NMR Spectroscopy Research Articles

Discovery, Isolation, and Characterization of 23-Spirocholestane Derivatives as Novel Plant Root Growth Inhibitors from Ypsilandra thibetica.

In the present study, we first discovered that the 70% ethanol extract of Ypsilandra thibetica significantly inhibited Arabidopsis root growth. Through a bioactivity-guided strategy, 18 rare 23-spirocholestane derivatives (1-18), including 12 new ones (1-12), featuring a dioxane ring between C-24/C-23 of the aglycone moiety and C-1'/C-2' of the d-fucose ligand, were obtained from the strongest active elution fraction. Their structures were elucidated via a comprehensive method of MS and NMR spectroscopy, single-crystal X-ray diffraction, and chemical methods. Evaluation of their inhibitory effects of all isolates on Arabidopsis root growth revealed that 5/6, 3/4, 1, and 2 exhibited pronounced activity, with EC50 values of 6.89, 9.13, 18.01, and 26.83 μM, respectively. Then, a preliminary structure-activity relationship (SAR) analysis of these compounds was conducted. Furthermore, transcriptome data indicated that Arabidopsis responded to the stress caused by these bioactive compounds through the modulation of ethylene and auxin signaling pathways and the activation of various detoxification-related genes. Finally, the herbicidal evaluation showed that 3/4 and 5/6 significantly inhibited the root growth of Echinochloa crusgalli, while 3/4 remarkably suppressed the root growth of Lolium multiflorum. These findings highlight that 23-spirocholestane derivatives represent promising candidates for the development of new bioherbicides.

Organotin(IV) Alkoxides, Siloxides, and Related Stannoxanes. Characterisation and Thermogravimetric Studies.

A series of C,O-chelated organotin(IV) alkoxides, L2PhSnOtBu (4), L2PhSnOMe (6), L2Sn(OtBu)2 (11), and siloxides L2PhSnOSiPh3 (3), L2Sn(OSiPh3)2 (10) (L=[2-(CH2O)2CH]C6H4), was prepared by salt elimination reactions. They were obtained from the organotin(IV) iodides L2PhSnI (1) or L2SnI2 (2) upon reactions with tBuOK, MeONa or Ph3SiONa, respectively, in dry THF or methanol. Under non-inert conditions, compounds 4 and 6 undergo combined hydrolysis and condensation to give the hexaorganodistannoxane (L2PhSn)2O (5). The stannoxane 5 is easily hydrolysed to L2PhSnOH (7), which quickly converts back when heated. Basic hydrolysis of diiodide 2 produces the cyclic oxide (L2SnO)3 (8). Its reaction with an equimolar amount of Ph3SiONa gives only a mixture of the expected L2SnI(OSiPh3) (9), 10 and the precursor, 2. Yet, 8 shows a unique reactivity pattern when combine with m-tolyl boronic acid, affording stannaboroxane (L2SnO)2OB(m-tol) (12). All the isolated species were characterised in solution by NMR spectroscopy and mass spectrometry. The solid-state molecular structures of 1-5, 10-12 were established by single-crystal X-ray diffraction (XRD). Additionally, thermogravimetric analysis of 3-5, 8, 10, and 12 was conducted.

Exploring the anticancer potential of extracts and compounds from the heartwood of Cotinus coggygria Scop. wild growing in Serbia.

Cotinus coggygria has a long history of use in traditional medicine in Europe and Asia. The aim of study was to explore the cytotoxicity of extracts (EE-ethanol, MME-methylene chloride/methanol, and WE-water) and compounds (butin, butein, fisetin, sulfuretin, taxifolin, eriodictyol, fustin, cotinignan A, sulfuretin auronol, 3-O-methylepifustin, 3-O-methylfustin, and sitosterol-3-O-β-D-glucoside) isolated from C. coggygria. Mechanisms of anticancer effects of three extracts, butin, butein, and sulfuretin were examined. Compounds were isolated from the EE using silica gel column chromatography and semipreparative HPLC. Structure elucidation was performed using NMR spectroscopy. Cytotoxicity was evaluated using MTT assay. The effects on cell cycle and cell death were investigated by flow cytometry. The antimigration effects were examined by scratch assay, while expression of the MMP2, MMP9, and VEGFA were measured by quantitative real time PCR. The antioxidant effects were examined by flow cytometry. 3-O-methylepifustin, epitaxifolin, and sulfuretin auronol were found for the first time in C. coggygria. The extracts and compounds showed selective cytotoxicity against HeLa, MDA-MB-231, HL-60, K562, A375, PC-3, and DU 145 cells. HeLa cells were the most sensitive to the cytotoxicity of MME (IC50 value of 47.45µg/mL), while leukemia K562 and HL-60 cells were the most sensitive to the MME and EE (IC50 values in the range from 31.04 to 44.57µg/mL). Butein exerted strong cytotoxicity on HeLa, K562, and MDA-MB-231 cells (IC50 values of 8.66 µM, 13.91 µM, and 22.36 µM). EE, butin, butein, sulfuretin, and fisetin were highly selective against leukemia K562 cells when compared with normal fibroblasts MRC-5 (selectivity index: 4.01, 5.15, 6.17, 7.05, > 4.41, respectively). Butein and fisetin showed high selectivity in the cytotoxic activity against HeLa cells when compared with MRC-5 cells (selectivity index: 9.91 and > 6.61). Three extracts, butin, butein, and sulfuretin, initiated apoptosis in HeLa cells by activating caspase-8 and caspase-9. The extracts, butin, butein, and sulfuretin inhibited HeLa cell migration. EE, MME, butein, and sulfuretin exerted cytoprotective effects in normal fibroblasts. This research might suggest promising anticancer effects and underscores the need for additional research on C. coggygria extracts and compounds to assess their potential in cancer prevention and therapy.

Metal-Assisted Synthesis of Diverse Porphyrinoids by Cyclization of an N-Confused Thia-Pentapyrrane.

Oxidation of thia-pentapyrrane S-P4 with terminal β-linked pyrrole and thiophene units in the presence of various metal ions has been found to afford distinct porphyrinoids. Specifically, N-confused thiasapphyrin (1), Cu(III) norrole (2), neo-confused phlorin (3), and p-benzinorrole (4) were obtained, when S-P4 was oxidized with p-chloranil in acetonitrile in the presence of Ni2+, Cu2+, Cd2+, and Co2+, respectively. The structures of 1-4 have been clearly elucidated by NMR spectroscopy, HRMS, and X-ray crystal diffraction (for 2-4). This work indicates that the oxidative cyclization by linking highly reactive β-linked pyrrole unit with less reactive thiophene unit assisted by various metal ions shows great potential in the construction of various novel porphyrinoids.

Theoretical and Spectroscopic Analysis of Square-Planar Tellurium(II) and Selenium(II) Diphenyl Thiourea Complexes in p2 Electronic Configurations.

In this work, we performed a detailed mathematical ligand field theory analysis of square-planar (D4h) main group complexes in p2 electronic configurations, and the results were subsequently used to generate an energy-level correlation diagram. We synthesized the model p2 tellurium(II) diphenyl thiourea coordination complex for further spectroscopic investigation. Dissolution of TeO2 in concentrated HCl resulted in the formation of a [TeCl6]2- complex in acidic media, and subsequent addition of diphenyl thiourea resulted in the reduction of Te4+ to Te2+ (observed by 125Te NMR spectroscopy) and the formation of a cis-Te(dptu)2Cl2 complex, which was characterized by single-crystal X-ray diffraction (XRD). Using in situ optical/magnetic spectroscopy - specifically, UV-vis and magnetic circular dichroism (MCD) spectroscopy - we observed absorbance bands and polarized transitions consistent with the calculated p-orbital splitting in a square planar (D4h) ligand field. Using the results of our spectroscopic investigation, we generated a molecular orbital (M.O.) diagram for the cis-Te(dptu)2Cl2 complex. We then used the M.O. diagram, in conjunction with the energy level correlation diagram, to assign the electronic transitions observed in the spectra of the cis-Te(dptu)2Cl2 complex. The analogous selenium(II) complex, cis-Se(dptu)2Cl2, was used to elucidate the observed transitions with minimal contribution from spin-orbit coupling. Our work examined how in situ spectroscopy and complementary ligand field theory analysis can be used to elucidate the electronic structures of main group coordination complexes.

Jejupeptins A and B: Polyketide-Cyclic Peptide Hybrids with Anti-Corticosterone Activity from Streptomyces sp. KCB15JA151.

Two new polyketide-cyclic peptide hybrids jejupeptins A (1) and B (2), together with a known compound eurystatin B (3), were isolated from a culture of Streptomyces sp. KCB15JA151. The chemical structures of the compounds were elucidated using a combination of 1D and 2D NMR spectroscopy and DP4+ probability analyses. Comprehensive spectroscopic analysis revealed that 1 and 2 are the first examples of hybrid peptide-polyketides possessing an unprecedented 4-amino-3-hydroxymethyl-3-methyl-2-oxopentanoic acid moiety. A plausible biosynthetic pathway for these compounds was proposed. Biological evaluation demonstrated that compounds 1 and 2 exhibit protective effects against corticosterone-induced apoptosis and cellular oxidative stress without any associated cytotoxicity.

Continuous Delivery of Hyperpolarized Xenon-129 Gas Using a "Stopped-Flow" Clinical-Scale Cryogen-Free Hyperpolarizer.

In 2022, the FDA approved hyperpolarized (HP) 129Xe gas as an inhalable contrast agent for functional lung imaging. For clinical imaging, HP 129Xe is usually given as a bolus inhalation. However, for preclinical applications (e.g., pulmonary imaging in small rodents), the continuous delivery of HP 129Xe is greatly desired to enable MRI scanning under conditions of physiological continuous animal breathing patterns. Moreover, HP 129Xe gas can be utilized for other applications including materials science and bioanalytical chemistry, where a continuous flow of hyperpolarized gas through an NMR sample over several minutes is also desired for sensing of 129Xe inside an NMR spectrometer. 129Xe is often hyperpolarized using continuous-flow spin-exchange optical pumping, which employs a lean (1-2%) mixture of Xe and a carrier gas (e.g., He and N2). The low Xe concentration in the produced output reduces the NMR detection sensitivity, and thus, Xe cryo-collection is typically employed to achieve near-100% pure gas-phase Xe before administration to the sample or subject. However, the need for cryo-collection undermines a key advantage of continuous-flow production, i.e., the continuous flowing in a hyperpolarizer HP 129Xe gas is trapped inside the hyperpolarizer, and the produced HP 129Xe gas is released at once when the production cycle (30-60 min) is completed. An alternative HP 129Xe production technology employs a "stopped-flow" approach, where a batch of HP gas is hyperpolarized over time and quickly released from a hyperpolarizer. Here, a clinical-scale "stopped-flow" 129Xe hyperpolarizer was employed to hyperpolarize a 1.3 L-atm batch of 50:50 Xe:N2 gas mixture inside a glass cell with an ultralong lifetime of the HP 129Xe state (T1 > 2 h). The produced HP 129Xe gas was slowly delivered into a 5 mm NMR tube via PEEK tubing under a wide range of gas flow rates: 3-180 standard cubic centimeters per minute (sccm). The polarization of the gas ejected from the hyperpolarizer was quantified using in situ low-field NMR polarimetry and additionally verified using a 0.35 T clinical MRI scanner. Continuous-flow delivery of HP 129Xe was demonstrated for up to 15 min with a gas flow rate of 45-150 sccm over a 2.5-m length of PEEK tubing, suffering only small losses in 129Xe polarization. These observations are additionally supported by 129Xe relaxation measurements inside the PEEK tubing employed for gas delivery and the 5 mm NMR tube employed for polarimetry. 129Xe polarization of 16-19% was obtained in the delivered gas, starting with an "in-polarizer" 129Xe polarization of 19%. We envision that this method can be employed for on-demand cryogen-free delivery of hyperpolarized gas using "stopped-flow" 129Xe hyperpolarizers for a broad range of applications, from preclinical imaging to biosensors, and to spectroscopy of materials surfaces.

Otitiglycomycins A and B: Glycolipids from the Strain Nocardia otitidiscavarum 20S-13 with Antiviral Activity against Zika Virus.

The Zika virus (ZIKV), an emerging orthoflavivirus, presents a significant public health threat due to its rapid dissemination and association with severe neurological complications. The urgent need for effective antiviral agents has driven research into novel bioactive compounds derived from unique natural sources. Microorganisms inhabiting extreme environments are particularly promising for such discoveries due to their potential to produce unique metabolites. In this study, we explored microorganisms from the underexplored French Polynesian microbial mats known as "Kopara" to identify new bioactive natural products. Using a molecular networking-based dereplication strategy, we investigated various culture and extraction techniques of the strain Nocardia otitidiscaviarum 20-S13, leading to the discovery of two novel glycoglycerolipids, otitiglycomycins A and B (1 and 2). Structure elucidation of these compounds was achieved through NMR spectroscopy, X-ray crystallography, and TDDFT-specific rotation prediction. We found that otitiglycomycin A (1), but not otitiglycomycin B (2), suppresses ZIKV infection at non cytotoxic concentrations without effects on cell viability. Time-of-drug addition assays along with virus inactivation and binding assays demonstrated that 1 neutralizes ZIKV infectivity by preventing the virus from attaching to the host cell membrane.

Automated Investigation of Metal-ligand Interactions by a Newly Established Robotic Workflow for Titrations.

In this work, we present a new workflow to set up an automated platform for the investigation of metal complex formation in solutions. With the utilization of this robot titration platform, the generation of an abundancy of solvated metal complexes in differing coordination number is possible in a simple manner. The generated complexes can subsequently be sampled into differing vessels to examine them in detail. We present sampling for UV/Vis and NMR spectroscopy at chosen model systems, however, the platform can easily be adapted to provide samples for other techniques, e.g., for infrared spectroscopy.

Synthesis of [Ni23Se12X3(PEt3)10] (X = Br, I) via Post-synthetic Modification.

Treatment of [Ni23Se12Cl3(PEt3)10] (1-Cl) with excess Me3SiX (X = Br, I) results in formation of [Ni23Se12X3(PEt3)10] (X = Br, 1-Br; X = I, 1-I) in good yields. 1-Br and 1-I are exceptionally rare examples of atomically precise nickel nanoclusters (APNCs). Both 1-Br and 1-I were characterized by X-ray crystallography, NMR spectroscopy, and ESI-mass spectrometry. Both clusters feature a compact [Ni13]7+ kernel capped by a [Ni10(μ-Se)9X3]- shell. Cluster 1-Br could also be isolated cleanly using a bottom-up synthetic approach, via reaction of [Ni(1,5-cod)2] and PEt3 with SePEt3 and [NiBr2(PEt3)2]. Under these conditions, it could be isolated in 43% yield. In contrast, reaction of [Ni(1,5-cod)2] and PEt3 with SePEt3 and [NiI2(PEt3)2] results in formation of [Ni3(μ3-Se)2I2(PEt3)4] (2-I) as the only isolable product. These results highlight the challenges inherent in the bottom-up synthesis of Ni nanoclusters, and demonstrate the value of postsynthetic modification in the synthesis of 3d metal APNCs.

Isolation, Structure Elucidation and Biological Evaluation of Lomaiviticins F–H, Dimeric Benzofluorene Glycosides from Marine-Derived Micromonospora sp. Bacterium

The discovery of new natural products remains a cornerstone of therapeutic innovation, and effective analytical tools for rapid dereplication can significantly accelerate this process. Using Isotopic Fine Structure (IFS) mass spectrometry, we rapidly identified three new dimeric benzofluorene glycosides, lomaiviticins F–H (1–3), from a marine-derived Micromonospora sp. bacterium. These compounds were isolated and structurally elucidated through advanced spectroscopic techniques, including FT-ICR-MS and NMR. Lomaiviticins F–H exhibit unique structural features, notably the 4-O-methyl-l-angolosamine moieties, which differentiate them from previously known lomaiviticins A–E. The discovery of these compounds highlights distinct biosynthetic linkages within the lomaiviticin family, particularly the C2–C2′ conjoining bonds characteristic of the dimers. Compounds 1–3 were evaluated for in vitro cytotoxicity against a panel of human cancer cell lines; the resulting IC50 values confirmed that the dimeric diazofluorenes of lomaiviticins A and B are critical for anticancer activity. These findings emphasize the utility of IFS in expediting natural product discovery while providing valuable insights into structural and functional characterizations of bioactive compounds.

Ester polymers Synthesized by Azo dye

The current study included the preparation of azo compound (A4) from the aromatic amine reactant (2-aminobenzoate methyl) by the nitrification method and conjugation with pharmaceutical phenolic compounds (pyridoxine hydrochloride, ortho-vanillin, para-vanillin, and kojic acid). Then, the compound (A4) was converted into new ester polymers. By reacting it with succinic acid and apic acid. All compounds and polymers were then characterized by IR, UV-Vis, mass spectrometry and 1H NMR spectroscopy. The effect of pH was studied in the electronic absorption spectra of azo compounds (A4) in the visible region, in a range of wavelengths (470) nm, using different buffer solutions with different pH values.

Extreme Defect Tolerance for Electrochemical Intercalation in Wadsley-Roth Structures Demonstrated by Metastable NaNb7O18.

Careful control over the defect chemistry of crystalline compounds is typically critical to transport phenomena (ion, electron, phonon). In one-dimensional (1D) ion conductors, even small concentrations of defects in the diffusion pathway can be pernicious. Wadsley-Roth block phases are 1D ion conductors with high redox capacity and among the highest diffusivity of any battery electrode materials. The origin of their high-rate transport has been attributed to parallel tunnels that could impart defect tolerance, but direct evidence is limited. Herein, a new lithium-ion battery negative electrode material, NaNb7O18, is described that exhibits extreme defect tolerance. Multimodal characterization combining neutron diffraction, 23Na solid-state NMR spectroscopy, and DFT calculations reveals that more than half of the Na+ in NaNb7O18 is in diffusion tunnel-blocking cuboctahedral environments (similar to the perovskite A-site). Despite the high point-defect concentration, NaNb7O18 can reversibly lithiate to Li7NaNb7O18 and cycle 200 mAh·g-1 in 10 h and 100 mAh·g-1 in 3 min in large 4-23 μm (D10-D90) particles. Operando synchrotron diffraction shows an anisotropic and asymmetric lithiation/delithiation process with two first-order phase transitions including one with nearly zero volume change. LixNaNb7O18 also exhibits evidence for reversible Nb-Nb bond formation. From the same operando diffraction measurements, Nb-Nb distances between edge-sharing octahedra at the block peripheries vary from ca. 3.4 to 2.8 and back to 3.4 Å over one lithium insertion/extraction cycle, in quantitative agreement with the Nb-Nb bond formation charge storage mechanism recently proposed from the computational lithiation of several different Wadsley-Roth compounds.

Effect of Halogen Substitution on the Regioselective Deiodination of Thyroid Hormone Analogues by Deiodinase Mimics.

The deiodination of L-thyroxine (T4) by the three isoforms of selenium-containing iodothyronine deiodinases (DIOs) is an important process in the human body for the maintenance of the thyroid hormone homeostasis. Selenium compounds are known to mimic the function of DIO3 by catalyzing the 5-deiodination of T4 and a co-operative halogen and chalcogen bonding is responsible for their activity. The substitution of 4'-OH group of T4 by an electron withdrawing group not only alters the reactivity but also changes the regioselectivity of deiodination. However, the effect of other halogen atoms (F, Cl or Br) in place of iodine in T4 on the regioselectivity has not been explored. In this paper, we describe simple synthetic methodologies toward various halogen analogues of T4. We also show that 2D NMR spectroscopy can be used as a powerful tool to identify the location of various halogen substitutions on the phenolic or tyrosyl rings. The deiodination experiments with peri-substituted naphthalene diselenol reveal that the regioselectivity or specificity towards iodine atom is not altered upon introduction of more electronegative halogen atoms (F, Cl and Br), reinforcing the concept of halogen bonding in the deiodination reactions.

Structural Requirements of Synthetic Anionophores for Inorganic Phosphate and Phosphate Esters

AbstractThe transmembrane transport of anions is a promising application of synthetic anion receptors. Numerous anionophores have been developed for chloride over the past decades. Despite the biological relevance of phosphate and phosphate esters, very few reports on their transport by synthetic systems exist. Here we report a systematic study on the transport of diphenyl phosphate, phenyl phosphate, and inorganic phosphate by five different anionophores. The transport of these phosphates into liposomes was monitored by fluorescence spectroscopy, 31P NMR spectroscopy, and an ion selective electrode. The results of these experiments showed that diphenyl phosphate is readily transported by most chloride ionophores. The transport of phenyl phosphate is more challenging but can be enhanced by better shielding of the phosphate group. Inorganic phosphate is the most challenging to transport and this was achieved using a macrocyclic anionophore with eight preorganised H‐bond donors. These results pave the way for the development of anionophores for inorganic phosphate as well as phosphate esters.

MDN-0057 to MDN-0060, a Family of Broad-Spectrum Antibiotics against Gram-Negative Pathogens Produced by Ophiosphaerella korrae.

A novel family of antibiotics, MDN-0057 to MDN-0060 (1-4), was isolated from liquid cultures of the fungus Ophiosphaerella korrae. These compounds incorporate two isocyanide groups in their complex structures that were elucidated by extensive spectroscopic analyses, including HRESIMS, and 1D and 2D NMR experiments. The relative configurations were determined by using J-based configuration analyses and the interpretation of key NOESY correlations consistent with the existence of a major conformation in solution. Mosher ester derivatization analysis allowed the establishment of their absolute configurations. All four compounds displayed in vitro antibacterial activity with a broad spectrum against Gram-negative pathogens.

Porous nonwoven calendered fabrics (membranes) based on electrospun prepolymers of modified polyimides

AbstractThe article presents data on the method of obtaining porous nonwoven polyimide fabrics (membranes), their deformation and strength characteristics, heat resistance, and surface properties. The membranes are produced as a result of a multistep processing of copoly(urethane‐imides) prepolymers that includes the synthesis of copoly(urethane‐amiс acids) of a given chemical composition, the molding of nonwoven fabrics (mats) by electrodeposition of copoly(urethane‐amic acids), the compaction of the volumetric structure of electrodeposited nonwoven fabrics by calendering on hot rollers, the thermal cyclization (imidization) of amic acid units of copolymers during calendering to form imides, and the controlled selective thermal destruction of the urethane groups in the copolymers conditioning the transition from poly(urethane‐imides) to polyimides, which is accompanied by the formation of pores in nonwoven polyimide fabrics, resulting in porous polyimide webs with specific properties. In the synthesis of the polymers studied, polycaprolactone diol, 2,4‐toluene diisocyanate, 4,4′‐oxydianiline, pyromellitic dianhydride, and 3,3′,4,4′‐oxydiphthalic anhydride were used. The polymers were characterized using X‐ray, 1H NMR spectroscopy, thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, and scanning electron spectroscopy. The deformation and strength properties of the nonwoven polyimide fabrics were also determined. Chemical composition of the synthesized polymer systems and the conditions for creating porous polyimide nonwoven fabrics influence the physical properties of the resulting fabrics. Porous polyimide nonwoven fabrics hold promise for the development of advanced filtration materials with enhanced strength, heat resistance, and resistance to aggressive amide solvents, which could be used in the pharmaceutical and biotechnology industries. The nonwoven fabrics are based on copoly(urethane imides) in terms of dimethylformamide (DMF) permeability and phthalocyanine rejection with a diameter of 240 nm. The DMF permeability was 280 kg/m2 h bar, the phthalocyanine rejection was 98%.Highlights Nonwoven poly(urethane‐amic acid) materials were obtained by electrodeposition. Nonwovens were rolled at high temperatures and pressure. The materials were compacted and acquired the structure of poly(urethane‐imides). Porous polyimide materials were obtained by annealing poly(urethane‐imides). The obtained materials have the properties of ultrafiltration membranes.

The 31P Spectral Modulus (PSM) as an Assay of Metabolic Status

The phosphorus-31 (31P) spectral modulus (PSM) is a measure of the metabolic status of cells, tissues, and organs. The PSM can be calculated from 31P nuclear magnetic resonance (31P NMR) spectra obtained from cell, tissue, or organ preparations. These 31P NMR spectra can be a measure of intact living cells, tissues, or organs, or appropriate biochemical extracts of such preparations. The 31P NMR spectrum is comprised of signals derived from organophosphate metabolites that resonate from 10 δ to −25 δ on the phosphorus chemical shift δ scale. The PSM is the ratio of the high-energy phosphate to that of the low-energy phosphate spectral integrals. These integrals may be conveniently grouped into high-energy and low-energy spectral regions, respectively, into 31P chemical shifts located between −0.13 δ to −25 δ and between 10 δ to −0.13 δ. High-energy phosphates are typically described as providing the energy necessary for the activity of cellular metabolism; chemically, they contain one or more phosphate anhydride bonds. This study demonstrates that, (1) in general, the higher the metabolic activity, the higher the PSM, and (2) the modulus calculation does not require a highly resolved 31P spectrum and can be calculated solely from the integral. The PSM was calculated among cells, tissues, and organs considered normal, diseased, and stressed. In diseased (mean 1.29 ± 0.73) and stressed (mean 1.23 ± 0.75) cells, tissues, and organs, PSM values are typically low or low relative to normal cells, tissues, or organs (mean 1.65 ± 0.90), following time-course measurements, in dynamic decline. The PSM is useful in determining the metabolic status of cells, tissues, or organs and can be employed as a calculable numeric assay for determining health status statically or over time. Calculation of the PSM can be carried out with spectra of low signal-to-noise; it relies on the minimal resolution required to detect an integral curve having a clear spectral integral inflection point at ca. −0.13 δ. Detection of an integral curve alone enables the calculation of a PSM even at levels of phosphorus concentration so low as to prevent detection of the individual or groups of metabolites, such as with in vivo or ex vivo cell, tissue, or organ determinations. This study (1) presents the foundations and fundamentals of the PSM, a living index of tissue metabolic health, and (2) demonstrates the use of spectral scan analysis in opening new vistas of biology and medicine for measuring the metabolic status of stressed and diseased tissues at a range of detectable levels for monitoring therapeutic interventions.

Probing the Thermo-oxidative Degradation of Ethylene Vinyl Alcohol (EVOH) by Time-Resolved Rheology and NMR Spectroscopy

Probing the Thermo-oxidative Degradation of Ethylene Vinyl Alcohol (EVOH) by Time-Resolved Rheology and NMR Spectroscopy

New Si-containing heterocycles on the base of fenamic acid

New Si-containing heterocycles on the base of fenamic acid