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The flavivirus life cycle is strictly dependent on cellular lipid metabolism. Polyphenols like gallic acid and its derivatives are promising lead compounds for new therapeutic agents as they can exert multiple pharmacological activities, including the alteration of lipid metabolism. The evaluation of our collection of polyphenols against West Nile virus (WNV), a representative medically relevant flavivirus, led to the identification of N,N'-(dodecane-1,12-diyl)bis(3,4,5-trihydroxybenzamide) and its 2,3,4-trihydroxybenzamide regioisomer as selective antivirals with low cytotoxicity and high antiviral activity (half-maximal effective concentrations [EC50s] of 2.2 and 0.24 μM, respectively, in Vero cells; EC50s of 2.2 and 1.9 μM, respectively, in SH-SY5Y cells). These polyphenols also inhibited the multiplication of other flaviviruses, namely, Usutu, dengue, and Zika viruses, exhibiting lower antiviral or negligible antiviral activity against other RNA viruses. The mechanism underlying their antiviral activity against WNV involved the alteration of sphingolipid metabolism. These compounds inhibited ceramide desaturase (Des1), promoting the accumulation of dihydrosphingomyelin (dhSM), a minor component of cellular sphingolipids with important roles in membrane properties. The addition of exogenous dhSM or Des1 blockage by using the reference inhibitor GT-11 {N-[(1R,2S)-2-hydroxy-1-hydroxymethyl-2-(2-tridecyl-1-cyclopropenyl)ethyl]octanamide} confirmed the involvement of this pathway in WNV infection. These results unveil the potential of novel antiviral strategies based on the modulation of the cellular levels of dhSM and Des1 activity for the control of flavivirus infection., We thank Theodore C. Pierson (National Institutes of Health, USA) for the subgenomic replicon of WNV. This work was supported by the Spanish Ministry of Science and Innovation AEI/10.13039/501100011033 under grants PID2019-105117RR-C21 (to M.A.M.-A.), PID2019-105117RR-C22 (to M.-J.P.-P.), and PID2020-119195RJ-I00 (to N.J.d.O.) and by the AECSIC under grant PIE-201980E100 (to M.-J.P.-P. and A.S.-F.). This research work was also funded by the European Commission-NextGenerationEU (regulation EU 2020/2094) through CSIC’s Global Health Platform (PTI Salud Global). P.M.-C. was supported by an FPI fellowship (PRE2020-093374) from AEI/10.13039/501100011033. The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Salmonella enterica causes intracellular infections that can be limited to the intestine or spread to deeper tissues. In most cases, intracellular bacteria show moderate growth. How these bacteria face host defenses that recognize peptidoglycan, is poorly understood. Here, we report a high-resolution structural analysis of the minute amounts of peptidoglycan puri- fied from S. enterica serovar Typhimurium (S. Typhimurium) infecting fibroblasts, a cell type in which this pathogen undergoes moderate growth and persists for days intracellularly. The peptidoglycan of these non-proliferating bacteria contains atypical crosslinked muropep- tides with stem peptides trimmed at the L-alanine-D-glutamic acid-(γ) or D-glutamic acid-(γ)- meso-diaminopimelic acid motifs, both sensed by intracellular immune receptors. This pepti- doglycan has a reduced glycan chain average length and ~30% increase in the L,D-cross- link, a type of bridge shared by all the atypical crosslinked muropeptides identified. The L,D- transpeptidases LdtD (YcbB) and LdtE (YnhG) are responsible for the formation of these L, D-bridges in the peptidoglycan of intracellular bacteria. We also identified in a fraction of muropeptides an unprecedented modification in the peptidoglycan of intracellular S. Typhi- murium consisting of the amino alcohol alaninol replacing the terminal (fourth) D-alanine. Alaninol was still detectable in the peptidoglycan of a double mutant lacking LdtD and LdtE, thereby ruling out the contribution of these enzymes to this chemical modification. Remark- ably, all multiple mutants tested lacking candidate enzymes that either trim stem peptides or form the L,D-bridges retain the capacity to modify the terminal D-alanine to alaninol and all attenuate NF-κB nuclear translocation. These data inferred a potential role of alaninol-con- taining muropeptides in attenuating pro-inflammatory signaling, which was confirmed with a synthetic tetrapeptide bearing such amino alcohol. We suggest that the modification of D- alanine to alaninol in the peptidoglycan of non-proliferating intracellular S. Typhimurium is an editing process exploited by this pathogen to evade immune recognition inside host cells., This work was funded by grants PID2020-112971GB-I00/10.13039/501100011033 (F.G-dP.) and PID2019-104070RB-C21 (S.V.) of the Spanish Ministry of Science and Innovation, VR2018-02823 of the Swedish Research Council (F.C.), KAW2012.0184 of the Knut and Alice Wallenberg Foundation (F.C.), and SMK2062 of the Kempe Foundation (F.C.). S.C. was recipient of an EMBO Short-Term Fellowship number 6426 for a stay in the lab of F.C. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Resumen del póster presentado a las II Jornadas Científicas PTI + Salud Global, celebradas los días 5 y 6 de octubre de 2022 en el Auditorio Santiago Grisolía de Valencia (España).

Unprecedented 3D hexa-adducts of [60]fullerene peripherally decorated with twelve tryptophan (Trp) or tyrosine (Tyr) residues have been synthesized. Studies on the antiviral activity of these novel compounds against HIV and EV71 reveal that they are much more potent against HIV and equally active against EV71 than the previously described dendrimer prototypes AL-385 and AL-463, which possess the same number of Trp/Tyr residues on the periphery but attached to a smaller and more flexible pentaerythritol core. These results demonstrate the relevance of the globular 3D presentation of the peripheral groups (Trp/Tyr) as well as the length of the spacer connecting them to the central core to interact with the viral envelopes, particularly in the case of HIV, and support the hypothesis that [60]fullerene can be an alternative and attractive biocompatible carbon-based scaffold for this type of highly symmetrical dendrimers. In addition, the functionalized fullerenes here described, which display twelve peripheral negatively charged indole moieties on their globular surface, define a new and versatile class of compounds with a promising potential in biomedical applications., This work has been supported by the Spanish MINECO/FEDER (Projects CTQ2017-84327-P and CTQ2017-83531-R), the Spanish MICINN (Projects PID2019-104070RB-C21 and PID2019- 104070RB-C22), the Spanish Agencia Estatal Consejo Superior de Investigaciones Científicas (CSIC, Projects CSIC-PIE- 201980E100 and CSIC-PIE-201980E028), “The Centers of Excellence” of the KU Leuven (EF-05/15 and PF-10/18), EU FP7 (FP7/ 2007–2013) Project EUVIRNA (Grant 408 Agreement 264286), EU FP7 SILVER (Contract HEALTH-F3-2010-260644), a grant from the Belgian Interuniversity Attraction Poles (IAP) Phase VII-P7/45 (BELVIR) and the EU FP7 Industry-Academia Partnerships and Pathways Project AIROPICO. The Spanish MEC/MINECO is also acknowledged for a grant to O. M.-M. We also thank Charlotte Vanderheydt, Caroline Collard, Kim Donckers, Sandra Claes and Evelyne Van Kerckhove for help with the processing of the antiviral data.

Trabajo fin de Máster defendido en el Instituto de Ciencia y Tecnología de Polímeros (ICTP-CSIC), el 23 de junio de 2022, Curso 2021-2022 - Máster Universitario en Alta Especialización en Plásticos y Caucho (UIMP-CSIC), [EN] The aim of this work is to obtain electrospun materials from polylactic acid (PLA) reinforced with nanoparticles of zinc oxide (ZnO) for potential medical and piezoelectric applications. PLA is a biodegradable and biocompatible biopolymer and zinc oxide has a proven antimicrobial effect. Furthermore, both materials have piezoelectric properties. The obtained materials have been characterized to study the reinforcing effect that nanoparticles can have on the PLA polymeric matrix. Firstly, samples of unreinforced and reinforced nanofibres with the content of 0.5, 1, 3, 5, 10, 20% by weight of zinc nanoparticles have been prepared. Fibres with a preferential orientation have also been studied to compare the effect of the configuration on the final properties. A study of the diameter distribution, orientation, and morphology of the nanofibres has been carried out by scanning electron microscopy. Thermal analysis has been carried out by difference scattering calorimetry and thermogravimetric analysis. Crystallinity has been studied by X-ray diffraction and the mechanical properties using a tensile strain-stress experiment. Finally, given the medical interest, a study of in vitro degradation of randomly distributed samples has been done., [ES] El presente trabajo tiene como objetivo la obtención de materiales electrohilados de ácido polilactico (PLA) nanorreforzados con nanopartículas de óxido de cinc (ZnO) para sus potenciales aplicaciones biomédicas o piezoeléctricas. El PLA es un biopolímero, biodegradable y biocompatible y el óxido de cinc tiene un probado efecto antimicrobiano. Además, ambos materiales presentan propiedades piezoeléctricas. Los materiales obtenidos han sido caracterizados a fin de estudiar el efecto reforzante que puedan tener las nanopartículas en la matriz polimérica de PLA. Primero, se han preparado muestras de nanofibras no reforzadas y reforzadas aleatoriamente distribuidas con un contenido del 0,5; 1; 3; 5; 10 y 20% en peso de nanopartículas de cinc. También se han estudiado fibras con una orientación preferencial, para comparar el efecto de la configuración en las propiedades finales del material. Sobre las nanofibras se ha realizado un estudio de la distribución de diámetros, orientación y morfología por microscopía electrónica de barrido. Se ha realizado un análisis térmico por medio de calorimetría diferencia de barrido y análisis termogravimétrico. La cristalinidad se ha estudiado por difracción de rayos X, y las propiedades mecánicas por un ensayo mecánico de tracción simple unidireccional. Por último, dado el interés médico de estos materiales se ha hecho un estudio de la degradación in vitro de las muestras aleatoriamente distribuidas.

Propofol infusion syndrome is a rare condition that mainly affects critically ill patients who receive high doses of this hypnotic for a long time. We describe the case of a patient who presented hepatotoxicity in the immediate postoperative period of two surgeries in which she had received conventional doses of propofol for a short period of time. After studying the patient and monitoring her evolution, we arrived at a differential diagnosis of propofol infusion syndrome due to increased susceptibility. This syndrome should be considered in patients presenting hepatotoxicity in the immediate postoperative period, even when low doses of propofol have been administered.

Resumen El sindrome por infusion de propofol es una entidad poco frecuente que afecta principalmente a pacientes criticos que reciben dosis elevadas de este hipnotico durante un tiempo prolongado. Describimos el caso de una paciente que presento en dos ocasiones hepatotoxicidad en el periodo postoperatorio inmediato de dos cirugias en las que habia recibido dosis convencionales de propofol en un periodo corto de tiempo. Despues de su estudio, evolucion y diagnostico diferencial, se orienta como posible sindrome por infusion de propofol a causa de una susceptibilidad aumentada. Ante la aparicion de una hepatotoxicidad en el postoperatorio inmediato deberia tenerse presente esta entidad como posible causa aunque las dosis administradas sean bajas.

Dedicated to Prof. Dr. Jan Balzarini (KU Leuven, Belgium), in recognition of his exem- plary life-long dedication to virology and con- stant encouragement, We have recently described a novel family of compounds of reduced size and dual anti-HIV and anti-EV71 ac- tivity that encompasses tripodal and tetrapodal derivatives. The tripodal prototype, AL-470, has a nitro group at the focal point of the central scaffold and three attached tryptophan residues, each of which bearing an iso- phthaloyl moiety at the C2 position of the indole ring. A nitro to amino substitution has allowed us now to introduce a chemically addressable functionality to perform further structural modifications consisting of both direct and linker-mediated attachment of several aromatic groups, including the fluorescent dye Alexa Fluor 647 and the antibody-recruiting 2,4-dinitrophenyl motif. Some of the derivatives turned out to be more potent and selective than AL-470 against HIV-1, HIV-2 and EV-A71. The fluorescent probe demonstrated a specific tropism for intestines and lungs, two important niches for the human microbiome in health and disease, This work was supported by the Spanish MICINN (Projects PID2019- 104070RB-C21 and PID2019-104070RB-C22), and by the Spanish “Agencia Estatal Consejo Superior de Investigaciones Científicas” (CSIC, Projects CSIC-PIE-201980E100 and CSIC-PIE-201980E028). “The Cen- ters of Excellence” of the KU Leuven (EF-05/15 and PF-10/18), EU FP7 (FP7/2007-2013) Project EUVIRNA (Grant 408 Agreement 264286), EU FP7 SILVER (Contract HEALTH-F3-2010-260644), a grant from the Belgian Interuniversity Attraction Poles (IAP) Phase VII–P7/45 (BEL- VIR) and the EU FP7 Industry-Academia Partnerships and Pathways Project AIROPICO. The Spanish MEC/MINECO is also acknowledged for grants to B.M-G and O.M-M. We thank Charlotte Vanderheydt, Sandra Claes, Caroline Collard, Daisy Ceusters and Kim Donckers, for helping with the evaluation and processing of the antiviral data. This work has been awarded with the Ramón Madroñero (XX call) prize within the “Prizes for Young Researchers of the Spanish Society of Medicinal Chemistry (SEQT).

Redox homeostasis in trypanosomatids is based on the low-molecular-weight trypanothione, an essential dithiol molecule that is synthetized by trypanothione synthetase (TryS) and maintained in its reduced state by trypa- nothione disulfide reductase (TryR). The fact that both enzymes are indispensable for parasite survival and absent in the mammalian hosts makes them ideal drug targets against leishmaniasis. Although many efforts have been directed to developing TryR inhibitors, much less attention has been focused on TryS. The screening of an in-house library of 144 diverse molecules using two parallel biochemical assays allowed us to detect 13 inhibitors of L. infantum TryS. Compounds 1 and 3 were characterized as competitive inhibitors with Ki values in the low micromolar range and plausible binding modes for them were identified by automated ligand docking against refined protein structures obtained through computational simulation of an entire catalytic cycle. The proposed binding site for both inhibitors overlaps the polyamine site in the enzyme and, additionally, 1 also occupies part of the ATP site. Compound 4 behaves as a mixed hyperbolic inhibitor with a Ki of 0.8 μM. The activity of 5 is clearly dependent on the concentration of the polyamine substrate, but its kinetic behavior is clearly not compatible with a competitive mode of inhibition. Analysis of the activity of the six best inhibitors against intracellular amastigotes identified 5 as the most potent leishmanicidal candidate, with an EC50 value of 0.6 μM and a selectivity index of 35., This work has been supported by the Spanish MICINN (Projects PID2019-104070RB-C21 and PID2019-104070RBC22), the Spanish National Research Council (CSIC, Projects CSIC-PIE-201980E100 and CSIC-PIE-201980E028), and the Comunidad de Madrid (PLATESA2-CM ref S-2018/BAA-4370). The MCIN is also acknowledged for the pre- doctoral fellowship to M.A.C.