Displaying publications 101 - 120 of 534 in total

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  1. Fulltext Synthesis and characterisation of Mononuclear and Tetranuclear Zinc (II) complexes of Schiff bases derived from Phenylenediamine
    Hadariah Bahron, Siti Solihah Khaidir, Amalina Mohd Tajuddin, Syed Abdul Illah Alyahya Syed Abd Kadir
    Pertanika Journal of Science & Technology, 2017;25(103):309-316.
    MyJurnal
    A mononuclear and new tetranuclear metal complexes of Zn(II) with Schiff base ligands L1 and L2 respectively, were synthesised. L1 was obtained through the condensation of salicylaldehyde with ortho-phenylenediamine while L2 was the product of reaction between of ortho-vanillin with 2,4,6-trimethyl-m-phenylenediamine. The ligands and complexes were characterised via elemental analysis, melting point, IR and NMR spectroscopy. The shifting of v(C=N), v(C-OH) and v(O-CH3) infrared peaks upon coordination with Zn(II) indicated that these three moieties play a significant role in the complexation. It was found that L1 acted as tetradentate ligand, coordinating with Zn(II) centres through phenolic oxygen and imine nitrogen. The ligand L2 acted as a hexadentate ligand, bonded to metal via phenolic oxygen, imine nitrogen and methoxy oxygen, where four Zn(II) centres formed bridges to connect two ligands.
    Matched MeSH terms: Magnetic Resonance Spectroscopy
  2. Delineation of the intimate details of the backbone conformation of pyridine nucleotide coenzymes in aqueous solution
    Bose KS, Sarma RH
    Biochem Biophys Res Commun, 1975 Oct 27;66(4):1173-9.
    PMID: 2
    Matched MeSH terms: Magnetic Resonance Spectroscopy
  3. Fulltext Hydrocephaly Analysis Supported by Computerized Tomography and Nuclear Magnetic Resonance
    Zhang T, Zhou Y, Su G, Shi D, Gopinath SCB, Lakshmipriya T, et al.
    J Anal Methods Chem, 2019;2019:5872347.
    PMID: 31662948 DOI: 10.1155/2019/5872347
    Hydrocephalus is widely known as "hydrocephaly" or "water in the brain," a building up of abnormal cerebrospinal fluid in the brain ventricles. Due to this abnormality, the size of the head becomes larger and increases the pressure in the skull. This pressure compresses the brain and causes damage to the brain. Identification by imaging techniques on the hydrocephalus is mandatory to treat the disease. Various methods and equipment have been used to image the hydrocephalus. Among them, computerized tomography (CT) scan and nuclear magnetic resonance (NMR) are the most considered methods and gives accurate result of imaging. Apart from imaging, cerebrospinal fluid-based biomarkers are also used to identify the condition of hydrocephalus. This review is discussed on "hydrocephalus" and its imaging captured by CT scan and NMR to support the biomarker analysis.
    Matched MeSH terms: Magnetic Resonance Spectroscopy
  4. Correlation data of (Z)-1-[4-(trifluoromethyl)benzylidene]thiosemicarbazide via spectroscopic methods and Density Functional Theory studies
    Osman UM, Farizal ASN, Kadir MA, Razali MH, Rozaini MZH, Arshad S
    Data Brief, 2019 Dec;27:104673.
    PMID: 31720328 DOI: 10.1016/j.dib.2019.104673
    New compound, namely (Z)-1-[4-(trifluoromethyl)benzylidene]thiosemicarbazide was successfully synthesized using thiosemicarbazide with 4-(trifluoromethyl)-benzaldehyde in ethanol solution. The data presented in this articles is related to our research articles entitled "Crystal Structure of (Z)-1-[4-(Trifluoromethyl)benzylidene]thiosemicarbazide" (Osman et al., 2017) [1]. This work shows the continue data from experimental spectroscopic measurement which are Fourier Transform Infrared (FTIR) and 13C Nuclear Magnetic Resonance (13C NMR). Assessment on the correlation with theoretical computational data was also carried out through GaussView 5.0.9 and Gaussian09 software. Molecular Electrostatic Potential (MEP) and Highest Occupied Molecular Orbital-Lowest Unoccupied Molecular Orbital (HOMO-LUMO) were also illustrated.
    Matched MeSH terms: Magnetic Resonance Spectroscopy
  5. Preparation of Spectroscopy Study on Organistannum (IV) Compound with Dicarboxylic Acids
    Yip FW, Yang Farina, Ibrahim Baba, Abdul Hamid Othman
    Sains Malaysiana, 2004;33.
    Organostannum(IV) complexes derived from dicarboxylic acids have been successfully synthesised from triphenylstannum(IV) hydroxide (Ph3SnOH). The complexes were obtained by refluxing Ph3SnOH and the respective dicarboxylic acids (malonic, succinic, glutaric and adipic acids) using a Dean and Stark apparatus in the appropriate solvent. The free ligands and complexes were characterised by C, Hand Sn elemental analysis and spectroscopic methods such as infrared and nuclear magnetic resonance (1H, 13C NMR). Structure determination of triphenylstannum(IV) succinate, 2, showed that each dicarboxylate anion was bonded monodentatically to two triphenylstannum(IV) moieties. The geometry surrounding each stannum atom is close to a tetrahedron. Spectroscopic data obtained for all complexes were found to be similar and thus it may be concluded that all complexes have the same structure as 2.
    Matched MeSH terms: Carbon-13 Magnetic Resonance Spectroscopy
  6. Synthesis and characterization of some diorganotin(IV) complexes of 2,3-dihydroxybenzaldehyde N(4)-substituted thiosemicarbazone
    Swesi AT, Yang Farina, Ibrahim Baba
    Sains Malaysiana, 2007;36:21-26.
    Organotin compounds especially the dialkyltin derivatives are reported to possess anti-tumour properties. The diorganotin(IV) complexes of the type Me2SnL1, Me2SnL2, Bu2SnL1, Bu2SnL2 and Ph2SnL1 (L1 and L2 is the anion of the thiosemicarbazone ligand formed by the condensation reaction of 2,3-dihydroxybenzaldehyde with thiosemicarbazide or its N(4)-methyl substituent) were synthesized using 1:1 metal-to-ligand reactant ratios. The newly synthesized complexes were characterized using elemental analysis, infrared and nuclear magnetic resonance (1H, 13C, 119Sn) spectroscopic techniques. Complex formation between the organotin(IV) moiety and the anions of 2,3-dihydroxybenzaldehyde thiosemicarbazone and 2,3-dihydroxybenzaldehyde 4-methylthiosemicarbazone occurred with chelation at the o-dihydroxy positions. The complexes are proposed to have tetrahedral geometry.
    Matched MeSH terms: Magnetic Resonance Spectroscopy
  7. Optimization of microencapsulation process for self-healing polymeric material
    Then S, Gan SN, Noor Hayaty Abu Kasim
    Sains Malaysiana, 2011;40:1179-1186.
    A series of poly(urea-formaldehyde) (PUF) microcapsules filled with dicyclopentadiene (DCPD) was successfully prepared by in situ polymerization. The effect of diverse process parameters and ingredients on the morphology of the microcapsules was observed by SEM, optical microscopy (OM) and digital microscopy. Different techniques for the characterization of the chemical structure and the core content were considered such as FT-IR and 1H-NMR as well as the characterization of thermal properties by DSC. High yields of free flowing powder of spherical microcapsules were produced. The synthesized microcapsules can be incorporated into another polymeric host material. In the event the host material cracks due to excessive stress or strong impact, the microcapsules would rupture to release the DCPD, which could polymerize to repair the crack.
    Matched MeSH terms: Proton Magnetic Resonance Spectroscopy
  8. Synthesis of dipeptide benzoylalanylglycine methyl ester and corrosion inhibitor evaluation by tafel equation
    Abdurrahman J, Wahyuningrum D, Achmad S, Bundjali B
    Sains Malaysiana, 2011;40.
    Corrosion is one of the major problems in petroleum mining and processing industry. The pipelines used to transport crude oil from reservoir to the processing installation were made from carbon steel that is susceptible towards corrosion. One of the best methods to prevent corrosion that occurred at the inner parts of carbon steel pipelines is to use organic corrosion inhibitor. One of the potent organic corrosion inhibitors is amino acids derivatives. In this study, dipeptide compound namely benzoylalanylglycine methyl ester and benzoylalanylglycine have been synthesized. The structure elucidation of the products was performed by IR, MS and NMR spectroscopy. The determination of corrosion inhibition activity utilized the Tafel method. The corrosion inhibition efficiency of glycine methyl ester, benzoylalanine, dipeptide benzoylalanylglycine methyl ester and dipeptide benzoylalanylglycine were 63.34%, 35.86%, 68.40% and 27.72%, respectively. These results showed that the formation of dipeptide benzoylalanylglycine methyl ester, derived from carboxylic protected glycine and amine protected alanine, increased the corrosion inhibition activity due to the loss of acidity center in the structure of glicine and L-alanine that would induce the corrosive environment towards carbon steel.
    Matched MeSH terms: Magnetic Resonance Spectroscopy
  9. Fulltext Fluid-solid phase transition of n-alkane mixtures: Coarse-grained molecular dynamics simulations and diffusion-ordered spectroscopy nuclear magnetic resonance
    Shahruddin S, Jiménez-Serratos G, Britovsek GJP, Matar OK, Müller EA
    Sci Rep, 2019 Jan 30;9(1):1002.
    PMID: 30700804 DOI: 10.1038/s41598-018-37799-7
    Wax appearance temperature (WAT), defined as the temperature at which the first solid paraffin crystal appears in a crude oil, is one of the key flow assurance indicators in the oil industry. Although there are several commonly-used experimental techniques to determine WAT, none provides unambiguous molecular-level information to characterize the phase transition between the homogeneous fluid and the underlying solid phase. Molecular Dynamics (MD) simulations employing the statistical associating fluid theory (SAFT) force field are used to interrogate the incipient solidification states of models for long-chain alkanes cooled from a melt to an arrested state. We monitor the phase change of pure long chain n-alkanes: tetracosane (C24H50) and triacontane (C30H62), and an 8-component surrogate n-alkane mixture (C12-C33) built upon the compositional information of a waxy crude. Comparison to Diffusion Ordered Spectroscopy Nuclear Magnetic Resonance (DOSY NMR) results allows the assessment of the limitations of the coarse-grained models proposed. We show that upon approach to freezing, the heavier components restrict their motion first while the lighter ones retain their mobility and help fluidize the mixture. We further demonstrate that upon sub-cooling of long n-alkane fluids and mixtures, a discontinuity arises in the slope of the self-diffusion coefficient with decreasing temperature, which can be employed as a marker for the appearance of an arrested state commensurate with conventional WAT measurements.
    Matched MeSH terms: Magnetic Resonance Spectroscopy
  10. Experimental and DFT investigation on the influence of electron donour/acceptor on the hydrogen bonding interactions of 1-(1,3-benzothiazol-2-yl)-3-(r-benzoylthiourea)
    Wun FML, Muhd Hafizi Zainal, Syahidah Mohd Tahir, Ishak B. Ahmad, Mohammad B. Kassim
    Sains Malaysiana, 2018;47:923-929.
    The presence of two different chromophores in benzothiazole molecule namely benzothiazole and aromatic rings lead to
    interesting chemical and biological properties that attract more researches on the compounds. Three new benzothiazolylbenzoythiourea
    compounds namely 1-(1,3-benzothiazol-2-yl)-3-(benzoylthiourea) (BBT), 1-(1,3-benzothiazol-2-yl)-3-
    (4-chlorobenzoylthiourea) (BBT-4Cl) and 1-(1,3-benzothiazol-2-yl)-3-(4-methoxybenzoylthiourea) (BBT-4OCH3
    ) with
    different electron withdrawing substituents (R) at the para positions on the benzene ring of benzoylthiourea ring have
    been synthesized from the reaction of R-benzoyl isothiocyanate (R= H, Cl, and OCH3
    ) and 2-aminobenzothiazole. The
    compounds were characterized by spectroscopic techniques (infrared, 1
    H proton NMR and UV-Vis). The IR spectra showed
    the frequency signals of n (C=O), n (C=S), n (N-H) at 1664-1673, 1238-1249 and 3031-3055 cm-1, respectively. The 1
    H
    proton NMR spectra showed the presence of N-H amine and amide signals in the region of (12.14-12.35) and (14.17-14.43)
    ppm, respectively. The proton signals of the two benzothiazole and benzoylthiourea moieties appear at 7.08-8.16 ppm.
    A theoretical study based on Density Functional Theory (DFT) and Time-Dependent (TD) DFT was conducted to optimize
    the geometrical structure and investigate the electronic properties of title compounds. The highest occupied molecular
    orbital (HOMO) was found on the benzothiazole moiety; while, the lowest-unoccupied molecular orbital (LUMO) was
    located at the benzoylthiourea fragment. The DFT optimized structures possessed an intramolecular hydrogen bonding
    and the types of para substituents used influenced the properties of hydrogen bonding.
    Matched MeSH terms: Magnetic Resonance Spectroscopy
  11. Fulltext A Novel Hydrazinecarbothioamide as a Potential Corrosion Inhibitor for Mild Steel in HCl
    Al-Amiery AA, Kadhum AAH, Mohamad AB, Junaedi S
    Materials (Basel), 2013 Apr 02;6(4):1420-1431.
    PMID: 28809218 DOI: 10.3390/ma6041420
    2-(1-methyl-4-((E)-(2-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-ylidene)-hydrazineecarbothioamide (HCB) was synthesized as a corrosion inhibitor from the reaction of 4-aminoantipyrine, thiosemicarbazide and 2-methylbenzaldehyde. The corrosion inhibitory effects of HCB on mild steel in 1.0 M HCl were investigated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The results showed that HCB inhibited mild steel corrosion in acidic solution and inhibition efficiency increased with an increase in the concentration of the inhibitor. The inhibition efficiency was up to 96.5% at 5.0 mM. Changes in the impedance parameters suggested that HCB adsorbed on the surface of mild steel, leading to the formation of a protective film. The novel corrosion inhibitor synthesized in the present study was characterized using Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectral data.
    Matched MeSH terms: Magnetic Resonance Spectroscopy
  12. Fulltext Continuous Monitoring of the Hydration Behavior of Hydrophilic Matrix Tablets Using Time-Domain NMR
    Tsuji T, Ono T, Taguchi H, Leong KH, Hayashi Y, Kumada S, et al.
    Chem Pharm Bull (Tokyo), 2023;71(7):576-583.
    PMID: 37394606 DOI: 10.1248/cpb.c23-00214
    Time-domain NMR (TD-NMR) was used for continuous monitoring of the hydration behavior of hydrophilic matrix tablets. The model matrix tablets comprised high molecular weight polyethylene oxide (PEO), hydroxypropyl methylcellulose (HPMC), and polyethylene glycol (PEG). The model tablets were immersed in water. Their T2 relaxation curves were acquired by TD-NMR with solid-echo sequence. A curve-fitting analysis was conducted on the acquired T2 relaxation curves to identify the NMR signals corresponding to the nongelated core remaining in the samples. The amount of nongelated core was estimated from the NMR signal intensity. The estimated values were consistent with the experiment measurement values. Next, the model tablets immersed in water were monitored continuously using TD-NMR. The difference in hydration behaviors of the HPMC and PEO matrix tablets was then characterized fully. The nongelated core of the HPMC matrix tablets disappeared more slowly than that of the PEO matrix tablets. The behavior of HPMC was significantly affected by the PEG content in the tablets. It is suggested that the TD-NMR method has potential to be utilized to evaluate the gel layer properties, upon replacement of the immersion medium: purified (nondeuterated) water is replaced with heavy (deuterated) water. Finally, drug-containing matrix tablets were tested. Diltiazem hydrochloride (a highly water-soluble drug) was employed for this experiment. Reasonable in vitro drug dissolution profiles, which were in accordance with the results from TD-NMR experiments, were observed. We concluded that TD-NMR is a powerful tool to evaluate the hydration properties of hydrophilic matrix tablets.
    Matched MeSH terms: Magnetic Resonance Spectroscopy
  13. Fulltext Cardiac biomarkers in chronic kidney disease are independently associated with myocardial edema and diffuse fibrosis by cardiovascular magnetic resonance
    Arcari L, Engel J, Freiwald T, Zhou H, Zainal H, Gawor M, et al.
    J Cardiovasc Magn Reson, 2021 06 07;23(1):71.
    PMID: 34092229 DOI: 10.1186/s12968-021-00762-z
    BACKGROUND: High sensitivity cardiac troponin T (hs-cTnT) and NT-pro-brain natriuretic peptide (NT-pro BNP) are often elevated in chronic kidney disease (CKD) and associated with both cardiovascular remodeling and outcome. Relationship between these biomarkers and quantitative imaging measures of myocardial fibrosis and edema by T1 and T2 mapping remains unknown.

    METHODS: Consecutive patients with established CKD and estimated glomerular filtration rate (eGFR) 

    Matched MeSH terms: Magnetic Resonance Spectroscopy
  14. Fulltext Late Temporal Lobe Extensive Osteoradionecrosis Post Radiation for Nasopharyngeal Carcinoma: Case Series
    Tang CL, Kumar R, Toh CJ, Azura S, Tan GC, Gendeh BS
    Indian J Otolaryngol Head Neck Surg, 2017 Sep;69(3):409-414.
    PMID: 28929077 DOI: 10.1007/s12070-015-0909-5
    Osteoradionecrosis is one of the most serious complications of radiotherapy for nasopharyngeal carcinoma. We report three cases of osteoradionecrosis in temporal lobe who presented differently few years after completion of radiotherapy. Cranial magnetic resonance image showed lesions in temporal lobe either unilateral or bilateral with mass effect. One of the cases even showed disease progression few years after the initial diagnosis of osteoradionecrosis. Diagnosis of osteoradionecrosis for all three patients was confirmed by biopsy.
    Matched MeSH terms: Magnetic Resonance Spectroscopy
  15. Dihydropyrimidones: As novel class of β-glucuronidase inhibitors
    Ali F, Khan KM, Salar U, Iqbal S, Taha M, Ismail NH, et al.
    Bioorg Med Chem, 2016 08 15;24(16):3624-35.
    PMID: 27325448 DOI: 10.1016/j.bmc.2016.06.002
    Dihydropyrimidones 1-37 were synthesized via a 'one-pot' three component reaction according to well-known Biginelli reaction by utilizing Cu(NO3)2·3H2O as catalyst, and screened for their in vitro β-glucuronidase inhibitory activity. It is worth mentioning that amongst the active molecules, compounds 8 (IC50=28.16±.056μM), 9 (IC50=18.16±0.41μM), 10 (IC50=22.14±0.43μM), 13 (IC50=34.16±0.65μM), 14 (IC50=17.60±0.35μM), 15 (IC50=15.19±0.30μM), 16 (IC50=27.16±0.48μM), 17 (IC50=48.16±1.06μM), 22 (IC50=40.16±0.85μM), 23 (IC50=44.16±0.86μM), 24 (IC50=47.16±0.92μM), 25 (IC50=18.19±0.34μM), 26 (IC50=33.14±0.68μM), 27 (IC50=44.16±0.94μM), 28 (IC50=24.16±0.50μM), 29 (IC50=34.24±0.47μM), 31 (IC50=14.11±0.21μM) and 32 (IC50=9.38±0.15μM) found to be more potent than the standard d-saccharic acid 1,4-lactone (IC50=48.4±1.25μM). Molecular docking study was conducted to establish the structure-activity relationship (SAR) which demonstrated that a number of structural features of dihydropyrimidone derivatives were involved to exhibit the inhibitory potential. All compounds were characterized by spectroscopic techniques such as (1)H, (13)C NMR, EIMS and HREI-MS.
    Matched MeSH terms: Carbon-13 Magnetic Resonance Spectroscopy; Proton Magnetic Resonance Spectroscopy
  16. Fulltext Bioconversion of rebaudioside I from rebaudioside A
    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
  17. Investigation of interaction studies of cefpirome with ACE-inhibitors in various buffers
    Nawaz M, Arayne MS, Sultana N, Abbas HF
    Spectrochim Acta A Mol Biomol Spectrosc, 2015 Feb 25;137:1050-4.
    PMID: 25300038 DOI: 10.1016/j.saa.2014.08.152
    This work describes a RP-HPLC method for the determination and interaction studies of cefpirome with ACE-inhibitors (captopril, enalapril and lisinopril) in various buffers. The separation and interaction of cefpirome with ACE-inhibitors was achieved on a Purospher Star, C18 (5 μm, 250×4.6 mm) column. Mobile phase consisted of methanol: water (80:20, v/v, pH 3.3); however, for the separation of lisinopril, it was modified to methanol-water (40:60, v/v, pH 3.3) and pumped at a flow rate of 1 mL min(-1). In all cases, UV detection was performed at 225 nm. Interactions were carried out in physiological pH i.e., pH 1 (simulated gastric juice), 4 (simulated full stomach), 7.4 (blood pH) and 9 (simulated GI), drug contents were analyzed by reverse phase high performance liquid chromatography. Method was found linear in the concentration range of 1.0-50.0 μg mL(-1) with correlation coefficient (r(2)) of 0.999. Precision (RSD%) was less than 2.0%, indicating good precision of the method and accuracy was 98.0-100.0%. Furthermore, cefpirome-ACE-inhibitors' complexes were also synthesized and results were elucidated on the basis of FT-IR, and (1)H NMR. The interaction results show that these interactions are pH dependent and for the co-administration of cefpirome and ACE-inhibitors, a proper interval should be given.
    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods
  18. Fulltext New cholinesterase inhibitory constituents from Lonicera quinquelocularis
    Khan D, Khan HU, Khan F, Khan S, Badshah S, Khan AS, et al.
    PLoS One, 2014;9(4):e94952.
    PMID: 24733024 DOI: 10.1371/journal.pone.0094952
    A phytochemical investigation on the ethyl acetate soluble fraction of Lonicera quinquelocularis (whole plant) led to the first time isolation of one new phthalate; bis(7-acetoxy-2-ethyl-5-methylheptyl) phthalate (3) and two new benzoates; neopentyl-4-ethoxy-3, 5-bis (3-methyl-2-butenyl benzoate (4) and neopentyl-4-hydroxy-3, 5-bis (3-methyl-2-butenyl benzoate (5) along with two known compounds bis (2-ethylhexyl phthalate (1) and dioctyl phthalate (2). Their structures were established on the basis of spectroscopic analysis and by comparison with available data in the literature. All the compounds (1-5) were tested for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities in dose dependent manner. The IC50 (50% inhibitory effect) values of compounds 3 and 5 against AChE were 1.65 and 3.43 µM while the values obtained against BChE were 5.98 and 9.84 µM respectively. Compounds 2 and 4 showed weak inhibition profile.
    Matched MeSH terms: Carbon-13 Magnetic Resonance Spectroscopy; Proton Magnetic Resonance Spectroscopy
  19. Application of differential scanning calorimetry (DSC), HPLC and pNMR for interpretation primary crystallisation caused by combined low and high melting TAGs
    Saadi S, Ariffin AA, Ghazali HM, Miskandar MS, Boo HC, Abdulkarim SM
    Food Chem, 2012 May 1;132(1):603-12.
    PMID: 26434338 DOI: 10.1016/j.foodchem.2011.10.095
    The main goal of the present work was to assess the mechanism of crystallisation, more precisely the dominant component responsible for primary crystal formations and fat agglomerations. Therefore, DSC results exhibited significant effect on temperature transition; peak sharpness and enthalpy at palm stearin (PS) levels more than 40wt.%. HPLC data demonstrated slight reduction in the content of POO/OPO at PS levels less than 40wt.%, while the excessive addition of PS more than 40wt.% increased significantly PPO/POP content. The pNMR results showed significant drop in SFC for blends containing PS less than 40wt.%, resulting in low SFC less than 15% at body temperature (37°C). Moreover, the values of viscosity (η) and shear stress (τ) at PS levels over 40wt.% expressed excellent internal friction of the admixtures. All the data reported indicate that PPO/POP was the major component of primary nucleus developed. In part, the levels of PS should be less than 40wt.%, if these blends are designed to be used for margarine production.
    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods*
  20. Discrimination of three Pegaga (Centella) varieties and determination of growth-lighting effects on metabolites content based on the chemometry of 1H nuclear magnetic resonance spectroscopy
    H M, Khatib A, Shaari K, Abas F, Shitan M, Kneer R, et al.
    J Agric Food Chem, 2012 Jan 11;60(1):410-7.
    PMID: 22084897 DOI: 10.1021/jf200270y
    The metabolites of three species of Apiaceae, also known as Pegaga, were analyzed utilizing (1)H NMR spectroscopy and multivariate data analysis. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) resolved the species, Centella asiatica, Hydrocotyle bonariensis, and Hydrocotyle sibthorpioides, into three clusters. The saponins, asiaticoside and madecassoside, along with chlorogenic acids were the metabolites that contributed most to the separation. Furthermore, the effects of growth-lighting condition to metabolite contents were also investigated. The extracts of C. asiatica grown in full-day light exposure exhibited a stronger radical scavenging activity and contained more triterpenes (asiaticoside and madecassoside), flavonoids, and chlorogenic acids as compared to plants grown in 50% shade. This study established the potential of using a combination of (1)H NMR spectroscopy and multivariate data analyses in differentiating three closely related species and the effects of growth lighting, based on their metabolite contents and identification of the markers contributing to their differences.
    Matched MeSH terms: Magnetic Resonance Spectroscopy/methods*
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