that combines the pharmacological properties of a new tamoxifen derivative and its laser dye features with a highly selective photodynamic therapy.

Díaz, Mario; Scholz, Laura E.; Marrero-Alonso, Jorge; Boto, Alicia; Marín, Raquel; Lobo, Fernando; Hernández, Dácil; Amesty, Ángel; Estévez-Braun, Ana; Quinto-Alemany, David; Puertas-Avedaño, Ricardo; Lahoz Zamarro, Fernando

Optical Materials 84: 442-446 (2018)
DOIDigital.CSIC

Synthesis of Diketopiperazine Scaffolds with Tailored N‐ and α‐Chains by Selective Modification of Customizable Units

The selective manipulation of Hyp customizable units in DKP substrates allows the generation of a rigid scaffold with four tailor‐made chains which are spatially‐orientated. The key step is a domino radical scission‐oxidation process which allows the generation of N‐substituted DKPs. The versatility of this methodology to produce scaffolds in high optical purity for material and drug discovery is described herein.

Saavedra, Carlos J.; Cuevas, Fernando; Romero-Estudillo, Iván; Boto, Alicia

 

Advanced Synthesis and Catalysis (2020)
DOIDigital.CSIC

Impact of Saharan dust exposure on airway inflammation in patients with ischemic heart disease

Epidemiological studies found that increases in the concentrations of airborne particulate matter (PM) smaller than 10 microns diameter (PM10) in the ambient air due to desert dust outbreaks contribute to global burden of diseases, primarily as a result of increased risk of cardiovascular morbidity and mortality. No studies have investigated the possible association between desert dust inhalation and airway inflammation in patients with ischemic heart disease (IHD). Induced sputum was collected in 38 patients and analysed to determine markers of airway inflammation (Transforming Growth Factor-β1 [TGF-β1] and hydroxyproline) concentrations. For the purpose of the investigation, PM10 and reactive gases concentrations measured in the European Air Quality Network implemented in the Canary Islands were also used. We identified Saharan desert dust using meteorology and dust models. Patients affected by smoking, chronic obstructive pulmonary disease (COPD), asthma, pulmonary abnormalities, acute bronchial or pulmonary disease were excluded. The median of age of patients was 64.71 years (56.35–71.54) and 14 (38.84%) of them were women. TGF-β1 and hydroxyproline in sputum were highly associated to PM10 inhalation from the Saharan desert. According to a regression model, an increase of 1 µg/m3 of PM10 concentrations due to desert dust, results in an increase of 3.84 pg/gwt of TGF-β1 (R2 adjusted= 89.69%) and of 0.80 μg/gwt of hydroxyproline (R2 adjusted= 85.28%) in the sputum of patients. The results of this study indicate that the exposure to high PM10 concentrations due to Saharan dust events are associated with intense inflammatory reaction in the airway mucosae of IHD-patients.

Domínguez-Rodríguez, Alberto; Rodríguez, Sergio; Báez-Ferrer, Néstor; Abreu-González, Pedro; Abreu-González, Juan; Avanzas, Pablo; Carnero, Manuel; Morís, César; López-Darias, Jessica; Hernández-Vaquero, Daniel

Translational Research - the Journal of Laboratory and Clinical Medicine: 1-14 (2020)
DOIDigital.CSIC

FRET mechanism between a fluorescent breast-cancer drug and photodynamic therapy sensitizers

Tamoxifen is one of the most frequently used drugs for the treatment of estrogen receptor positive breast cancer, which is the most prevalent form of hormone dependent breast cancer. A few years ago, we developed a fluorescent derivative of tamoxifen formed by the covalent binding of tamoxifen to a common dye biomarker. The new compound, known as FLTX1, showed the pharmacological activity of the tamoxifen moiety and efficient fluorescence properties, which could be used synergistically to improve the effect of the drug. In this paper, we demonstrate that irradiation at the absorption band of FLTX1 can result in fluorescence resonance energy transfer to photosensitizers such as Rose Bengal and Merocyanine 540, activating the production of reactive oxygen species (ROS). Indeed, the generation of ROS was demonstrated using a colorimetric assay. Since FLTX1 mostly binds estrogen-receptor overexpressing cancer cells, the results obtained are very promising and suggest a new therapeutic strategy combining chemo- and photodynamic therapies.

Lahoz, Fernando; Scholz, Laura E.; Boto, Alicia; Díaz, Mario

Spectrochimica Acta - A - Molecular and Biomolecular Spectroscopy 239: 118498 (2020)
DOIDigital.CSIC

Quantum Mechanical–NMR-Aided Configuration and Conformation of Two Unreported Macrocycles Isolated from the Soft Coral Lobophytum sp.: Energy Calculations versus Coupling Constants

Two new macrocyclic cembranoids were isolated from the South China Sea soft coral Lobophytum sp. Quantum mechanical–nuclear magnetic resonance (QM–NMR) methods were decisive in their structural elucidation. Better performance in arriving at definitive structures was obtained by QM–NMR methods upon incorporation of 3JHH values. The validity of this approach also supported an alternative conformational proposal versus that obtained by X-ray crystallography.

Li, Song-Wei; Cuadrado, Cristina; Yao, Li-Gong; Hernández Daranas, Antonio; Guo, Yue-Wei

Organic Letters (2020)
DOIDigital.CSIC

Bayesian Inversion of Wrapped Satellite Interferometric Phase to Estimate Fault and Volcano Surface Ground Deformation Models

Bayesian inference and an improved downsampling method is used to determine earthquake and volcano source parameters using a popular geodetic observation method, satellite radar interferometry. The main novelty of the proposed approach is that the interferometric wrapped phase can be directly inverted, circumventing the ill‐posed phase unwrapping processing step. Phase unwrapping errors severely affect the estimation of earthquake and volcano source parameters using interferometric observations. Therefore, it is desirable to avoid phase unwrapping completely. To overcome the need for phase unwrapping, we propose a downsampling algorithm and a method to estimate the covariance function of the wrapped phase and establish an appropriate misfit function between the observed and simulated wrapped phase. Uncertainties in source parameters are assessed with a Bayesian approach, and finally, the robustness of the inversion methodology is tested in multiple simulations including variable decorrelation and atmospheric noise simulations. The method is shown to be robust in challenging noise scenarios. It features an improvement in performance with the Bayesian approach, compared to similar previous methods, avoiding any influence of seed starting models and escaping local minima. The impact of a small percentage of incorrectly unwrapped phase observations in current state‐of‐the‐art methods is shown to strongly affect the estimation process. We conclude that in the cases where phase unwrapping is difficult or even impossible, the proposed inversion methodology with wrapped phase will provide an alternative approach to assess earthquake and volcano source model parameters.

Jiang, Yu; González, Pablo J.

JGR-Solid Earth 125 (5): e2019JB018313 (2020)
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