Chirality plays a fundamental role in nature, but its detection and quantification still face many limitations. To date, the enantiospecific analysis of mixtures necessarily requires prior separation of the individual components. The simultaneous enantiospecific detection of multiple chiral molecules in a mixture represents a major challenge, which would lead to a significantly better understanding of the underlying biological processes; e.g. via enantiospecifically analysing metabolites in their native environment. Here, we report on the first in situ enantiospecific detection of a thirty‐nine‐component mixture. As a proof of concept, eighteen essential amino acids at physiological concentrations were simultaneously enantiospecifically detected using NMR spectroscopy and a chiral solvating agent. This work represents a first step towards the simultaneous multicomponent enantiospecific analysis of complex mixtures, a capability that will have substantial impact on metabolism studies, metabolic phenotyping, chemical reaction monitoring, and many other fields where complex mixtures containing chiral molecules require efficient characterisation.
Dibromomethane (DBM) and 1,2‐dibromoethane (DBA) are two brominated volatile contaminants used in several industrial applications which are often detected in groundwater. The electrochemical degradation of DBM and DBA was studied at different cathode potentials (−0.8, −1 and −1.2 V versus Standard Hydrogen Electrode) in aqueous solution using an inexpensive graphite fiber brush electrode.
The degradation followed first‐order kinetics with respect to the nominal concentration of the brominated compounds, and the kinetic constant increased concomitantly with the decrease of the cathode potential. During the electrochemical dehalogenation 96.8% and 99.8% of the bromide in DBM and DBA was released as bromine ions, respectively. The main non‐brominated compounds detected during the degradation of DBM and DBA were methane and ethene, respectively. In addition, traces of formic acid for DBM and acetic acid for DBA degradation were detected by NMR spectroscopy. The non‐toxicity of the effluent was confirmed by a Microtox test. The efficient electrochemical degradation of DBM and DBA and the lack of toxic products open the door for a simple and non‐toxic electrochemical approach for removing aliphatic brominated compounds from aquifers and other water sources.
31P-NMR Metabolomics Revealed Species-Specific Use of Phosphorous in Trees of a French Guiana Rainforest, by Gargallo-Garriga, A.; Sardans, J.; Llusià, J.; Peguero, G.; Asensio, D.; Ogaya, R.; Urbina, I.; Langenhove, L.V.; Verryckt, L.T.; Courtois, E.A.; Stahl, C.; Grau, O.; Urban, O.; Janssens, I.A.; Nolis, P.; Pérez-Trujillo, M.; Parella, T.; Peñuelas, J. Molecules2020, 25, 3960. https://doi.org/10.3390/molecules25173960
Productivity of tropical lowland moist forests is often limited by availability and functional allocation of phosphorus (P) that drives competition among tree species and becomes a key factor in determining forestall community diversity. We used non-target 31P-NMR metabolic profiling to study the foliar P-metabolism of trees of a French Guiana rainforest. The objective was to test the hypotheses that P-use is species-specific, and that species diversity relates to species P-use and concentrations of P-containing compounds, including inorganic phosphates, orthophosphate monoesters and diesters, phosphonates and organic polyphosphates. We found that tree species explained the 59% of variance in 31P-NMR metabolite profiling of leaves. A principal component analysis showed that tree species were separated along PC 1 and PC 2 of detected P-containing compounds, which represented a continuum going from high concentrations of metabolites related to non-active P and P-storage, low total P concentrations and high N:P ratios, to high concentrations of P-containing metabolites related to energy and anabolic metabolism, high total P concentrations and low N:P ratios. These results highlight the species-specific use of P and the existence of species-specific P-use niches that are driven by the distinct species-specific position in a continuum in the P-allocation from P-storage compounds to P-containing molecules related to energy and anabolic metabolism.
From 22-6-2020, all authorized SeRMN users can make use of the self-service mode in the 250auto, 360MHz and 400MHz spectrometers, exclusively from 9AM to 5PM, using the booking program (http://sermn.uab.cat/reserves/). The experiment request service is also active for all those samples that are not recorded in self-service mode:
At the moment, the 250robot spectrometer is reserved exclusively for this type of work.
It is very important that the following mandatory rules are respectedt 1. Self-service exclusively from 9AM to 5PM. SeRMN access is not allowed outside of this time slot as there will be no SeRMN staff. 2. Only 1 person per machine is allowed. Always respect two meters of distance separation between people. 3. It is necessary to follow the established protocols of hygiene and safety at a personal level (mask, hand disinfection …) 4. Before and, above all, after using the keyboard and other tools to carry out the experiments (spinner, calibrator …) it is necessary to disinfect them with the hygiene material that you will find available.
Any questions or clarifications, you can contact the staff of the SeRMN who will be present from 9AM to 5PM or through the address .
Herein, we perform for the first time a preliminary NMR and computational study of the spiroglycol structure. Spiroglycol is a highly symmetrical molecule, but it should be chiral due to the presence of a chiral axis. The presence of two enantiomers was demonstrated performing NMR enantiodifferentiation experiments using α,α′-bis(trifluoromethyl)-9,10-anthracenedimethanol (ABTE) as a chiral solvating agent (CSA). The addition of 0.6 equiv of ABTE allows the differentiation of several spiroglycol proton signals. The lack of resolution observed in the proton spectrum can be tackled through the corresponding 13C NMR spectrum where a significant enantiodifferentiation at the spirocarbon atom was observed. In order to physically separate both enantiomers, a SPG derivatization with camphorsulfonic acid and Mosher’s acid was performed affording the corresponding diastereoisomeric ester mixtures. Computations performed with the Gaussian16 package showed that the enantiodifferentiation is mainly due to the different compound thermodynamics stability.
Després de més de dos mesos d’obligat tancament, el SeRMN reobrirà les seves instal.lacions a partir del proper dilluns dia 25 de Maig. Ja que s’han de mantenir certes precaucions de seguretat i higiene, començarem amb un funcionament limitat, provisional i progressiu a mida que es vagi normalitzant la situació del COVID19. Les normes bàsiques de funcionament són:
1. No hi ha autoservei. No cal fer reserva en el nostre sistema de reserves com es fa habitualment. Les mostres seran analitzades exclusivament pel personal del SeRMN.
2. Prèviament, cal fer una sol.licitud de prestació de servei per a cada mostra a través dels formularis de la nostra plana web:
3. Pels usuaris que treballin a l’edifici de les Facultats de Ciències i Biociències, cal portar la mostra presencialment al SeRMN en horari de matí (9AM-1PM). És important que la mostra estigui ben etiquetada i prèviament desinfectada. L’accés al SeRMN està restringit. Just a l’entrada del SeRMN hi haurà una taula de recepció per desinfectar/deixar/recuperar les mostres (veure http://sct.uab.cat/sermn/sample_delivery_provisional).
4. Degut a l’accés restringit que hi ha a l’edifici de les Facultats de Ciències i Biociències, recomanen als usuaris externs sense autorització d’accés a l’edifici (altres facultats de la UAB, instituts i empreses del PRUAB, i instituts i empreses externes al PRUAB) que es posin en contacte amb el personal del SeRMN per email o per telèfon (93 581 3785 o al 93 581 2291) per concretar el lliurament/recollida de mostres.
Per qualsevol dubte o qüestió, podeu contactar-nos a través del nostre mail institucional () o en els nostres correus personals.
After more than two months of forced closure, the SeRMN will reopen its facilities from next Monday, May 25. Since certain safety and hygiene precautions must be maintained, we will start with a limited, provisional and progressive operation as the COVID-19 situation normalizes. The basic rules of operation are:
1-. There is no self-service. There is no need to make a reservation in our booking system as usual. Samples will be analyzed exclusively by the SeRMN staff.
2-. Previously, a request for service for each sample through the forms on our website is required:
3.- For users working in the building of the Faculties of Sciences and Biosciences, the sample must be brought in person at the SeRMN in the morning (9 AM-1PM). It is important that the sample is well labeled and previously disinfected. The access to the SeRMN lab is restricted. Right at the entrance of the SeRMN there will be a reception table where you must disinfect / leave / recover your samples (see http://sct.uab.cat/sermn/sample_delivery_provisional).
4. Due to the restricted access to the building of the Faculties of Sciences and Biosciences, we strongly recommend to external users without authorization access to the building (other faculties of the UAB, institutes and companies of the PRUAB, and institutes and companies external to the PRUAB) that contact with the staff of the SeRMN by email or telephone (93 581 3785 or 93 581 2291) to specify the delivery of samples.
For any questions or concerns, you can contact us via our institutional email () or in our personal emails.
Progression of Alzheimer’s disease and effect of scFv-h3D6 immunotherapy in the 3xTg-AD mouse model: An in vivo longitudinal study using Magnetic Resonance Imaging and Spectroscopy by Güell-Bosch J, Lope-Piedrafita S, Esquerda-Canals G, Montoliu-Gaya L, and Villegas S. NMR in Biomedicine 33(5):e4263; DOI: 10.1002/nbm.4263.
Alzheimer’s disease (AD) is an incurable disease that affects most of the 47 million people estimated as living with dementia worldwide. The main histopathological hallmarks of AD are extracellular β-amyloid (Aβ) plaques and intracellular neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau protein. In recent years, Aβ-immunotherapy has been revealed as a potential tool in AD treatment. One strategy consists of using single-chain variable fragments (scFvs), which avoids the fragment crystallizable (Fc) effects that are supposed to trigger a microglial response, leading to microhemorrhages and vasogenic edemas, as evidenced in clinical trials with bapineuzumab. The scFv-h3D6 generated by our research group derives from this monoclonal antibody, which targets the N-terminal of the Aβ peptide and recognizes monomers, oligomers and fibrils.
In this study, 3xTg-AD mice were intraperitoneally and monthly treated with 100 μg of scFv-h3D6 (a dose of ~3.3 mg/kg) or PBS, from 5 to 12 months of age (-mo), the age at which the mice were sacrificed and samples collected for histological and biochemical analyses. During treatments, four monitoring sessions using magnetic resonance imaging and spectroscopy (MRI/MRS) were performed at 5, 7, 9, and 12 months of age. MRI/MRS techniques allow, in a non-invasive manner, to draw an in vivo picture of concrete aspects of the pathology and to monitor its development across time. Compared with the genetic background, 3xTg-AD mice presented a smaller volume in almost all cerebral regions and ages examined, an increase in both the intra and extracellular Aβ1-42 at 12-mo, and an inflammation process at this age, in both the hippocampus (IL-6 and mIns) and cortex (IL-6). In addition, treatment with scFv-h3D6 partially recovered the values in brain volume, and Aβ, IL-6, and mIns concentrations, among others, encouraging further studies with this antibody fragment.
ABSTRACT:The detection of ultra-long-range (4JCHand higher) heteronuclear connectivities can complement the conventionaluse of HMBC/HSQMBC data in structure elucidation NMR studies of proton-deficient natural products, where two-bond andthree-bond correlations are usually observed. The performance of the selHSQMBC experiment with respect to its broadbandHSQMBC counterpart is evaluated. Despite its frequency-selectivity nature, selHSQMBC efficiently prevents any unwanted signalphase and intensity modulations due to passive proton−proton coupling constants typically involved in HSQMBC. As a result,selHSQMBC offers a significant sensitivity enhancement and provides pure in-phase multiplets, improving the detection levels forshort- and long-range cross-peaks corresponding to small heteronuclear coupling values. This is particularly relevant for experimentsoptimized to smallnJCHvalues (2−3 Hz), referred to as LR-selHSQMBC, where key cross-peaks that are not visible in the equivalentbroadband LR-HSQMBC spectrum can become observable in optimum conditions.
The optimum detection and accurate measurement of longer-range ( 4 J and higher) heteronuclear NMR correlations is described. The magnitude and/or the sign of a wide range of large and small long-range couplings can be simultaneously determined for protonated and non-protonated 13 C and 15 N nuclei using the LR-selHSQMBC experiment.