Search Results (183)

Pistacia terebinthus L. which has been traditionally used in diet and medicine, remains underexplored in Greece, particularly regarding its chemical composition and antioxidant activity. The current study aims to comparatively evaluate the chemical profile of cold-pressed terebinth fruit oils, obtained from wild trees growing in the Greek Island of Chios (North East Aegean Sea), harvested during three years (2019, 2020 and 2021). The oils’ lipid profile was dominated by oleic acid (C18:1 cis-9) (42–45%) followed by palmitic acid (C16:0) (24–30%) and linoleic acid (C18:2 cis-9,12) (19–22%). Their phenolic acid content, expressed as anacardic acids—known for their bioactive properties—was quantified via q-¹H-NMR and found to be markedly high (1.91–2.98 mmol/kg oil). Total phenolic content (TPC) of the fruit extract showed interesting high value (185.92 ± 2.61 mg GAE/g) accompanied by strong antioxidant activity (DPPH, exhibiting > 80% inhibition at a concentration of 100 µg/mL) which was positively correlated with TPC. Additionally, the fruits demonstrated a rich nutritional profile, particularly in crude fibers (38.9%) and essential minerals (K, Mg, and Zn), along with low sodium content, suggesting notable dietary benefits. The cold-pressed oil exhibited high lipid content and low specific extinction coefficients (K₂₃₂, K₂₇₀), indicating minimal oxidation and confirming the oil’s freshness. These findings highlight the potential of P. terebinthus fruit oil as a high-value functional raw material with nutritional and antioxidant properties. Comparable to olive oil in lipid quality, Greek turpentine fruit and oil could play a promising role towards further applications in the food, cosmetic and pharmaceutical sectors. Full article

Background: Theophylline, which is biologically important and found in tea, coffee, and cocoa beans, can be synthesized chemically or by direct extraction and concentration from natural sources. Theophylline derivatives have garnered attention in recent years for their potential therapeutic effects on Mycobacterium tuberculosis, antihistaminic, anti-inflammatory, and anticancer. Also, trifluoromethyl (CF₃) group has also been widely used in drug and agrochemical design. Methods: In this study, a series of new theophylline derivatives containing substituted trifluoromethyl and trifluoromethoxy groups were synthesized. The structures of these new compounds were confirmed by NMR, FT-IR, and elemental analyses. Additionally, the anticancer activities of the molecules were analyzed against VEGFR-2, CYP P450, and estrogen receptor by molecular docking method. Furthermore, in vitro biological effects of the compounds were comprehensively evaluated in cancer (A549 and HeLa) and normal (BEAS-2B) cells. Cell viability was assessed by MTT assay, and selectivity index (SI) values were calculated to determine tumor-specific toxicity. Results: N(7)-substituted theophyllines were prepared by the reaction of 1,3-dimethyl-3,7-dihydro-1H-purine-2,6-dione (theophylline) and trifluoromethyl substituted benzyl halide compounds. The synthesized N(7)-substituted theophyllines were obtained as white powder in high yield. The structure of synthesized compounds was confirmed by various spectroscopic techniques such as ¹H, ¹³C, ¹⁹F NMR, and FT-IR spectroscopy, and elemental analysis. The highest interaction was recorded as −5.69 kcal/mol for 3-CF₃ substituted against VEGFR-2 structure while the best binding affinity was determined for 4-OCF₃ substituted with −6.69 kcal/mol against Human Cytochrome P450 with in silico analysis. The in vitro anticancer activities of the molecules were also evaluated against A549 and HeLa cells, and displayed considerably higher cytotoxicity with 2-CF₃, 3-CF_3, and 4-CF₃ substituted molecules in Hela and A549 cell line. To elucidate the molecular mechanism, apoptosis-related gene expression changes were analyzed by RT-qPCR in A549 and HeLa cells treated with compound 2-CF₃. Significant upregulation of pro-apoptotic markers and downregulation of anti-apoptotic genes were observed. Consistently, ELISA-based quantification confirmed increased protein levels of Caspase-3, BAX, and Cytochrome C, and decreased BCL-2, validating the apoptotic mechanism at the protein level. Also, the antibacterial and antibiofilm activity details of the molecules were evaluated against DNA Gyrase, and SarA crystal structures by molecular docking method. The highest interaction was recorded as −5.56 kcal/mol for 2-CF₃ substituted with H-bonds with Asn46, Val71, Asp73, and Thr165 against DNA Gyrase crystal structure while 3-CF₃ substituted has the best binding affinity against SarA. The in vitro antimicrobial effects of the molecules were also evaluated. Conclusions: The synthesized molecules may provide insight into the development of potential therapeutic agents to the increasing antimicrobial resistance and biofilm-forming capacity of microorganisms. Additionally, compound 2-CF₃ substituted exhibited promising and selective anticancer activity through apoptosis induction, supported by gene and protein level evidence. Full article

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 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

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

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

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

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

The dynamic evolution of alkalinity during hydration/carbonation of CO₂-conditioned cements results in the formation of polymorphic hydrated calcium silicates (C-S-H), whose differences in carbon sequestration capacity have not been systematically investigated. However, the micro-nano structures and carbon sequestration capacities of C-S-H are controlled by the dynamic effects of pore solution alkalinity and Ca/Si. Accordingly, different alkalinity and Ca/Si were set to simulate the cement hydration environment for the synthesis of C-S-H, and tests such as thermogravimetric and ²⁹Si nuclear magnetic resonance (NMR) were used to investigate the effects and mechanisms of initial alkalinity and Ca/Si on the morphology of the synthesized C-S-H, the CO₂ uptake. The results showed that the C-S-H synthesized at pH 7.2–12.0 and Ca/Si ratio of 1.0–2.3 was in flocculated and acicular forms, which were well crystallized and dominated by Q², while its CO₂ uptake was positively correlated with Ca/Si. On the contrary, the synthesized C-S-H was poorly crystallized under the conditions of pH increasing to 13.5 and Ca/Si ratios of 1.0–2.3. With the increase in Ca/Si, the synthesized C-S-H evolved from Q²-dominated foil to Q¹-dominated porous structure, and its CO₂ uptake was non-positively correlated with Ca/Si. This was mainly related to the average pore diameter of C-S-H and its silica-oxygen tetrahedral structure. This was mainly related to the average pore diameter of C-S-H and its silica-oxygen tetrahedral structure. Full article

Objective: Peroxides in pharmaceutical products and excipients pose risks by oxidizing drug molecules, leading to potential toxicity and reduced efficacy. Accurate peroxide quantification is essential to ensure product safety and potency. This study explores the use of quantitative proton nuclear magnetic resonance (¹H qNMR) spectroscopy as a sensitive and specific method for quantifying peroxide levels in pharmaceutical excipients. Methods: ¹H qNMR spectroscopy was employed to measure peroxide levels down to 0.1 ppm in excipients, focusing on poly(vinylpyrrolidone) (PVP) and polyvinylpyrrolidone/vinyl acetate (PVPVA). Different grades and vendors were analyzed, and the impact of various manufacturing processes on hydrogen peroxide content was examined. Results: Peroxide levels varied among different grades of PVP and PVPVA, as well as between vendors. Furthermore, manufacturing processes influenced the hydrogen peroxide content in selected excipients. These variations highlight the importance of controlling peroxide levels in raw materials and during production. Conclusions: ¹H qNMR spectroscopy is a valuable tool for accurately quantifying peroxide levels in pharmaceutical excipients. The study emphasizes the need for regular monitoring of peroxide content to ensure the stability, quality, and safety of excipients and drug products. Accurate peroxide measurement can prevent oxidative degradation, preserving both the safety and efficacy of pharmaceutical formulations. Full article

New technology has opened opportunities for research and exploration of deep-water ecosystems, highlighting deep-sea coral reefs as a rich source of novel bioactive natural products. During our ongoing investigation of the chemodiversity of the Irish deep sea and the soft coral Anthothela grandiflora, we report 12 unreported cadinene-like functionalized sesquiterpenes, anthoteibinenes F–Q. The metabolites were isolated using both bioassay- and ¹H NMR-guided approaches. One-/two-dimensional NMR spectroscopy and high-resolution mass spectrometry were used for structure elucidation, while a combination of NOESY NMR experiments, GIAO NMR calculations coupled with DP4+ probabilities measures, and ECD comparisons were incorporated to propose relative and absolute configurations of the anthoteibinenes. The metabolites were screened against the Respiratory Syncytial Virus (RSV), ESKAPE pathogens, five Candida albicans strains, and one strain of C. auris. Full article

Nuclear magnetic resonance (NMR) spectroscopy is gaining prominence as a vital quantitative method for sample analysis, with significant progress being made in the investigation of heteronuclei like phosphorus, a key element in numerous physiological functions. This paper provides a comprehensive review of the principles, methodologies, and applications of quantitative ³¹P nuclear magnetic resonance (qNMR) spectroscopy. It begins with an introduction to the fundamental principles of NMR spectroscopy, highlighting the specific advantages of qNMR and the unique properties of the ³¹P nucleus, including its high natural abundance and broad chemical shift range. While ¹H qNMR is widely used, signal overlap in complex mixtures can limit its accuracy. Additionally, this work explores diverse applications of ³¹P qNMR across fields such as food analysis, pharmaceuticals, and biology, emphasizing its contributions to real-time drug quantification, metabolomics, and environmental analysis. A key advantage of ³¹P NMR is its ability to provide exclusive detection and direct quantification of phosphorus in phosphorus-containing compounds. The internal standard method is favored for its simplicity, as it avoids the need for calibration curves, while the external standard method is better suited for natural products with established reference materials. This review aims to consolidate the applied prospects of ³¹P qNMR, emphasizing its potential to expand the horizons of quantitative detection technologies and facilitate advancements in future research and practical applications. Full article