Search Results (368)

This study aimed to quantitatively and qualitatively evaluate the content of carnosic acid (CA), 12-O-methyl-carnosic acid (12MCA), carnosol (CS), rosmanol (RO) and 7-O-methyl-epi-rosmanol (7MER) in 61 Lamiaceae plants growing in Greece, using ¹H-qNMR spectroscopy as a simple, rapid and direct method without sample deterioration. For this purpose, methanol extracts from 18 genera (e.g., Salvia, Mentha, Melissa, Ocimum) were analyzed using isolated and fully characterized metabolites, previously identified by our group, as standards. At least one of the target compounds was detected in 22 species, predominantly belonging to the genus Salvia. Notably, 7MER and RO were not detected in any extract. CA, CS and 12MCA were exclusively found in Salvia species, with S. somalensis, S. officinalis and S. fruticosa emerging as the richest sources of these diterpenes. Among them, S. somalensis showed the highest concentration of CA (>30 mg/g), while 12MCA was most abundant in S. microphylla. These results highlight Salvia as the most promising genus for the accumulation of bioactive abietane-type diterpenes. The implementation of ¹H-qNMR for such chemical profiling provides a reliable approach toward the phytochemical standardization of plant extracts, supporting their further use in nutraceutical or pharmaceutical formulations. Full article

This work systematically altered the molar ratio of CaO and MgO (R = [CaO]/[(CaO + MgO)], mol%) to elucidate the underlying mechanisms driving the observed changes in macroscopic properties. The results indicated that as CaO increasingly replaced MgO, the rise in the content of non-bridging oxygen led to the depolymerization of the glass structure. A quantitative analysis of Qⁿ units in the [SiO₄] tetrahedron using ²⁹Si MAS NMR revealed that a non-monotonic variation appeared when the Q⁴ unit reached a minimum at R = 0.7. Meanwhile, the chemical environment of aluminum also varies with the R, and the presence of high-coordinated aluminum species is observed when Ca²⁺ and Mg²⁺ ions coexist. In terms of overall performance, both density and molar volume exhibited a linear trend. However, thermal stability, viscosity, characteristic temperatures (including melting temperature, Littleton softening temperature, working point temperature, and glass transition temperature), and mechanical properties showed deviations from linearity. Additionally, four non-isothermal thermodynamics was employed to quantitatively assess the thermal stability of samples C-0.7 and C-1. The insights gained from this study will aid in the development of advanced glass materials with tailored properties for industrial applications. Full article

This work presents the synthesis, characterization and evaluation of physicochemical and biological properties of two new aminoporphyrazine derivatives bearing magnesium(II) cations in their cores and peripheral pyrrolyl groups. The synthesis was carried out in several stages, using classical methods and the Microwave-Assisted Organic Synthesis (MAOS) approach. The obtained compounds were characterized using spectral techniques: UV-Vis spectrophotometry, mass spectrometry, ¹H and ¹³C NMR spectroscopy. The porphyrazine derivatives were tested for their electrochemical properties (CV and DPV), which revealed four redox processes, of which in compound 7 positive shifts of oxidation potentials were observed, resulting from the presence of free phenolic hydroxyl groups. In spectroelectrochemical measurements, changes in UV-Vis spectra associated with the formation of positive-charged states were noted. Photophysical studies revealed the presence of characteristic absorption Q and Soret bands, low fluorescence quantum yields and small Stokes shifts. The efficiency of singlet oxygen generation (Φ_Δ) was higher for compound 6 (up to 0.06), but compound 7, despite its lower efficiency (0.02), was distinguished by a better biological activity profile. Toxicity tests using the Aliivibrio fischeri bacteria indicated the lower toxicity of 7 compared to 6. The most promising result was the strong photodynamic activity of porphyrazine 7 against the Methicillin-resistant Stapylococcus aureus (MRSA) strain, leading to a more-than-5.6-log decrease in viable counts after the colony forming units (CFU) after light irradiation. Compound 6 did not show any significant antibacterial activity. The obtained data indicate that porphyrazine 7 is a promising candidate for applications in photodynamic therapy of bacterial infections. Full article

Background/Objectives: An increasing number of apparently healthy individuals are adhering to a gluten-free lifestyle without any underlying medical indications, although the evidence for the health benefits in these individuals remains unclear. Although it has already been shown that a low- or gluten-free diet alters the gut microbiota, few studies have examined the effects of this diet on healthy subjects. Therefore, our aim was to evaluate whether and how a prolonged low-gluten diet impacts gut microbiota composition and function in healthy adults, bearing in mind its intimate link to the host’s health. Methods: Forty healthy volunteers habitually consuming a gluten-containing diet (HGD, high-gluten diet) were included in a randomised control trial consisting of two successive 8-week dietary intervention periods on a low-gluten diet (LGD). After each 8-week period, gut microbiota composition was assessed by 16S rRNA gene sequencing, molecular quantification by qPCR, and a cultural approach, while its metabolic capacity was evaluated through measuring faecal fermentative metabolites by ¹H NMR. Results: A prolonged period of LGD for 16 weeks reduced gut microbiota richness and decreased the relative abundance of bacterial species with previously reported potential health benefits such as Akkermansia muciniphila and Bifidobacterium sp. A decrease in certain plant cell wall polysaccharide-degrading species was also observed. While there was no major modification affecting the main short-chain fatty acid profiles, the concentration of the intermediate metabolite, ethanol, was increased in faecal samples. Conclusions: A 16-week LGD significantly altered both composition and metabolic production of the gut microbiota in healthy individuals, towards a more dysbiotic profile previously linked to adverse effects on the host’s health. Therefore, the evaluation of longer-term LDG would consolidate these results and enable a more in-depth examination of its impact on the host’s physiology, immunity, and metabolism. Full article

Glass curators often question how their treatments affect the long-term stability of historical glass. While damp cotton swabs are commonly used to remove surface salts and dust, the use of water remains controversial, particularly for heavily altered glass, due to concerns about worsening hydration. This study investigates the effect of water rinsing on an unstable soda-lime glass altered for six months (monoliths) and fifteen months (powders) at 35 °C and 85% relative humidity. Samples were then rinsed with Milli-Q water at 20 °C or 50 °C, and the monolithic glass was subsequently subjected to an additional 15 months of alteration under the same conditions. The glass surface was characterized by optical and scanning electron microscopy (SEM) as well as Raman spectroscopy to identify the nature of the salts. The evolution of the hydrated layer was assessed using transmission FTIR, Raman and solid-state NMR spectroscopies, ToF-SIMS, and thermogravimetric analysis (TGA). The results show that rinsing effectively removes surface salts—primarily sodium carbonate—and induces structural changes in the hydrated layer, promoting silicate network polymerization. Upon resuming alteration, rinsed monolithic samples exhibit no further degradation after the additional 15 months of alteration. These findings offer promising insights for conservation practices and may help curators refining their treatment strategies for altered glass. Full article

Retinoids are used in cosmetics as anti-aging ingredients, along with other substances. However, due to limitations in use (such as photodegradation), it seems necessary to look for retinoid alternatives to be applied in cosmetic products. Bakuchiol, a natural alternative of retinoids, isolated from Psolarea corylifolia, is one such compound. It has great cosmetic potential and its mechanism of action is not yet fully explored. From the point of view of the bioactive compound, it is also essential to develop a method for rapid quality control of cosmetic preparations containing bakuchiol. The aim of this study was to apply and compare methods for the quantification of bakuchiol in cosmetic products using UV-Vis, ¹H qNMR, and HPLC. The results show the possibility of using the ¹H NMR method in the routine quality control of cosmetics with bakuchiol because of its comparable results with HPLC analysis and significantly shorter analysis time. Full article

This study evaluated the in vitro anti-inflammatory activity of serotonin derivatives from safflower seed powder and elucidated their mechanism against ulcerative colitis using network pharmacology. Compounds were extracted and purified via silica gel column chromatography, Sephadex LH-20 and semi-preparative HPLC. Structural characterization employed NMR and UPLC-Q-TOF-MS/MS with literature comparisons. Anti-inflammatory efficacy was assessed in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Network pharmacology predicted targets, molecular docking analyzed binding interactions and molecular dynamics simulations assessed complex stability. Eleven serotonin derivatives were isolated; N-trans-Feruloyl-3,5-dihydroxyindolin-2-one (1) and Bufoserotonin A (2) were identified in safflower seed meal for the first time. Compounds 1, 3–7 and 10 significantly reduced inflammatory factors, with N-feruloyl serotonin (4, FS) showing the strongest activity. Mechanistic studies revealed FS targets key molecules (STAT3, EGFR, ESR1, PTGS2, NF-κB1, and JUN), modulating PI3K-Akt, MAPK and cancer-related pathways. Molecular dynamics simulations confirmed FS-EGFR complex stability. Thus, two novel derivatives were isolated and FS demonstrated significant anti-inflammatory and potential anti-ulcerative colitis effects through multi-target, multi-pathway synergy, providing a foundation for developing safflower seed meal therapeutics. Full article

L-thyroxine (T4) is an important hormone for diagnosing and evaluating thyroid function disorders. As outlined in ISO17511, having a certified reference material (CRM) is crucial for ensuring that the results of clinical tests are traceable to the SI-unit. This study employed two principal methods to evaluate the purity of T4, mass balance (MB) and quantitative nuclear magnetic resonance (qNMR), both of which are SI-traceable (International System of Units) approaches. The MB method involved a detailed analysis of impurities, including water, structurally related compounds, and volatile and non-volatile substances. A variety of techniques were employed to characterize T4 and its impurities, including liquid-phase tandem high-resolution mass spectrometry, ultraviolet spectrophotometry, infrared spectroscopy, and both ¹H-NMR and ¹³C-NMR. Additionally, impurities were quantified using Karl Fischer coulometric titration, ion chromatography, gas chromatography–mass spectrometry, and inductively coupled plasma–mass spectrometry. In qNMR, ethylparaben was used as the internal standard for direct value assignment. The results showed T4 purities of 94.92% and 94.88% for the MB and qNMR methods, respectively. The water content was determined to be 3.563% (n = 6), representing the highest impurity content. Ten structurally related organic impurities were successfully separated, and five of them were quantified. Ultimately, a purity of 94.90% was assigned to T4 CRM, with an expanded uncertainty of 0.34% (k = 2). Full article

This study introduces a newly synthesized Co(II) phthalocyanine complex (Co-Pc, 4) incorporating two (mercapto-terphenyl)thio-dione substituents, along with a detailed exploration of its structural, spectroscopic, and binding characteristics. The key precursor, 4-[(4′′-mercapto-[1,1′:4′,1′′-terphenyl]-4-yl)thio]phthalonitrile (compound 3), was first obtained and subsequently used to construct the phthalocyanine macrocycle through cyclotetramerization in the presence of cobalt and zinc salts under heat and vacuum in dimethylformamide. The resulting compounds (3 and 4) were characterized using a comprehensive array of analytical techniques, including elemental analysis, UV–Vis spectroscopy, FT-IR, ¹H-NMR, and Q-TOF mass spectrometry. Additionally, density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were employed to elucidate the electronic structure and geometrical features of Co-Pc 4, providing theoretical support for the experimental findings. The integration of theoretical and experimental findings provides in-depth insight into the electronic behavior and reactivity of compound 4, highlighting its promise as a candidate for photovoltaic applications. Further studies may investigate how structural modifications influence these properties, potentially leading to improved device performance. Full article

This study aims to identify the chemical structure and immunomodulatory activity of exopolysaccharides (EPSs) from Acetilactobacillus jinshanensis BJ01 and suggest its potential applications in the pharmaceutical field and as functional food additives. The EPS-1 produced by A. jinshanensis BJ01 was purified using column chromatography. The lyophilized powder obtained by vacuum freeze-drying was used for structural characterization and immunomodulatory activity analysis. Gel permeation chromatography (GPC) determined its molecular weight as 156.58 kDa. High-performance anion-exchange chromatography (HPAEC) identified that the EPS-1 is composed of mannose, xylose, and glucose. The structural characterization of EPS-1 by gas chromatography–mass spectrometry (GC-MS) and 1D/2D nuclear magnetic resonance (NMR) spectroscopy demonstrated that EPS-1 is primarily composed of α-D-Manp-(1→, →2,6)-α-D-Manp-(1→, →2)-α-D-Manp-(1→, and →3)-α-D-Manp-(1→. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) illustrated that EPS-1 exhibited a round, flake-like morphology. In vitro experiments with RAW264.7 macrophages demonstrated the high immunomodulatory activity of EPS-1. Significant upregulation of iNOS, IL-6, and TNF-α mRNA levels was confirmed by qRT-PCR (p < 0.05). Western blotting revealed that EPS-1 (6.25 μg/mL) induced phosphorylation of NF-κB (p65, IκBα) and MAPK (ERK) signaling proteins. This study provides the first structural and immunomodulatory characterization of an exopolysaccharide from A. jinshanensis BJ01, highlighting its potential as a novel immune adjuvant. Full article

Objectives: The aim of this study was to evaluate the impact of a novel antioxidant formulation (RE:PAIR, RP-25) containing CoQ10, alpha-lipoic acid, and Chaga extract on mitochondrial dysfunction and oxidative stress. To explore the activity of the formulation on neuronal cells, we explored cell metabolism and its activity as an antioxidant, using a combination of NMR-based metabolomics and UHPLC-HRMS analytical techniques. Methods: SH-SY5Y neuroblastoma cells were treated with RP-25, and cell viability was assessed via CCK-8 assay. Metabolomic profiles of the treated and untreated cells were analyzed by 1D-NMR, providing insights into both intracellular metabolites (endometabolome) and excreted metabolites (exometabolome). Additionally, a UHPLC-HRMS method was developed for quality control and analysis of the RP-25 formulation. Multivariate statistical approaches, including PLS-DA and volcano plot analyses, were used to identify key metabolic changes. Changes in mitochondrial membrane potential were assessed by means of TMRE assay, while radical oxygen species (ROS) were measured by means of the DCHF assay. Results: RP-25 treatment did not affect cell viability but significantly increased metabolic pathways, including amino acid biosynthesis, oxidative phosphorylation, and glycolysis. Higher levels of ATP, glutamate, tyrosine, and proline were observed in treated cells than in control cells, indicating enhanced cellular energy production, as also proved by the increased stability of the mitochondrial membrane after RP-25 treatment, an index of preserved mitochondrial functions. In support, the formulation RP-25 showed antioxidant activity when cells underwent peroxide oxygen stimulation. This effect was mainly due to the combination of Chaga, CoQ10, and ALA, main components of the RP25 formulation. Moreover, the analysis of enriched pathways highlighted that RP formulation influenced mitochondrial energy and oxidative stress response. Conclusions: RP-25 demonstrated biological activity in that it mitigated mitochondrial dysfunction and oxidative stress in neuronal cells, with potential implications in neuronal diseases associated with dysfunctional mitochondria. Full article

The interaction between cucurbit[8]uril (Q[8]) and the guest 1-methyl-4-(4-(1-methylpyridin-1-ium-4-yl)benzamido)pyridin-1-ium (PB²⁺) has been thoroughly investigated. Multiple techniques were employed, including ¹H NMR spectroscopy, mass spectrometry, isothermal titration calorimetry (ITC), UV–vis absorption spectrophotometry, and quantum chemistry calculations. The experimental results and calculation analysis have clearly shown that in aqueous solution, the host Q[8] preferentially encapsulates the phenylpyridinium salt moiety of the PB²⁺ guest within its hydrophobic cavity, forming a 1:2 inclusion complex. Full article

Biflavonoids are a unique subclass of dietary polyphenolic compounds known for their diverse bioactivities. Despite these benefits, these biflavonoids remain largely underexplored due to their limited natural availability and harsh conditions required for their synthesis, which restricts broader research and application in functional foods and nutraceuticals. To address this gap, we synthesized a library of rare biflavonoids using a radical–nucleophile coupling reaction previously reported by our group. The food grade coupling reaction under weakly alkaline water at room temperature led to isolation of 28 heterocoupled biflavones from 11 monomers, namely 3′,4′-dihydroxyflavone, 5,3′,4′-trihydroxyflavone, 6,3′,4′-trihydroxyflavone, 7,3′,4′-trihydroxyflavone, diosmetin, chrysin, acacetin, genistein, biochanin A, and wogonin. The structures of the dimers are characterized by nuclear magnetic resonance spectroscopy (NMR) and high-resolution mass spectroscopy (HRMS). In addition, we evaluated the antioxidant potential of these biflavones using a DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay and the DPPH value ranges between 0.75 to 1.82 mM of Trolox/mM of sample across the 28 synthesized dimers. Additionally, a three-dimensional quantitative structure–activity relationship (3D-QSAR) analysis was conducted to identify structural features associated with enhanced antioxidant activity. The partial least squares (PLS) regression QSAR model showed acceptable r² = 0.936 and q² = 0.869. Additionally, the average local ionization energy (ALIE), electrostatic potential (ESP), Fukui index (F-), and electron density (ED) were determined to identify the key structural moiety that was capable of donating electrons to neutralize reactive oxygen species. Full article

1,2,4-Oxadiazole derivatives containing anisic acid or cinnamic acid were designed and synthesized, which were expected to be an effective Succinate dehydrogenase (SDH) inhibitor, and their structures were characterized by ¹H NMR, ¹³C NMR, and ESI-MS. The antifungal activity of the compounds against plant pathogenic fungi was screened by the mycelial growth inhibition test in vitro. Compounds 4f and 4q showed significant antifungal activities against Rhizoctonia solani (R. solani), Fusarium graminearum (F. graminearum), Exserohilum turcicum (E. turcicum), Botrytis cinerea (B. cinerea), and Colletotrichum capsica (C. capsica). The EC₅₀ values of 4q were 38.88 μg/mL, 149.26 μg/mL, 228.99 μg/mL, and 41.67 μg/mL against R. solani, F. graminearum, E. turcicum, and C. capsica, respectively, and the EC₅₀ values of 4f were 12.68 μg/mL, 29.97 μg/mL, 29.14 μg/mL, and 8.81 μg/mL, respectively. Compound 4f was better than commercial carbendazim against Exserohilum turcicum. Compounds 4f and 4q showed an antifungal effect on C. capsica of capsicum in vivo. Molecular docking simulation showed that 4f and 4q interacted with the target protein through the hydrogen bond and hydrophobic interaction, in which 4q can form hydrogen bonds with TRP173 and ILE27 of SDH, and 4f had hydrogen bonds with TYR58, TRP173, and SER39. This also explains the possible mechanism of action between the inhibitor and target protein. Full article

Nuclear magnetic resonance (NMR) spectroscopy is a powerful analytical approach that enables both the structural determination and precise quantification of small molecules, such as metabolites. However, achieving precise quantification with NMR involves more than simply comparing integrals derived from NMR peaks to a concentration reference; quantitative NMR (qNMR) is a distinct and specialized application within the field. To obtain absolute quantitative results, spectra must be acquired under strict experimental conditions. Unfortunately, these acquisition parameters can be challenging to implement experimentally and often require trade-offs that compromise high throughput or practicality. In such situations, alternative strategies based on relative quantification and advanced software tools offer valuable solutions. This review aims to provide non-specialists with the key concepts and methodologies required for accurate NMR-based quantification in biomedical research, focusing on practical guidelines and experimental considerations. Unlike prior reviews, it prioritizes accessibility and practical implementation for researchers outside the field, emphasizing key experimental workflows and applications in biological and clinical studies. It clarifies the distinctions between absolute and relative concentration determinations and emphasizes the critical importance of sample preparation, pulse sequence selection, and rigorous control of experimental parameters. Recent technological advancements, such as high-field spectrometers and cryoprobes, have significantly enhanced the sensitivity and accuracy of NMR, enabling the reliable detection of low-concentration metabolites. Quantitative NMR thus offers critical potential in elucidating metabolic processes, supporting drug development, and aiding disease diagnosis. Full article