NMR Technology Research Articles

Diverse Ring‐seco Limonoids from Munronia unifoliolata and Their Biological Activities

Comprehensive SummaryTwenty‐two new limonoids, mufolinoids A—V (1—22), including six rings A, B‐seco limonoids (1—6), twelve ring A‐seco limonoids (7—18), four ring‐intact limonoids (19—22), together with thirteen known compounds (23—35) were isolated from Munronia unifoliolata. Their structures including absolute configurations were elucidated by combination of NMR, HR‐MS, single‐crystal X‐ray diffraction and calculations of ECD and NMR technologies. Compounds 24, 25, 33, 34 could be significantly reversed the multidrug resistance of MCF‐7/doxorubicin (DOX) cells, and the reversal fold (RF) was much higher than that of positive drug Verapamil. Compounds 24, 28, and 29 exhibited significant anti‐inflammatory activity with the IC50 values in the range of 17.7—39.4 μmol/L. Furthermore, compound 29 could markedly inhibit the release of IL‐1β by inhibiting the initiation and assembly of NLRP3 inflammasome, which demonstrates the great potential of limonoids as an anti‐inflammatory agent.

Evaluation of double-tuned single-sided planar microcoils for the analysis of small 13 C enriched biological samples using 1 H-13 C 2D heteronuclear correlation NMR spectroscopy.

Microcoils provide a cost-effective approach to improve detection limits for mass-limited samples. Single-sided planar microcoils are advantageous in comparison to volume coils, in that the sample can simply be placed on top. However, the considerable drawback is that the RF field that is produced by the coil decreases with distance from the coil surface, which potentially limits more complex multi-pulse NMR pulse sequences. Unfortunately, 1 H NMR alone is not very informative for intact biological samples due to line broadening caused by magnetic susceptibility distortions, and 1 H-13 C 2D NMR correlations are required to provide the additional spectral dispersion for metabolic assignments in vivo or in situ. To our knowledge, double-tuned single-sided microcoils have not been applied for the 2D 1 H-13 C analysis of intact 13 C enriched biological samples. Questions include the following: Can 1 H-13 C 2D NMR be performed on single-sided planar microcoils? If so, do they still hold sensitivity advantages over conventional 5mm NMR technology for mass limited samples? Here, 2D 1 H-13 C HSQC, HMQC, and HETCOR variants were compared and then applied to 13 C enriched broccoli seeds and Daphnia magna (water fleas). Compared to 5mm NMR probes, the microcoils showed a sixfold improvement in mass sensitivity (albeit only for a small localized region) and allowed for the identification of metabolites in a single intact D. magna for the first time. Single-sided planar microcoils show practical benefit for 1 H-13 C NMR of intact biological samples, if localized information within ~0.7mm of the 1mm I.D. planar microcoil surface is of specific interest.

Associations of circulating polyunsaturated fatty acids with coronary artery calcium score in hospitalized patients with suspected coronary artery disease

Abstract Background Inadequate intake of polyunsaturated fatty acids (PUFAs) is recognized as a modifiable risk factor for atherosclerotic cardiovascular disease (CVD) (1,2). The n-6 PUFA linoleic acid (LA) constitutes the predominant portion of total dietary PUFAs (3). However, whereas cardiometabolic effects of PUFAs belonging to the n-3 series have been studied for decades, less attention has been payed to potential health effects from n-6 PUFAs (4). Further, there has been concern regarding possible proinflammatory properties of several n-6 PUFA related metabolites. Purpose We explored correlations of serum total PUFAs, LA and the n-3 PUFA docosahexaenoic acid (DHA) with the inflammation marker GlycA. Further, we evaluated associations of total PUFAs, LA and DHA with the extension of atherosclerosis, as determined by the Agatston coronary artery calcium (CAC) score (5). Methods The study includes 250 patients who were hospitalized due to acute chest pain and referred to coronary CT angiography (CCTA) during in hospital stay. Exclusion criteria included diagnosis of acute myocardial infarction and/or revascularization within 24 hours after admittance. Serum levels of total PUFAs, LA, DHA and GlycA were analyzed by NMR technology in samples that had been frozen and stored at −80°C. After logarithmic transformation, relations of total PUFA, LA, and DHA with GlycA were evaluated by Pearson correlation analyses. The associations with CAC score were visualized in generalized additive regression plots and further evaluated in linear regression models including age, gender, body mass index, diabetes, hypertension and smoking status as independent covariables. Results Mean (SD) age was 57.6 (12.0) years, and 91 (36.4%) of the patients were women. Median (25th-75th percentiles) serum levels (in mmol/L) were for total PUFA 6.36 (5.76–7.06), LA 5.00 (4.51–5.55), DHA 0.36 (0.31–0.43) and GlycA 1.04 (0.94–1.13). Interestingly, GlycA was strongly, positively correlated with total PUFA (r=0.54). LA (r=0.53) and DHA (r=0.27), all P<0.001. In contrast, total PUFA and LA were inversely associated with CAC score both providing standardized betas of −0.17, P=0.03 after multivariable adjustments. No significant associations were found between CAC score and DHA or GlycA (P≥0.22). Further, the addition of GlycA to the multivariable model did not materially affect the relationship between CAC score and total PUFA or LA, which remained statistically significant (P=0.04). Conclusion In patients undergoing CCTA due to acute chest pain, serum levels of total PUFA and LA were strongly positively correlated with the pro-inflammatory marker GlycA. Still, total PUFA and LA were both inversely associated with the CAC score and the associations remained statistically significant after adjustments for CVD risk factors and GlycA levels. Future studies should further address the diverse effects of n-6 PUFAs on inflammatory pathways, atherogenesis and coronary calcification. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): Western Norway Regional Health Authority

Soluble poly(aryl piperidinium) with extended aromatic segments as anion exchange membranes for alkaline fuel cells and water electrolysis

Superacid-catalyzed polymerization of N-methyl-4-piperidone and aromatic hydrocarbons followed by quaternization is regarded as a reliable synthetic pathway to prepare anion exchange membrane (AEM) materials with superior conductivity and excellent alkaline stability, which is crucial for their application in alkaline fuel cells and alkaline water electrolysers. In this work, we design and prepare soluble p-quaterphenyl-containing poly(aryl piperidinium) (PQP-100) to increase the rigidity and hydrophobicity of aryl ether-free polymer backbones. Consequently, robust PQP-100 AEM exhibits improved microphase-separated morphology as conformed by SAXS and AFM observation. In comparison with biphenyl and p-terphenyl-based poly(aryl piperidinium), PQP-100 AEM possesses high hydroxide conductivity (118.72 mS/cm at 80 °C) and ability to be fabricated ultrathin membrane up to 4 μm without reinforcement. 75% of original conductivity is maintained for PQP-100 membrane after 1344 h of alkaline stability test in 1 M NaOH at 80 °C due to the degradation of piperidiniums via nucleophilic substitution. The practical device performance of PQP-100 membrane shows a peak power density (PPD) of 496 mW/cm2 in H2/O2 fuel cells at 60 °C and a current density of 1544 mA/cm2 at 2.0 V in alkaline water electrolysers circulating 1 M KOH at 85 °C, and the thinner membranes reduce the output of both fuel cells and electrolysers. Moreover, the durability of fuel cell and electrolyser at 200 mA/cm2 also manifest the performance loss over 85 and 402 h of operation, mainly attributed to the chemical degradation of PQP-100 membrane as evidenced by post-cell analysis using NMR technology.

Interactions between PAMAM-NH2 and 6-Mercaptopurine: Qualitative and Quantitative NMR studies.

Despite being used as an anti-leukemic drug, the poor solubility of 6-mercaptopurine (6-MP) limits its use in topical and parenteral applications. Dendrimers are commonly used as drug carriers to improve their solubility in aqueous solution. In this work, the interactions between 6-MP and the amine-terminated poly(amidoamine) dendrimers (PAMAM-NH2 ) were investigated by various NMR technology. The chemical shift titrations disclosed that the 6-MP interacted with the surface of PAMAM-NH2 mainly through electrostatics. The determination of diffusion coefficient and relaxation measurements further confirmed the presence of interactions in 6-MP/PAMAM-NH2 complexes. In addition, the encapsulation of 6-MP within the cavity of PAMAM-NH2 was revealed through nuclear Overhauser effect spectroscopy and Saturation Transfer Double Difference analysis. Finally, the binding strength (H-8 is 100% and H-2 is 70%) of 6-MP to PAMAM-NH2 was quantitatively expressed using epitope maps. This study provides a systematic methodology for qualitative and quantitative studies of the interactions between dendrimers and drug molecules in general.

Solid State NMR Investigation for Molecular States of Specialized Formulation to Improve the Water Solubility of Poorly Water-soluble Drugs

70-90% of recently developed new drug candidates are poorly soluble in water, which creates a series of thorny challenges in developing its oral dosage forms, resulting in low bioavailability. In pre-formulation study, various specialized formulations have been developed to improve drug solubility. Intermolecular interactions between drug and excipients in the formulations can modify the drug state and achieve the improvement of drug solubility. Therefore, the understanding of intermolecular interaction is essential to design formulations with higher quality and to assure the quality as a pharmaceutical product. Solid-state NMR has attracted much attention as a promising method to evaluate the molecular state of a drug and the interaction between a drug and excipient in its formulation. I have applied solid-state NMR and its characteristic technique, namely magic-angle spinning (MAS), for various specialized formulations including amorphous solid dispersion, supersaturated solution, drug-loaded organic nanotube, and drug nanosuspension. The intermolecular interactions of drug and excipient in amorphous solid dispersion have been identified by 13C and 15N solid-state NMR. High-resolution MAS determined the interaction modes of drug and excipient in a supersaturated solution. The two-step dissolution profile of drug from organic nanotube was understood, based on the molecular states revealed by the combination of various solid-state NMR techniques. A suspended-state NMR clarified the nanostructure of drug nanoparticles dispersed in water. It is expected that more qualified pharmaceutical formulations with improved drug solubility can be designed based on the remarkable development of recent solid-state NMR technology.

Plasma metabolite changes in anestrous dairy cows with negative energy balance identified using 1H NMR technology

ABSTRACT The objective of the present study was to investigate the different plasma metabolites between anestrus and estrus postpartum dairy cows and to provide a theoretical basis for prevention of anestrus in dairy farm cows. In the experiment, one hundred and sixty-seven Holstein dairy cows were selected with similar age and parity. According to the concentration of β-hydroxybutyric acid, non-esterified fatty acids and glucose in plasma during 14 to 21 days in milk, all dairy cows were determined as having a status of energy balance. According to the results of clinical symptom, rectal and B ultrasound examination at 60 to 90 days postpartum, these cows were divided into twenty estrus and twenty-four anestrus group, other dairy cows were removed. 1H nuclear magnetic resonance technology was utilized to detect the plasma metabolites changes and screen different plasma metabolites between anestrus and estrus cows. Ten different metabolites including alanine, glutamic acid, asparagine, creatine, choline, phosphocholine, glycerophosphocholine, low-density lipoprotein, and very-low-density lipoprotein were significantly decreased in anestrous cows compared with estrous cows. Metabolic pathway analyses indicated that differential metabolites were primarily involved in amino acid and glycerophospholipid metabolism. These metabolites and their enrichment pathways indicate that reduced steroid hormone synthesis precursors result in lower levels of estradiol and progesterone and cause anestrus in negative energy balance. These data provide a better understanding of the changes that may affect estrus of postpartum dairy cows at NEB status and lay the ground for further research.

Investigation on the stability in plant metabolomics with a special focus on freeze-thaw cycles: LC–MS and NMR analysis to Cassiae Semen (Cassia obtusifolia L.) seeds as a case study

Metabolomics is a rapid and sensitive tool for the detection of dynamic metabolic compositions in the study of systemic metabolic consequences. However, it is also susceptible to a tiny variation of pre-analytical handling procedures. To provide reproducible results, specific knowledge on metabolites perturbance along with different freeze-thaw cycles (FTCs) is needed for further metabolomics studies. In this paper, five FTCs of germinated Cassiae Semen (CS) were chosen as a case study to investigate the influence of FTC effect based on UHPLC-Q-Orbitrap-MS and NMR technologies. A total of 108 metabolites were relatively quantified by LC–MS and NMR analyses. Principal component analysis (PCA) showed that the first and second FTC samples are welly separated from the other groups; however, the extent of FTC-induced effects are smaller after the third cycle. Upon five consecutive FTCs, alterations which consisted of decreased stachyose, sucrose, norrubrofusarin-6-O-β-d-glucopyranoside, and quercetin 3-(3″-acetylgalactoside), as well as increased phenylalanine, leucine, isoleucine, methionine, phenylalanine, mannose, gluconic acid, and valine, could be observed. FTC does not exert the same effect on all metabolites. Although a large number of secondary metabolites were stable when subjected to five FTCs, FTC effects may lead to false-positive in the discovery of biomarker. In the case of reusing plant seed samples, no more than three consecutive freeze-thaw cycles were found advisable. This work provides unique perspectives on the FTC effects, which may fill in some existing gaps in the knowledge of the stability of plant metabolites during sample pre-handling.

The Nonlinear Creep Behaviors of Sandstone Under the Different Confining Pressures Based on NMR Technology

The Nonlinear Creep Behaviors of Sandstone Under the Different Confining Pressures Based on NMR Technology

A highly active and stable organic-inorganic combined solid acid for the transesterification of glycerol under mild conditions

Solid acid catalyst plays a crucial role in the petroleum refinery industry and bio-refinery technology. In this work, p-phenolsulfonic acid (PSA) was successfully grafted onto the surface of KH560-modified zirconium phosphate (K-ZrP) in a facile routine. The structure and property of this organic-inorganic combined solid acid PSA/K-ZrP-x were characterized via XRD, FTIR, 13C solid-state NMR, TG, N2 adsorption-desorption, SEM, pyridine-adsorption FTIR and XPS technologies. The characterization results showed that KH560 can bond with ZrP and promote the grafting of PSA on the surface of K-ZrP via the condensation reaction between its epoxy ring and the phenolic hydroxyl group in PSA. Consequently, PSA/K-ZrP-2 exhibited excellent performance and stability in the transesterification between glycerol and methyl acetate among the tested H3PW12O40, Amberlyst-45, HBEA, HZSM-5, ZrP, AlCl3 and FeCl3 catalysts. The calculated conversion of glycerol reached 81.3% with a 97.9% selectivity for monoacetin (MAG) and diacetin (DAG) with a 2.2% dosage of [H+] at 100 °C for 4 h. The highest specific activity of PSA/K-ZrP-2 reached 24028.2 mg-glycerol/g-cat/h in a short reaction time (at 0.17 h), and it could be recycled five times without obvious deactivation.

Using TD-NMR relaxometry and 1D 1H NMR spectroscopy to evaluate aging of Nellore beef

The aim of this study was to explore the use of TD-NMR relaxometry and 1H NMR spectroscopy-based for detecting differences in meat quality attributes. There was limited association between various TD-NMR signals and any physicochemical parameters of fresh and aged meat differing in tenderness ratings. Samples were then divided into three groups based on statistical changes in metabolite concentration. Group A samples possessed near linear increases in metabolite concentration over aging time; whereas samples assigned to Groups B and C were characterized by increases in metabolites that peaked between 7 and 14 days, and up to 14 days aging, respectively. 1H NMR spectroscopy discriminated meat quality using changes in metabolites reflective of glycolysis, the citric acid cycle, protein degradation, amino acid generation and purine metabolisms. These data suggest segregation of meat quality is possible using both NMR technologies but additional work is necessary to understand fully their utility in a commercial industry setting.

Inspecting Insulin Products Using Water Proton NMR. I. Noninvasive vs Invasive Inspection.

There is a clear need to transition from batch-level to vial/syringe/pen-level quality control of biologic drugs, such as insulin. This could be achieved only by noninvasive and quantitative inspection technologies that maintain the integrity of the drug product. Four insulin products for patient self-injection presented as prefilled pens have been noninvasively and quantitatively inspected using the water proton NMR technology. The inspection output is the water proton relaxation rate R2(1H2O), a continuous numerical variable rather than binary pass/fail. Ten pens of each product were inspected. R2(1H2O) displays insignificant variation among the 10 pens of each product, suggesting good insulin content uniformity in the inspected pens. It is also shown that transferring the insulin solution out of and then back into the insulin pen caused significant change in R2(1H2O), presumably due to exposure to O2 in air. Water proton NMR can noninvasively and quantitatively inspect insulin pens. wNMR can confirm product content uniformity, but not absolute content. Its sensitivity to sample transferring provides a way to detect drug product tampering. This opens the possibility of inspecting every pen/vial/syringe by manufacturers and end-users.

Fluorescence Spectroscopy and 13C NMR Spectroscopy Characteristics of HA in Black Soil at Different Corn Straw Returning Modes.

A three-year field experiment was conducted to analyze the effects of straw enrichment and deep incorporation on the humus composition and the structure of humic acid (HA) in black soil. The differences in the HA structure between different straw returning methods were detected by three-dimensional fluorescence spectroscopy and 13C NMR technology. The purpose of this paper is to provide a theoretical basis and data support for improving the straw returning system. Four different treatments, including no straw applied (CK), straw mulching (SCR), straw deep ploughing (MBR), and straw enrichment and deep incorporation (SEDI: harvested the corn straw from four rows together with a finger-plate rake and then crushed and buried them in one row in the 20∼40 cm deep level in the subsoil with a wind-driven input cylindrical plough), were used in this study. Our results showed that compared to CK treatment, SEDI significantly increased the contents of organic carbon (SOC), soil humic acid carbon (HAC), fulvic acid carbon (FAC), and humin C content (HM-C) in the subsurface soil layer by 27.47%, 34.33%, 19.66%, and 31.49%, respectively. Among all the straw returning treatments, SEDI treatment had the most significant effect in increasing the contents of HEC, HAC, and FAC. Straw returning not only reduced the degree of condensation and oxidation of the HA structure but also increased the proportion of alkyl C and enhanced the hydrophobicity of the HA structure in subsurface soil. Moreover, SEDI treatment significantly increased the proportion of aliphatic C/aromatic C of the HA structure in subsurface soil and improved the aliphatic property of HA, which had a significant effect on the HA structure compared to other treatments.

Conformational features and ionization states of Lys side chains in a protein studied using the stereo-array isotope labeling (SAIL) method.

Although both the hydrophobic aliphatic chain and hydrophilic -amino group of the Lys side chain presumably contribute to the structures and functions of proteins, the dual nature of the Lys residue has not been fully investigated using NMR spectroscopy, due to the lack of appropriate methods to acquire comprehensive information on its long consecutive methylene chain. We describe herein a robust strategy to address the current situation, using various isotope-aided NMR technologies. The feasibility of our approach is demonstrated for the PHS/V66K variant of staphylococcal nuclease (SNase), which contains 21Lys residues, including the engineered Lys-66 with an unusually low p of 5.6. All of the NMR signals for the 21Lys residues were sequentially and stereospecifically assigned using the stereo-array isotope-labeled Lys (SAIL-Lys), [U-C,N; ,,,-D]-Lys. The complete set of assigned H, C, and N NMR signals for the Lys side-chain moieties affords useful structural information. For example, the set includes the characteristic chemical shifts for the C, C, and N signals for Lys-66, which has the deprotonated -amino group, and the large upfield shifts for the H and C signals for the Lys-9, Lys-28, Lys-84, Lys-110, and Lys-133 side chains, which are indicative of nearby aromatic rings. The C and N chemical shifts of the SNase variant selectively labeled with either [-C;,-D]-Lys or SAIL-Lys, dissolved in HO and DO, showed that the deuterium-induced shifts for Lys-66 were substantially different from those of the other 20Lys residues. Namely, the deuterium-induced shifts of the C and N signals depend on the ionization states of the -amino group, i.e., 0.32 ppm for C [ND-NH] vs. 0.21 ppm for C [ND-NH] and 1.1 ppm for N[ND-NH] vs. 1.8 ppm for N[ND-NH]. Since the 1D C NMR spectrum of a protein selectively labeled with [-C;,-D]-Lys shows narrow ( 2 Hz) and well-dispersed C signals, the deuterium-induced shift difference of 0.11 ppm for the protonated and deprotonated -amino groups, which corresponds to 16.5 Hz at a field strength of 14 T (150 MHz for C), could be accurately measured. Although the isotope shift difference itself may not be absolutely decisive to distinguish the ionization state of the -amino group, the C, C, and N signals for a Lys residue with a deprotonated -amino group are likely to exhibit distinctive chemical shifts as compared to the normal residues with protonated -amino groups. Therefore, the isotope shifts would provide a useful auxiliary index for identifying Lys residues with deprotonated -amino groups at physiological pH levels.

Molecular recognition patterns between vitamin B12 and human serum albumin explored through STD–NMR and spectroscopic methods

Ligand–receptor molecular recognitionis the basis of biological process. The Saturation Transfer Difference–NMR (STD–NMR) technique has been recently used to gain qualitative and quantitative information about physiological interactions at atomic-resolution. The molecular recognition patterns between Vitamin B12 (VB12) and human serum albumin (HSA) were investigated by STD–NMR supplemented by other spectroscopies and molecular docking. STD–NMR delivered a complete picture that the substituent groups on the tetrapyrrole ring of VB12 interacted with site III of HSA through binding epitope mapping and competitive probe experiments. STD–NMR and fluorescence results proved the moderate binding capability of VB12 and clarified a static, spontaneous, and temperature-sensitive binding mechanism. 3D-fluorencence, FT-IR and circular dichroism spectra showed a compact protein structure by interacting with VB12. Size distribution and surface hydrophobicity showed the surface properties changes of HSA caused by the binding of VB12. Computer simulation confirmed the recognition mode in theory and was compared with experiments. This work is beneficial for understanding the safety and biological action of VB12, and will attract researchers interested in NMR technology.

Practical and Sustainable Modification Method on Activated Carbon to Improve the Decolorization Process in the Acetaminophen Pharmaceutical Industry.

Decolorization plays an important part in the industrial production of acetaminophen (APAP) drugs. The impurities generated from the APAP pharmaceutical industry decolorization refining process were primarily separated and purified, and their structures were determined by MS and 1H NMR technology. Then the catalytic effects of three samples of modified powdered activated carbon (PAC) on APAP in heterogeneous solution systems and the adsorption catalysis system were systematically investigated, which indicated that PAC catalyzed the APAP oxidative coupling side reaction and thus increased the impurities in the APAP product. The M-T-RAC (thermal regeneration PAC modified by ammonium sulfate) possessing more acidic surface groups can effectively inhibit this side reaction. Furthermore, according to the different catalytic results of O-T-RAC (thermal regeneration PAC modified by hydrogen peroxide) in solid–liquid catalytic and adsorption catalytic systems, we speculated that the multimer impurities were generated by the oxidative coupling reaction of APAP being oxidized to rated N-acetyl-p-benzoquinone (NAPQI) during decolorization, while free radical polymerization of APAP mainly occurred in the pores of the spent PAC. The pore textural structure and chemical properties of M-T-RAC were further characterized to ensure its feasibility of industrial application. The process of simulating industrial decolorization substantiated the excellent ability of M-T-RAC to inhibit side reactions. This study contributes to the development of green materials for sustainable recycling of activated carbon to reduce pollution and costs, and provides an effective advice for the pharmaceutical process.

Experimental and molecular docking investigation of the inclusion complexes between 20(S)-protopanaxatriol and four modified β-cyclodextrins

20(S)-Protopanaxatriol (PPT) is a type of ginsenoside isolated from panax notoginseng or ginseng, which is an essential ingredient in functional food, healthcare products and traditional medicine. However, the research and development of PPT are restricted due to its poor solubility. To circumvent the associated problems, a novel bridged-bis [6-(2,2’-(ethylenedioxy) bis (ethylamine))-6-deoxy-β-CD] (H4) was successfully synthesized. The four inclusion complexes of the mono-[6-(1,4-butanediamine)-6-deoxy-β-CD] (H1), mono-[6-(2,2’-(ethylenedioxy) bis (ethylamine)-6-deoxy-β-CD] (H2) and their corresponding bridged bis(β-CD)s (H3, H4) with PPT were prepared and studied by UV, 1H NMR, 2D ROESY, FT-IR, XRD and SEM technology. The UV-spectrometric titration showed that H1-4 and PPT formed 1:1 inclusion complexes and the binding constants were 297.61, 322.25, 937.88 and 1742 M−1, respectively. It was further revealed that the size/shape-matching relationship, hydrophobic interactions and hydrogen bond interactions play the crucial role in determining the stability of H1-4/PPT inclusion complexes. The solubility of PPT was evidently enhanced by193, 265, 453 and 593 times after the formation of inclusion complexes with H1-4, respectively. Furthermore, molecular docking was used to verify the inclusion mode of H4/PPT inclusion complex and also to investigate the stability of H4/PPT in water phase. The molecular simulation results agreed well with the experimental results. This research provides an effective way to obtain novel PPT-based functional food and healthcare products.

Study on the Microstructural Degradation Characteristics of Concrete-Rock Combination after Exposed to High Temperatures Using Nmr Technology

Study on the Microstructural Degradation Characteristics of Concrete-Rock Combination after Exposed to High Temperatures Using Nmr Technology

Mobile low field magnetic resonance hardware development

Typically, NMR systems are bulky and expensive laboratory based equipment. For half a century after its scientific discovery taking NMR outside of a laboratory environment is still not a common practice due to the complexity of the underlining physical phenomena and its low sensitivity, to the myriad of technical challenges when integrating a complete system. The scarcity of compact and mobile NMR systems has prevented its proliferation into many other areas and applications.This paper describes the progress in the development of compact electronic spectrometers that we coupled with handheld sensors in order to provide complete mobile solutions. The key to this progress has been the modern advances in computing, electronics and permanent magnet technologies. Mobile NMR is now feasible as a valuable, non-invasive tool for industrial and medical applications. By leveraging the strengths of NMR, which is to probe at the molecular level and gain information about molecular structure, organisation, abundance and orientation, NMR is intrinsically suitable for non-destructive testing of a wide range of materials and their manufacturing processes.The development of complete NMR systems benefits from working across various disciplines and organisations. By embracing a collaborative approach we believe it will accelerate NMR technology to become more ubiquitous in the near future.

Photorelease of Nitric Oxide in Water-Soluble Diruthenium Nitrosyl Complexes with Phosphonate Substituted Pyridylpyrrole

The diethylphosphonate ligand HL 1 substituted pyridylpyrrole was synthesized by treatment of 2-bromo-6-(1H'-pyrrol-2-yl)pyridine and diethylphosphite in presence of base triethylamine and catalyst Pd(PPh 3 ) 4 under refluxing toluene conditions. The HL 1 ligand was treated with bromotrimethylsilane and followed hydrolysis by methanol to afford diphosphonic acid ligand H 3 L 2 . Treatment of H 3 L 2 with [Ru(NO)Cl 3 ] in presence of triethylamine in refluxing thf was generated diruthenium nitrosyl complex [Ru(L 2 )(NO)(Cl)] 2 ·(Et 3 NH) 2 ([ 1 ]·(Et 3 NH) 2 ), which is water soluble. The ligands and metal complex were fully characterized by NMR, IR, ESI-MS and single crystal X-ray diffraction technology. The solid state structure analysis displays 1 2- is dinuclear species, of which two ruthenium atoms are linked by two PO 3 2- groups. Photorelease of nitric oxide from 1 2- was monitored by UV-Vis spectra and the amount of the NO was determined by Griess reaction and DPPH radical scavenging reaction.