Search Results (95)

In this study, we report the synthesis and characterization of Fe₃O₄ nanoparticles coated with dextran. The structural and optical properties of the Dx:Fe₃O₄ synthesized composites were investigated by Fourier Transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and UV–Vis absorption spectroscopy. For the first time in this paper, the photophysics of Dx:Fe₃O₄ composites in water is studied using fluorescence and phosphorescence molecular spectrometry. An analysis of the absorption spectra of the Dx:Fe₃O₄ composite reveals the broad absorption bands with maxima at wavelengths of 227 nm, 264 nm, and 340 nm. Dx:Fe₃O₄ composite nanoparticles in water exhibit strong fluorescence with a quantum yield of 0.24% in contrast to 0.07% for dextran. Phosphorescence spectra confirm the formation of new emission bands within the Dx:Fe₃O₄ solution evidenced by the maxima shift for both dextran and Dx:Fe₃O₄ composites. Full article

Hemocyanins are oxygen-transporting proteins found in crustaceans and other arthropods, playing key roles in immune defense and metabolic regulation. Due to their stability and bioactive properties, Hcs have gained increasing interest in biotechnological and biomedical applications. However, detailed biophysical characterization is crucial to understanding their functional potential. In this study, the hemocyanin was extracted and purified from Macrobrachium acanthurus (HcMac) using ultracentrifugation and size-exclusion chromatography. The molecular mass of HcMac was determined by SDS-PAGE electrophoresis, MALDI-TOF mass spectrometry, and analytical ultracentrifugation. Spectroscopic analyses, including UV-Vis absorption, fluorescence emission, and light scattering intensity, were used to assess the structural stability of the compound under various pH conditions. HcMac was identified as a hexameric protein (~450 kDa) composed of monomeric subunits of 75 and 76 kDa. The protein maintained its oligomeric stability and oxygen-binding affinity in the pH range of 5.0–7.4. However, extreme pH conditions (below 4.4 and above 7.5) induced structural alterations, leading to dissociation and conformational changes, as evidenced by fluorescence emission and UV-Vis spectra. The isoelectric point was determined to be between pH 4.3 and 5.3, consistent with other crustacean HCs. These findings reinforce the structural robustness of HcMac and suggest its potential for biotechnological applications. The high stability of HcMac under physiological pH conditions indicates its suitability for biomedical research, including immunomodulatory and antimicrobial applications. Future studies integrating bioinformatics, proteomics, and immunological assays will be essential to explore the therapeutic potential of HcMac. Full article

In this study, we synthesized a novel trimethoprim derivative, 4-(((2-amino-5-(3,4,5-trimethoxybenzyl) pyrimidine-4-yl)imino)methyl)benzene-1,3-diol (HD), by the reaction of trimethoprim with 2,4-dihydroxybenzaldehyde. We then prepared metal complexes of this derivative with Cu(II), Co(II), Ni(II), Ag(I), and Zn(II) and functionalized them with ZnO and Au nanoparticles. Their structures were confirmed through ¹H NMR, mass spectrometry, FTIR, conductivity, thermal analysis, magnetic susceptibility, X-ray diffraction, UV-Vis spectroscopy, and TEM, revealing octahedral geometries for all complexes. Surface features were investigated using density functional theory (DFT) analysis. Pharmacokinetic parameters and target enzymes for HD and its complexes were computed using the SwissADME web tool, with the BOILED-Egg model indicating that HD and its Cu complex should be passively permeable via the blood-brain barrier and highly absorbed by the gastrointestinal tract (GIT), unlike the Ni, Co, Ag, and Zn complexes, which are predicted to show low GIT absorption. Molecular docking studies with the Caspase-3 enzyme (PDB code: 3GJQ) using the AutoDock 4.2 software demonstrated binding energies of −7.66, −8.36, −9.05, −8.62, −6.90, and −7.81 kcal/mol for HD and the Cu, Co, Ni, Ag, and Zn complexes, respectively, compared to −6.54 and −4.63 kcal/mol for TMP and 5-FU (5-fluorouracil), indicating a potential superior anticancer potential of the novel compounds. The anticancer activities of these complexes were evaluated using the MTT assay. The IC₅₀ values for 5-FU, TMP, HD, Cu-HD, HD@ZnONPs, Cu-HD@ZnONPs, HD@AuNPs, and Cu-HD@AuNPs were found to be 32.53, 80.76, 114.7, 61.66, 77, 53.13, 55.06, and 50.81 µg/mL, respectively. Notably, all derivatives exhibited higher activity against the HepG-2 cancer cell line than TMP, except for HD, which showed similar effectiveness to TMP. Real-time PCR analysis revealed that the Au-HD@AuNPs and Cu-HD@AuNPs significantly increased caspase-3 inhibition by 4.35- and 4.5-fold and P53 expression by 3.05- and 3.41-fold, respectively, indicating enhanced pro-apoptotic gene expression and apoptosis induction in HepG2 cells. Our findings demonstrate that these novel derivatives possess significant anticancer properties, with some complexes showing superior activity compared to standard drugs such as 5-Fluorouracil (5-FU) and Trimethoprim (TMP). This study highlights the potential of these nanocomposites as promising candidates for cancer therapy. Full article

Temperature is a critical environmental factor that influences the growth, development, metabolism, and overall physiological performance of fish. Eleutheronema tetradactylum is an economically significant fish species; however, its molecular mechanism’s response to long-term cold stress is still unclear. In this study, we investigated the physiological responses of the liver in E. tetradactylum exposed to a constant temperature of 18 °C for durations of both 7 and 14 days, utilizing liquid chromatography–mass spectrometry (LC-MS), metabolomics, and conventional biochemical assays. The antioxidant status, liver histology, and metabolite profiles were examined at different time points. Our results revealed that, following sustained cold exposure, the activities of key antioxidant enzymes—superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)—initially increased and then decreased. Additionally, levels of malondialdehyde (MDA), a marker of oxidative damage, significantly elevated after 7 and 14 days of cold stress. Histopathological examination of liver tissues showed varying degrees of vacuolation and nuclear atrophy in hepatocytes, indicating oxidative damage. Metabolomic profiling identified 87 and 116 differentially expressed metabolites in the liver on days 7 and 14, respectively. Pathway enrichment analysis revealed significant alterations in pathways related to carbohydrate digestion and absorption, glutathione metabolism, and glycerolipid metabolism. These findings suggest that mechanisms regulating cell membrane fluidity, energy metabolism, autophagy, and antioxidant defense are crucial for the adaptation of E. tetradactylum to cold stress. Overall, this study provides valuable insights into the molecular and physiological adaptations of E. tetradactylum to low temperature, highlighting the activation of protective antioxidant responses and modifications of metabolic pathways in the liver. Full article

This study investigates the therapeutic potential of Lippia origanoides essential oil (LOEO) in neurological and pharmaceutical applications. The chemical composition of LOEO was analyzed using gas chromatography–mass spectrometry (GC-MS), revealing major constituents, such as carvacrol, thymol, and γ-gurjunene, known for their antioxidant and antimicrobial properties. LOEO demonstrated significant acetylcholinesterase (AChE)-inhibitory activity, particularly in a nanoformulation that enhances bioavailability and stability. Additionally, the major constituent carvacrol, when tested in isolation, also exhibited AChE-inhibitory activity comparable to that of the nanoformulation. Molecular docking analysis indicated strong binding affinities between LOEO compounds and AChE, supporting its therapeutic potential for neurodegenerative diseases like Alzheimer’s. Additionally, in silico pharmacokinetic predictions revealed favorable absorption and blood–brain barrier penetration profiles for key constituents. Despite promising results, this study acknowledges the need for in vivo validation and long-term stability assessments of the nanoformulation. Future research should focus on pharmacodynamic studies and evaluating the oil’s effectiveness in animal models. These findings highlight LOEO as a valuable candidate for developing natural therapies for neurodegenerative diseases. Full article

Over the last decades, a novel immunological function was established for the sodium–glucose co-transporter 1 (SGLT1), a protein involved in sugar absorption in the small intestine. High-glucose dosage and pharmacological concentrations of a C-glucoside analog showed a protective role in in vitro and in vivo models of severe inflammation states; experimental evidence suggests the engagement of SGLT1 in these processes. The mechanism of action underlying the protection is still unclear. To enhance our understanding of the molecular mechanisms responsible for this protection, we have developed a synthesis for the preparation of hydrogen isotope-labeled versions of the C-glucoside hit compound. Specifically, we report the synthesis of the deuterium-labeled derivative, which can be utilized for mass spectrometry-based research to examine the compound’s metabolic pathway, distribution, and cellular/tissue localization. The synthetic method developed can be extended to produce the tritiated analog, serving as a radioactive tracer. Full article

In this work, we describe the synthesis of three new meso-arylporphyrins, named meso-tetrakis [4-(nicotinoyloxy)phenyl] porphyrin (H₂TNPP), meso-tetrakis [4-(picolinoyloxy)phenyl] porphyrin (H₂TPPP), and meso-tetrakis [4-(isonicotinoyloxy) phenyl] porphyrin (H₂TIPP). These new synthesized meso-arylporphyrins are characterized using spectroscopic analysis: Fourier Transform Infrared Spectroscopy (FTIR) and One-dimensional Nuclear Magnetic Resonance (1D NMR), and mass spectrometry (MS). The photophysical studies (UV–visible absorption, singlet oxygen (¹O₂) luminescence, and fluorescence emissions) demonstrate their potential uses as photosensitizers (PSs) in photodynamic therapy (PDT) applications. An in vitro investigation of the anti-fungal activity of H₂TNPP, H₂TPPP, and H₂TIPP against Candida (C.) species (C. albicans, C. glabrata, and C. tropicalis) reveals that their minimum inhibitory concentration (MIC) values ranged from 1.25 to 5 mg/mL. In addition, their in vitro anti-fungal susceptibilities against three dermatophyte clinical isolates (Trichophyton rubrum, Microsporum canis, and Trichophyton mentagrophytes) are also evaluated and they demonstrate good anti-fungal activities. A molecular docking study of these meso-arylporphyrins as anti-fungal agents against C. tropicalis extracellular aspartic proteinases, Protein data Bank in Europe (PDBe code: 1J71) and Trichophyton rubrum Sialidases (PDBe code: 7P1D) underlines the possible interactions of H₂TNPP, H₂TPPP, and H₂TIPP with the key amino acid residues of these fungal target proteins. Full article

Artemisia dracunculus/(tarragon) is a perennial plant used in traditional medicine and the food industry. The plant is known to have beneficial effects on health, such as antibacterial, antifungal, antiseptic, carminative, anti-inflammatory, antipyretic, anthelmintic, etc. In this study, the compounds present in the highest concentrations in the essential oils obtained by different extraction methods from tarragon found on the Romanian market were identified by gas chromatography–mass spectrometry. The biological activity of these compounds was predicted using the computational tools ADMETlab3.0, admetSAR3.0, CLC-Pred2.0, and AntiBac-Pred. Also, the main molecular target of these compounds was predicted and the interactions with this protein were evaluated using molecular docking. The compounds identified in high concentrations in the obtained essential oils are estragole, cis-β-ocimene, trans-β-ocimene, limonene, eugenol methyl ether, eugenol acetate, eugenol, caryophyllene oxide, and α-pinene. The absorption, distribution, metabolism, excretion, and toxicity profiles of these compounds show that they are generally safe, but some of them can cause skin sensitization and respiratory toxicity and are potential inhibitors of the organic anion transporters OATP1 and OATP2. Several of these compounds exert antibacterial activity against some species of Staphylococcus, Streptococcus, and Prevotella. All compounds reveal potential cytotoxicity for several types of cancer cells. These findings may guide further experimental studies to identify medical and pharmacological applications of tarragon extracts or specific compounds that can be isolated from these extracts. Full article

Background/Objectives: Lagopsis supina, a traditional Chinese medicine valued for its diuretic properties, has limited research on its antioxidant, adipogenic, and anti-inflammatory effects. This study aimed to investigate the chemical composition and biological activities of Lagopsis supina extract (LSE). Methods: LSE was prepared and evaluated for antioxidant activity, effects on adipocyte differentiation in 3T3-L1 preadipocytes, and anti-inflammatory properties in RAW 264.7 macrophages. Ultra-high-performance liquid chromatography-electrospray ionization Orbitrap tandem mass spectrometry (UHPLC-ESI-Orbitrap-MS/MS)-based molecular networking was used to characterize its secondary metabolites. Results: LSE exhibited antioxidant activity in DPPH and ABTS assays. It significantly enhanced the differentiation of 3T3-L1 preadipocytes into mature adipocytes during early and intermediate stages by upregulating adipogenic transcription factors such as PPARγ, C/EBPα, and C/EBPβ, along with promoting cyclin E expression. LSE also increased PPARγ activity and the expression of its target genes, such as Glut 4, PEPCK, FABP4, and Plin2. Moreover, LSE inhibited lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophages by downregulating pro-inflammatory mediators (iNOS, COX-2, TNF-α, IL-6) and inhibiting extracellular signal-regulated kinase (ERK) phosphorylation. Chemical profiling revealed eight major compound groups: glycosides, organic acids, terpenoids, flavonoids, phenylglycosides, phenolics, fatty acids, and others characterized by their mass fragmentation patterns, precursors, and UV absorption spectra. In silico analysis confirmed these compounds’ bioactivities, demonstrating strong interactions and binding affinities with antioxidant, adipogenic, and anti-inflammatory protein targets. Conclusions: These findings highlight LSE’s triple therapeutic potential: antioxidant activity, adipogenesis promotion, and inflammation attenuation. LSE emerges as a promising therapeutic candidate for managing obesity and related inflammatory complications. Full article

Eutrophication is a major environmental issue affecting freshwater ecosystems worldwide. While its impact on the composition of dissolved organic matter (DOM) is well recognized, the relationships between DOM’s optical and molecular properties across eutrophication gradients remain underexplored. This review synthesizes recent research on DOM’s optical properties (derived from UV-Vis absorption and fluorescence spectroscopy) and molecular characteristics (analyzed using Fourier-transform ion cyclotron resonance mass spectrometry, FT-ICR MS) in freshwater systems of varying trophic states. Generalized additive model (GAM) analysis was used to assess correlations between DOM’s properties and the trophic state index (TSI). The dissolved organic carbon (DOC), a₂₅₄, SUVA₂₅₄, S_R, HIX, BIX, and FI averaged 11.44 ± 11.97 mg/L, 23.23 ± 16.95 m⁻¹. 2.98 ± 0.99 L·mg⁻¹·m⁻¹, 1.42 ± 0.38, 2.38 ± 1.31, 1.08 ± 0.16, and 2.11 ± 0.44, respectively, from mesotrophic to middle-eutrophic sites. The GAM results revealed a significant linear correlation between DOC and DOM’s optical properties, including a₂₅₄, SUVA₂₅₄, and FI, with the TSI, suggesting that DOM accumulation intensifies with eutrophication. DOM’s molecular properties, such as O/C and H/C ratios, double bond equivalents (DBEs), and CHOS% content, exhibited nonlinear correlations with the TSI. These trends imply a shift in DOM sources from terrestrial and macrophyte-derived inputs to those dominated by algal- and sediment-derived sources as eutrophication progresses. We concluded that DOM’s molecular indices alone may not serve as a reliable indicator of freshwater trophic states; future studies should focus on integrating both optical and molecular indices to offer a more comprehensive assessment of freshwater trophic states. Given the limited number of molecular variables examined in this study, this work only offers a preliminary investigation into the relationship between DOM molecular changes and freshwater eutrophication. More systematic studies focusing on the molecular-level analyses of DOM across varying trophic states on a broader geographic scale are needed. Full article

A Black Hole Quencher-3 (BHQ-3) derivative was synthesized through an azo-coupling reaction between Methylene Violet 3RAX and a tertiary aniline functionalized with a pendant primary amine, allowing subsequent peptide conjugation. The synthesized compounds were characterized using NMR, UV–vis absorption, fluorescence spectroscopy, and mass spectrometry. The spectral properties of a Cy5/BHQ-3 amine pair were investigated through titration experiments in PBS (pH 7.4). The results confirmed Förster Resonance Energy Transfer (FRET), along with additional dynamic quenching, as evidenced by the Stern–Volmer analysis. The Stern–Volmer constant (K_SV) was determined to be 1.40 × 10⁵ M⁻¹. These findings confirm the potential of this system for use in molecular probes and bioimaging applications. Full article

Oligo(phenylene ethynylene)s (OPEs) are π-conjugated systems with promising optical, bioactive, and electrical properties, making them valuable candidates for molecular electronics and biosensors. Controlling the arrangement and orientation of π-conjugated systems is crucial in developing molecular devices. Recently, we developed insulated diarylacetylene dimers using a [c2]daisy chain rotaxane strategy, which brings two cores into close proximity without covalent bonding and shields them with permethylated α-cyclodextrins. Here, we synthesized an insulated OPE dimer using a similar rotaxane strategy to investigate its optical properties. The rotaxane structure and optical properties were evaluated using nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization high-resolution mass spectrometry (ESI-HRMS), and absorption and fluorescence spectroscopy. This study is expected to contribute to the development of optical and electronic materials utilizing OPEs. Full article

In this study, we report a novel platinum–doxorubicin conjugate that demonstrates superior therapeutic indices to cisplatin, doxorubicin, or their combination, which are commonly used in cancer treatment. This new molecular structure (1) was formed by conjugating an amphiphilic Pt(IV) prodrug of cisplatin with doxorubicin. Due to its amphiphilic nature, the Pt(IV)–doxorubicin conjugate effectively penetrates cell membranes, delivering both cisplatin and doxorubicin payloads intracellularly. The intracellular accumulation of these payloads was assessed using graphite furnace atomic absorption spectrometry and fluorescence imaging. Since the therapeutic effects of cisplatin and doxorubicin stem from their ability to target nuclear DNA, we hypothesized that the amphiphilic Pt(IV)–doxorubicin conjugate (1) would effectively induce nuclear DNA damage toward killing cancer cells. To test this hypothesis, we used flow the cytometric analysis of phosphorylated H2AX (γH2AX), a biomarker of nuclear DNA damage. The Pt(IV)–doxorubicin conjugate (1) markedly induced γH2AX in treated MDA-MB-231 breast cancer cells, showing higher levels than cells treated with either cisplatin or doxorubicin alone. Furthermore, MTT cell viability assays revealed that the enhanced DNA-damaging capability of complex 1 resulted in superior cytotoxicity and selectivity against human cancer cells compared to cisplatin, doxorubicin, or their combination. Overall, the development of this amphiphilic Pt(IV)–doxorubicin conjugate represents a new form of combination therapy with improved therapeutic efficacy. Full article

This manuscript presents the results from the synthesis and characterization of a slag analogue with a nominal composition of 17 wt% LiMnO₂ and 83 wt% Ca₂SiO₄ encountering fairly high cooling rates in order to study the evolution of Mn-species. The Mn species was also simulated from 1223 K to 1773 K using a thermodynamic model, assuming a homogeneous melt. The micro-composition including the Mn species of the solidified slag was determined experimentally, and was used as basis for molecular dynamics (MD) simulation. The MD simulation provides information on structure and viscosity at high temperatures, which are otherwise difficult to access. These parameters significantly influence oxidation state of redox-active elements and the solidified product. The micro-composition analyzed by electron probe micro analysis (EPMA) and synchrotron-based micro-X-ray fluorescence (micro-XRF) showed that Mn-rich and Ca-Si-rich phases are separated. While the Mn-O phases did not contain noticeable Ca, the Ca₂SiO₄ phase had incorporated 0.6 wt% of Mn. The slag solidified into round-shaped and droplet-shaped grains of a Li-Mn-oxide, some Mn₃O₄ and Ca₂SiO₄. The powder X-ray diffraction (PXRD) confirmed the formation of larnite; the identity of the Li-Mn-oxide, however, remained inconclusive. The Mn oxidation state (OS) was identified using synchrotron-based micro-X-ray absorption near edge spectroscopy (micro-XANES). The Mn-O grains matched well with Li-Mn-oxides and a Mn OS: +3, e.g., LiMn³⁺O₂. Small areas matching hausmannite (Mn²⁺Mn₂³⁺O₄) were also identified. The OS of Mn in the silicate phase could not be identified. For comparison, a slowly cooled slag analogue with similar composition, but higher Si content, was also subjected to micro-XANES. The slowly cooled slag formed long Mn-rich needles in a matrix of large calcium silicate crystals. The Mn-rich crystals matched well with the XANES spectrum of a Mn³⁺ Li-oxide like LiMn³⁺O₂. At the rim of the needles, the Mn-spectra matched well the hausmannite (Mn²⁺Mn₂³⁺O₄) reference. In the silicate phases, Mn had an OS: +2, unambiguously. The melt structure at different temperatures of two compositions, i.e., LiMn³⁺O₂ and Ca₂SiO₄, was simulated using molecular dynamics (MD). They serve as model compositions, assuming a heterogeneous melt. The results show significant different degrees of polymerization and viscosity. Information from MD simulations can support the identification of potentially different oxygen permeability and with that prediction of oxidation states. The bulk composition was identified by inductively coupled plasma optical emission spectrometry (ICP-OES), bulk structure by PXRD and bulk species by lab-XANES. The synchrotron micro analysis including micro-XRD were performed at the microfocus beamline I18 at the Diamond Light Source. Pure reference compounds were prepared and characterized with the same multi-modal approach. Full article

The increasing need for new treatments for obesity and diabetes has led to the development of new drugs and food supplements that could reduce carbohydrate absorption. Many starch blockers, based on common bean proteinaceous inhibitors against α-amylase (α-AI), are already present on the market. The extraction and purification of α-amylase inhibitor from a promising common bean cultivar from Sardinia (Nieddone) is described, highlighting the unique value of the Nieddone cultivar, particularly for its inhibitory activity on digestive enzymes and its complete lack of a hemagglutination effect on human red blood cells. The purification of α-AI involved two chromatographic steps (IEC and SEC) and was essential for revealing certain properties of the inhibitor. The purified inhibitor has a tetrameric structure (α₂β₂) and a molecular weight of approximately 42 kDa, as determined by SEC and SDS-PAGE, confirming it as a lectin-like inhibitor. The identification of the α-AI sequence was obtained by bottom-up high-resolution mass spectrometry, which allowed us to identify a unique peptide from the α chain and six unique peptides from the β chains. α-AI exhibited an optimum temperature of around 40 °C and two pH optima at 5 and 6.5, respectively. Its remarkable stability at high temperatures was measured (approximately 25% of activity retained even after 5 h at 100 °C), whereas the raw extract lost its activity entirely after just 10 min at 90 °C. Thus, the purification process significantly enhances the thermal stability of α-AI. The demonstrated effectiveness of the purified α-AI against the α-amylase enzyme in pigs, humans and insects underscores the protein’s potential for treating obesity and diabetes, as well as for managing insect pests. Full article