These are the scientific articles published by SeRMN personnel. Posts may contain a short description of the research work objective and relevance, in addition to the abstract of the article, the bibliographic reference, and the article DOI if available.
Pulsed-Field Gradients (PFGs) play an important role in the development and understanding of modern NMR methods. With the ultimate goal of constructing robust pulse sequences that create high-quality NMR spectra with minimum set-up, PFGs are utilized to achieve an exclusive selection of a specific coherence transfer pathway as well as purging all kinds of undesired magnetization. PFG reduces the number of needed phase cycle steps to a bare minimum, allowing for accelerated NMR data acquisition in shorter spectrometer times. The potential and diversity of several PFG-based NMR elements are presented, as well as instances of their implementation in time-efficient NMR solutions. Practical aspects such as NMR data collecting needs and the attainment of pure in-phase absorption lineshapes are discussed for the most useful NMR experiments.
ISBN13: 9781839164002 Publisher: Royal Society of Chemistry Published: 17/05/2023
M. Sebastiana, A. Gargallo-Garriga, J. Sardans, M. Pérez-Trujillo, F. Monteiro, A. Figueiredo, M. Maia, R. Nascimento, M. Sousa Silva, A. N. Ferreira, C. Cordeiro, A. P. Marques, L. Sousa, R. Malhó & J. Peñuelas
Mycorrhizas are known to have a positive impact on plant growth and ability to resist major biotic and abiotic stresses. However, the metabolic alterations underlying mycorrhizal symbiosis are still understudied. By using metabolomics and transcriptomics approaches, cork oak roots colonized by the ectomycorrhizal fungus Pisolithus tinctorius were compared with non-colonized roots. Results from this global metabolomics analysis suggest decreases in root metabolites which are common components of exudates, and in compounds related to root external protective layers which could facilitate plant-fungal contact and enhance symbiosis. Root metabolic pathways involved in defense against stress were induced in ectomycorrhizal roots that could be involved in a plant mechanism to avoid uncontrolled growth of the fungal symbiont in the root apoplast. Several of the identified symbiosis-specific metabolites, such as GABA, may help to understand how ectomycorrhizal fungi such as P. tinctorius benefit their host plants.
Some of our recent research work was presented at the European NMR meeting Euromar 2021 that was going to take place at Portoroz (Slovenia), but which was finally virtual from the 5th to the 8th of July 2021.
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 analyzing 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 (AAs) 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 characterization.
L. T. Kuhn, K. Motiram-Corral, T. J. Athersuch, T. Parella, M. Pérez-Trujillo, Angew. Chem. Int. Ed.59 (2020) 23615.
The use of the methylotrophic yeast Pichia pastoris (Komagataella phaffi) to produce heterologous proteins has been largely reported. However, investigations addressing the potential of this yeast to produce bulk chemicals are still scarce. In this study, we have studied the use of P. pastoris as a cell factory to produce the commodity chemical 3-hydroxypropionic acid (3-HP) from glycerol. 3-HP is a chemical platform which can be converted into acrylic acid and to other alternatives to petroleum-based products. To this end, the mcr gene from Chloroflexus aurantiacus was introduced into P. pastoris. This single modification allowed the production of 3-HP from glycerol through the malonyl-CoA pathway. Found results benchmark P. pastoris as a promising platform to produce bulk chemicals for the revalorization of crude glycerol and, in particular, to produce 3-HP.
Some of the SeRMN staff has presented our recent research work at the biannual Spanish and IberAmerican NMR meeting, 10th GERMN biennial /9th IberAmerican/7th Iberian NMR Meeting. This year it was a virtual meeting taking place from 26 to 29 April 2021.
Pau Nolis presented an oral communication entitled “Reducing experimental time using Multiple Fid Acquisition“. P. Nolis, K. Motiram-Corral, M. Pérez-Trujillo, T. Parella.
Speeding-up NMR molecular analysis is an important research field which has been continuously advancing since NMR early days. The relevant benefits are clear and evident: i) reduce analysis time per sample => reduce analysis cost; ii) gain spectrometer time to analyze new samples => improve spectrometer efficiency. Multiple FID Acquisition (MFA) strategy consists in the design of NMR pulse sequence experiments accommodating N acquisition windows, each registering different relevant structural information. This strategy is faster than perform a traditional sequential acquisition of N separated experiments. Several design strategies and practical experiments will be shown and discussed.
Míriam Pérez-Trujillo presented an oral communication entitled “Simultaneous Enantiospecific Detection of Multiple Metabolites in Mixtures using NMR Spectroscopy“. L. T. Kuhn, K. Motiram-Corral, T. J. Athersuch, T. Parella, M. Pérez-Trujillo.
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 analyzing metabolites in their native environment. Here, we report on the first in situ enantiospecific detection of a thirty-ninecomponent mixture. As a proof of concept, eighteen essential amino acids (AAs) 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 characterization.
Nuclear magnetic resonance (NMR) spectroscopy remains one of the core analytical platforms for metabolomics, providing complementary chemical information to others, such as mass spectrometry, and offering particular advantages in some areas of research on account of its inherent robustness, reproducibility, and phenomenal dynamic range. While routine experimental protocols for profiling and related statistical analysis pipelines have been established, they often present considerable challenges to the analyst, including spectral overlap, accurate and precise quantification, and chemical shift variation. Consequently, there is still much activity across all areas of NMR spectroscopic analysis in relation to metabolomics. Furthermore, there remain many biological systems and sample types that have not been extensively explored using NMR spectroscopy-based metabolomics.In this Special Issue, several advances in methodology, and new applications in the field of NMR-based metabolomics, have been presented. In addition, the SI includes authoritative review articles focused on the state-of-the-art of quantitative NMR spectroscopy in biomedical metabolomics applications, and novel applications in the agri-food sector.
Yentel Mateo-Otero, Pol Fernández-López, Ariadna Delgado-Bermúdez, Pau Nolis, Jordi Roca, Jordi Miró, Isabel Barranco, Marc Yeste
Background
Metabolomic approaches, which include the study of low molecular weight molecules, is an emerging -omics technology useful for the identification of biomarkers. In this field, nuclear magnetic resonance (NMR) spectroscopy approach has already been used to uncover (in)fertility biomarkers in the seminal plasma (SP) of several mammalian species. However, NMR studies profiling SP metabolome to uncover in vivo fertility biomarkers are yet to be carried out in pigs. Thus, this study aimed to evaluate the putative relationship between the presence/concentration of SP-metabolites and in vivo fertility outcomes. To this end, 24 entire ejaculates (three ejaculates per boar) were collected from artificial insemination (AI)-boars throughout a year (one ejaculate every four months). Immediately after collection, ejaculates were centrifuged (1,500×g for 10 min twice) to obtain SP-samples and were stored (− 80°C) for subsequent metabolomic analysis by NMR spectroscopy. Fertility outcomes from 1,525 inseminations were recorded over a year, including farrowing rate, litter size, stillbirths per litter and the duration of pregnancy. These data were corrected to isolate the direct boar effect on each in vivo fertility parameter using a multivariate statistical model.
Results
A total of 24 metabolites were identified and quantified in all SP-samples. ROC curve analysis showed that lactate levels in SP had discriminative capacity for farrowing rate (area under the curve (AUC) = 0.764; P < 0.05) while carnitine (AUC = 0.847), hypotaurine (AUC = 0.819), sn-glycero-3-phosphocholine (AUC = 0.833), glutamate (AUC = 0.799) and glucose (AUC = 0.750) had it for litter size (P < 0.05). Similarly, citrate (AUC = 0.743), creatine (AUC = 0.812), phenylalanine (AUC = 0.750), tyrosine (AUC = 0.753) and malonate (AUC = 0.868) levels had discriminative capacity for stillbirths per litter (P < 0.05); and malonate (AUC = 0.767) and fumarate (AUC = 0.868) concentrations for gestation length (P < 0.05).
Conclusions
Considering these results, the assessment of selected SP-metabolites in ejaculates through NMR spectroscopy could be considered as a promising non-invasive tool to predict in vivo fertility outcomes in pigs. Moreover, supplementing AI-doses with specific metabolites should also be contemplated as a way to improve their fertility potential.
M. Saladrigas-García, M. D’Angelo, H. L. Ko, S. Traserra, P. Nolis, Y. Ramayo-Caldas, J. M. Folch, P. Vergara, P. Llonch, J. F. Pérez & S. M. Martín-Orúe
The aim of this study was to determine the possible impact of early socialization and an enriched neonatal environment to improve adaptation of piglets to weaning. We hypothesized that changes in the microbiota colonization process and in their metabolic response and intestinal functionality could help the animals face weaning stress. A total of 48 sows and their litters were allotted into a control (CTR) or an enriched treatment (ENR), in which piglets from two adjacent pens were combined and enriched with toys. The pattern of caecal microbial colonization, the jejunal gene expression, the serum metabolome and the intestinal physiology of the piglets were assessed before (-2 d) and after weaning (+ 3d). A differential ordination of caecal microbiota was observed after weaning. Serum metabolome suggested a reduced energetic metabolism in ENR animals, as evidenced by shifts in triglycerides and fatty acids, VLDL/LDL and creatine regions. The TLR2 gene showed to be downregulated in the jejunum of ENR pigs after weaning. The integration of gene expression, metabolome and microbiota datasets confirmed that differences between barren and enriched neonatal environments were evident only after weaning. Our results suggest that improvements in adaptation to weaning could be mediated by a better response to the post-weaning stress.
Simultaneous Enantiospecific Detection of Multiple Compounds in Mixtures using NMR Spectroscopy, by Lars T. Kuhn, Kumar Motiram-Corral, Toby J. Athersuch, Teodor Parella, Míriam Pérez-Trujillo*
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.
Simultaneous enantiospecific detection of a mixture of amino acids by NMR spectroscopy
This work has been selected to be presented as a talk at 2021 scientific conferences:
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.
