Displaying publications 21 - 40 of 50 in total

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  1. Sidek S, Ramli N, Rahmat K, Ramli NM, Abdulrahman F, Kuo TL
    Eur Radiol, 2016 Dec;26(12):4404-4412.
    PMID: 26943134
    OBJECTIVE: To compare the metabolite concentration of optic radiation in glaucoma patients with that of healthy subjects using Proton Magnetic Resonance Spectroscopy (1H-MRS).

    METHODS: 1H-MRS utilising the Single-Voxel Spectroscopy (SVS) technique was performed using a 3.0Tesla MRI on 45 optic radiations (15 from healthy subjects, 15 from mild glaucoma patients, and 15 from severe glaucoma patients). A standardised Volume of Interest (VOI) of 20 × 20 × 20 mm was placed in the region of optic radiation. Mild and severe glaucoma patients were categorised based on the Hodapp-Parrish-Anderson (HPA) classification. Mean and multiple group comparisons for metabolite concentration and metabolite concentration ratio between glaucoma grades and healthy subjects were obtained using one-way ANOVA.

    RESULTS: The metabolite concentration and metabolite concentration ratio between the optic radiations of glaucoma patients and healthy subjects did not demonstrate any significant difference (p > 0.05).

    CONCLUSION: Our findings show no significant alteration of metabolite concentration associated with neurodegeneration that could be measured by single-voxel 1H-MRS in optic radiation among glaucoma patients.

    KEY POINTS: • Glaucoma disease has a neurodegenerative component. • Metabolite changes have been observed in the neurodegenerative process in the brain. • Using SVS, no metabolite changes in optic radiation were attributed to glaucoma.

    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods; Proton Magnetic Resonance Spectroscopy/methods*
  2. Hani AF, Kumar D, Malik AS, Walter N, Razak R, Kiflie A
    Acad Radiol, 2015 Jan;22(1):93-104.
    PMID: 25481518 DOI: 10.1016/j.acra.2014.08.008
    Quantitative assessment of knee articular cartilage (AC) morphology using magnetic resonance (MR) imaging requires an accurate segmentation and 3D reconstruction. However, automatic AC segmentation and 3D reconstruction from hydrogen-based MR images alone is challenging because of inhomogeneous intensities, shape irregularity, and low contrast existing in the cartilage region. Thus, the objective of this research was to provide an insight into morphologic assessment of AC using multilevel data processing of multinuclear ((23)Na and (1)H) MR knee images.
    Matched MeSH terms: Proton Magnetic Resonance Spectroscopy/methods*
  3. Fadzillah NA, Man Yb, Rohman A, Rosman AS, Ismail A, Mustafa S, et al.
    J Oleo Sci, 2015;64(7):697-703.
    PMID: 25994556 DOI: 10.5650/jos.ess14255
    The authentication of food products from the presence of non-allowed components for certain religion like lard is very important. In this study, we used proton Nuclear Magnetic Resonance ((1)H-NMR) spectroscopy for the analysis of butter adulterated with lard by simultaneously quantification of all proton bearing compounds, and consequently all relevant sample classes. Since the spectra obtained were too complex to be analyzed visually by the naked eyes, the classification of spectra was carried out.The multivariate calibration of partial least square (PLS) regression was used for modelling the relationship between actual value of lard and predicted value. The model yielded a highest regression coefficient (R(2)) of 0.998 and the lowest root mean square error calibration (RMSEC) of 0.0091% and root mean square error prediction (RMSEP) of 0.0090, respectively. Cross validation testing evaluates the predictive power of the model. PLS model was shown as good models as the intercept of R(2)Y and Q(2)Y were 0.0853 and -0.309, respectively.
    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods*
  4. Jamila N, Khairuddean M, Khan SN, Khan N
    Magn Reson Chem, 2014 Jul;52(7):345-52.
    PMID: 24700704 DOI: 10.1002/mrc.4071
    The genus Garcinia is reported to possess antimicrobial, anti-inflammatory, anticancer, hepatoprotective and anti-HIV activities. Garcinia hombroniana in Malaysia is used to treat itching and as a protective medicine after child birth. This study was aimed to isolate the chemical constituents from the bark of G. hombroniana and explore their possible pharmacological potential. Ethyl acetate extract afforded one new (1) and six (2-7) known 3 → 8 rotameric biflavonoids. Their structures were elucidated by UV, IR and NMR (1D and 2D) spectroscopy together with electron ionization/ESI mass spectrometric techniques and were identified as (2R, 3S) volkensiflavone-7-O-rhamnopyranoside (1), volkensiflavone (2), 4″-O-methyl-volkensiflavone (3), volkensiflavone-7-O-glucopyranoside (4), morelloflavone (5), 3″-O-methyl-morelloflavone (6) and morelloflavone-7-O-glucopyranoside (7). The absolute configuration of compound 1 was assigned by circular dichroism spectroscopy as 2R, 3S. The coexistence of conformers of isolated biflavonoids in solution at 25 °C in different solvents was confirmed by variable temperature NMR studies. At room temperature (25 °C), compounds 1-7 exhibited duplicate NMR signals, while at elevated temperature (90 °C), a single set of signals was obtained. Compound 5 showed significant in vitro antioxidant activities against 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis-3-ethyl benzthiazoline-6-sulfonic acid radicals. The antibacterial studies showed that compounds 5 and 6 are the most active against Staphylococcus aureus, Bacillus subtilis and Escherichia coli. Compounds 3 and 6 also showed moderate antituberculosis activity against H38 Rv. Based on the research findings, G. hombroniana could be concluded as a rich source of flavanone-flavone (3 → 8) biflavonoids that exhibit rotameric behaviour at room temperature and display significant antioxidant and antibacterial activities.
    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods
  5. Sim YL, Ariffin A, Khan MN
    J Org Chem, 2008 May 16;73(10):3730-7.
    PMID: 18410141 DOI: 10.1021/jo702695k
    The apparent second-order rate constant (k OH) for hydroxide-ion-catalyzed conversion of 1 to N-(2'-methoxyphenyl)phthalamate (4) is approximately 10(3)-fold larger than k OH for alkaline hydrolysis of N-morpholinobenzamide (2). These results are explained in terms of the reaction scheme 1 --> k(1obs) 3 --> k(2obs) 4 where 3 represents N-(2'-methoxyphenyl)phthalimide and the values of k(2obs)/k(1obs) vary from 6.0 x 10(2) to 17 x 10(2) within [NaOH] range of 5.0 x 10(-3) to 2.0 M. Pseudo-first-order rate constants (k(obs)) for alkaline hydrolysis of 1 decrease from 21.7 x 10(-3) to 15.6 x 10(-3) s(-1) with an increase in ionic strength (by NaCl) from 0.5 to 2.5 M at 0.5 M NaOH and 35 degrees C. The values of k obs, obtained for alkaline hydrolysis of 2 within [NaOH] range 1.0 x 10(-2) to 2.0 M at 35 degrees C, follow the relationship k(obs) = kOH[HO(-)] + kOH'[HO (-)] (2) with least-squares calculated values of kOH and kOH' as (6.38 +/- 0.15) x 10(-5) and (4.59 +/- 0.09) x 10(-5) M (-2) s(-1), respectively. A few kinetic runs for aqueous cleavage of 1, N'-morpholino-N-(2'-methoxyphenyl)-5-nitrophthalamide (5) and N'-morpholino-N-(2'-methoxyphenyl)-4-nitrophthalamide (6) at 35 degrees C and 0.05 M NaOH as well as 0.05 M NaOD reveal the solvent deuterium kinetic isotope effect (= k(obs) (H 2) (O)/ k(obs) (D 2 ) (O)) as 1.6 for 1, 1.9 for 5, and 1.8 for 6. Product characterization study on the cleavage of 5, 6, and N-(2'-methoxyphenyl)-4-nitrophthalimide (7) at 0.5 M NaOD in D2O solvent shows the imide-intermediate mechanism as the exclusive mechanism.
    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods
  6. Fages A, Duarte-Salles T, Stepien M, Ferrari P, Fedirko V, Pontoizeau C, et al.
    BMC Med, 2015 Sep 23;13:242.
    PMID: 26399231 DOI: 10.1186/s12916-015-0462-9
    BACKGROUND: Hepatocellular carcinoma (HCC), the most prevalent form of liver cancer, is difficult to diagnose and has limited treatment options with a low survival rate. Aside from a few key risk factors, such as hepatitis, high alcohol consumption, smoking, obesity, and diabetes, there is incomplete etiologic understanding of the disease and little progress in identification of early risk biomarkers.

    METHODS: To address these aspects, an untargeted nuclear magnetic resonance metabolomic approach was applied to pre-diagnostic serum samples obtained from first incident, primary HCC cases (n = 114) and matched controls (n = 222) identified from amongst the participants of a large European prospective cohort.

    RESULTS: A metabolic pattern associated with HCC risk comprised of perturbations in fatty acid oxidation and amino acid, lipid, and carbohydrate metabolism was observed. Sixteen metabolites of either endogenous or exogenous origin were found to be significantly associated with HCC risk. The influence of hepatitis infection and potential liver damage was assessed, and further analyses were made to distinguish patterns of early or later diagnosis.

    CONCLUSION: Our results show clear metabolic alterations from early stages of HCC development with application for better etiologic understanding, prevention, and early detection of this increasingly common cancer.

    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods*
  7. Bawadikji AA, Teh CH, Sheikh Abdul Kader MAB, Abdul Wahab MJB, Syed Sulaiman SA, Ibrahim B
    Am J Cardiovasc Drugs, 2020 Apr;20(2):169-177.
    PMID: 31435902 DOI: 10.1007/s40256-019-00364-2
    BACKGROUND: Warfarin is prescribed as an oral anticoagulant to treat/prevent thromboembolism in conditions such as atrial fibrillation. As there is a narrow therapeutic window, treatment with warfarin is challenging. Pharmacometabonomics using nuclear magnetic resonance (NMR) spectroscopy may provide novel techniques for the identification of novel biomarkers of warfarin.

    PURPOSE: The aim was to determine the metabolic fingerprint that predicts warfarin response based on the international normalized ratio (INR) in patients who are already receiving warfarin (phase I: identification) and to ascertain the metabolic fingerprint that discriminates stable from unstable INR in patients starting treatment with warfarin (phase II: validation).

    EXPERIMENTAL APPROACH: A total of 94 blood samples were collected for phase I: 44 patients with stable INR and 50 with unstable INR. Meanwhile, 23 samples were collected for phase II: nine patients with stable INR and 14 with unstable INR. Data analysis was performed using multivariate analysis including principal component analysis and partial least square-discriminate analysis (PLS-DA), followed by univariate and multivariate logistic regression (MVLR) to develop a model to identify unstable INR biomarkers.

    KEY RESULTS: For phase I, the PLS-DA model showed the following results: sensitivity 93.18%, specificity 91.49% and accuracy 92.31%. In the MVLR analysis of phase I, ten regions were associated with unstable INR. For phase II, the PLS-DA model showed the following results: sensitivity 66.67%, specificity 61.54% and accuracy 63.64%.

    CONCLUSIONS AND IMPLICATIONS: We have shown that the pharmacometabonomics technique was able to differentiate between unstable and stable INR with good accuracy. NMR-based pharmacometabonomics has the potential to identify novel biomarkers in plasma, which can be useful in individualizing treatment and controlling warfarin side effects, thus, minimizing undesirable effects in the future.

    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods
  8. Mostafa H, Amin AM, Teh CH, Murugaiyah VA, Arif NH, Ibrahim B
    J Subst Abuse Treat, 2017 06;77:1-5.
    PMID: 28476260 DOI: 10.1016/j.jsat.2017.02.015
    BACKGROUND: Alcohol use disorders (AUD) is a phase of alcohol misuse in which the drinker consumes excessive amount of alcohol and have a continuous urge to consume alcohol which may lead to various health complications. The current methods of alcohol use disorders diagnosis such as questionnaires and some biomarkers lack specificity and sensitivity. Metabolomics is a novel scientific field which may provide a novel method for the diagnosis of AUD by using a sensitive and specific technique such as nuclear magnetic resonance (NMR).

    METHODS: A cross sectional study was conducted on three groups: individuals with alcohol use disorders (n=30), social drinkers (n=54) and alcohol-naive controls (n=60). 1H NMR-based metabolomics was used to obtain the metabolic profiles of plasma samples. Data were processed by multivariate principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) followed by univariate and multivariate logistic regressions to produce the best fit-model for discrimination between groups.

    RESULTS: The OPLS-DA model was able to distinguish between the AUD group and the other groups with high sensitivity, specificity and accuracy of 64.29%, 98.17% and 91.24% respectively. The logistic regression model identified two biomarkers in plasma (propionic acid and acetic acid) as being significantly associated with alcohol use disorders. The reproducibility of all biomarkers was excellent (0.81-1.0).

    CONCLUSIONS: The applied plasma metabolomics technique was able to differentiate the metabolites between AUD and the other groups. These metabolites are potential novel biomarkers for diagnosis of alcohol use disorders.

    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods*
  9. Mostafa H, Amin AM, Teh CH, Murugaiyah V, Arif NH, Ibrahim B
    Drug Alcohol Depend, 2016 12 01;169:80-84.
    PMID: 27788404 DOI: 10.1016/j.drugalcdep.2016.10.016
    BACKGROUND: Alcohol-dependence (AD) is a ravaging public health and social problem. AD diagnosis depends on questionnaires and some biomarkers, which lack specificity and sensitivity, however, often leading to less precise diagnosis, as well as delaying treatment. This represents a great burden, not only on AD individuals but also on their families. Metabolomics using nuclear magnetic resonance spectroscopy (NMR) can provide novel techniques for the identification of novel biomarkers of AD. These putative biomarkers can facilitate early diagnosis of AD.

    OBJECTIVES: To identify novel biomarkers able to discriminate between alcohol-dependent, non-AD alcohol drinkers and controls using metabolomics.

    METHOD: Urine samples were collected from 30 alcohol-dependent persons who did not yet start AD treatment, 54 social drinkers and 60 controls, who were then analysed using NMR. Data analysis was done using multivariate analysis including principal component analysis (PCA) and orthogonal partial least square-discriminate analysis (OPLS-DA), followed by univariate and multivariate logistic regression to develop the discriminatory model. The reproducibility was done using intraclass correlation coefficient (ICC).

    RESULTS: The OPLS-DA revealed significant discrimination between AD and other groups with sensitivity 86.21%, specificity 97.25% and accuracy 94.93%. Six biomarkers were significantly associated with AD in the multivariate logistic regression model. These biomarkers were cis-aconitic acid, citric acid, alanine, lactic acid, 1,2-propanediol and 2-hydroxyisovaleric acid. The reproducibility of all biomarkers was excellent (0.81-1.0).

    CONCLUSION: This study revealed that metabolomics analysis of urine using NMR identified AD novel biomarkers which can discriminate AD from social drinkers and controls with high accuracy.

    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods
  10. Amin AM, Sheau Chin L, Teh CH, Mostafa H, Mohamed Noor DA, Sk Abdul Kader MA, et al.
    J Pharm Biomed Anal, 2017 Nov 30;146:135-146.
    PMID: 28873361 DOI: 10.1016/j.jpba.2017.08.018
    Clopidogrel high on treatment platelets reactivity (HTPR) has burdened achieving optimum therapeutic outcome. Although there are known genetic and non-genetic factors associated with clopidogrel HTPR, which explain in part clopidogrel HTPR, yet, great portion remains unknown, often hindering personalizing antiplatelet therapy. Nuclear magnetic resonance (1H NMR) pharmacometabolomics analysis is useful technique to phenotype drug response. We investigated using 1H NMR analysis to phenotype clopidogrel HTPR in urine. Urine samples were collected from 71 coronary artery disease (CAD) patients who were planned for interventional angiographic procedure prior to taking 600mg clopidogrel loading dose (LD) and 6h post LD. Patients' platelets function testing was assessed with the VerifyNow® P2Y12 assay at 6h after LD. Urine samples were analysed using 1H NMR. Multivariate statistical analysis was used to identify metabolites associated with clopidogrel HTPR. In pre-dose samples, 16 metabolites were associated with clopidogrel HTPR. However, 18 metabolites were associated with clopidogrel HTPR in post-dose samples. The pathway analysis of the identified biomarkers reflected that multifactorial conditions are associated with clopidogrel HTPR. It also revealed the implicated role of gut microbiota in clopidogrel HTPR. Pharmacometabolomics not only discovered novel biomarkers of clopidogrel HTPR but also revealed implicated pathways and conditions.
    Matched MeSH terms: Proton Magnetic Resonance Spectroscopy/methods
  11. Sha'aban A, Zainal H, Khalil NA, Abd Aziz F, Ch'ng ES, Teh CH, et al.
    Molecules, 2022 Mar 25;27(7).
    PMID: 35408523 DOI: 10.3390/molecules27072126
    BACKGROUND: Low-dose aspirin (LDA) is the backbone for secondary prevention of coronary artery disease, although limited by gastric toxicity. This study aimed to identify novel metabolites that could predict LDA-induced gastric toxicity using pharmacometabolomics.

    METHODS: Pre-dosed urine samples were collected from male Sprague-Dawley rats. The rats were treated with either LDA (10 mg/kg) or 1% methylcellulose (10 mL/kg) per oral for 28 days. The rats' stomachs were examined for gastric toxicity using a stereomicroscope. The urine samples were analyzed using a proton nuclear magnetic resonance spectroscopy. Metabolites were systematically identified by exploring established databases and multivariate analyses to determine the spectral pattern of metabolites related to LDA-induced gastric toxicity.

    RESULTS: Treatment with LDA resulted in gastric toxicity in 20/32 rats (62.5%). The orthogonal projections to latent structures discriminant analysis (OPLS-DA) model displayed a goodness-of-fit (R2Y) value of 0.947, suggesting near-perfect reproducibility and a goodness-of-prediction (Q2Y) of -0.185 with perfect sensitivity, specificity and accuracy (100%). Furthermore, the area under the receiver operating characteristic (AUROC) displayed was 1. The final OPLS-DA model had an R2Y value of 0.726 and Q2Y of 0.142 with sensitivity (100%), specificity (95.0%) and accuracy (96.9%). Citrate, hippurate, methylamine, trimethylamine N-oxide and alpha-keto-glutarate were identified as the possible metabolites implicated in the LDA-induced gastric toxicity.

    CONCLUSION: The study identified metabolic signatures that correlated with the development of a low-dose Aspirin-induced gastric toxicity in rats. This pharmacometabolomic approach could further be validated to predict LDA-induced gastric toxicity in patients with coronary artery disease.

    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods
  12. Zainuddin N, Karpukhina N, Law RV, Hill RG
    Dent Mater, 2012 Oct;28(10):1051-8.
    PMID: 22841162 DOI: 10.1016/j.dental.2012.06.011
    The purpose of this study was to characterize commercial glass polyalkenoate cement (GPC) or glass ionomer cement (GIC), Glass Carbomer(®), which is designed to promote remineralization to fluorapatite (FAp) in the mouth. The setting reaction of the cement was followed using magic angle spinning nuclear magnetic resonance (MAS-NMR) spectroscopy.
    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods*
  13. Chan KL, Sugiyama H, Saito I, Hara M
    Phytochemistry, 1995 Nov;40(5):1373-4.
    PMID: 8534399
    The kapurimycin A3-guanine adduct was formed by alkylation of the antitumour antibiotic with d(CGCG)2. The site of alkylation of the guanine was confirmed by comparative NMR studies with N-7-methyl-guanine in DMSO-d6.
    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods
  14. Pariyani R, Ismail IS, Azam A, Khatib A, Abas F, Shaari K, et al.
    J Pharm Biomed Anal, 2017 Feb 20;135:20-30.
    PMID: 27987392 DOI: 10.1016/j.jpba.2016.12.010
    Orthosiphon stamineus (OS) is a popular medicinal herb used in traditional Chinese medicine as a diuretic agent and for renal system disorders. This study employed 1H NMR based metabolomics approach to investigate the possible protective activity of OS in cisplatin induced nephrotoxicity owing to its diuretic and antioxidant activities. Aqueous (OSAE) and 50% aqueous ethanolic (OSFE) extracts of OS leaves were orally administered at 400mg/kg BW doses to rats which were then intraperitoneally injected with cisplatin at 5mg/kg BW dose. The 1H NMR profile of the urine samples collected on day 5 after cisplatin administration were analyzed by multivariate pattern recognition techniques, whereby 19 marker metabolites suggestive in the involvement of TCA cycle, disturbed energy metabolism, altered gut microflora and BCAA metabolism pathways were identified. It was observed that OSFE caused significant changes (p<0.05) in the levels of 8 markers namely leucine, acetate, hippurate, lysine, valine, 2-oxoglutarate, 3-HBT and acetoacetate resulting in a moderate ameliorative effect, however, it did not completely protect from nephrotoxicity. OSAE did not demonstrate significant down regulatory effects on any markers, albeit, it potentiated the cisplatin nephrotoxicity by inducing significant increase in glucose, glycine, creatinine, citrate, TMAO, acetate and creatine levels. A Principal Component Analysis (PCA) of the 1H NMR spectra of OS extracts identified that OSFE had higher concentrations of the secondary metabolites such as caffeic acid, chlorogenic acid, protocatechuic acid and orthosiphol, among others. Whereas, OSAE was characterized by higher concentrations of acetate, lactate, succinic acid, valine and phosphatidylcholine. This research denotes the first comprehensive analysis to identify the effects of OS extracts on cisplatin nephrotoxicity.
    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods*
  15. Prakash I, Bunders C, Devkota KP, Charan RD, Ramirez C, Snyder TM, et al.
    Molecules, 2014 Oct 28;19(11):17345-55.
    PMID: 25353385 DOI: 10.3390/molecules191117345
    To supply the increasing demand of natural high potency sweeteners to reduce the calories in food and beverages, we have looked to steviol glycosides. In this work we report the bioconversion of rebaudioside A to rebaudioside I using a glucosyltransferase enzyme. This bioconversion reaction adds one sugar unit with a 1→3 linkage. We utilized 1D and 2D NMR spectroscopy (1H, 13C, COSY, HSQC-DEPT, HMBC, 1D TOCSY and NOESY) and mass spectral data to fully characterize rebaudioside I.
    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods
  16. Abdul Hamid NA, Mediani A, Maulidiani M, Abas F, Park YS, Leontowicz H, et al.
    J Pharm Biomed Anal, 2017 May 10;138:80-91.
    PMID: 28189049 DOI: 10.1016/j.jpba.2017.01.046
    It is known from our previous studies that kiwifruits, which are used in common human diet, have preventive properties of coronary artery disease. This study describes a combination of (1)H NMR spectroscopy, multivariate data analyses and fluorescence measurements in differentiating of some kiwifruit varieties, their quenching and antioxidant properties. A total of 41 metabolites were identified by comparing with literature data Chenomx database and 2D NMR. The binding properties of the extracted polyphenols against HSA showed higher reactivity of studied two cultivars in comparison with the common Hayward. The results showed that the fluorescence of HSA was quenched by Bidan as much as twice than by other fruits. The correlation between the binding properties of polyphenols in the investigated fruits, their relative quantification and suggested metabolic pathway was established. These results can provide possible application of fruit extracts in pharmaceutical industry.
    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods
  17. Islam MS, Al-Majid AM, Barakat A, Soliman SM, Ghabbour HA, Quah CK, et al.
    Molecules, 2015 May 07;20(5):8223-41.
    PMID: 25961163 DOI: 10.3390/molecules20058223
    This paper describes an efficient and regioselective method for the synthesis of novel fluorinated spiro-heterocycles in excellent yield by cascade [5+1] double Michael addition reactions. The compounds 7,11-bis(4-fluorophenyl)-2,4-dimethyl- 2,4-diazaspiro[5.5] undecane-1,3,5,9-tetraone (3a) and 2,4-dimethyl-7,11-bis (4-(trifluoromethyl)phenyl)-2,4-diazaspiro[5.5]undecane-1,3,5,9-tetraone (3b) were characterized by single-crystal X-ray diffraction, FT-IR and NMR techniques. The optimized geometrical parameters, infrared vibrational frequencies and NMR chemical shifts of the studied compounds have also been calculated using the density functional theory (DFT) method, using Becke-3-Lee-Yang-Parr functional and the 6-311G(d,p) basis set. There is good agreement between the experimentally determined structural parameters, vibrational frequencies and NMR chemical shifts of the studied compounds and those predicted theoretically. The calculated natural atomic charges using NBO method showed higher polarity of 3a compared to 3b.The calculated electronic spectra are also discussed based on the TD-DFT calculations.
    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods
  18. Abdulazeez I, Ismail IS, Mohd Faudzi SM, Christianus A, Chong SG
    Drug Chem Toxicol, 2024 Jan;47(1):115-130.
    PMID: 37548163 DOI: 10.1080/01480545.2023.2242005
    Sodium taurocholate (NaT) is a hydrophobic bile salt that exhibits varying toxicity and antimicrobial activity. The accumulation of BSs during their entero-hepatic cycle causes cytotoxicity in the liver and intestine and could also alter the intestinal microbiome leading to various diseases. In this research, the acute toxicity of sodium taurocholate in different concentrations (3000 mg/L, 1500 mg/L, 750 mg/L, 375 mg/L, and 0 mg/L) was investigated on four months old zebrafish by immersion in water for 96 h. The results were determined based on the fish mortality, behavioral response, and NMR metabolomics analysis which revealed LC50 of 1760.32 mg/L and 1050.42 mg/L after 72 and 96 h treatment, respectively. However, the non-lethal NaT concentrations of 750 mg/L and 375 mg/L at 96 h exposure significantly (p ≤ 0.05) decreased the total distance traveled and the activity duration, also caused surface respiration on the zebrafish. Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) revealed that the metabolome of the fish treated with 750 mg/L was discriminated from that of the control by PC1. Major significantly downregulated metabolites by NaT-induction include valine, isoleucine, 2-hydroxyvalerate, glycine, glycerol, choline, glucose, pyruvate, anserine, threonine, carnitine and homoserine. On the contrary, taurine, creatine, lactate, acetate and 3-hydroxybutyrate were upregulated suggesting cellular consumption of lipids, glucose and amino acids for adenosine triphosphate (ATP) generation during immune and inflammatory response. whereby these metabolites were released in the process. In conclusion, the research revealed the toxic effect of NaT and its potential to trigger changes in zebrafish metabolism.
    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods
  19. Xu J, Jiang H, Li J, Cheng KK, Dong J, Chen Z
    PLoS One, 2015;10(4):e0119654.
    PMID: 25849323 DOI: 10.1371/journal.pone.0119654
    Wilson's disease (WD), also known as hepatoleticular degeneration (HLD), is a rare autosomal recessive genetic disorder of copper metabolism, which causes copper to accumulate in body tissues. In this study, rats fed with copper-laden diet are used to render the clinical manifestations of WD, and their copper toxicity-induced organ lesions are studied. To investigate metabolic behaviors of 'decoppering' process, penicillamine (PA) was used for treating copper-laden rats as this chelating agent could eliminate excess copper through the urine. To date, there has been limited metabolomics study on WD, while metabolic impacts of copper accumulation and PA administration have yet to be established.
    Matched MeSH terms: Proton Magnetic Resonance Spectroscopy/methods*
  20. Ma NL, Teh KY, Lam SS, Kaben AM, Cha TS
    Bioresour Technol, 2015 Aug;190:536-42.
    PMID: 25812996 DOI: 10.1016/j.biortech.2015.03.036
    This study demonstrates the use of NMR techniques coupled with chemometric analysis as a high throughput data mining method to identify and examine the efficiency of different disruption techniques tested on microalgae (Chlorella variabilis, Scenedesmus regularis and Ankistrodesmus gracilis). The yield and chemical diversity from the disruptions together with the effects of pre-oven and pre-freeze drying prior to disruption techniques were discussed. HCl extraction showed the highest recovery of oil compounds from the disrupted microalgae (up to 90%). In contrast, NMR analysis showed the highest intensity of bioactive metabolites obtained for homogenized extracts pre-treated with freeze-drying, indicating that homogenizing is a more favorable approach to recover bioactive substances from the disrupted microalgae. The results show the potential of NMR as a useful metabolic fingerprinting tool for assessing compound diversity in complex microalgae extracts.
    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods*
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