Nuclear Magnetic Resonance Metabolite Profiling Research Articles

400-MHz Nuclear Magnetic Resonance Metabolite Profiles of Jaw Cysts, Jaw Abscesses, Saliva, and Urine Obtained by Massive D2O Dilution of Samples

400-MHz Nuclear Magnetic Resonance Metabolite Profiles of Jaw Cysts, Jaw Abscesses, Saliva, and Urine Obtained by Massive D2O Dilution of Samples

Metabolite profile of two Allium cepa L. aggregatum group cultivars by Nuclear Magnetic Resonance

Abstract. Basundari FRA, Sulistyaningsih E, Murti RH, Nuringtyas TR. 2021. Metabolite profile of two Allium cepa L. aggregatum group cultivars by Nuclear Magnetic Resonance. Biodiversitas 22: 3127-3135. Shallot, an Allium species with high economic value, is widely cultivated in Indonesia. The species includes numerous cultivars with unique characteristics, such as harvesting time, yield, taste, odor, and bulb color. Tuk Tuk and Trisula, the cultivars used in this experiment, have different bulb colors. Tuk Tuk’s bulb color is light red, while that of Trisula is dark red. This color difference may be attributed to variations in the metabolite contents of the shallot bulbs. The present experiment aimed to reveal differences in the metabolite contents of the two shallot cultivars by using Nuclear Magnetic Resonance (NMR) and then determine the specific metabolites contributing to these differences. Bulbs of Tuk Tuk and Trisula were planted in the field under the same conditions and then collected. The bulb samples were powdered, freeze-dried, and subjected to a two-phase extraction method with CDCl3 and D2O as solvents to separate the nonpolar metabolites from polar ones. The extracts were analyzed by 1H-NMR, and the spectra collected were analyzed using MNOVA software and Metaboanalyst.ca. A total of 23 metabolites were successfully identified and characterized in this experiment. The contents of eight of these metabolites, namely, sucrose, glutamine, citric acid, choline, methiin, propiin, threonine, and formic acid, were significantly higher in Trisula than in Tuk Tuk. These differences may be correlated with variations in the color intensity, pungency, and other traits of the cultivars. The results demonstrate that NMR metabolite profiling could effectively differentiate metabolite profile variations among shallot cultivars.

NMR Metabolite Profiles in Male Meat-Eaters, Fish-Eaters, Vegetarians and Vegans, and Comparison with MS Metabolite Profiles.

Metabolomics may help to elucidate mechanisms underlying diet-disease relationships and identify novel risk factors for disease. To inform the design and interpretation of such research, evidence on diet-metabolite associations and cross-assay comparisons is needed. We aimed to compare nuclear magnetic resonance (NMR) metabolite profiles between meat-eaters, fish-eaters, vegetarians and vegans, and to compare NMR measurements to those from mass spectrometry (MS), clinical chemistry and capillary gas-liquid chromatography (GC). We quantified 207 serum NMR metabolite measures in 286 male participants of the European Prospective Investigation into Cancer and Nutrition (EPIC)-Oxford cohort. Using univariate and multivariate analyses, we found that metabolite profiles varied by diet group, especially for vegans; the main differences compared to meat-eaters were lower levels of docosahexaenoic acid, total n-3 and saturated fatty acids, cholesterol and triglycerides in very-low-density lipoproteins, various lipid factions in high-density lipoprotein, sphingomyelins, tyrosine and creatinine, and higher levels of linoleic acid, total n-6, polyunsaturated fatty acids and alanine. Levels in fish-eaters and vegetarians differed by metabolite measure. Concentrations of 13 metabolites measured using both NMR and MS, clinical chemistry or GC were mostly similar. In summary, vegans’ metabolite profiles were markedly different to those of men consuming animal products. The studied metabolomics platforms are complementary, with limited overlap between metabolite classes.

Cross-sectional metabolic profiles of mental health in population-based cohorts of 11- to 12-year-olds and mid-life adults: The Longitudinal Study of Australian Children.

Poorer mental health in adulthood is associated with increased risk of cardiovascular disease and reduced life expectancy. However, little is known of the molecular pathways underpinning this relationship and how early in life adverse metabolite profiles relate to self-reported variation in mental health. We examined cross-sectional associations between mental health and serum metabolites indicative of cardiovascular health, in large Australian population-based cohorts at two stages of the life-course. We characterised cross-sectional serum nuclear magnetic resonance metabolite profiles of positively and negatively framed mental health in a large population-based sample of Australian 11- to 12-year-olds (n = 1172; 51% girls) and mid-life adults (n = 1322; mean age 45 years; 87% women). We examined multiple standard self-report mental health scales, spanning psychosocial health, general well-being, life satisfaction, and health-related quality of life. Linear regression was used to investigate the cross-sectional association between mental health and each metabolite (n = 73) in children and adults separately, unadjusted and adjusted for age, sex, socioeconomic position and body mass index. Better child and adult mental health were associated with lower levels of the inflammatory marker glycoprotein acetyls, and a favourable, less atherogenic lipid/lipoprotein profile. Patterns of association in children were generally weaker than in adults. Associations were generally modest and partially attenuated when adjusted for body mass index. In general, metabolite profiles associated with better child and adult mental health closely aligned with those predictive of better cardiovascular health in adults. Our findings support previous evidence for the likely bidirectional relationship between mental health and cardiovascular disease risk, by extending this evidence base to the molecular level and in children.

1H HR-MAS NMR-based metabolomics analysis for dry-fermented sausage characterization

Proton high-resolution magic angle spinning (1H HR-MAS) nuclear magnetic resonance (NMR) spectroscopy in combination with principal component analysis (PCA) was employed to characterize dry-fermented sausages salchichón type throughout the manufacturing process. 1H HR-MAS NMR metabolite profiling was achieved from a small sample of intact sausage after 0, 2, 4, 7, 11 and 14days of drying. Intriguingly, the obtained results enabled the identification of the three main stages in the traditional production of salchichón. Formulation, fermentation and drying-ripening periods showed distinct and characteristic metabolomic profiles. Compositional changes related to microbial activity, as well as proteolytic and lipolytic phenomena, decisive steps in such a ripening process, could be monitored through the NMR spectra. This study shows the potential of 1H HR-MAS as a rapid method for probing metabolomic profiles and compositional changes during sausages processing.

A pilot study of NMR-based sensory prediction of roasted coffee bean extracts

Nuclear magnetic resonance (NMR) spectroscopy can be considered a kind of “magnetic tongue” for the characterisation and prediction of the tastes of foods, since it provides a wealth of information in a nondestructive and nontargeted manner. In the present study, the chemical substances in roasted coffee bean extracts that could distinguish and predict the different sensations of coffee taste were identified by the combination of NMR-based metabolomics and human sensory test and the application of the multivariate projection method of orthogonal projection to latent structures (OPLS). In addition, the tastes of commercial coffee beans were successfully predicted based on their NMR metabolite profiles using our OPLS model, suggesting that NMR-based metabolomics accompanied with multiple statistical models is convenient, fast and accurate for the sensory evaluation of coffee.

Metabolomics as a Novel Approach for Early Diagnosis of Pediatric Septic Shock and Its Mortality

Septic shock is a significant cause of morbidity and mortality in the pediatric population. Early recognition of septic shock and appropriate treatment increase survival rate; thus, developing new diagnostic tools may improve patients' outcomes. To determine whether a metabolomics approach could be useful in the diagnosis and prognosis of septic shock in pediatric intensive care unit (PICUs). Serum samples were collected from 60 patients with septic shock, 40 PICU patients with systemic inflammatory response syndrome (not suspected of having an infection), and 40 healthy children. Proton nuclear magnetic resonance spectroscopy spectra were analyzed and quantified using targeted profiling methodology. Multivariate statistical analysis was applied to detect specific patterns in metabolic profiles and to highlight differences between patient samples. Supervised analysis afforded good predictive models and managed to separate patient populations. Some of the metabolite concentrations identified in serum samples changed markedly, indicating their influence on the separation between patient groups. These metabolites represent a composite biopattern of the pediatric metabolic response to septic shock and might be considered as the basis for a biomarker panel for the diagnosis of septic shock and its mortality in PICU. Our results indicate that nuclear magnetic resonance metabolite profiling might serve as a promising approach for the diagnosis and prediction of mortality in septic shock in a pediatric population and that quantitative metabolomics methods can be applied in the clinical evaluations of pediatric septic shock.

1H-NMR 스펙트럼의 다변량통계분석을 통한 넙치(Paralichthys olivaceus)의 백신 반응의 지표물질 분석

To investigate the relationship between metabolic changes in <TEX>$^1H$</TEX>-nuclear magnetic resonance (NMR) spectra and fish vaccination, serum was collected from olive flounders treated with a formalin-killed Edwardsiella tarda vaccine and used for <TEX>$^1H$</TEX>-NMR metabolite profiling. Principal component analysis and partial least squares were applied to the <TEX>$^1H$</TEX>-NMR profile to reduce its complexity and establish class-related clusters. Relative lipid regions were distinguished in vaccinated and non-vaccinated serum. Then, the lipids were extracted from the serum and analyzed. Triolein was identified.

Impact of High-Fat and High-Carbohydrate Diets on Liver Metabolism Studied in a Rat Model with a Systems Biology Approach

The aim of the present study was to investigate the use of an integrated metabolomics and proteomics approach in the elucidation of diet-induced effects on hepatic metabolism in a rat model. Nuclear magnetic resonance (NMR)-based metabolomics of liver extracts revealed a pronounced effect of a high-fat diet on the hepatic betaine content, whereas a carbohydrate-rich diet induced increases in hepatic glucose. In addition, the metabolomic investigations revealed that the high-fat diet was associated with increased hepatic lipid levels, which was not evident with the carbohydrate-rich diet. The proteomic investigations revealed strong high-fat diet effects on the expression of 186 proteins in the liver including malate dehydrogenase. Comparison of malate dehydrogenase expression determined by proteomics and NMR metabolite profiles revealed correlations between malate dehydrogenase and lactate, glucose, and glutamine/glutamate signals, thereby demonstrating a diet-induced regulation that was evident at both proteomic and metabolomic levels.

Toward Arabidopsis thaliana hydrophilic metabolome: assessment of extraction methods and quantitative 1H NMR

Our goal was to establish the hydrophilic metabolome of heterotrophic Arabidopsis thaliana cells grown in suspension, a cellular model of plant sink tissues. Water-soluble metabolites were extracted using four protocols: perchloric acid, boiling ethanol, methanol and methanol/chloroform (M/Chl). They were detected and quantified using (1)H nuclear magnetic resonance (NMR) spectroscopy at 400 MHz. Extraction yields and reproducibility of the extraction methods were investigated. The effects of cell harvest protocol, cell grinding and lyophilization and storage conditions on the measured metabolic profiles were also studied. These quantitative studies demonstrated for the first time that the four extraction protocols commonly used do lead to quite similar molecular compositions as analyzed by (1)H NMR. The M/Chl method proved effective and reliable to prepare series of physiologically significant extracts from plant cells for (1)H NMR analysis. Reproducibility of the detected metabolome was assessed over long periods of time by analyzing a large number of separate extracts prepared from independent cultures. Larger variations in the NMR metabolite profiles could be correlated to changes in physiological parameters of the culture medium. Quantitative resolved (1)H NMR of cell extracts proved to be robust and reliable for routine metabolite profiling of plant cell cultures.

Quantitative 1H nuclear magnetic resonance metabolite profiling as a functional genomics platform to investigate alkaloid biosynthesis in opium poppy.

Opium poppy (Papaver somniferum) produces a diverse array of bioactive benzylisoquinoline alkaloids and has emerged as a versatile model system to study plant alkaloid metabolism. The plant is widely cultivated as the only commercial source of the narcotic analgesics morphine and codeine. Variations in plant secondary metabolism as a result of genetic diversity are often associated with perturbations in other metabolic pathways. As part of a functional genomics platform, we used (1)H nuclear magnetic resonance (NMR) metabolite profiling for the analysis of primary and secondary metabolism in opium poppy. Aqueous and chloroform extracts of six different opium poppy cultivars were subjected to chemometric analysis. Principle component analysis of the (1)H NMR spectra for latex extracts clearly distinguished two varieties, including a low-alkaloid variety and a high-thebaine, low-morphine cultivar. Distinction was also made between pharmaceutical-grade opium poppy cultivars and a condiment variety. Such phenotypic differences were not observed in root extracts. Loading plots confirmed that morphinan alkaloids contributed predominantly to the variance in latex extracts. Quantification of 34 root and 21 latex metabolites, performed using Chenomx NMR Suite version 4.6, showed major differences in the accumulation of specific alkaloids in the latex of the low-alkaloid and high-thebaine, low-morphine varieties. Relatively few differences were found in the levels of other metabolites, indicating that the variation was specific for alkaloid metabolism. Exceptions in the low-alkaloid cultivar included an increased accumulation of the alkaloid precursor tyramine and reduced levels of sucrose, some amino acids, and malate. Real-time polymerase chain reaction analysis of 42 genes involved in primary and secondary metabolism showed differential gene expression mainly associated with alkaloid biosynthesis. Reduced alkaloid levels in the condiment variety were associated with the reduced abundance of transcripts encoding several alkaloid biosynthetic enzymes.

Natural COX-2 inhibitors and effects on colon cancer cells

The cyclooxygenase-2 enzyme (COX-2) is involved in prostaglandin biosynthesis and thus plays a significant role in the process of inflammation. Different types of natural compounds can affect the COX-2 enzymatic activity [1]. In recent years it has also been suggested that COX-2 is involved in cancer development [2]. As many natural compounds are present in the human diet this study has focused on discovery of natural COX-2 inhibitors present in food. A number of human fecal water samples (the aqueous phase of feces) from vegetarians were collected and assessed for effects on COX-2 enzymatic activity and also for effects on protein expression level in human colon cancer cells (HT-29). Of 14 samples analyzed, 13 decreased COX-2 protein levels in the cells (19–63% inhibition) [3]. Most samples also significantly decreased prostaglandin (PGE2) production in HT-29 cells [3]. Solid phase extraction was performed to trace the activity of the fecal water samples. The resulting water fraction was found to be responsible for the inhibitory activity of the samples, suggesting that the active compounds are most likely polar in nature. The chemical content of fecal water was analyzed using chromatographic techniques. Gas chromatography-mass spectrometry was used to study the content of the fecal water, with an emphasis on finding phenolic compounds, whereas nuclear magnetic resonance (NMR) was used to obtain an overview of the total fecal water content. The NMR metabolite profiles of vegetarian fecal water samples were very similar, suggesting that the colonic content of the individuals in the study population were similar in composition. A variety of compounds were identified including several phenolic compounds, amino acids and fatty acids. To the best of our knowledge, the use of NMR as a tool in studying colonic contents represents a new approach that would potentially be very useful in colon cancer research.

NMR metabolite profiling analysis reveals changes in phospholipid metabolism associated with the re‐establishment of desiccation tolerance upon osmotic stress in germinated radicles of cucumber

The adaptation of metabolism is thought to play a role in the acquisition of desiccation tolerance (DT). However, the importance of such a role and whether specific regulatory pathways exist remain to be assessed. Using in vitro 31P and 13C nuclear magnetic resonance (NMR) spectroscopy and biochemical assays, we analysed metabolite profiles of perchloric extracts from germinating radicles of cucumber to identify changes in carbon and phosphate metabolism associated with DT. Emerged radicles measuring 2 mm long can be rendered tolerant to desiccation by incubation in a polyethylene glycol (PEG) solution with a water potential of 1.5 MPa. However, in 4-mm-long emerged radicles, this treatment was ineffective. This manipulable system enabled the discrimination of changes in metabolites associated with DT from those associated with the response to osmotic stress. Independent of radicle length, the PEG treatment resulted in an increase in sucrose (Suc) content, whereas glucose (Glc), fructose (Fru) and the hexose phosphate pool, as well as phosphoenolpyruvate decreased three- to fourfold. In addition, three derivatives arising early during phospholipid catabolism (glycerylphosphorylcholine, glycerylphosphorylethanolamine and glycerylphosphorylinositol) appeared in the PEG-treated radicles. Interestingly, phospholipid degradation was much more pronounced in osmotically challenged radicles that remain sensitive to drying. This was proved by the appearance of catabolites, such as phosphocholine and phosphoethanolamine, solely in 4 mm PEG-treated radicles. Furthermore, glycerol-3-phosphate and its derivative 3-phosphoglycerate increased significantly. Our data suggest that the metabolic response leading to the re-establishment of DT is not entirely identical to that of an osmotic response. It is inferred that membrane remodelling and/or increased phospholipid catabolism is an adaptive response common to osmotic adjustment and DT but is controlled differently in tolerant and sensitive radicles.