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The ongoing COVID-19 pandemic highlights the necessity for a more fundamental understanding of the coronavirus life cycle. The causative agent of the disease, SARS-CoV-2, is being studied extensively from a structural standpoint in order to gain insight into key molecular mechanisms required for its survival. Contained within the untranslated regions of the SARS-CoV-2 genome are various conserved stem-loop elements that are believed to function in RNA replication, viral protein translation, and discontinuous transcription. While the majority of these regions are variable in sequence, a 41-nucleotide s2m element within the genome 3' untranslated region is highly conserved among coronaviruses and three other viral families. In this study, we demonstrate that the SARS-CoV-2 s2m element dimerizes by forming an intermediate homodimeric kissing complex structure that is subsequently converted to a thermodynamically stable duplex conformation. This process is aided by the viral nucleocapsid protein, potentially indicating a role in mediating genome dimerization. Furthermore, we demonstrate that the s2m element interacts with multiple copies of host cellular microRNA (miRNA) 1307-3p. Taken together, our results highlight the potential significance of the dimer structures formed by the s2m element in key biological processes and implicate the motif as a possible therapeutic drug target for COVID-19 and other coronavirus-related diseases., (© The Author(s) 2021. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Several publications describing high-resolution structures of amyloid-β (Aβ) and other fibrils have demonstrated that magic-angle spinning (MAS) NMR spectroscopy is an ideal tool for studying amyloids at atomic resolution. Nonetheless, MAS NMR suffers from low sensitivity, requiring relatively large amounts of samples and extensive signal acquisition periods, which in turn limits the questions that can be addressed by atomic-level spectroscopic studies. Here, we show that these drawbacks are removed by utilizing two relatively recent additions to the repertoire of MAS NMR experiments-namely, 1 H detection and dynamic nuclear polarization (DNP). We show resolved and sensitive two-dimensional (2D) and three-dimensional (3D) correlations obtained on 13 C, 15 N-enriched, and fully protonated samples of M 0 Aβ 1-42 fibrils by high-field 1 H-detected NMR at 23.4 T and 18.8 T, and 13 C-detected DNP MAS NMR at 18.8 T. These spectra enable nearly complete resonance assignment of the core of M 0 Aβ 1-42 (K16-A42) using submilligram sample quantities, as well as the detection of numerous unambiguous internuclear proximities defining both the structure of the core and the arrangement of the different monomers. An estimate of the sensitivity of the two approaches indicates that the DNP experiments are currently ∼6.5 times more sensitive than 1 H detection. These results suggest that 1 H detection and DNP may be the spectroscopic approaches of choice for future studies of Aβ and other amyloid systems., Competing Interests: The authors declare no competing interest., (Copyright © 2021 the Author(s). Published by PNAS.)

There is a growing interest in the neuroscience community to map the distribution of brain metabolites in vivo. Magnetic resonance spectroscopic imaging (MRSI) is often limited by either a poor spatial resolution and/or a long acquisition time, which severely restricts its applications for clinical and research purposes. Building on a recently developed technique of acquisition-reconstruction for 2D MRSI, we combined a fast Cartesian 1 H-FID-MRSI acquisition sequence, compressed-sensing acceleration, and low-rank total-generalized-variation constrained reconstruction to produce 3D high-resolution whole-brain MRSI with a significant acquisition time reduction. We first evaluated the acceleration performance using retrospective undersampling of a fully sampled dataset. Second, a 20 min accelerated MRSI acquisition was performed on three healthy volunteers, resulting in metabolite maps with 5 mm isotropic resolution. The metabolite maps exhibited the detailed neurochemical composition of all brain regions and revealed parts of the underlying brain anatomy. The latter assessment used previous reported knowledge and a atlas-based analysis to show consistency of the concentration contrasts and ratio across all brain regions. These results acquired on a clinical 3 T MRI scanner successfully combined 3D 1 H-FID-MRSI with a constrained reconstruction to produce detailed mapping of metabolite concentrations at high resolution over the whole brain, with an acquisition time suitable for clinical or research settings., (© 2021 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.)

Excessive manganese is neurotoxic, which means that it can affect the concentrations of metabolite in 1 H MRS. In addition, manganese is paramagnetic and it may influence the relaxation times of the metabolite. The aim of this study is to assess the sensitivity of the metabolite relaxation properties and concentrations to exogenous manganese deposition in the globus pallidus (GP) of rat brain after repeated manganese injection. Proton magnetic resonance spectroscopy ( 1 H MRS) experiments in vivo and ex vivo were carried out to evaluate the changes in the metabolite concentration and the major metabolite relaxation times, and histological experiments were also performed after repeated manganese administration. Only the T 1 value for N-acetylaspartate (NAA) of the GP was significantly reduced after 1 day of manganese injection compared with that of the control group (p < 0.025). The T 1 and T 2 values for NAA and total creatine (tCr) (p < 0.025), along with the amounts of NAA, tCr, myo-inositol, choline, and glutamate (p < 0.0086) in the GP, were all significantly decreased after 5 days of manganese administration compared with that of the control group. The changes in the concentration and relaxation properties of NAA and tCr in the GP of rat brain indicated that manganese represented paramagnetism and neurotoxicity after repeated administration. Accurate knowledge of relaxation properties and concentrations of NAA and tCr in this study could help appropriate selection of sequence parameters to improve the ability to distinguish the brain regions affected in cases of manganese poisoning., (© 2021 John Wiley & Sons, Ltd.)

Background: The glutamate (Glu) and gamma aminobutyric acid (GABA) hypotheses of schizophrenia were proposed in the 1980s. However, current findings on those metabolite levels in schizophrenia have been inconsistent, and the relationship between their abnormalities and the pathophysiology of schizophrenia remains unclear. To summarize the nature of the alterations of glutamatergic and GABAergic systems in schizophrenia, we conducted meta-analyses of proton magnetic resonance spectroscopy ( 1 H-MRS) studies examining these metabolite levels., Methods: A systematic literature search was conducted using Embase, Medline, PsycINFO, and PubMed. Original studies that compared four metabolite levels (Glu, glutamine [Gln], Glx [Glu+Gln], and GABA), as measured by 1 H-MRS, between individuals at high risk for psychosis, patients with first-episode psychosis, or patients with schizophrenia and healthy controls (HC) were included. A random-effects model was used to calculate the effect sizes for group differences in these metabolite levels of 18 regions of interest between the whole group or schizophrenia group and HC. Subgroup analysis and meta-regression were performed based on the status of antipsychotic treatment, illness stage, treatment resistance, and magnetic field strength., Results: One-hundred-thirty-four studies met the eligibility criteria, totaling 7993 participants with SZ-spectrum disorders and 8744 HC. 14 out of 18 ROIs had enough numbers of studies to examine the group difference in the metabolite levels. In the whole group, Glx levels in the basal ganglia (g = 0.32; 95% CIs: 0.18-0.45) were elevated. Subgroup analyses showed elevated Glx levels in the hippocampus (g = 0.47; 95% CIs: 0.21-0.73) and dorsolateral prefrontal cortex (g = 0.25; 95% CIs: 0.05-0.44) in unmedicated patients than HC. GABA levels in the MCC were decreased in the first-episode psychosis group compared with HC (g = -0.40; 95% CIs: -0.62 to -0.17). Treatment-resistant schizophrenia (TRS) group had elevated Glx and Glu levels in the MCC (Glx: g = 0.7; 95% CIs: 0.38-1.01; Glu: g = 0.63; 95% CIs: 0.31-0.94) while MCC Glu levels were decreased in the patient group except TRS (g = -0.17; 95% CIs: -0.33 to -0.01)., Conclusions: Increased glutamatergic metabolite levels and reduced GABA levels indicate that the disruption of excitatory/inhibitory balance may be related to the pathophysiology of schizophrenia-spectrum disorders., (© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)

A new NMR-based method for the discrimination of olive oils of any grade from seed oils and mixtures thereof was developed with the aim of allowing the verification of olive oil authenticity. Ten seed oils and seven monovarietal and blended extra virgin olive oils were utilized to develop a principal component analysis (PCA) based analysis of 1 H NMR spectra to rapidly and accurately determine the authenticity of olive oils. Another twenty-eight olive oils were utilized to test the principal component analysis (PCA) based analysis. Detection of seed oil adulteration levels as low as 5% v / v has been shown using simple one-dimensional proton spectra obtained using a 400 MHz NMR spectrometer equipped with a room temperature inverse probe. The combination of simple sample preparation, rapid sample analysis, novel processing parameters, and easily interpreted results, makes this method an easily accessible tool for olive oil fraud detection by substitution or dilution compared to other methods already published.

Context: Stomach ulcer is one of the most common gastrointestinal problems in the world., Objective: This study aimed to isolate flavonoid compounds from methanol extract of the aerial parts of Stachytarpheta jamaicensis (L.) Vahl. and evaluate its protective and therapeutic effects against gastric ulcer., Materials and Methods: Chromatographic techniques were used for the identification of the isolated compounds. To explore the effects of the plant extract, it was administrated by oral gavage for one week either before or post-ethanol ulcer induction. Ranitidine was also evaluated as a reference drug. Stomach pH, gastric juice volume, lesions number, glutathione, superoxide dismutase, malondialdehyde, succinate dehydrogenase, lactate dehydrogenase, acid phosphatase, Interleukin-10, intracellular adhesion molecule-1, prostaglandin E2, and total protein levels were estimated in gastric tissue. Stomach histopathological features were also monitored., Results: Six flavonoid compounds were isolated, where five of them were isolated for the first time (vitexin, isovitexin, apigenin 7,4'-dimethyl ether, 5,7,2'-trimethoxyflavone, and scutellarein), while apigenin was previously reported. Treatment with plant extract recorded amelioration in all the biochemical parameters., Conclusion: The methanol extract of plant aerial parts had prophylactic and treatment effects against gastric ulcer in rats, where its treatment effect exceeded its protective role. The extract recorded anti-inflammatory, and antioxidant effects due to the presence of flavonoid compounds.

Economical-driven counterfeit and inferior aged Chinese Baijiu has caused serious concern of publicity in China. In this study, a total of 167 authentic Chinese Baijiu samples with different vintages including 3 flavor types were carefully collected. Gas chromatography (GC) was used to determine main volatile components and proton nuclear magnetic resonance ( 1 H NMR) spectroscopy was employed to obtain non-targeted fingerprints of Chinese Baijiu samples. Partial least squares regression (PLSR) models, which were confirmed by internal and external validation, were established for effectively identifying actual storage vintage of Chinese Baijiu with various brands, flavor types. Centering (Ctr), pareto scaling (Par), unit variance scaling (UV) data pretreatment methods, principal components (PCs), and three modified variable selection methods were proposed to successfully optimize the vintage model and effectively extract important vintage characteristic factors. This study demonstrated that NMR and GC combined with multivariate statistical analysis are effective tools for validating vintage authenticity of Chinese Baijiu., (Copyright © 2021. Published by Elsevier Ltd.)

Microalgae biotechnology has made it possible to derive secondary bioactive metabolites from microalgae strains that have opened up their entire potential to uncover a wide range of novel metabolic capabilities and turn these into bio-products for the development of sustainable bio-refineries. Nuclear Magnetic Resonance Technology (NMR) has been one of the most successful and functional research technology over the past two decades to analyse the composition, structure and functionality of distinct metabolites in the different microalgae strains. This technology offers qualitative as well as quantitative knowledge about the endogenous metabolites and lipids of low molecular mass to offer a good picture of the physiological state of biological samples in metabolomics and lipidomics studies. Henceforth, this review is aimed at introducing the metabolomics and lipidomics studies into the field of NMR technology and also highlights the protocols for the isolation and metabolic measurements of metabolites from microalgae that should be redirected to resource recovery and value-added products with a systematic and holistic approach for scalability or sustainability., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Low-grade systemic inflammation contributes to ageing-related cognitive decline, possibly by triggering a neuroinflammatory response through glial activation. Using proton magnetic resonance spectroscopy ( 1 H-MRS) at 7T in normal human individuals from 18 to 79 years in a cross-sectional study, we previously observed higher regional levels of myo-inositol (mIns), total creatine (tCr) and total choline (tCho) in older than younger age groups. Moreover, visuo-spatial working memory (vsWM) correlated negatively with tCr and tCho in anterior cingulate cortex (ACC) and mIns in hippocampus and thalamus. As mIns, tCr and tCho are higher in glia than neurons, this suggest a potential in vivo connection between cognitive ageing and higher regional levels of glia-related metabolites. In the present study, we tested whether these metabolic differences may be related to low-grade systemic inflammation. In the same individuals, plasma concentrations of the proinflammatory markers C-reactive protein (CRP), interleukin 8 (IL-8), and tumour necrosis factor α (TNF-α) were measured on the same day as 1 H-MRS assessments. We tested whether CRP, IL-8, and TNF-α concentrations correlated with the levels of glia-related metabolites. CRP and IL-8, but not TNF-α, were higher in older (69-79 years) than younger (18-26 years) individuals. CRP correlated positively with thalamic mIns and negatively with vsWM. IL-8 correlated positively with ACC tCho and hippocampal mIns, but not with vsWM. Mediation analysis revealed an indirect effect of IL-8 on vsWM via ACC tCho. Together, these findings corroborate the role of glial cells, perhaps via their role in neuroinflammation, as part of the neurobiological link between systemic inflammation and cognitive ageing., (© 2021 International Society for Neurochemistry.)

Serum albumin possesses esterase and pseudo-esterase activities towards a number of endogenous and exogenous substrates, but the mechanism of interaction of various esters and other compounds with albumin is still unclear. In the present study, proton nuclear magnetic resonance ( 1 H NMR) has been applied to the study of true esterase activity of albumin, using the example of bovine serum albumin (BSA) and p -nitrophenyl acetate (NPA). The site of BSA esterase activity was then determined using molecular modelling methods. According to the data obtained, the accumulation of acetate in the presence of BSA in the reaction mixture is much more intense as compared with the spontaneous hydrolysis of NPA, which indicates true esterase activity of albumin towards NPA. Similar results were obtained for p -nitophenyl propionate (NPP) as substrate. The rate of acetate and propionate release confirms the assumption that there is a site of true esterase activity in the albumin molecule, which is different from the site of the pseudo-esterase activity Sudlow II. The results of molecular modelling of BSA and NPA interaction make it possible to postulate that Sudlow site I is the site of true esterase activity of albumin.

Type C hepatic encephalopathy (HE) is a neuropsychiatric disease caused by chronic liver disease. Management of type C HE remains an important challenge because treatment options are limited. Both the antibiotic rifaximin and probiotics have been reported to reduce the symptoms of HE, but longitudinal studies assessing their effects on brain metabolism are lacking and the molecular mechanisms underpinning their effects are not fully understood. Therefore, we evaluated in detail the effects of these different treatments on the neurometabolic changes associated with type C HE using a multimodal approach including ultra-high field in vivo 1 H MRS. We analyzed longitudinally the effect of rifaximin alone or in combination with the probiotic Vivomixx on the brain metabolic profile in the hippocampus and cerebellum of bile duct ligated (BDL) rats, an established model of type C HE. Overall, while rifaximin alone appeared to induce no significant effect on the neurometabolic profile of BDL rats, its association with the probiotic resulted in more attenuated neurometabolic alterations in BDL rats followed longitudinally (i.e. a smaller increase in Gln and milder decrease in Glu and Cr levels). Given that both rifaximin and some probiotics are used in the treatment of HE, the implications of these findings may be clinically relevant., (© 2021. The Author(s).)

Gallbladder cancer (GBC) is an aggressive malignancy of gastrointestinal tract. Due to uncontrolled growth, GBC cells rapidly synthesize biomolecules including lipids. The lipids are integral component of cell membrane with a wide range of cellular functions. In this study, we measured the clinicopathological features in 40 cases of histologically confirmed GBC and 16 cases of chronic cholecystitis (CC). The female to male ratio in the GBC and CC groups were 3.44:1 and 2.2:1, respectively. The GBC patients exhibited well to poorly differentiated tumor. In the CC group, all patients showed cholecystitis with no evidence of dysplasia or malignancy. The majority of GBC and CC patients reported pain. Using 1 H NMR spectroscopy, we observed 4-folds increase in the level of choline containing phospholipids (CCPLs) in the gallbladder of GBC patients as compared to CC patients. Other lipid metabolites such as cholesterol ester, C18-cholesterol and saturated fatty acids were insignificantly changed between GBC and CC patients. Moreover, the level of CCPLs in the GBC patients with BMI <25 kg/m 2 was significantly higher as compared to CC patients. Further, a significant increase in the CCPLs level was observed in GBC female patients in comparison to CC patients. From the computational analyses, we observed that the genes involved in the biosynthesis of phosphatidylcholine (PtdCho) indirectly interact with the RELA, which encodes the NF-κB p65 subunit. The genes involved in the PtdCho biosynthesis were also correlated with the overall and disease-free survival of cholangiocarcinoma patients. The study opens new window for exploring the diagnostic and therapeutic potential of CCPLs in GBC patients., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The aim of the study was to investigate differences in metabolic profiles between patients with major depressive disorder (MDD) with full remission (FR) and healthy controls (HCs). A total of 119 age-matched MDD patients with FR (n = 47) and HCs (n = 72) were enrolled and randomly split into training and testing sets. A 1 H-nuclear magnetic resonance (NMR) spectroscopy-based metabolomics approach was used to identify differences in expressions of plasma metabolite biomarkers. Eight metabolites, including histidine, succinic acid, proline, acetic acid, creatine, glutamine, glycine, and pyruvic acid, were significantly differentially-expressed in the MDD patients with FR in comparison with the HCs. Metabolic pathway analysis revealed that pyruvate metabolism via the tricarboxylic acid cycle linked to amino acid metabolism was significantly associated with the MDD patients with FR. An algorithm based on these metabolites employing a linear support vector machine differentiated the MDD patients with FR from the HCs with a predictive accuracy, sensitivity, and specificity of nearly 0.85. A metabolomics-based approach could effectively differentiate MDD patients with FR from HCs. Metabolomic signatures might exist long-term in MDD patients, with metabolic impacts on physical health even in patients with FR., (© 2021. The Author(s).)

The diagnosis and treatment of bipolar depression (BDep) poses complex clinical challenges for psychiatry. Proton magnetic resonance spectroscopy ( 1 H-MRS) is a useful imaging tool for investigating in vivo levels of brain neuro-metabolites, critical to understanding the process of mood dysregulation in Bipolar Disorder. Few studies have evaluated longitudinal clinical outcomes in BDep associated with 1 H-MRS metabolic changes. This study aimed to longitudinally assess brain 1 H-MRS metabolites in the anterior cingulate cortex (ACC) correlated with improvement in depression (from BDep to euthymia) after lithium treatment in BDep patients versus matched healthy controls (HC). Twenty-eight medication-free BDep patients and 28 HC, matched for age and gender, were included in this study. All subjects were submitted to a 3-Tesla brain 1 H-MRS scan in the ACC using a single-voxel (8cm 3 ) PRESS sequence at baseline. At follow-up (6 weeks), 14 BDep patients repeated the exam in euthymia. Patients with current BDep had higher baseline Myo-inositol/Cr (mI/Cr) and Choline/Cr (Cho/Cr) compared to HC. After six weeks, mI/Cr or Cho/Cr levels in subjects that achieved euthymia no longer differed to levels in HC, while high Cho/Cr levels persisted in non-responders . Elevated ACC mI/Cr and Cho/Cr in BDep might indicate increased abnormal membrane phospholipid metabolism and phosphatidylinositol (PI) cycle activity. Return of mI/Cr and Cho/Cr to normal levels after lithium-induced euthymia suggests a critical regulatory effect of lithium targeting the PI cycle involved in mood regulation., Competing Interests: Declaration of Competing Interest None of the authors report biomedical financial interests or potential conflicts of interest., (Copyright © 2021. Published by Elsevier B.V.)

A method for increasing the solubilities of industrial azo pigments in DMSO by adding DBU (1,8-diaza-7-bicyclo[5.4.0]undecene) has been developed. This facilitated the acquisition of solution 13 C NMR spectra of the pigments. This method was applied to four types of azo pigments: naphthol AS (3-hydroxy-2-naphthoic acid anilide) pigments, naphthol pigments, pyrazolone pigments and acetoacetanilide pigments. This represents the first solution 13 C NMR spectra for naphthol AS pigments. Altogether 18 industrial azo pigments were analysed using 1D and 2D NMR techniques. The proton and corresponding carbon NMR resonances of these pigments have all been assigned., (© 2021 John Wiley & Sons, Ltd.)

Most umami substances were developed in aqueous extracts. In this study, we compared the molecular weight distributions and sensory characteristics of ethanol and aqueous Takifugu obscurus muscle extracts, and assessed their taste-related metabolites and peptide profile (<3 kDa) using nuclear magnetic resonance and nano liquid chromatography-mass spectrometry. The potential antioxidant peptide in ethanolic fraction was screened using Peptide Ranker, BIOPEP and quantum chemical simulations. The results indicated that 60% ethanolic extract fraction (60%-F) had the highest umami intensity and more palatable overall taste among all pufferfish extracts. It can be caused by more umami enhancing components such as Asp, Asn, Ala and 5'-AMP, and considerable umami-potential smaller peptides in 60%-F. 60%-F also showed an antioxidant activity, and several antioxidant peptides was screened. The present study indicated the relationship between extract solution and taste characterization, which provided more possibility for the exploitation of umami substances and screening potential activity peptides., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The lipophilicity of a drug is an important parameter for its eventual development by the pharmaceutical industry. It is usually measured by HPLC following partition of the compound between water and 1-octanol. We present here an alternative, simple, sensitive and quantitative 1 H nuclear magnetic resonance (NMR) method for the experimental measurement of partition coefficients of natural compounds and pharmaceutical drugs. It is based on measuring concentrations in the water phase, before and after partitioning and equilibration between water and octanol, using the ERETIC (Electronic Reference To Access In Vivo Concentration) technique. The signal to noise ratio is improved by a Water Suppression by Excitation Sculpting sequence. Quantification is based on an electronic reference signal and does not need addition of a reference compound. The log P values of 22 natural metabolites and four pharmaceutical drugs were determined and the experimental results are in excellent agreement with literature data. The experiments were run on ~2 mg material. This technique proved to be robust, reproducible and suitable for log P values between -2 and +2., (© 2021 John Wiley & Sons, Ltd.)

Biologically important ions such as Ca, K, Mg, Fe, and Zn play major roles in numerous biological processes, and their homeostatic balance is necessary for the maintenance of cellular activities. Sudden and severe loss in homeostasis of just one biologically important ion can cause a cascade of negative effects. The ability to quickly, accurately, and reliably quantify biologically important ions in samples of human bio-fluids is something that has been sorely lacking within the field of metabolomics. 1 H-NMR spectra. The foundation of our investigation was the a-priori knowledge that free ethylenediaminetetraacetic acid (EDTA) produces two clear single peaks on 1 H-NMR spectra, and that EDTA chelated to different ions produces unique 1 H-NMR spectral patterns due to 3D conformational changes in the chemical structure of chelated-EDTA and varying degrees of electronegativity. The aim of this study was to develop and test a 1 H-NMR-based method, with application specifically to the field of metabolomics, to quantify biologically important ions within the physiological pH range of 6.50-7.50 using EDTA as a chelating agent. Our method produced linear, accurate, precise, and repeatable results for Ca, Mg, and Zn; however, K and Fe did not chelate with EDTA.

Cyclodextrins and their derivatives have been used for chiral high-performance liquid chromatography selectors, while they are costly to use as mobile phase additives in high-performance liquid chromatography. Here, we report application of phenyl column coated permanently with methylated β-cyclodextrin for chiral high-performance liquid chromatography. A 0.1% (v/v) phosphoric acid solution containing 1 M NaCl and 0.5% (w/v) methylated β-cyclodextrin was subjected to a phenyl column at a flow rate of 0.5 mL/min at 30°C for 2 h. Using the precoating phenyl column, all the enantiomers of the four phenethylamines (norepinephrine, epinephrine, octopamine, and synephrine) were successfully separated simultaneously by high-performance liquid chromatography with a mobile phase without methylated β-cyclodextrin at a flow rate of 0.2 mL/min at 30°C. The enantioseparation ability was retained for successive analyses during 1 week. It is suggested that inclusion complex of methylated β-cyclodextrin with a phenyl group on the surface of the stationary phase could be formed and that the inclusion complex could form the ternary complex with the injected analytes. The longer retention time of (S)-enantiomers of analytes than corresponding (R)-enantiomers for high-performance liquid chromatography could be explained from the higher stability of the methylated β-cyclodextrin complexes with (S)-enantiomers, which were confirmed by capillary electrophoresis and 1 H NMR spectroscopy experiments., (© 2021 Wiley-VCH GmbH.)

The biomedical application of discrete supramolecular metal-based structures, specifically self-assembled metallacages, is still an emergent field of study. Capitalizing on the knowledge gained in recent years on the development of 3-dimensional (3D) metallacages as novel drug delivery systems and theranostic agents, we explore here the possibility to target [Pd 2 L 4 ] 4+ cages (L = 3,5-bis(3-ethynylpyridine)phenyl ligand) to the brain. In detail, a new water-soluble homoleptic cage ( C PepH3 ) tethered to a blood brain barrier (BBB)-translocating peptide was synthesized by a combination of solid-phase peptide synthesis (SPPS) and self-assembly procedures. The cage translocation efficacy was assessed by inductively coupled mass spectrometry (ICP-MS) in a BBB cellular model in vitro . Biodistribution studies of the radiolabeled cage [[ 99m TcO 4 ] - ⊂ C PepH3 ] in the CD1 mice model demonstrate its brain penetration properties in vivo . Further DFT studies were conducted to model the structure of the [[ 99m TcO 4 ] - ⊂ cage] complex. Moreover, the encapsulation capabilities and stability of the cage were investigated using the [ReO 4 ] - anion, the "cold" analogue of [ 99m TcO 4 ] - , by 1 H NMR spectroscopy. Overall, our study constitutes another proof-of-concept of the unique potential of supramolecular coordination complexes for modifying the physiochemical and biodistribution properties of diagnostic species.

Tobacco products generally contain tobacco-derived nicotine (TDN; having ∼99+% ( S )-(-)-nicotine). Recent United States regulation has led some producers to transition to synthetic ("tobacco-free") nicotine. For example, Puff Bar is now marketed with tobacco-free nicotine (TFN; presumed to be racemic). To evaluate the claim that these new products contain TFN, we evaluated the presence of the two nicotine optical isomers by 1 H NMR spectroscopy, polarimetry, and gas chromatography-mass spectrometry. Older Puff Bars were found to contain ( S )-(-)-nicotine, and newer "TFN" Puff Bars were found to contain both ( R )-(+) and ( S )-(-) isomers-indicating TFN, albeit with slightly more of the ( S )-(-)-nicotine form.

Our purpose is to detect the metabolic alterations in acute stroke-like lesions (SLLs) and further investigate the correlations between metabolic concentrations and focal cerebral blood flow in patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) using proton MR spectroscopy ( 1 H-MRS) and arterial spin labeling (ASL). A total of 23 patients with MELAS at acute stage of stroke-like episodes (SLEs) and 20 normal controls (NC) were recruited in this study, respectively. All subjects underwent conventional MRI and 1 H-MRS. In addition, ASL was performed in each patient. The measurements of creatine (Cr), choline (Cho), N-acetyl aspartate (NAA), lactate (Lac), glutamine/glutamate (Glx) levels and the ratios of Cho/Cr, NAA/Cr, Lac/Cr and Glx/Cr in acute SLLs for MELAS patients and left parietal and occipital lobes for NC were measured using LC-model software. Furthermore, in MELAS group, the associations between relative cerebral blood flow (rCBF) and metabolite concentrations in acute SLLs were also assessed. In MELAS group, acute SLLs were identified with metabolic abnormalities and increased rCBF. Specifically, compared with controls, MELAS patients exhibited significantly higher Lac, Cho levels and Lac/Cr, Cho/Cr ratios, and lower NAA, Glx levels and NAA/Cr and Glx/Cr ratios. Moreover, for MELAS patients, Lac concentration in acute SLLs was positively correlated with focal rCBF. This study exhibited the neural injury with increasing lactate and cerebral blood flow in the acute SLEs. It might shed light on the underlying biochemical mechanism of mitochondrial cytopathy and angiopathy in MELAS., (Copyright © 2021 Elsevier B.V. and Mitochondria Research Society. All rights reserved.)

Under the assistance of 13 C NMR and 1 H- 13 C HSQC, we develop a novel 1 H NMR assay for the substitution sites and degrees in hydroxypropyl chitosan (HPCS) by optimizing sample preparation and measurement method. We find that the chemical shift of HOD peak increases linearly with the increase of DCl concentration but declines with the rise of measurement temperature. According to the regression line, the HOD peak could be moved to a desired position of non-interference with other peaks by changing DCl concentration. Other DCl-responsive peaks are found and elucidated. Accordingly, the substitution fraction (NH 2 -substitution and OH-substitution) and the degree of acetylation are well discriminated and determined. The total molar degree of substitution (MS) obtained is basically consistent with those of elemental analysis and the existing NMR methods. This structural analysis is extendable to other amino-containing saccharides. The 1 H NMR method could be used widely in acid-soluble polysaccharides and their derivatives., (Copyright © 2021. Published by Elsevier Ltd.)

Apples Malus domestica, known as a rich source of triterpene acids, induced more variety and quantity of triterpene acids in response to herbivory or mechanical damage. There were 3 major induced compounds: pomaceic acid and euscaphic acid, both of which are known apple triterpene acids, and 2α,19α-dihydroxy-3-oxours-12-en-28-oic acid (named eriobotoric acid), which was first identified in apples. In this study, the 3 compounds' induction curves after damage, varietal differences in induction amounts, and physiological roles against pest insects were further investigated. Eriobotoric acid showed clear antifeedant activity against lepidopteran insect Spodoptera litura but not against apple pests., (© The Author(s) 2021. Published by Oxford University Press on behalf of Japan Society for Bioscience, Biotechnology, and Agrochemistry.)

We conducted a study to identify the fecal metabolite profile and its proximity to the ruminal metabolism of Nelore steers based on an untargeted metabolomic approach. Twenty-six Nelore were feedlot with same diet during 105 d. Feces and rumen fluid were collected before and at slaughter, respectively. The metabolomics analysis indicated 49 common polar metabolites in the rumen and feces. Acetate, propionate, and butyrate were the most abundant polar metabolites in both bio-samples. The rumen presented significantly higher concentrations of the polar compounds when compared to feces (P < 0.05); even though, fecal metabolites presented an accentuated representability of the ruminal fluid metabolites. All fatty acids present in the ruminal fluid were also observed in the feces, except for C20:2n6 and C20:4n6. The identified metabolites offer information on the main metabolic pathways (higher impact factor and P < 0.05), as synthesis and degradation of ketone bodies; the alanine, aspartate and glutamate metabolisms, the glycine, serine; and threonine metabolism and the pyruvate metabolism. The findings reported herein on the close relationship between the ruminal fluid and feces metabolic profiles may offer new metabolic information, in addition to facilitating the sampling for metabolism investigation in animal production and health routines.

Objectives: Milletia speciosa Champ (MS), a traditional Chinese medicine, has the abilities of antistress, antifatigue, anti-oxidation and so on. In our previous study, MS was found to antidepression while the underlying mechanism of which needs further elucidation., Methods: Here, a proton nuclear magnetic resonance (1H-NMR)-based metabonomics combined network pharmacology research approach was performed to investigate the antidepressive mechanism of MS act on mouse with chronic unpredictable mild stress-induced depression., Key Findings: Results showed that MS could alleviate the ethology of depression (including sucrose preference degree, crossing lattice numbers and stand-up times) and disordered biochemical parameters (5-hydroxytryptamine, norepinephrine and brain-derived neurotrophic factor). Metabonomics study and network pharmacology analysis showed that MS might improve depression through synergistically regulating five targets including Maoa, Maob, Ache, Ido1 and Comt, and three metabolic pathways such as tryptophan metabolism, synthesis of neurotransmitter and phospholipid metabolism., Conclusions: This study for the first time preliminary clarified the potential antidepressive mechanism of MS and provided theoretical basis for developing MS into novel effective antidepressant., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Royal Pharmaceutical Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Tuberculosis (TB) is a major cause of morbidity and mortality in children, and early diagnosis and treatment are crucial to reduce long-term morbidity and mortality. In this study, we explore whether urine nuclear magnetic resonance (NMR)-based metabolomics could be used to identify differences in the metabolic response of children with different diagnostic certainty of TB. We included 62 children with signs and symptoms of TB and 55 apparently healthy children. Six of the children with presumptive TB had bacteriologically confirmed TB, 52 children with unconfirmed TB, and 4 children with unlikely TB. Urine metabolic fingerprints were identified using high- and low-field proton NMR platforms and assessed with pattern recognition techniques such as principal components analysis and partial least squares discriminant analysis. We observed differences in the metabolic fingerprint of children with bacteriologically confirmed and unconfirmed TB compared to children with unlikely TB (p = 0.041 and p = 0.013, respectively). Moreover, children with unconfirmed TB with X-rays compatible with TB showed differences in the metabolic fingerprint compared to children with non-pathological X-rays (p = 0.009). Differences in the metabolic fingerprint in children with different diagnostic certainty of TB could contribute to a more accurate characterisation of TB in the paediatric population. The use of metabolomics could be useful to improve the prediction of TB progression and diagnosis in children.

The anterior cingulate cortex (ACC), a brain region that mediates affect and cognition by connecting the frontal cortex to limbic structures, has been consistently implicated in the neurobiology of Bipolar Disorder (BD). Proton magnetic resonance spectroscopy ( 1 H-MRS) studies have extensively compared in vivo neurometabolite levels of BD patients and healthy controls (HC) in the ACC. However, these studies have not been analyzed in a systematic review or meta-analysis and nor has the influence of mood state and medication on neurometabolites been examined in this cortical region. A systematic review and a meta-analysis of 1 H-MRS studies comparing ACC neurometabolite profiles of adult BD patients and HC subjects was conducted, retrieving 27 articles published between 2000 and 2018. Overall increased ACC levels of Glx [glutamine (Gln) + glutamate)/Creatine], Gln, choline (Cho) and Cho/Creatine were found in BD compared to HC. Bipolar depression was associated with higher Cho levels, while euthymia correlated with higher glutamine (Gln) and Cho. Mood stabilizers appeared to affect ACC Glu and Gln metabolites. Increased ACC Cho observed in euthymia, depression and in medication-free groups could be considered a trait marker in BD and attributed to increased cell membrane phospholipid turnover. Overall increased ACC Glx was associated with elevated Gln levels, particularly influenced by euthymia, but no abnormality in Glu was detected. Further 1 H-MRS studies, on other voxels, should assess more homogeneous (mood state-specific), larger BD samples and account for medication status using more sensitive 1 H-MRS techniques., (Copyright © 2021 Elsevier B.V. and ECNP. All rights reserved.)

Objective: Proton magnetic resonance spectroscopy ( 1 H-MRS) can benefit the differentiation of gliomas preoperative grading and facilitate guiding biopsy. This study was to investigate the optimal metabolite or metabolic ratios of MRS for the biopsy target delineating by using the technique of MRS imaging guided frame-less stereotactic biopsy., Methods: During a 4 year period between the Sep 2012 and Oct 2016, 57 patients (25 women, 32 men; mean age, 46.4) with histologic diagnosis of glioma, who underwent the 1 H-MRS imaging guided frameless stereotactic biopsy, were retrospectively reviewed. The metabolite or metabolic ratios values of MRS was measured. And the sensitivity, specificity, accuracy as well as the area under the curve (AUC) of those parameters for glioma grading are calculated based on the receiver operating characteristic curve (ROC) analysis., Results: 65 stereotactic biopsy samples from 57 patients were histopathologically clarified to HGGs (25) or LGGs (40) for quantitative analysis. The Cho, Cho/NAA and Cho/Cr values of LGGs group were significantly lower than that of HGGs (P = 0.09, 0.001, 0.003), and the NAA value of LGGs group was significantly higher than that of HGGs (P = 0.001). The cutoff value of 3.65 for the Cho/NAA ratio provided the best combination of sensitivity (92.0%), specificity (95.0%), and diagnostic accuracy (93.8%) for identifying glioma grade, which was superior to other parameters., Conclusion: The results of our study provided evidence that Cho/NAA ratio had the superior diagnostic performance in distinguishing glioma grade, indicating that the spot of highest Cho/NAA ratio was optimal metabolic targets for spectroscopic guided tissue sampling in homogenous glioma., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

In recent years, the use of Sideritis species as bioactive agents is increasing exponentially. The present study aimed to investigate the chemical constituents, as well as the anti-ageing potential of the cultivated Sideritis euboea Heldr. The chemical fingerprinting of the ethyl acetate residue of this plant was studied using 1D and 2D-NMR spectra. Isomeric compounds belonging to acylated flavone derivatives and phenylethanoid glycosides were detected in the early stage of the experimental process through 2D-NMR techniques. Overall, thirty-three known compounds were isolated and identified. Some of them are reported for the first time not only in S. euboea , but also in genus Sideritis &nbsp; L . The anti-ageing effect of the ethyl acetate residue and the isolated specialized products was assessed as anti-hyaluronidase activity. In silico docking simulation revealed the interactions of the isolated compounds with hyaluronidase. Furthermore, the in vitro study on the inhibition of hyaluronidase unveiled the potent inhibitory properties of ethyl acetate residue and apigenin 7- O - β -d-glucopyranoside. Though, the isomers of apigenin 7- O -p-coumaroyl-glucosides and also the 4'-methyl-hypolaetin 7- O -[6'''- O -acetyl- β -d-allopyranosyl]-(1→2)- β -d-glucopyranoside exerted moderate hyaluronidase inhibition. This research represents the first study to report on the anti-hyaluronidase activity of Sideritis species, confirming its anti-inflammatory, cytotoxic and anti-ageing effects and its importance as an agent for cosmetic formulations as also anticancer potential.

This study assessed the pyrolysis liquids obtained by slow pyrolysis of industrial hemp leaves, hurds, and roots. The liquids recovered between a pyrolysis temperature of 275-350 °C, at two condensation temperatures 130 °C and 70 °C, were analyzed. Aqueous and bio-oil pyrolysis liquids were produced and analyzed by proton nuclear magnetic resonance (NMR), gas chromatography-mass spectrometry (GC-MS), and atmospheric pressure photoionization Fourier transform ion cyclotron resonance mass spectrometry (APPI FT-ICR MS). NMR revealed quantitative concentrations of the most abundant compounds in the aqueous fractions and compound groups in the oily fractions. In the aqueous fractions, the concentration range of acetic acid was 50-241 gL -1 , methanol 2-30 gL -1 , propanoic acid 5-20 gL -1 , and 1-hydroxybutan-2-one 2 gL -1 . GC-MS was used to compare the compositions of the volatile compounds and APPI FT-ICR MS was utilized to determine the most abundant higher molecular weight compounds. The different obtained pyrolysis liquids (aqueous and oily) had various volatile and nonvolatile compounds such as acetic acid, 2,6-dimethoxyphenol, 2-methoxyphenol, and cannabidiol. This study provides a detailed understanding of the chemical composition of pyrolysis liquids from different parts of the industrial hemp plant and assesses their possible economic potential.

In addition to the trichilianones A-D recently reported from Trichilia adolfi , a continuing investigation of the chemical constituents of the ethanol extract of the bark of this medicinal plant yielded the five new limonoids 1 - 5 . They are characterized by having four fused rings and are new examples of prieurianin-type limonoids, having a ε-lactone which in 4 and 5 is α, β- unsaturated. The structures of the isolated metabolites were determined by high field NMR spectroscopy and HR mass spectrometry. The new metabolites were shown to have the ε-lactone fused with a tetrahydrofuran ring which is connected to an oxidized hexane ring joined with a cyclo-pentanone having a 3-furanyl substituent. As the crude extract possesses antileishmanial activity, the compounds were assayed for cytotoxic and antiparasitic activities in vitro in murine macrophage cells (raw 264.7 cells) and in Leishmania amazoniensis as well as L. braziliensis promastigotes. Metabolites 1 - 3 and 5 showed moderate cytotoxicity (between 30-94 µg/mL) but are not responsible for the antileishmanial effect of the extract.

The diagnosis of mechanical asphyxia remains one of the most difficult issues in forensic pathology. Asphyxia ultimately results in cardiac arrest (CA) and, as there are no specific markers, the differential diagnosis of primitive CA and CA secondary to asphyxiation relies on circumstantial details and on the pathologist experience, lacking objective evidence. Histological examination is currently considered the gold standard for CA post-mortem diagnosis. Here we present the comparative results of histopathology versus those previously obtained by 1 H nuclear magnetic resonance (NMR) metabolomics in a swine model, originally designed for clinical purposes, exposed to two different CA causes, namely ventricular fibrillation and asphyxia. While heart and brain microscopical analysis could identify the damage induced by CA without providing any additional information on the CA cause, metabolomics allowed the identification of clearly different profiles between the two groups and showed major differences between asphyxiated animals with good and poor outcomes. Minute-by-minute plasma sampling allowed to associate these modifications to the pre-arrest asphyxial phase showing a clear correlation to the cellular effect of mechanical asphyxia reproduced in the experiment. The results suggest that metabolomics provides additional evidence beyond that obtained by histology and immunohistochemistry in the differential diagnosis of CA.

In the present study, we investigated the correlation between histopathological, metabolic, and volumetric changes in the brain and plasma under experimental conditions. Adult male Wistar rats received fractionated whole-brain irradiation (fWBI) with a total dose of 32 Gy delivered in 4 fractions (dose 8 Gy per fraction) once a week on the same day for 4 consecutive weeks. Proton magnetic resonance spectroscopy ( 1 H MRS) and imaging were used to detect metabolic and volumetric changes in the brain and plasma. Histopathological changes in the brain were determined by image analysis of immunofluorescent stained sections. Metabolic changes in the brain measured by 1 H MRS before, 48 h, and 9 weeks after the end of fWBI showed a significant decrease in the ratio of total N-acetylaspartate to total creatine (tNAA/tCr) in the corpus striatum. We found a significant decrease in glutamine + glutamate/tCr (Glx/tCr) and, conversely, an increase in gamma-aminobutyric acid to tCr (GABA/tCr) in olfactory bulb (OB). The ratio of astrocyte marker myoinositol/tCr (mIns/tCr) significantly increased in almost all evaluated areas. Magnetic resonance imaging (MRI)-based brain volumetry showed a significant increase in volume, and a concomitant increase in the T 2 relaxation time of the hippocampus. Proton nuclear magnetic resonance ( 1 H NMR) plasma metabolomics displayed a significant decrease in the level of glucose and glycolytic intermediates and an increase in ketone bodies. The histomorphological analysis showed a decrease to elimination of neuroblasts, increased astrocyte proliferation, and a mild microglia response. The results of the study clearly reflect early subacute changes 9-11 weeks after fWBI with strong manifestations of brain edema, astrogliosis, and ongoing ketosis., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Rationale: Proton magnetic resonance spectroscopy ( 1 H-MRS) is a cross-species neuroimaging technique that can measure concentrations of several brain metabolites, including glutamate and GABA. This non-invasive method has promise in developing centrally acting drugs, as it can be performed repeatedly within-subjects and be used to translate findings from the preclinical to clinical laboratory using the same imaging biomarker., Objectives: This review focuses on the utility of single-voxel 1 H-MRS in developing novel glutamatergic or GABAergic drugs for the treatment of psychiatric disorders and includes research performed in rodent models, healthy volunteers and patient cohorts., Results: Overall, these studies indicate that 1 H-MRS is able to detect the predicted pharmacological effects of glutamatergic or GABAergic drugs on voxel glutamate or GABA concentrations, although there is a shortage of studies examining dose-related effects. Clinical studies have applied 1 H-MRS to better understand drug therapeutic mechanisms, including the glutamatergic effects of ketamine in depression and of acamprosate in alcohol dependence. There is an emerging interest in identifying patient subgroups with 'high' or 'low' brain regional 1 H-MRS glutamate levels for more targeted drug development, which may require ancillary biomarkers to improve the accuracy of subgroup discrimination., Conclusions: Considerations for future research include the sensitivity of single-voxel 1 H-MRS in detecting drug effects, inter-site measurement reliability and the interpretation of drug-induced changes in 1 H-MRS metabolites relative to the known pharmacological molecular mechanisms. On-going technological development, in single-voxel 1 H-MRS and in related complementary techniques, will further support applications within CNS drug discovery.

Intrauterine growth restriction (IUGR) is a fetal adverse condition, ascribed by limited oxygen and nutrient supply from the mother to the fetus. Management of IUGR is an ongoing challenge because of its connection with increased fetal mortality, preterm delivery and postnatal pathologies. Untargeted nuclear magnetic resonance ( 1 H NMR) metabolomics was applied in 84 umbilical cord blood and maternal blood samples obtained from 48 IUGR and 36 appropriate for gestational age (AGA) deliveries. Orthogonal projections to latent structures discriminant analysis (OPLS-DA) followed by pathway and enrichment analysis generated classification models and revealed significant metabolites that were associated with altered pathways. A clear association between maternal and cord blood altered metabolomic profile was evidenced in IUGR pregnancies. Increased levels of the amino acids alanine, leucine, valine, isoleucine and phenylalanine were prominent in IUGR pregnancies indicating a connection with impaired amino acid metabolism and transplacental flux. Tryptophan was individually connected with cord blood discrimination while 3-hydroxybutyrate assisted only maternal blood discrimination. Lower glycerol levels in IUGR samples ascribed to imbalance between gluconeogenesis and glycolysis pathways, suggesting poor glycolysis. The elevated levels of branched chain amino acids (leucine, isoleucine and valine) in intrauterine growth restricted pregnancies were linked with increased insulin resistance.

The aim of the present study is to determine the potent biological activities and carry out isolation studies on Barbarea integrifolia . The antioxidant capacity of the species was evaluated by total phenolic content, FRAP, CUPRAC, and DPPH radical scavenging activity. Anticancer activity studies were performed by MTT assay in MDA-MB-231, MCF-7, Hep3B, PC-3, A549, HCT116, L-929 cell lines. It was observed that the remaining aqueous fraction has higher total phenolic content while higher activity in the CUPRAC and FRAP assays was displayed for the methanolic extract and chloroform fraction. The extracts showed anticancer activity as compared with vincristine. It was observed that chloroform fraction has the highest anticancer activity on MCF-7 cell line, while ethyl acetate fraction has the highest anticancer activity on Hep-3B and A549 cell lines. Methanolic extract has the highest anticancer activity on HCT116 and MDA-MB-23 cell lines. The isolation studies have been performed using several chromatographic methods. The chemical structures of compounds have been identified by means of 1 H NMR, 13 C NMR, 2D-NMR, and MS. Five major compounds, one steroid ( β -Sitosterol), one phenolic acid (Rosmarinic acid), one flavonol heteroside (kaempferol 7- O - α -l-rhamnoside-3- O - β -d-(2- O - β - d -glucosyl)- β -d-glucoside), and two glucosinolates (Gluconasturtiin, Gluconasturtiin choline salt) have been isolated., (© 2021 Walter de Gruyter GmbH, Berlin/Boston.)

Short-TE proton MRS is used to study metabolism in the human brain. Common analysis methods model the data as a linear combination of metabolite basis spectra. This large-scale multi-site study compares the levels of the four major metabolite complexes in short-TE spectra estimated by three linear-combination modeling (LCM) algorithms. 277 medial parietal lobe short-TE PRESS spectra (TE = 35 ms) from a recent 3 T multi-site study were preprocessed with the Osprey software. The resulting spectra were modeled with Osprey, Tarquin and LCModel, using the same three vendor-specific basis sets (GE, Philips and Siemens) for each algorithm. Levels of total N-acetylaspartate (tNAA), total choline (tCho), myo-inositol (mI) and glutamate + glutamine (Glx) were quantified with respect to total creatine (tCr). Group means and coefficient of variations of metabolite estimates agreed well for tNAA and tCho across vendors and algorithms, but substantially less so for Glx and mI, with mI systematically estimated as lower by Tarquin. The cohort mean coefficient of determination for all pairs of LCM algorithms across all datasets and metabolites was R 2 ¯ = 0.39, indicating generally only moderate agreement of individual metabolite estimates between algorithms. There was a significant correlation between local baseline amplitude and metabolite estimates (cohort mean R 2 ¯ = 0.10). While mean estimates of major metabolite complexes broadly agree between linear-combination modeling algorithms at group level, correlations between algorithms are only weak-to-moderate, despite standardized preprocessing, a large sample of young, healthy and cooperative subjects, and high spectral quality. These findings raise concerns about the comparability of MRS studies, which typically use one LCM software and much smaller sample sizes., (© 2021 John Wiley & Sons, Ltd.)

The applicability of generative adversarial networks (GANs) capable of unsupervised anomaly detection (AnoGAN) was investigated in the management of quality of 1 H-MRS human brain spectra at 3.0 T. The AnoGAN was trained in an unsupervised manner solely on simulated normal brain spectra and used for filtering out abnormal spectra with a broad range of abnormalities, which were simulated by including abnormal ranges of SNR, linewidth and metabolite concentrations and spectral artifacts such as ghost, residual water, and lipid. The AnoGAN was able to filter out those spectra with SNR less than ~11-12 dB with an accuracy of ~80% or higher (assuming a normal SNR range to be 15-18 dB). It also detected with an accuracy of ~80% or higher those spectra, in which NAA levels were reduced by ~25-30% or more from the lower bound and elevated by ~20-30% or more from the upper bound of the normal concentration range (7.5-17 mmol/L), while the concentrations of the rest of the metabolites were all within the normal ranges. Despite the fact that those spectra contaminated with ghost, residual water or lipid have never been involved in the training or optimization of the AnoGAN, they were correctly classified as abnormal regardless of the types of the artifacts, depending solely on their intensity. Although the current version of our AnoGAN requires further technical improvement particularly for the detection of linewidth-associated abnormality and validation on in vivo data, our unsupervised deep learning-based approach could be an option in addition to those previously reported supervised deep learning-based approaches in the binary classification of spectral quality with an extended abnormal spectra regime., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Curcumin, together with demethoxycurcumin and bisdemethoxycurcumin as a whole called curcuminoids, is an active phytochemical constituent present in the turmeric. When it comes to their analysis, most will rely on UV-Visible spectroscopy, HPLC and LC-MS methods. Looking to improve productivity, time and simplicity, we are proposing a 1 H NMR based approach for curcuminoids analysis and its applications to different geographical regions. In the present work, sample preparation protocol is reported for the simultaneous determination of curcuminoids using 1 H NMR. For the quantification of curcuminoids, 6-7 ppm vinylic proton region in the 1 H NMR spectrum was used, where acetone was observed as the suitable solvent in terms of curcuminoids solubility and proper resolution of peak. The result shows that curcumin (46.8-59.50%) was major among all varieties, followed by DMC (22.15-27.70%) and BDMC (17.52-30.29%) except in Andhrapradesh variety, where BDMC (30.29%) was more than DMC (22.89%). These studies were further supported by HPLC analysis., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Thiazolidinediones are very important and used as a drug for the treatment of type 2 diabetes. Here, we report a convenient approach to synthesis 3-m-tolyl-5-arylidene-2,4-thiazolidinediones (TZDs) derivatives 7a-e in two steps with moderate to good yield using morpholine as a catalyst. All the structures were confirmed by their spectral IR, 1H NMR and 13C NMR data. The anti-diabatic activity of all synthesized molecules is evaluated by docking with peroxisome proliferator-activated receptor-γ (PPARγ). Preliminary flexible docking studies reveals that our compounds 7a, 7d and 7e showed better binding affinity with the protein and could be a potential candidate for the treatment of type 2 diabetes in near future., Competing Interests: The authors have declared that no competing interests exist.

We have applied nuclear magnetic resonance spectroscopy based plasma phenotyping to reveal diagnostic molecular signatures of SARS-CoV-2 infection via combined diffusional and relaxation editing (DIRE). We compared plasma from healthy age-matched controls ( n = 26) with SARS-CoV-2 negative non-hospitalized respiratory patients and hospitalized respiratory patients ( n = 23 and 11 respectively) with SARS-CoV-2 rRT-PCR positive respiratory patients ( n = 17, with longitudinal sampling time-points). DIRE data were modelled using principal component analysis and orthogonal projections to latent structures discriminant analysis (O-PLS-DA), with statistical cross-validation indices indicating excellent model generalization for the classification of SARS-CoV-2 positivity for all comparator groups (area under the receiver operator characteristic curve = 1). DIRE spectra show biomarker signal combinations conferred by differential concentrations of metabolites with selected molecular mobility properties. These comprise the following: (a) composite N -acetyl signals from α-1-acid glycoprotein and other glycoproteins (designated GlycA and GlycB) that were elevated in SARS-CoV-2 positive patients [ p = 2.52 × 10 -10 (GlycA) and 1.25 × 10 -9 (GlycB) vs controls], (b) two diagnostic supramolecular phospholipid composite signals that were identified (SPC-A and SPC-B) from the - + N-(CH 3 ) 3 choline headgroups of lysophosphatidylcholines carried on plasma glycoproteins and from phospholipids in high-density lipoprotein subfractions (SPC-A) together with a phospholipid component of low-density lipoprotein (SPC-B). The integrals of the summed SPC signals (SPC total ) were reduced in SARS-CoV-2 positive patients relative to both controls ( p = 1.40 × 10 -7 ) and SARS-CoV-2 negative patients ( p = 4.52 × 10 -8 ) but were not significantly different between controls and SARS-CoV-2 negative patients. The identity of the SPC signal components was determined using one and two dimensional diffusional, relaxation, and statistical spectroscopic experiments. The SPC total /GlycA ratios were also significantly different for control versus SARS-CoV-2 positive patients ( p = 1.23 × 10 -10 ) and for SARS-CoV-2 negatives versus positives ( p = 1.60 × 10 -9 ). Thus, plasma SPC total and SPC total /GlycA are proposed as sensitive molecular markers for SARS-CoV-2 positivity that could effectively augment current COVID-19 diagnostics and may have value in functional assessment of the disease recovery process in patients with long-term symptoms.

Objective: The aims of this retrospective study were to assess the value of the quantitative analysis of apparent diffusion coefficient (ADC) and proton magnetic resonance spectroscopy (1H-MRS) metabolites in differentiating grades of pediatric gliomas., Patients and Methods: Two hundred and nine pathology-confirmed pediatric gliomas (143 low-grade gliomas [LGGs] and 66 high-grade gliomas [HGGs]) were retrospectively analyzed on preoperative diffusion-weighted magnetic resonance imaging, of which 84 also underwent 1H-MRS. The mean tumor ADC (ADCmean), minimum tumor ADC (ADCmin), tumor/normal brain ADC ratio (ADC ratio), and metabolites (choline/creatine ratio [Cho/Cr], N-acetylaspartate/creatine ratio [NAA/Cr], N-acetylaspartate/choline ratio [NAA/Cho], presence of lactate and lipid peaks) between LGGs and HGGs were analyzed., Results: There were significant negative correlations between the ADC values and glioma grade. Receiver operating characteristic analysis showed that the cutoff ADCmean value of 1.192 × 10-3 mm2/s for the differentiation between low- and high-grade pediatric gliomas provided a sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of 77.6%, 80.3%, 78.5%, 89.5% and 62.4%, respectively; the cutoff ADCmin value of 0.973 × 10-3 mm2/s resulted in a sensitivity, specificity, accuracy, PPV, and NPV of 86.0%, 90.9%, 87.6%, 95.3%, and 75.0%, respectively; the cutoff ADC ratio value of 1.384 resulted in a sensitivity, specificity, accuracy, PPV, and NPV of 73.4%, 87.9%, 78.0%, 92.9%, and 60.4%, respectively. A tendency for a positive correlation was found between Cho/Cr and glioma grade. A negative correlation was demonstrated between NAA/Cr or NAA/Cho and glioma grade. Statistical analysis demonstrated a threshold value of 2.601 for Cho/Cr to provide a sensitivity, specificity, accuracy, PPV, and NPV of 81.8%, 51.7%, 71.4%, 76.3%, and 60.0%, respectively, in dividing LGGs and HGGs; a threshold value of 0.705 for NAA/Cr to provide a sensitivity, specificity, accuracy, PPV, and NPV of 76.4%, 75.9%, 76.2%, 85.7%, and 62.9%, respectively; a threshold value of 0.349 for NAA/Cho to provide a sensitivity, specificity, accuracy, PPV, and NPV of 87.3%, 86.2%, 86.9%, 92.3%, and 78.1%, respectively., Conclusions: The ADC values and metabolites appeared to be significantly correlated to grade in pediatric gliomas. The predictive values may be helpful for preoperative diagnostic predictions., Competing Interests: The authors declare no conflict of interest., (Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc.)

A set of 917 wines of Czech origin were analysed using nuclear magnetic resonance spectroscopy (NMR) with the aim of building and evaluating multivariate statistical models and machine learning methods for the classification of 6 types based on colour and residual sugar content, 13 wine grape varieties and 4 locations based on 1 H NMR spectra. The predictive models afforded greater than 93% correctness for classifying dry and medium dry, medium, and sweet white wines and dry red wines. The trained Random Forest (RF) model classified Pinot noir with 96% correctness, Blaufränkisch 96%, Riesling 92%, Cabernet Sauvignon 77%, Chardonnay 76%, Gewürtztraminer 60%, Hibernal 60%, Grüner Veltliner 52%, Pinot gris 48%, Sauvignon Blanc 45%, and Pálava 40%. Pinot blanc and Chardonnay, varieties that are often mistakenly interchanged, were discriminated with 71% correctness. The findings support chemometrics as a tool for predicting important features in wine, particularly for quality assessment and fraud detection., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The 15 N- 1 H heteronuclear single-quantum correlation (HSQC) technique in protein NMR spectroscopy suffers from line-broadening effects, such as chemical exchange of labile protons with solvent, and exchange broadening for residues undergoing conformational dynamics. The amide resonance of β 2 -microglobulin residue S88 is not observed in the HSQC spectrum but can be obtained through 13 C-detect experiments that circumvent the problem of amide-solvent exchange broadening. Line broadening of S88 resonance beyond detection in the HSQC spectrum is not attributed to conformational exchange but rather to solvent exchange occurring on the order of ~10 3  s -1 ., (Copyright © 2020 The Author(s). Published by Elsevier B.V. All rights reserved.)

Superoxide dismutase 1 (SOD1) is known to be involved in the pathogenesis of Amyotrophic Lateral Sclerosis (ALS) and is therefore considered to be an important ALS drug target. Identifying potential drug leads that bind to SOD1 and characterizing their interactions by nuclear magnetic resonance (NMR) spectroscopy is complicated by the fact that SOD1 is a homodimer. Creating a monomeric version of SOD1 could alleviate these issues. A specially designed monomeric form of human superoxide dismutase (T2M4SOD1) was cloned into E. coli and its expression significantly enhanced using a number of novel DNA sequence, leader peptide and growth condition optimizations. Uniformly 15N-labeled T2M4SOD1 was prepared from minimal media using 15NH4Cl as the 15N source. The T2M4SOD1 monomer (both 15N labeled and unlabeled) was correctly folded as confirmed by 1H-NMR spectroscopy and active as confirmed by an in-gel enzymatic assay. To demonstrate the utility of this new SOD1 expression system for NMR-based drug screening, eight pyrimidine compounds were tested for binding to T2M4SOD1 by monitoring changes in their 1H NMR and/or 19F-NMR spectra. Weak binding to 5-fluorouridine (FUrd) was observed via line broadening, but very minimal spectral changes were seen with uridine, 5-bromouridine or trifluridine. On the other hand, 1H-NMR spectra of T2M4SOD1 with uracil or three halogenated derivatives of uracil changed dramatically suggesting that the pyrimidine moiety is the crucial binding component of FUrd. Interestingly, no change in tryptophan 32 (Trp32), the putative receptor for FUrd, was detected in the 15N-NMR spectra of 15N-T2M4SOD1 when mixed with these uracil analogs. Molecular docking and molecular dynamic (MD) studies indicate that interaction with Trp32 of SOD1 is predicted to be weak and that there was hydrogen bonding with the nearby aspartate (Asp96), potentiating the Trp32-uracil interaction. These studies demonstrate that monomeric T2M4SOD1 can be readily used to explore small molecule interactions via NMR., Competing Interests: The authors have declared that no competing interests exist.

The utility of low sample volume in vitro diagnostic (IVDr) proton nuclear magnetic resonance ( 1 H NMR) spectroscopic experiments on blood plasma for information recovery from limited availability or high value samples was exemplified using plasma from patients with SARS-CoV-2 infection and normal controls. 1 H NMR spectra were obtained using solvent-suppressed 1D, spin-echo (CPMG), and 2-dimensional J-resolved (JRES) spectroscopy using both 3 mm outer diameter SampleJet NMR tubes (100 μL plasma) and 5 mm SampleJet NMR tubes (300 μL plasma) under in vitro diagnostic conditions. We noted near identical diagnostic models in both standard and low volume IVDr lipoprotein analysis (measuring 112 lipoprotein parameters) with a comparison of the two tubes yielding R 2 values ranging between 0.82 and 0.99 for the 40 paired lipoprotein parameters samples. Lipoprotein measurements for the 3 mm tubes were achieved without time penalty over the 5 mm tubes as defined by biomarker recovery for SARS-CoV-2. Overall, biomarker pattern recovery for the lipoproteins was extremely similar, but there were some small positive offsets in the linear equations for several variables due to small shimming artifacts, but there was minimal degradation of the biological information. For the standard untargeted 1D, CPMG, and JRES NMR experiments on the same samples, the reduced signal-to-noise was more constraining and required greater scanning times to achieve similar differential diagnostic performance (15 min per sample per experiment for 3 mm 1D and CPMG, compared to 4 min for the 5 mm tubes). We conclude that the 3 mm IVDr method is fit-for-purpose for quantitative lipoprotein measurements, allowing the preparation of smaller volumes for high value or limited volume samples that is common in clinical studies. If there are no analytical time constraints, the lower volume experiments are equally informative for untargeted profiling.

The study of cerebral metabolites relies heavily on detection methods and sample preparation. Animal experiments in vivo require anesthetic agents that can alter brain metabolism, whereas ex vivo experiments demand appropriate fixation methods to preserve the tissue from rapid postmortem degradation. In this study, the metabolic profiles of mouse hippocampi using proton magnetic resonance spectroscopy ( 1 H-MRS) were compared in vivo and in situ with or without focused beam microwave irradiation (FBMI) fixation. Ten major brain metabolites, including lactate (Lac), N-acetylaspartate (NAA), total choline (tCho), myo-inositol (mIns), glutamine (Gln), glutamate (Glu), aminobutyric acid (GABA), glutathione (GSH), total creatine (tCr) and taurine (Tau), were analyzed using LCModel. After FBMI fixation, the concentrations of Lac, tCho and mIns were comparable with those obtained in vivo under isoflurane, whereas other metabolites were significantly lower. Except for a decrease in NAA and an increase in Tau, all the other metabolites remained stable over 41 hours in FBMI-fixed brains. Without FBMI, the concentrations of mIns (before 2 hours), tCho and GABA were close to those measured in vivo. However, higher Lac (P < .01) and lower NAA, Gln, Glu, GSH, tCr and Tau were observed (P < .01). NAA, Gln, Glu, GSH, tCr and Tau exhibited good temporal stability for at least 20 hours in the unfixed brain, whereas a linear increase of tCho, mIns and GABA was observed. Possible mechanisms of postmortem degradation are discussed. Our results indicate that a proper fixation method is required for in situ detection depending on the targeted metabolites of specific interests in the brain., (© 2020 John Wiley & Sons Ltd.)

Bile exerts multiple functions in the liver and gut and is involved in multiple disease processes. It is secreted continuously from the liver and stored in the gallbladder until needed, and closely reflects the available bile acid pool. The study objective was therefore to develop a reliable MRS protocol and to assess variability of bile acid determination in human gallbladder. MRS measurements were performed on a 3 T MR scanner with 20 subjects to optimize protocols (26 measurements) and conduct a prospective reproducibility study (18 measurements). Measurements were carried out with subjects lying in either supine (23 scans) or prone positions (21 scans) to compare results from the two positions. For reproducibility determination, six of the 20 volunteers (three males, three females, age = 34.9 ± 10.9 years, BMI = 23.4 ± 2.1 kg/m 2 ) were measured three times: back to back to assess technical variability and once again after three weeks to assess total variability, including additional physiological variability. A single voxel was measured in the gallbladder with respiratory triggering. For quantification, apparent T 2 times were determined and a non-water-suppressed spectrum was acquired. Total bile acids, glycine and taurine conjugated bile acids, and lipids including choline-containing phospholipids were determined. Higher quality and reliability of gallbladder spectra were obtained with subjects measured in prone compared with supine position. All measurements of the reproducibility sub-study were of sufficient quality to be included in the analysis. Average coefficients of variation within subjects for the main compounds were 37% for total variation (including physiological and technical variation) and 24% for technical variation alone. These values were much smaller than those between subjects, which were >54% for both back-to-back and three weeks separated measurements. These results suggest diagnostic applicability of the method, especially for longitudinal studies aiming at non-invasive characterization of bile composition in humans with various diseases and/or interventional maneuvers., (© 2020 John Wiley & Sons, Ltd.)