Quantitative 1H NMR spectroscopy

Integrated GWAS and metabolomic analyses identified metabolic pathways and candidate genes involved in free asparagine accumulation in durum wheat grain

Free asparagine content is a key factor in acrylamide formation in wheat products after high temperature processing. Our study aims to explore free asparagine natural variation in durum wheat to identify genes potentially involved in this trait. Two hundred and one durum wheat genotypes were sown in an experimental field for three years. An enzymatic assay was used on whole grain to evaluate free asparagine content, that ranged from 0.9 to 4.73 mmol/kg dry matter. A genome-wide association study (GWAS) identified six associated SNPs on chromosomes 6A, 7A, 2B, 4B, 7B. The whole grain metabolome of one-year samples revealed 40 metabolites, correlating with asparagine variations, that were enriched in pathways involved in amino acids metabolism. Combining GWAS and metabolomic data identified two L-lactate dehydrogenases, one polyamine oxidase, and one anthranilate-phosphoribosyl-transferase as candidate genes. This study paves the way to characterize the genetic determinants of free asparagine accumulation in wheat grain.

Quantitative 1H NMR optimization for high-throughput metabolite analysis in industrial bioprocess monitoring

Quantitative 1H NMR (1H qNMR) is an ideal tool for bioprocess monitoring because it can comprehensively detect and quantify diverse metabolites that significantly influence bioprocess performance. However, the long experiment time associated with the 1H qNMR, due to the long longitudinal relaxation time (T1) of some metabolites, does not meet the requirements for high-throughput analysis. We developed a high-throughput 1H qNMR method for bioprocess analysis using a short relaxation delay (D1) to reduce analytical time and a correction factor (k) to compensate for incomplete relaxation. A total of 27 metabolites were quantified using spectral deconvolution via a peak fitting algorithm and MCR-ALS. Methodological validation results indicated that the precision and accuracy of the developed qNMR method were consistently high across different D1 values, with LOQs ranging from 0.008 to 0.13 mM and LODs ranging from 0.024 to 0.38 mM. Notably, a longer D1 value generally resulted in lower LODs and LOQs for most metabolites. A D1 value of 4 s was optimal for balancing analysis time and performance. The method is broadly applicable for bioprocess monitoring and control, offering valuable guidance for optimizing CHO cell culture processes and improving yield.

NMR-Based Metabolomic Approach to Study Growth of Phaseolus vulgaris L. Seedlings Through Leaf Application of Nanofertilizers and Biofertilizers

This study investigated the effects of two nanofertilizers (NFs): copper nanoparticles (NPs) synthesised using cotton (CuC) and chitosan (CuCh) as well as two biofertilizers (BFs), nopal extract (NE) and commercial Biojal® worm humus (WH), on the growth of black bean seedlings. The treatments consisted of applying 50 mg L-1 of CuC, 50 mg L-1 of CuCh, 50 mg L-1 of NE, 100 mg L-1 of WH, their respective combinations, and an absolute control that consisted of distilled water. The CuC, CuCh, WH, and WH + CuC leaf applications resulted in an increase in plant height by 34.4%, 19.5%, 25.7%, and 20.3%, respectively. Furthermore, the CuC and WH applications led to an increase in the number of leaves by 53.2% and 36.9%, respectively. However, the addition of NE + CuC resulted in a 37.4% decrease in dry weight. A total of 44 metabolites were identified, including 7 sugars, 17 amino acids, 12 organic acids, 4 nucleosides, 1 alcohol, and 3 miscellaneous metabolites. The NE + CuC and WH treatments resulted in a notably higher concentration of various metabolites, including amino acids, organic acids, and sugars. Conversely, the CuCh treatment led to an increased concentration of nucleosides, amino acids, trigonelline, and nicotinamide adenine dinucleotide (NAD+).

Exploring Tyramine's Role in the Formation of Supramolecular Adducts with Nonsteroidal Anti-Inflammatory Drugs

In pharmaceutical crystal engineering, salification and co-crystallization are well-established strategies to enhance the physicochemical properties of nonsteroidal anti-inflammatory drugs (NSAIDs), which typically exhibit low aqueous solubility. This study introduces three new multicomponent crystalline systems of NSAIDs (S-naproxen, flurbiprofen, and ketoprofen) with the co-former tyramine, designed using knowledge-based methods. Additionally, a new polymorph of the diflunisal-tyramine system, synthesized via mechanochemical techniques, is reported. The new multicomponent systems were thoroughly characterized using solid-state NMR and single-crystal X-ray diffraction. Aqueous solubility tests conducted through solution 1H NMR experiments revealed increased equilibrium solubility for all samples, highlighting the efficacy of crystal engineering in modulating the physicochemical properties of drugs.

A Comprehensive Model for Separating Systematic Bias and Noise in Metabolomic Timecourse Data-A Nonlinear B-Spline Mixed-Effects Approach

The simultaneous detection of tens to hundreds of metabolites in a single metabolomic timecourse sample offers a unique but often unrealized opportunity for quantification validation. An individual timecourse fit for each metabolite fundamentally convolutes measurement noise with systematic sample bias (stemming from, for example, variable sample dilution, extraction, and normalization). However, since systematic bias, by its definition, influences all metabolites within a sample in a similar fashion, it can be identified and corrected through the simultaneous fit of all detected metabolites in a single timecourse model. This study presents a nonlinear B-spline mixed-effects model as a convenient formulation capable of estimating and correcting such bias. The proposed model was successfully applied to real cell culture data and validated using simulated timecourse data perturbed with varying degrees of random noise and systematic bias. The model was able to accurately correct systematic bias of 3%-10% to within 0.5% on average for typical data. An R package for the correction model has been developed to facilitate model adoption and use. The proposed nonlinear B-spline mixed-effects formulation is general enough for application to a broad range of research areas beyond just cell culture metabolomics.

Rapid Stereochemical Analysis of Glycosylations in Flow by Ion Mobility Spectrometry

Glycans are biologically important molecules that are difficult to synthesize and analyze due to their structural diversity and conformational flexibility. Stereoselective glycosylation reactions are key to achieving high-yielding glycan syntheses. The stereochemical outcome of glycosylations is significantly influenced by factors such as the choice of activator and leaving group systems, solvent type, temperature, concentration, and stoichiometry. We introduce a flow chemistry approach to efficiently screen glycosylation conditions, using minimal material and time to enable a rapid design-make-test-analyze cycle with precise parameter control for reaction optimization. Ion mobility spectrometry provides rapid separation and analysis of crude glycosylation reaction mixtures that requires less method development than liquid chromatography thus making it a valuable tool for optimizing glycosylation reactions.

Metabolism in hematology: Technological advances open new perspectives on disease biology and treatment

The term metabolism refers to the multi-faceted biochemical reactions within a cell or an organism that occur to maintain energy homeostasis, cell growth, and oxidative balance. Cells possess a high metabolic plasticity, allowing them to adapt to the dynamic requirements of their functional state and environment. Deregulated cellular metabolism is a hallmark of many diseases, including benign and malignant hematological conditions. In the last decade, multiple technological innovations in the metabolism field have made in-depth metabolic analysis broadly applicable. Such studies are shedding new light on normal and malignant hematopoiesis and open avenues to a better understanding of the biology of hematological diseases. In this review, we will first give a brief overview of central metabolic processes. Furthermore, we discuss the most commonly used methods to study metabolism. We begin by elaborating on the use of next-generation sequencing to detect metabolism-related genomic mutations and study transcriptional signatures. Furthermore, we discuss methods for measuring protein expression, such as mass spectrometry (MS), flow cytometry, and cytometry time-of-flight. Next, we describe the use of nuclear magnetic resonance spectroscopy, MS, and flow cytometry for metabolite quantification. Finally, we highlight functional assays to probe metabolic pathways in real-time. We illustrate how these technologies and their combination have advanced our understanding of the role of metabolism. Our goal is to provide hematologists with a comprehensive guide to modern techniques in metabolism research, their benefits and disadvantages, and how they guide our understanding of disease and potentially future personalized therapy decisions.

Complex arabinose-containing polysaccharides from cyanobacterium Nostoc sp.: Extraction, structural characterization and antioxidant activity

Freshwater Nostoc sp. polysaccharides (NSPs) have not been extensively studied, particularly regarding their structural and biological characteristics. This study assessed the extracted NSPs through a multi-faceted characterization approach using 1H and 13C NMR, FTIR spectroscopy, HP-SEC and HPAEC-PAD. The study presented novel insights into the extracted polysaccharide composition, extraction efficiency, and antioxidant activities. NSPs were extracted using two different ranges of heating regimes: cold (25 °C) and hot (95 °C), with hot extraction yielding up to 34.9 % of NSPs compared to 27.6 % from cold extraction. The NSPs were non-sulfated and mainly composed of four monosaccharide residues: (1 → 3)-β-d-mannopyranose-(1 → 4)-β-l-arabinopyranose-(1 → 4)-β-d-glucuronic acid-(1 → 4)-β-d-glucopyranose. Some glucose units were 6-O-methylated, and minor sidechain glycosylation by other monosaccharides was observed. β-d-glucuronic acid was present in higher amounts. The polysaccharides from the inner fluid (IF) fraction exhibited a higher molecular weight (up to 480 kDa) compared to outer layer (OL) fractions. The total phenolic content (TPC: 0.2 ± 0.0-2.8 ± 0.0 %), total sugar (9.1 ± 0.8-67.8 ± 0.4 %), and protein (1.2 ± 0.1-25.9 ± 0.6 %) content were determined. NSPs, especially from cold extraction (1B) exhibited the highest antioxidant activity, have potential applications in the skincare, food, pharmaceutical, and biotechnology industries due to their high yield, unique structural features.

Glycosyltransferases: glycoengineers in human milk oligosaccharide synthesis and manufacturing

Human milk oligosaccharides (HMOs) are a diverse group of complex carbohydrates that play crucial roles in infant health, promoting a beneficial gut microbiota, modulating immune responses, and protecting against pathogens. Central to the synthesis of HMOs are glycosyltransferases, a specialized class of enzymes that catalyse the transfer of sugar moieties to form the complex glycan structures characteristic of HMOs. This review provides an in-depth analysis of glycosyltransferases, beginning with their classification based on structural and functional characteristics. The catalytic activity of these enzymes is explored, highlighting the mechanisms by which they facilitate the precise addition of monosaccharides in HMO biosynthesis. Structural insights into glycosyltransferases are also discussed, shedding light on how their conformational features enable specific glycosidic bond formations. This review maps out the key biosynthetic pathways involved in HMO production, including the synthesis of lactose, and subsequent fucosylation and sialylation processes, all of which are intricately regulated by glycosyltransferases. Industrial methods for HMO synthesis, including chemical, enzymatic, and microbial approaches, are examined, emphasizing the role of glycosyltransferases in these processes. Finally, the review discusses future directions in glycosyltransferase research, particularly in enhancing the efficiency of HMO synthesis and developing advanced analytical techniques to better understand the structural complexity and biological functions of HMOs.

An Analytical Workflow to Quantify Biodegradable Polyesters in Soils and Its Application to Incubation Experiments

Soil biodegradable polyesters are designed to undergo to microbial utilization in aerobic soils, forming carbon dioxide and microbial biomass. These polyesters are thus viable substitutes for conventional, persistent polymers (e.g., polyethylene) in specific applications for which the transfer of some of the polymers into the soil is inevitable. While polymer biodegradability is often assessed in laboratory incubations using respirometric analysis of formed CO2, approaches to accurately quantify biodegradable polyesters in soils and to track their mass loss in field incubations over time remain missing. This study first introduces an analytical workflow combining Soxhlet extraction with proton nuclear magnetic resonance spectroscopy for the accurate, high-throughput, and chemically selective quantification of eight commercially important biodegradable polyesters (i.e., poly(butylene adipate-co-terephthalate), polylactic acid, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), polycaprolactone, polybutylene adipate, polybutylene azelate, and polybutylene succinate), and the nonbiodegradable polymer polystyrene, in six soils spanning a range of types and physicochemical properties. This work introduces an effective sample deployment-retrieval approach that, combined with the analytical method, allows the biodegradation of poly(butylene adipate-co-terephthalate) and polylactic acid from a biodegradable mulch film in three agricultural soils to be monitored. In combination, the two parts of this work lay the foundation to accurately quantify and monitor biodegradable polymers in soils.

Development of Flow-NMR Spectroscopy for Real-Time Monitoring and Kinetics Studies of Biomolecules: Case Study of Liraglutide Oligomerization

We report the development of a comprehensive flow-NMR methodology for mechanistic studies of biomolecules. This approach allows for systematic kinetic investigation via precise sample condition modulations. Traditionally utilized for reaction monitoring and kinetic studies of small molecules, the application of flow-NMR to larger biomolecules, such as peptide oligomers and proteins, has remained unexplored. Here, we present a pioneering study using flow-NMR to examine the pH-dependent oligomeric interconversion of liraglutide, a glucagon-like peptide 1 (GLP-1) receptor agonist known for its efficacy in managing type 2 diabetes and obesity. Liraglutide molecules are prone to forming distinct oligomers and even fibrils under certain conditions, influencing their stability, absorption, and bioavailability─factors critically important in pharmaceutical applications. The developed methodologies and suite of flow-NMR experiments collectively yield comprehensive insights into the interconversion process of liraglutide without resorting to combining multiple other techniques. It incorporates various 1D and pseudo-2D proton NMR experiments, including GUPPY-DOSY, a newly developed version of a flow-compatible DOSY experiment, to monitor critical parameters such as diffusion coefficients (D), transverse relaxation (R2), and structural similarity. The relative ease of setting up and executing this set of flow-NMR experiments offers a straightforward path to extending their application to the characterization of other complex systems, including therapeutic proteins and biologic drugs.

Applicability of NMR spectroscopy to quantify microplastics across varying concentrations in polymer mixtures

Quantitative nuclear magnetic resonance (qNMR) spectroscopy could potentially be used for environmental microplastic analyses, provided the challenges posed by mixed polymer samples with varying concentrations and overlapping signals are understood. This study investigates the feasibility of qNMR as a reliable and cost-efficient method for quantifying synthetic polymers in mixtures of low and varying concentrations, addressing key challenges and limitations. Polymer mixtures were analysed using deuterated chloroform (CDCl3) and deuterated tetrahydrofuran (THF-d8) as solvents, with polystyrene (PS), polybutadiene-cis (PB), polyisoprene-cis (PI), polyvinyl chloride (PVC), polyurethane (PU), and polylactic acid (PLA) as selected polymers. Mixtures contained either low and high concentrations of each polymer or equal concentrations of all six polymers. Polymer concentrations were measured using the internal standard method. The method showed low relative errors for low concentrations of PS in CDCl3 and PVC in THF-d8, with values of -5% and 0%, respectively, while PB and PI in CDCl3 show relative errors of +5% and -3%, respectively. We observe significant linearity between nominal and measured concentrations with R 2 values ranging from 0.9655 to 0.9981, except for PU, which had high relative errors and poor linearity (R 2 = 0.9548). Moreover, simultaneous quantification of six polymers in THF-d8 proves effective at intermediate concentrations. However, overlapping proton signals are observed, causing high-concentration polymers to mask low-concentration ones. While this study demonstrates low limit of quantification (LOQ) and advances in simultaneous polymer quantification, further research is needed to improve qNMR accuracy for mixed polymer samples and environmentally relevant concentrations.

Quantitative Nuclear Magnetic Resonance for Small Biological Molecules in Complex Mixtures: Practical Guidelines and Key Considerations for Non-Specialists

Nuclear magnetic resonance (NMR) spectroscopy is a powerful analytical approach that enables both the structural determination and precise quantification of small molecules, such as metabolites. However, achieving precise quantification with NMR involves more than simply comparing integrals derived from NMR peaks to a concentration reference; quantitative NMR (qNMR) is a distinct and specialized application within the field. To obtain absolute quantitative results, spectra must be acquired under strict experimental conditions. Unfortunately, these acquisition parameters can be challenging to implement experimentally and often require trade-offs that compromise high throughput or practicality. In such situations, alternative strategies based on relative quantification and advanced software tools offer valuable solutions. This review aims to provide non-specialists with the key concepts and methodologies required for accurate NMR-based quantification in biomedical research, focusing on practical guidelines and experimental considerations. Unlike prior reviews, it prioritizes accessibility and practical implementation for researchers outside the field, emphasizing key experimental workflows and applications in biological and clinical studies. It clarifies the distinctions between absolute and relative concentration determinations and emphasizes the critical importance of sample preparation, pulse sequence selection, and rigorous control of experimental parameters. Recent technological advancements, such as high-field spectrometers and cryoprobes, have significantly enhanced the sensitivity and accuracy of NMR, enabling the reliable detection of low-concentration metabolites. Quantitative NMR thus offers critical potential in elucidating metabolic processes, supporting drug development, and aiding disease diagnosis.

Selenium in Action: Exploring the Biological Wonders of Hydroselenite Salts

Despite the wealth of data related to the advantages of formulating a wide range of compounds as salts to ameliorate their biological properties, there is scant information regarding the therapeutic potential of selenium (Se) salts. In this work, we have formulated six antibiotics as hydroselenite salts in order to compare their in vitro antibacterial and anticancer effects and evaluate if this approach could enhance their water solubility. In this regard, in almost all the cases, their solubility was increased by one order of magnitude. All the compounds were screened against a panel of three Gram-positive and three Gram-negative bacteria. Likewise, their antiproliferative activity was evaluated in breast, prostate, glioblastoma, and pancreatic cancer cell lines. Normal human dermal fibroblasts (NHDF) were used to determine their selectivity indexes (SI). Additionally, these novel hydroselenite salts were submitted to the National Cancer Institute (NCI) to study their antitumoral potential. Compounds SLT-2 and SLT-6 showed potent cytotoxicity against the glioblastoma cancer cell line, and their ability to induce apoptosis and reactive oxygen species (ROS) was further assessed. To conclude, we have demonstrated that the formulation of several antibiotics as hydroselenite salts could be a feasible approach to obtain biologically active compounds with an enhanced effect.

Free Radical Copolymerization of N-Isopropylacrylamide and 2,3-Dihydroxypropyl Methacrylate: Reaction Kinetics and Characterizations

Poly(N-isopropylacrylamide) (PNIPAm) undergoes a sharp phase transition in aqueous solutions at around 32 °C, which is called the lower critical solution temperature; the tuning of the LCST of PNIPAm could be achieved by the copolymerization of N-isopropylacrylamide (NIPAm) with other hydrophilic/hydrophobic monomers to regulate the solvation state of PNIPAm and meet the requirements of possible applications. Herein, a hydrophilic monomer, 2,3-dihydroxypropyl methacrylate (DHPMA), w introduced to regulate the phase transition behavior of PNIPAm via free radical copolymerization. A series of poly(N-isopropylacrylamide-co-2,3-dihydroxypropyl methacrylate) (P(NIPAm-co-DHPMA)) was synthesized and characterized. The reaction kinetics were investigated in detail. In this copolymerization, the reactivity ratios of DHPMA and NIPAm were found to be 3.09 and 0.11, suggesting that DHPMA had greater preference for homopolymerization than for copolymerization, while NIPAm had greater preference for copolymerization than for homopolymerization. The phase transition temperature of P(NIPAm-co-DHPMA) copolymers varied from 31 to 42 °C by controlling the content of DHPMA in the copolymers from 0 to 58 mol%. Finally, the good cytocompatibility of P(NIPAm-co-DHPMA) was confirmed. These results provide insights into designing thermo-responsive polymers with suitable responsive behaviors that meet the requirements of different applications.

Pink pepper (Schinus terebinthifolius Raddi) essential oil: phytochemical composition and cytotoxic activity

Pink pepper (Schinus terebinthifolius Raddi) is a native species native from Central and South America that produces an essential oil (EOpp) with promising applications. This work aimed to investigate the chemical composition and cytotoxic activity of EOpp extracted from unripe (U-EOpp) and ripe (R-EOpp) pink pepper fruits. U-EOpp and R-EOpp were extracted using the hydrodistillation technique and analysed using NMR and GC-MS. U-EOpp and R-EOpp cytotoxic activity was assessed using HL-60 (acute promyelocytic leukemia) and SK-MEL-28 (malignant melanoma) cell lines by MTT assay. Results showed that α-pinene (29.16%), dl-Limonene (20.65%), and ρ-cymene (15.86%) were U-EOpp major components. In addition, l-phellandrene (38.91%), Sylvestrene (23.02%), and α-pinene (21.62%) were R-EOpp major components. U-EOpp showed cytotoxic activity at 37.5 and 18.7 µg/mL for SK-MEL-28 and HL-60, respectively. R-EOpp showed cytotoxic activity for HL-60 at 100 µg/mL. Therefore, EOpp may represent a remarkable source of active natural compounds used in traditional Brazilian medicine.

A deep learning framework for multiplet splitting classification in 1H NMR

One-dimensional 1H Nuclear Magnetic Resonance (NMR) stands out as the quickest and simplest among various NMR experimental setups. Unfortunately, it suffers from lengthy annotation times and does not always have a clear and unique interpretation. From NMR discovery, efforts have been dedicated to introducing an automated approach to streamline the characterization of chemical compounds while ensuring consistency of the results across the scientific community. Nonetheless, this remains an ongoing challenge that has garnered renewed interest with the emergence of deep learning techniques. Here, we present MuSe Net, a novel supervised probabilistic deep learning framework that can emulate the tasks performed by an expert spectroscopist in annotating one-dimensional NMR spectra generated by small molecules. Considering only the spectrum, MuSe Net detects and classifies multiplets with up to four coupling constants for their splitting phenotype, providing a segmentation of the spectral range. We exploit uncertainty quantification to produce a confidence score to both assess classification reliability and to detect signals that do not fit into any other phenotype class. The results of the evaluation against 48 experimental 1H NMR spectra of small molecules annotated by experts demonstrate that MuSe Net can deal with anomalies and unclear signals while correctly classifying multiplets and detecting overlapping peaks.

Structure-Activity Relationships and Evaluation of 2-(Heteroaryl-cycloalkyl)-1H-indoles as Tauopathy Positron Emission Tomography Radiotracers

Structure-activity relationship studies were performed on a library of synthesized compounds based on previously identified tau ligands. The top 13 new compounds had Ki values in the range of 5-14 nM in Alzheimer's disease (AD), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD) post-mortem brain tissues. One of the more promising new compounds ([3H]75) bound with high affinity in AD, PSP, and CBD tissues (KD's = 1-1.5 nM) and Pick's disease tissue (KD = 3.8 nM). Autoradiography studies with [3H]75 demonstrated specific binding in AD, PSP, and CBD post-mortem tissues. Nonhuman primate brain PET imaging with [18F]75 demonstrated a peak standardized uptake value (SUV) of ∼5 in the cerebellum, ∼4.5 in the cortex, and ∼4 in whole brain with SUV 2-to-90 min ratios of 3.9 in whole brain, 4.9 in cortex, and 4.5 in cerebellum. Compound [18F]75 is a promising candidate for translation to human brain PET imaging studies.

Impact of NPK fertilization on the metabolomic profile and nutritional quality of Portulaca oleracea L. using nuclear magnetic resonance analysis

Purslane is a plant with high nutritional content that is mainly produced in the central part of Mexico. The nutritional content of purslane depends on various factors such as climatic and soil conditions, phenology, and fertilization. This article describes the 1H NMR metabolomics profiling of purslane in relation to fertilization at two harvest stages: C1 and C2 (27 and 42 days after emergence). During the first stage, 30 metabolites were identified including free amino acids and organic acids. In the second stage, 35 metabolites were identified, with higher concentrations of carbohydrates and nucleosides being observed. Multivariate analysis revealed differences in the metabolome between harvests C1 and C2. Notably, higher abundances of fructose, galactose, α-glucose, β-glucose, myo-inositol, sucrose, and nucleosides such as adenosine and uridine were observed in C2. Discriminant analysis further demonstrated variations in metabolites among plants treated with different doses of nitrogen, phosphorus, and potassium at the two harvest stages studied. Plants treated with the highest dose of nitrogen (300 kg N ha-1) exhibited maximum levels of metabolites, while low nitrogen-treated plants (0 kg N ha-1) displayed an inverse trend. Amino acids such as alanine, asparagine, GABA, glutamine, histidine, isoleucine, leucine, phenylalanine, proline, threonine, tyrosine, and valine were found to be the most abundant in plants treated with N300. In contrast, untreated plants showed higher levels of citric acid and malic acid. Our results highlight the effectiveness of 1H NMR as a methodology for understanding the role of fertilization and nutrient content in optimizing the crop production of purslane.

Nuclear Magnetic Resonance Spectroscopic Characterization and Determination of the New Psychoactive Substance Benzylone: Application in a Biological Fluid

New psychoactive substances (NPS)-designed to mimic various legal or illegal substances-are an emerging worldwide health problem. Their identification and quantification in either complex seized samples or powders are critical; moreover, their determination in biological fluids is an intriguing goal in the forensic toxicology field. Synthetic cathinones are one of the most important groups among NPS. The current paper was designed as a pilot study to investigate the application of NMR techniques to identify and quantify unknown NPS compounds in deuterated dimethyl sulfoxide (DMSO-d6) and in urine using the synthetic cathinone benzylone (3,4-methylenedioxy-N-benzylcathinone, BMDP) as a pilot compound. In the first part of our study, nuclear magnetic resonance (NMR) spectroscopic characterization was performed using 1D and 2D homonuclear and heteronuclear NMR spectroscopic methods as long as diffusion ordered spectroscopy (DOSY). Following the above, the assignment of benzylone in DMSO-d6 was performed, and a distinct spectroscopic pattern was proposed. In the second part of our study, a NMR spectroscopic approach was applied for benzylone identification and quantification in a spiked with benzylone urine. Following the above, the assignment of benzylone in spiked urine was performed. A distinct pattern of the H11, H14, H15, and H8 signals on the 1H NMR spectra was observed and suggested as a "NMR spectroscopic pattern/signature" enabling the identification of benzylone moieties in urine. On the other hand, the applied NMR techniques showed low sensitivity in quantitating benzylone in spiked urine. Overall, our results are promising in using NMR for structure determination of unknown compounds in urine.

The association between metabolite concentrations and wellbeing in adults

The biological complexity of wellbeing is studied from various perspectives, including genetics and epigenetics. However, there is a knowledge gap concerning other layers, such as metabolomics, which is dynamic and changes throughout life. This study explores the association between metabolites and wellbeing in a sample (N = 4748) drawn from the Netherlands Twin Register. A latent factor score for wellbeing was constructed based on: Quality of Life, Life Satisfaction, and Subjective Happiness. A total of 231 blood metabolites were analyzed using 1HNMR technique. Linear regression models were performed for each metabolite, while correcting for family clustering, relevant covariates, and multiple testing. None of the metabolites were significantly associated with wellbeing after multiple testing correction. Despite the lack of significant findings, the 34 metabolites with the lowest p-value (0.25) pointed to the same metabolic pathway: endogenous lipid metabolism. This pathway has previously been linked to wellbeing in a GWAS and associated with related phenotypes in other metabolomic studies. In conclusion, this study confirms the biological complexity of wellbeing and speculates on a potential role of lipids. Further research is needed to confirm these hypotheses.

A Set of Three GdIII Spin Labels with Methanethiosulfonyl Groups for Bioconjugation Covering a Wide Range of EPR Line Widths

Spin labels based on GdIII complexes are important tools for the elucidation of the structure, dynamics and interaction of biomolecules by electron paramagnetic resonance (EPR) spectroscopy. Their EPR spectroscopic properties line width and relaxation times influence their performance in a particular application. To be able to apply a complex well-suited for a specific application, a set of GdIII complexes with different EPR spectroscopic properties ready-made for spin labeling will be highly useful. We prepared three GdIII complexes with DO3APic, NO3Pic, and PyMTA as the basic ligand units. They cover a wide range of EPR line widths but have in common a cysteine-targeting methanethiosulfonyl (MTS) group connected to a pyridine ring, which is an intrinsic part of the ligand. The reaction with a cysteine-containing pentapeptide (0.45 mM in the peptide, pH ∼ 7) was complete within 90 s and chemoselective. The MTS group hydrolyzed with half-lives of >24, 8, 2, and 1 h at pH 5, 6, 7, and 8, respectively. The structurally related nicotinic acid-substituted disulfide (NDS) group was found to be hydrolytically much more stable. However, the MTS spin label clearly won the competition for the pentapeptide over the NDS spin label. If high reactivity is essential, MTS is clearly the better choice.

Precision Dietary Intervention: Gut Microbiome and Meta-metabolome as Functional Readouts

Gut microbiome, the group of commensals residing within the intestinal tract, is closely associated with dietary patterns by interacting with food components. The gut microbiome is modifiable by the diet, and in turn, it utilizes the undigested food components as substrates and generates a group of small molecule-metabolites that addressed as "meta-metabolome" in this review. Profiling and mapping of meta-metabolome could yield insightful information at higher resolution and serve as functional readouts for precision nutrition and formation of personalized dietary strategies. For assessing the meta-metabolome, sample preparation is important, and it should aim for retrieval of gut microbial metabolites as intact as possible. The meta-metabolome can be investigated via untargeted and targeted meta-metabolomics with analytical platforms such as nuclear magnetic resonance spectroscopy and mass spectrometry. Employing flux analysis with meta-metabolomics using available database could further elucidate metabolic pathways that lead to biomarker discovery. In conclusion, integration of gut microbiome and meta-metabolomics is a promising supplementary approach to tailor precision dietary intervention. In this review, relationships among diet, gut microbiome, and meta-metabolome are elucidated, with an emphasis on recent advances in alternative analysis techniques proposed for nutritional research. We hope that this review will provide information for establishing pipelines complementary to traditional approaches for achieving precision dietary intervention.

Bio-Microcapsules of Polybutylene Succinate (PBS) and Isocyanates: Towards Sustainable, Safer, and Efficient Adhesives

This work describes the encapsulation of three different aliphatic isocyanates to reduce the risks associated with isocyanates' direct handling. The use of bio-based polybutylene succinate (bio-PBS) increases the sustainability factor as it allows for the use of microcapsules (MCs) from renewable sources with biodegradable features. The three different MCs (MCs-Monomer, MCs-Trimer, and MCs-Polymer) are spherical, crack-free, and matrix-type, containing an isocyanate payload between 67 wt% and 70 wt%. Protection against environmental moisture was improved, resulting in losses of less than 10% for most cases after one month. The bio-PBS MCs were found to be suitable as crosslinking agents in high-performance adhesive formulations for the footwear industry. Adhesive joints with encapsulated isocyanate exhibited peel strength values ranging from 3.28 to 4.56 N/mm, well above the minimum requirements for the intended footwear application. Additionally, these joints demonstrated improved creep resistance compared to those using non-encapsulated isocyanates. In this context, the MCs-Trimer stood out, providing exceptional thermal robustness to the joints, as they showed no failure or opening at 90 °C, consistent with commercial adhesives. These results confirm that bio-PBS MCs can be excellent components for future adhesive formulations and that matrix-type MCs can also be utilised for this purpose.

Nano-enabled dynamically responsive living acellular hydrogels

As a key building block of mammalian tissues, extracellular matrices (ECMs) stiffen under shear deformation and undergo cell-imparted healing after damage, features that regulate cell fate, communication, and survival. The shear-stiffening behavior is attributed to semi-flexible biopolymeric ECM networks. Inspired by the mechanical behavior of ECMs, we develop acellular nanocomposite living hydrogels (LivGels), comprising network-forming biopolymers and anisotropic hairy nanoparticle linkers that mimic the dynamic mechanical properties of living counterparts. We show that a bifunctional dynamic linker nanoparticle (nLinker), bearing semi-flexible aldehyde- and carboxylate-modified cellulose chains attached to rigid cellulose nanocrystals converts bulk hydrogels to ECM-like analogues via ionic and dynamic covalent hydrazone bonds. The nLinker not only enables the manipulation of nonlinear mechanics and stiffness within the biological window, but also imparts self-healing to the LivGels. This work is a step forward in designing living acellular soft materials with complex dynamic properties using bio-based nanotechnology.

Quantitative Blood Serum IVDr NMR Spectroscopy in Clinical Metabolomics of Cancer, Neurodegeneration, and Internal Medicine

Despite more than two decades of metabolomics having joined the "omics" scenery, to date only a few novel blood metabolite biomarkers have found their way into the clinic. This is changing now by massive large-scale population metabolic phenotyping for both healthy and disease cohorts. Here, nuclear magnetic resonance (NMR) spectroscopy is a method of choice, as typical blood serum markers can be easily quantified and by knowledge of precise reference concentrations, more and more NMR-amenable biomarkers are established, moving NMR from research to clinical application. Besides customized approaches, to date two major commercial platforms have evolved based on either 600 MHz (14.1 Tesla) or 500 MHz (11.7 Tesla) high-field NMR systems. This chapter provides an introduction into the field of quantitative in vitro diagnostics research (IVDr) NMR at 600 MHz and its application within clinical research of cancer, neurodegeneration, and internal medicine.

Carboxymethylation of β-Glucan from Pythium insidiosum: Structural characterization and preliminary adsorption evaluation of DON and T2 toxin

This study aimed to evaluate the impact of carboxymethylation on the structural and functional properties of β-glucan derived from the pathogenic oomycete Pythium insidiosum. β-Glucan was extracted and subjected to carboxymethylation (CM-glucan), with structural changes analyzed using 13C and 1H NMR spectroscopy. The modified β-glucan's ability to adsorb mycotoxins, specifically deoxynivalenol (DON) and T2 toxin, was assessed through in vitro adsorption assays. Results demonstrated that the adsorption of DON by CM-glucan increased from 0 % to 59.11 %, corresponding to the adsorption of approximately 1.18 μg of DON from the initial concentration (2 μg/mL). Similarly, the adsorption of T2 toxin increased slightly from 0 % to 4.54 %, corresponding to 0.09 μg of T2 toxin adsorbed from the initial concentration (2 μg/mL). These findings underscore the potential of chemical modifications to enhance the functional properties of natural polysaccharides, suggesting future applications in mycotoxin adsorption and other biological properties across various areas.

NMR-Based Analysis of Cellular Central Energy Metabolism and Exchange Rates

Cell cultures are widely used in studies to gain mechanistic insights of metabolic processes. The foundation of these studies lies on the quantification of intracellular and extracellular metabolites, and nuclear magnetic resonance (NMR) is one of the key analytical platforms used to this aim. Among the factors influencing the quality of the produced data are the sampling procedures as well as the acquisition and processing of spectroscopic data. Here we provide our workflow for obtaining quantitative metabolic data from adherent mammalian cells using NMR spectroscopy. The described protocol is compatible with other analytical methods like LC- or GC-MS-based lipidomics and untargeted metabolomics from the same sample. We also show how the collected extracellular data can be used to extract exchange flux rates, particularly useful for flux analysis studies and metabolic engineering of human-induced pluripotent stem cells.

Antioxidant and longevity inducing properties of coconut water on human dermal fibroblasts

Coconut water is a popular drink in tropical countries and worldwide due to its delicious taste, easy consumption and nutritionally rich properties. Our study aimed to identify bioactive compounds of coconut varieties and their antioxidant as well as longevity effects in 2 different groups of coconuts. These include the bleeding coconut varieties, which are currently most available in the market, namely the Ban Phaeo and Ratchaburi coconut varieties, and the traditional coconut varieties, including Kon-jib and Sampran coconut varieties. Proton nuclear magnetic resonance (1H NMR) was used to profile the metabolites in coconut water which revealed 27 metabolites including sugar, organic acids, fatty acids, flavonoids and phenolic compounds. A multivariate data analysis demonstrated an organic acid and phenolic metabolites as the antioxidant bioactive metabolites in coconut water. In addition, the coconut varieties had higher antioxidant bioactive metabolites compared to traditional coconut varieties, while traditional coconut varieties had higher sugar levels. Furthermore, the varieties containing higher antioxidants bioactive metabolites were chosen to examine the longevity effect on human dermal fibroblasts (HDFs). The results revealed that coconut water can significantly decrease cytosolic oxidation in hydrogen peroxide treated HDFs cell line and mediated longevity of fibroblast cells by modulating the expression of proteins in longevity pathway. Data from our study indicate that coconut water serves as source of antioxidants which can be mediated longevity of dermal cell. Moreover, this study provides the useful information for the coconut water production and distribution business.

Analytical tools to assess polymer biodegradation: A critical review and recommendations

Many petroleum-derived plastic materials are highly recalcitrant and persistent in the environment, posing significant threats to human and ecological receptors due to their accumulation in ecosystems. In recent years, research efforts have focused on advancing biological methods for polymer degradation. Enzymatic depolymerization has emerged as particularly relevant for biobased plastic recycling, potentially scalable for industrial use. Biodegradation involves adsorption to the plastic solid surface, followed by an interfacial reaction, resulting in cleavage of bonds of polymer chains exposed on the surface. Here, widely varying substrate-specific kinetics are observed, with the polymer's properties possessing a significant impact on the rate of this interfacial catalysis. Thus, there is a critical need for sensitive and accurate characterization of the material surface during and after interfacial depolymerization to fully understand the reaction mechanisms. Here, we provide a critical review of a range of techniques used in the analysis of material surfaces to characterize the chemical, topological, and morphological features relevant to the study of enzymatic biocatalysis, including microscopy techniques, spectroscopic techniques (e.g., X-ray diffraction analysis, Fourier transform infrared attenuated total reflectance spectroscopy, and mass spectrometry detection of analytes associated with degradation). Techniques for evaluation of surface energy and topology in their relevancy for sensitive detection of biological surface modifications are also discussed. In addition, this paper provides an overview of the strengths of these techniques and compares their performance in both sensitivity and throughput, including emerging techniques, which can be useful, particularly for the rapid analysis of the surface properties of polymeric materials in high-throughput screening of candidate biocatalysts. This research serves as a starting point in selecting and applying appropriate methodologies that provide direct evidence to the ongoing biotic degradation of polymeric materials.

Photocatalytic applications of covalent organic frameworks: synthesis, characterization, and utility

Photocatalysis has emerged as an energy efficient and safe method to perform organic transformations, and many semiconductors have been studied for use as photocatalysts. Covalent organic frameworks (COFs) are an established class of crystalline, porous materials constructed from organic units that are easily tunable. COFs importantly display semiconductor properties and respectable photoelectric behaviour, making them a strong prospect as photocatalysts. In this review, we summarize the design, synthetic methods, and characterization techniques for COFs. Strategies to boost photocatalytic performance are also discussed. Then the applications of COFs as photocatalysts in a variety of reactions are detailed. Finally, a summary, challenges, and future opportunities for the development of COFs as efficient photocatalysts are entailed.

Polymorphism of Pb5(PO4)3OHδ within the LK-99 mixture

During the synthetic exploration targeting the polycrystalline compound LK-99, an unexpected phase, Pb5(PO4)3OHδ, was identified as a byproduct. We elucidated the composition of this compound through single-crystal X-ray diffraction analysis. Subsequent synthesis of the target compounds was achieved via high-temperature solid-state pellet reactions. The newly identified Pb5(PO4)3OHδ has an orthorhombic crystal structure with space group Pnma, representing a unique structure differing from the hexagonal apatite phases of Pb10(PO4)6O and Pb5(PO4)3OH. Comprehensive temperature- and magnetic-field-dependent magnetization studies unveiled a temperature-independent magnetic characteristic of Pb5(PO4)3OHδ. Solid-state nuclear magnetic resonance spectroscopy was employed to decipher the origins of the phase stability and confirm the presence of hydrogen atoms in Pb5(PO4)3OHδ. These investigations revealed the presence of protonated oxygen sites, in addition to the interstitial water molecules within the structure, which may play critical roles in stabilizing the orthorhombic phase.

Microplastics pollution in the marine environment: A review of sources, impacts and mitigation

Over the past few years, microplastics (MPs) pollution in the marine environment has emerged as a significant environmental concern. Poor management practices lead to millions of tons of plastic waste entering oceans annually, primarily from land-based sources like mismanaged waste, urban runoff, and industrial activities. MPs pollution in marine environments poses a significant threat to ecosystems and human health, as it adsorbs pollutants, heavy metals, and leaches additives such as plasticizers and flame retardants, thus contributing to chemical pollution. The review article provides a comprehensive overview of MPs pollution, its sources, and impacts on marine environments, including human health, detection techniques, and strategies for mitigating microplastic contamination in marine environments. The paper provides current information on microplastic pollution in marine environments, offering insights for researchers, policymakers, and the public, as well as promoting sustainable practices to protect the environment.

Single-Component Starch-Based Hydrogels for Therapeutic Delivery

Hydrogels are interesting materials as delivery systems of various therapeutic agents, mainly due to the water-swollen network and the localized and sustained drug release. Herein, single-component starch-based hydrogels with enhanced degradation rates were produced by applying a facile synthesis and proposed for a novel delivery system of therapeutic molecules. Starch was oxidized with sodium periodate in water and mild conditions to generate aldehyde derivatives that, after a freeze-thaw procedure, were allowed to compact and stable hydrogels. Oxidized starch was also cross-linked with asparagine through a Schiff base reaction to link the active molecule directly to the polysaccharide structure. The materials were structurally and morphologically characterized, and the ability to adsorb and release over time an active molecule was proven by qNMR spectroscopy. The cytotoxicity was evaluated on CAL-27 cell line (oral squamous cell carcinoma). Results indicated that synthesized hydrogels lead to a "frozen proliferative" state on cells due to the swelling capability in the cell medium. This behavior was confirmed by flow cytometry data indicating the hydrogels induced less "early apoptosis" and more "late apoptosis" in the cells, compared to the untreated control. Since the proposed materials are able to control the cell proliferation, they could open a new scenario within the field of precise therapeutic applications.

Protective Contribution of Rosmarinic Acid in Rosemary Extract Against Copper-Induced Oxidative Stress

Rosemary extract (Rosmarinus officinalis) is a natural source of bioactive compounds with significant antioxidant properties. Among these, rosmarinic acid is celebrated for its potent antioxidant, anti-inflammatory, antimicrobial, and neuroprotective properties, making it a valuable component in both traditional medicine and modern therapeutic research. Neurodegenerative diseases like Alzheimer's and Parkinson's are closely linked to oxidative damage, and research indicates that rosmarinic acid may help protect neurons by mitigating this harmful process. Rosmarinic acid is able to bind cupric ions (Cu2+) and interfere with the production of reactive oxygen species (ROS) produced by copper through Fenton-like reactions. This study aims to further evaluate the contribution of rosmarinic acid within rosemary extract by comparing its activity to that of isolated rosmarinic acid. By using a detailed approach that includes chemical characterization, antioxidant capacity assessment, and neuroprotective activity testing, we have determined whether the combined components in rosemary extract enhance or differ from the effects of rosmarinic acid alone. This comparison is crucial for understanding whether the full extract offers added benefits beyond those of isolated rosmarinic acid in combating oxidative stress and Aβ-induced toxicity.

Antimicrobial starch-based cryogels and hydrogels for dual-active food packaging applications

The present study reports on the valorisation of starch waste biomass to produce dual-active cryogels and hydrogels able to adsorb water and deliver antimicrobial substances for fresh food packaging applications. Starch hydrogels were prepared by oxidation with sodium metaperiodate in water and mild conditions, while cryogels were obtained by freeze-drying process. To explore the role of starch composition on the final properties of materials, two starches differing in amylose/amylopectin ratio, were evaluated. The prepared materials were microstructurally and morphologically characterized by FTIR and NMR spectroscopy (1D, 2D, and DOSY experiments), and SEM microscopy. To provide the materials with active properties, they were loaded with antimicrobial molecules by absorption, or by crosslinking via Schiff-base reaction. All materials demonstrated high water absorption capacity and ability to deliver volatile molecules, including diacetyl and complex mixtures like mint essential oil. The release profiles of the adsorbed molecules were determined through quantitative NMR spectroscopy over time. The antibacterial activity was successfully demonstrated against Gram-positive bacterial strains for unloaded cryogels and hydrogels, and after loading with diacetyl and essential oil. The developed materials can be regarded as part of active pads for food packaging applications capable to control moisture inside the package and inhibit microbial contamination.

Highly selective solid-liquid extraction of microplastic mixtures as a pre-preparation tool for quantitative nuclear magnetic resonance spectroscopy studies

Despite various developments in the application of quantitative nuclear magnetic resonance (qNMR) spectroscopy toward microplastics in recent years, this method still lacks suitable sample preparation and fractionation procedures. As this poses a crucial obstacle for its utilisation on environmental samples, which contain various mixtures of polymers along with other matrix substances, this research aims to address this missing link by presenting an easy-to-apply procedure based on common laboratory equipment. The process selectively separates microplastics from inorganic constituents while performing the necessary fractionation of different types of microplastics prior to qNMR analysis. It allows subsequent quantification of polystyrene (PS), polybutadiene rubber (BR), polymethylmethacrylate (PMMA), polyvinylchloride (PVC), polyethylene terephthalate (PET) and polyamide (PA) from a single sample, establishing recovery rates greater than 88% for all tested polymer types. Additionally, we extended our previous qNMR protocol to include two common polymer types: polymethylmethacrylate (PMMA) and polyacrylonitrile (PAN), achieving limits of detection down to 1.76 μg ml-1 and 12.53 μg ml-1 as well as limits of quantification down to 5.88 μg ml-1 and 41.78 μg ml-1, respectively. Thus, the qNMR method presented herein is now applicable to eight abundant polymer types, allowing the quantification of up to three different types simultaneously.

Rapid and sensitive approaches for detecting food fraud: A review on prospects and challenges

Precise and reliable analytical techniques are required to guarantee food quality in light of the expanding concerns regarding food safety and quality. Because traditional procedures are expensive and time-consuming, quick food control techniques are required to ensure product quality. Various analytical techniques are used to identify and detect food fraud, including spectroscopy, chromatography, DNA barcoding, and inotrope ratio mass spectrometry (IRMS). Due to its quick findings, simplicity of use, high throughput, affordability, and non-destructive evaluations of numerous food matrices, NI spectroscopy and hyperspectral imaging are financially preferred in the food business. The applicability of this technology has increased with the development of chemometric techniques and near-infrared spectroscopy-based instruments. The current research also discusses the use of several multivariate analytical techniques in identifying food fraud, such as principal component analysis, partial least squares, cluster analysis, multivariate curve resolutions, and artificial intelligence.

Non-Targeted Nuclear Magnetic Resonance Analysis for Food Authenticity: A Comparative Study on Tomato Samples

Non-targeted NMR is widely accepted as a powerful and robust analytical tool for food control. Nevertheless, standardized procedures based on validated methods are still needed when a non-targeted approach is adopted. Interlaboratory comparisons carried out in recent years have demonstrated the statistical equivalence of spectra generated by different instruments when the sample was prepared by the same operator. The present study focused on assessing the reproducibility of NMR spectra of the same matrix when different operators performed individually both the sample preparation and the measurements using their spectrometer. For this purpose, two independent laboratories prepared 63 tomato samples according to a previously optimized procedure and recorded the corresponding 1D 1H NMR spectra. A classification model was built using the spectroscopic fingerprint data delivered by the two laboratories to assess the geographical origin of the tomato samples. The performance of the optimized statistical model was satisfactory, with a 97.62% correct sample classification rate. The results of this work support the suitability of NMR techniques in food control routines even when samples are prepared by different operators by using their equipment in independent laboratories.

Tuning and Matching Error-Compensated, Quantitative Solid-State Nuclear Magnetic Resonance

NMR spectroscopy has long been recognized as a powerful quantitative analytical tool. Quantification is commonly done against internal and external standards. A third approach is to quantify against an electronic reference, which combines the advantages of the two methods. The implementation of this approach in solid-state NMR is more challenging due to the single-coil design of double resonance probes. In this study, a novel approach for implementing the electronic referencing method in solid-state NMR by injecting the reference signal using a broadband antenna installed near the NMR receiver coil is presented. This method demonstrates excellent accuracy and precision, as it remains robust to changes in the electronic conditions of the probe, including tuning and matching errors.

Physicochemical Principles of AC Electrosynthesis: Reversible Reactions

Electrolysis integrates renewable energy into chemical manufacturing and is key to sustainable chemistry. Controlling the waveform beyond direct current (DC) addresses the long-standing obstacle of chemoselectivity, yet it also expands the parameter set to optimize, creating a demand for theoretical predictions. Here, we report the first analytical theory for predicting chemoselectivity in an alternating current (AC) electrosynthesis. The mechanism is a selective reversal of the unwanted redox reaction during periods of opposite polarity, reflected in the final reaction outcome as a time-averaged effect. In the ideal scenario of all redox reactions being reversible, square AC waveform biases the outcome toward more overoxidation/over-reduction, whereas sine AC waveform exhibits the opposite effect. However, in a more realistic scenario of some redox reactions being quasi-reversible, sine AC may behave mostly like square AC. These predictions are in numerical agreement with model experiments employing acetophenone and align qualitatively with the literature precedent. Collectively, this study provides theoretical proof for a growing trend that promotes changing waveforms to overcome limitations challenging to address by varying canonical electrochemical parameters.

Identification of procyanidins as α-glucosidase inhibitors, pancreatic lipase inhibitors, and antioxidants from the bark of Cinnamomum cassia by multi-bioactivity-labeled molecular networking

This study examined the suppressive effects of 16 selected plant-based foods on α-glucosidase and pancreatic lipase and their antioxidant properties. Among these, the bark of Cinnamomum cassia (Cinnamon, WLN-FM 15) showed the highest inhibitory activity against α-glucosidase and the highest antioxidant activity. Additionally, WLN-FM 15 showed promising results in the other tests. To further identify the bioactive constituents of WLN-FM 15, a multi-bioactivity-labeled molecular networking approach was used through a combination of GNPS-based molecular networking, DPPH-HPLC, and affinity-based ultrafiltration-HPLC. A total of nine procyanidins were identified as antioxidants and inhibitors of α-glucosidase and pancreatic lipase in WLN-FM 15. Subsequently, procyanidins A1, A2, B1, and C1 were isolated, and their efficacy was confirmed through functional assays. In summary, WLN-FM 15 has the potential to serve as a functional food ingredient with the procyanidins as its bioactive constituents. These results also suggest that the multi-bioactivity-labeled molecular networking approach is reliable for identifying bioactive constituents in plant-based foods.

The Metabolomic Footprint of Liver Fibrosis

Both experimental and clinical liver fibrosis leave a metabolic footprint that can be uncovered and defined using metabolomic approaches. Metabolomics combines pattern recognition algorithms with analytical chemistry, in particular, 1H and 13C nuclear magnetic resonance spectroscopy (NMR), gas chromatography-mass spectrometry (GC-MS) and various liquid chromatography-mass spectrometry (LC-MS) platforms. The analysis of liver fibrosis by each of these methodologies is reviewed separately. Surprisingly, there was little general agreement between studies within each of these three groups and also between groups. The metabolomic footprint determined by NMR (two or more hits between studies) comprised elevated lactate, acetate, choline, 3-hydroxybutyrate, glucose, histidine, methionine, glutamine, phenylalanine, tyrosine and citrate. For GC-MS, succinate, fumarate, malate, ascorbate, glutamate, glycine, serine and, in agreement with NMR, glutamine, phenylalanine, tyrosine and citrate were delineated. For LC-MS, only β-muricholic acid, tryptophan, acylcarnitine, p-cresol, valine and, in agreement with NMR, phosphocholine were identified. The metabolomic footprint of liver fibrosis was upregulated as regards glutamine, phenylalanine, tyrosine, citrate and phosphocholine. Several investigators employed traditional Chinese medicine (TCM) treatments to reverse experimental liver fibrosis, and a commentary is given on the chemical constituents that may possess fibrolytic activity. It is proposed that molecular docking procedures using these TCM constituents may lead to novel therapies for liver fibrosis affecting at least one-in-twenty persons globally, for which there is currently no pharmaceutical cure. This in-depth review summarizes the relevant literature on metabolomics and its implications in addressing the clinical problem of liver fibrosis, cirrhosis and its sequelae.

Coaxial-Tube Quantitative Nuclear Magnetic Resonance for Various Solutions Using SI-Traceable Concentration References

Quantitative nuclear magnetic resonance (qNMR) is an accepted method for determining analyte concentrations using quantitative substances in one spectrum. Conventional qNMR is performed using a mixture of analytes and reference substances. In coaxial-tube NMR, two tubes are used as different solutions, similar to normal NMR spectra. Currently, coaxial tubes with various diameters are available; however, coaxial-tube qNMR is limited, and a general analytical protocol is yet to be proposed. In this study, we established an effective volume ratio (EVR) measurement method using the weight density and qNMR methods. Various analyte concentrations were determined using coaxial-tube qNMR and an SI-traceable reagent. The EVR required for the qNMR concentration calculation was determined using a coefficient of variation (CV) of <1% for an inner tube of ϕ 3 mm or less. The peak integral of each substance was correlated with the effective volume, depending on the abundance of the tube and matched 1H in the solution. The T1 relaxation times differed depending on the substructure, and the T1 values of the formate and OH groups varied for each tube set. Thus, each partial structural characteristic of the peak must be understood before qNMR is performed. The concentrations of various substances, including hygroscopic substances, were determined using coaxial-tube qNMR. Coaxial tubes eliminate the need to mix the analyte with the reference substance; thus, we can quantify the analyte without causing pH and structural changes caused by other mixtures and reuse the analyte for other test systems.

Quantitative 31P NMR Spectroscopy Platform Method for the Assay of Oligonucleotides as Pure Drug Substances and in Drug Product Formulations Using the Internal Standard Method

One of the most widely used techniques for the quantification of small interfering ribonucleic acid (siRNA) is the ultraviolet (UV) spectroscopy method. However, due to uncertainties in the extinction coefficient affecting the accuracy of the method and a sample preparation including several dilution steps, the purpose of this study was to explore the possibility of determining the content of siRNA by a platform method using quantitative 31P nuclear magnetic resonance (31P-qNMR) and the internal standard method. In this paper, acquisition time, selection of a suitable internal certified reference material, signal selection used for quantification, relaxation delay, and precision are discussed. In addition, the robustness of the method and the ability to apply this platform method to both drug substance (DS) and drug product samples is also discussed. Quantifications of siRNA determined by the 31P-qNMR platform method were on average 98.5%w/w when adjusting for the sodium and water contents. The data confirmed the applicability of 31P-qNMR in siRNA content determinations. The quantifications were compared to quantifications determined by the traditional UV spectroscopy method by F- and t-tests. The statistical tests showed that the platform 31P-qNMR method provided more accurate results (mass balance close to 100% w/w) compared to the traditional UV spectroscopy method when analyzing DS samples.

Fermentation Analytical Technology (FAT): Monitoring industrial E. coli fermentations using absolute quantitative 1H NMR spectroscopy

BACKGROUND

To perform fast, reproducible, and absolute quantitative measurements in an automated manner has become of paramount importance when monitoring industrial processes, including fermentations. Due to its numerous advantages - including its inherent quantitative nature - Proton Nuclear Magnetic Resonance (1H NMR) spectroscopy provides an ideal tool for the time-resolved monitoring of fermentations. However, analytical conditions, including non-automated sample preparation and long relaxation times (T1) of some metabolites, can significantly lengthen the experimental time and make implementation in an industrial set up unfeasible.

RESULTS

We present a high throughput method based on Standard Operating Procedures (SOPs) and 1H NMR, which lays the foundation for what we call Fermentation Analytical Technology (FAT). Our method was developed for the accurate absolute quantification of metabolites produced during Escherichia coli industrial fermentations. The method includes: (1) a stopped flow system for non-invasive sample collection followed by sample quenching, (2) automatic robot-assisted sample preparation, (3) fast 1H NMR measurements, (4) metabolites quantification using multivariate curve resolution (MCR), and (5) metabolites absolute quantitation using a novel correction factor (k) to compensate for the short recycle delay (D1) employed in the 1H NMR measurements. The quantification performance was tested using two sample types: buffer solutions of chemical standards and real fermentation samples. Five metabolites - glucose, acetate, alanine, phenylalanine and betaine - were quantified. Absolute quantitation ranged between 0.64 and 3.40 mM in pure buffer, and 0.71-7.76 mM in real samples.

SIGNIFICANCE

The proposed method is generic and can be straight forward implemented to other types of fermentations, such as lactic acid, ethanol and acetic acid fermentations. It provides a high throughput automated solution for monitoring fermentation processes and for quality control through absolute quantification of key metabolites in fermentation broth. It can be easily implemented in an at-line industrial setting, facilitating the optimization of the manufacturing process towards higher yields and more efficient and sustainable use of resources.

Solid Lipid Nanoparticles Encapsulating a Benzoxanthene Derivative in a Model of the Human Blood-Brain Barrier: Modulation of Angiogenic Parameters and Inflammation in Vascular Endothelial Growth Factor-Stimulated Angiogenesis

Lignans, a class of secondary metabolites found in plants, along with their derivatives, exhibit diverse pharmacological activities, including antioxidant, antimicrobial, anti-inflammatory, and antiangiogenic ones. Angiogenesis, the formation of new blood vessels from pre-existing ones, is a crucial process for cancer growth and development. Several studies have elucidated the synergistic relationship between angiogenesis and inflammation in various inflammatory diseases, highlighting a correlation between inflammation and vascular endothelial growth factor (VEGF)-induced angiogenesis. Thus, the identification of novel molecules capable of modulating VEGF effects presents promising prospects for developing therapies aimed at stabilizing, reversing, or even arresting disease progression. Lignans often suffer from low aqueous solubility and, for their use, encapsulation in a delivery system is needed. In this research, a bioinspired benzoxantene has been encapsulated in solid lipid nanoparticles that have been characterized for their pharmacotechnical properties and their thermotropic behavior. The effects of these encapsulated nanoparticles on angiogenic parameters and inflammation in VEGF-induced angiogenesis were evaluated using human brain microvascular endothelial cells (HBMECs) as a human blood-brain barrier model.

One-Step Precise Characterization of Drug Delivery Systems by PULCON Magnetic Resonance Spectroscopy

Polymers are extensively used for the realization of drug delivery systems across multiple scales, from nanomedicines to microparticles and macroscopic implantable devices, for their favorable biodegradation profiles and tunable physicochemical features. The accurate quantification of the polymer content is key to finely controlling drug loading and release and ensuring reproducibility, yet it continues to be a major challenge in the design and development of delivery systems. In this study, we introduce a novel protocol based on the PULCON technique to quantify, with a routine NMR spectroscopy analysis, the precise concentration of polymers in various delivery systems. Specifically, the PULCON protocol is applied to characterize the physicochemical and pharmaceutical properties of nanoparticles, microparticles, and implantable devices realized by combining three extensively used polymers, namely, poly(lactic-co-glycolic acid) (PLGA), poly(vinyl alcohol) (PVA), and poly(ethylene glycol) (PEG). Without using internal calibration procedures, in a single step, the PULCON protocol precisely quantifies the concentration of each polymer and the drug content. This approach can be readily implemented on standard NMR spectrometers, enabling accurate characterization of drug delivery systems and facilitating their effective development.

Brewing alcohol 101: An undergraduate experiment utilizing benchtop NMR for quantification and process monitoring

In recent years there has been a renewed interest in benchtop NMR. Given their lower cost of ownership, smaller footprint, and ease of use, they are especially suited as an educational tool. Here, a new experiment targeted at upper-year undergraduates and first-year graduate students follows the conversion of D-glucose into ethanol at low-field. First, high and low-field data on D-glucose are compared and students learn both the Hz and ppm scales and how J-coupling is field-independent. The students then acquire their own quantitative NMR datasets and perform the quantification using an Electronic Reference To Access In Vivo Concentration (ERETIC) technique. To our knowledge ERETIC is not currently taught at the undergraduate level, but has an advantage in that internal standards are not required; ideal for following processes or with future use in flow-based benchtop monitoring. Using this quantitative data, students can relate a simple chemical process (fermentation) back to more complex topics such as reaction kinetics, bridging the gaps between analytical and physical chemistry. When asked to reflect on the experiment, students had an overwhelmingly positive experience, citing agreement with learning objectives, ease of understanding the protocol, and enjoyment. Each of the respondents recommended this experiment as a learning tool for others. This experiment has been outlined for other instructors to utilize in their own courses across institutions, with the hope that a continued expansion of low-field NMR will increase accessibility and learning opportunities at the undergraduate level.