Search Results (282)

Six new diterpenoids, including two verticillane ghardaqenoids A–B (1–2) and four dolabellane ghardaqenoids C–F (3–6), were isolated from the soft coral Heteroxenia ghardaqensis collected in the South China Sea. The structures of ghardaqenoids A, D, and E (1, 4, 5) were determined by X-ray diffraction. Ghardaqenoids B, C, and F (2, 3, 6) were identified on the basis of NMR data, DP4+, and ECD spectral data. In particular, compound 6 exhibited strong in vitro lipid-lowering activity in free fatty acid (FFA)-induced HepG2 cells and liver organoids. Further mechanistic studies revealed that compound 6 regulated AMPK-related proteins and genes, thereby inhibiting the accumulation of triglycerides (TG) and total cholesterol (TC). These findings suggested that pharmacological AMPK activation serves as a promising role in lipid-lowering therapeutic strategies. Full article

Iron (Fe) chelators are used to treat iron-overloaded disorders, metal detoxification, radionuclides, and molecular imaging; however, they can cause side effects. In this study, we identified and characterized Coprogen B (CPGB), a hexadentate trihydroxamate siderophore secreted by the opportunistic dimorphic fungus Talaromyces marneffei and compared its properties with deferoxamine (DFO). Siderophore production was enriched from a ΔsreA strain and purified via Amberlite XAD2 and Sephadex LH20 chromatography, followed by reverse-phase HPLC. Active fractions were confirmed by Ultraviolet–Visible (UV–Vis) spectral fingerprints (≈230 nm) for hydroxamate, with a band at 430–450 nm upon Fe(III) complexation, as well as by chrome azurol A assay, Nuclear Magnetic Resonane (NMR) spectroscopy, High-Performance Liquid Chromatography–Mass Spectrometry (HPLC-MS), and Matrix-Assisted Laser Desorption/Ionization–Time-of-Flight Mass Spectrometry (MALDI-TOF-MS). CPGB exhibited strong molar absorptivity and rapid, concentration-dependent chelation of Fe(III), yielding a sustained binding profile that matched or exceeded that of DFO over time. In determining n-octanol/water partitioning for CPGB and DFO (230 nm) and their Fe(III) complexes, the partitioning (P) assay revealed that CPGB was moderately hydrophilic (P = 0.505 ± 0.063; cLogP = −0.299 ± 0.053), while DFO was strongly hydrophilic (P = 0.098 ± 0.005; cLogP = −1.010 ± 0.022). Fe(III) complexation reduced lipophilicity: CPGB–Fe partitioned ~30–35% into octanol, while DFO–Fe complex partitioned ~7–8%, remaining largely aqueous. Overall, this outcome potentially suggested improved clearance in vivo. These data nominate CPGB as a promising alternative to existing iron chelators. The siderophore exhibited greater lipophilicity, emphasizing better passive membrane permeability than DFO, while siderophore–Fe(III) binding indicated increased biases toward the aqueous phase. Future in vivo studies are warranted to confirm its pharmacokinetics, safety, and therapeutic efficacy. Full article

The growing need for effective antimicrobial polymeric materials has prompted extensive development of functional chitosan derivatives with enhanced physicochemical and biological properties. In this work, the conjugates of chitosan with 4-anisaldehyde (ChT-AA) were synthesised through Schiff base formation at various molar ratios and characterised using FT-IR, ¹H NMR, and thermal analysis techniques (TGA/DSC). The spectral data confirmed the successful formation of imine (C=N) linkages and the incorporation of aromatic anisaldehyde fragments into the chitosan structure. Thermal analysis demonstrated increased stability and a higher glass transition temperature for ChT-AA compared with native chitosan, indicating reduced polymer chain mobility and enhanced structural rigidity. Viscoelastic gels based on the synthesised ChT-AA (1:3) and methylcellulose were prepared and evaluated for their rheological properties and antimicrobial performance. Rheological studies revealed non-Newtonian shear-thinning behaviour of these gels with pronounced thixotropy, confirming reversible network recovery after shear deformation. Antimicrobial evaluation of chitosan, its 4-anisaldehyde conjugate (ChT–AA, 1:3), and free 4-anisaldehyde revealed distinct activity patterns. The gels showed no inhibition in the disk diffusion assay, likely due to limited diffusion of the active components. In liquid media, both ChT and ChT–AA exhibited identical minimum inhibitory concentrations (MICs) against E. coli (0.313 mg/mL) and C. albicans (1.250 mg/mL), whereas ChT–AA showed two-fold stronger activity against S. aureus (0.313 mg/mL vs. 0.625 mg/mL for ChT). Free 4-anisaldehyde was most active against S. aureus (MIC = 0.175 mg/mL) but less effective against the other strains, confirming its narrower spectrum. These results indicate moderate antimicrobial efficacy in solution but limited activity in gel form due to restricted diffusion. Full article

The structure of N-[(2H-1,3-benzodioxol-5-yl)methyl]-2-(2,2,2-trichloroacetamido)benzamide was verified by using a combination of 1D and 2D NMR techniques. Fully assigned data from 1D NMR (¹H, ¹³C and DEPT 135) and 2D NMR (COSY, HMQC, HMBC) spectra was presented for the compound. The ¹H NMR spectrum of the ABX spin system in the benzodioxol moiety was simulated to predict the corresponding ⁿJ_HH coupling constants. The spectral assignments for the structure were supported by interpretive library search and HOSE predictions. Full article

The development of novel platinum-based anticancer agents remains a critical objective in medicinal inorganic chemistry, particularly in light of resistance and toxicity limitations associated with cisplatin. In this study, the synthesis, structural characterization, quantum chemical analysis, and cytotoxic evaluation of four new acetylplatinum(II) complexes (cis-[Pt(COMe)₂(PASO₂)₂], cis-[Pt(COMe)₂(DAPTA)₂], trans-[Pt(COMe)Cl(DAPTA)₂], and trans-[Pt(COMe)Cl(PASO₂)]: 1–4, respectively) bearing cage phosphine ligands PASO₂ (2-thia-1,3,5-triaza-phosphaadamantane 2,2-dioxide) and DAPTA (3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane) are presented. The coordination geometries and NMR spectral features of the cis/trans isomers were elucidated through multinuclear NMR and DFT calculations at the B3LYP/6-311++G(d,p)/LanL2DZ level, with strong agreement between experimental and theoretical data. Quantum Theory of Atoms in Molecules (QTAIM) analysis was applied to investigate bonding interactions and assess the covalent character of Pt–ligand bonds. Cytotoxicity was evaluated against five human cancer cell lines. The PASO₂-containing complex in cis-configuration, 1, demonstrated superior activity against thyroid (8505C) and head and neck (A253) cancer cells, with potency surpassing that of cisplatin. The DAPTA complex 2 showed enhanced activity toward ovarian (A2780) cancer cells. These findings highlight the influence of ligand structure and isomerism on biological activity, supporting the rational design of phosphine-based Pt(II) anticancer drugs. 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

Salinomycin is a polyether ionophorous antibiotic with promising antineoplastic properties. Published studies have revealed that the compound also exerts pronounced antidotal activity against cadmium (Cd) and lead (Pb) intoxications. It has been proven that salinomycin with Cd(II) forms a coordination compound of a composition [Cd(C₄₂H₆₉O₁₁)₂(H₂O)₂] and an octahedral molecular geometry, while the coordination compound of the antibiotic with Pb(II) has a square pyramidal structure and composition [Pb(C₄₂H₆₉O₁₁)(NO₃)]. To date, there is no published information about the ability of salinomycin to form complexes with the mercury ion (Hg(II)). Herein, we report, for the first time, a synthetic procedure for a complex compound of salinomycin with Hg(II). The coordination compound was characterized by a variety of methods, such as elemental analysis, attenuated total reflectance–Fourier transform infrared spectroscopy (ATR-FTIR), electrospray ionization–mass spectrometry (ESI-MS), powder X-ray diffraction, nuclear magnetic resonance spectroscopy (NMR), thermogravimetry with differential thermal analysis (TG-DTA), and thermogravimetry with mass spectrometry (TG-MS). The elemental analysis data revealed that the new compound is of the chemical composition [Hg(C₄₂H₆₉O₁₁)(H₂O)(OH)]. Based on the results from the spectral analyses, the most probable structure of the complex was proposed. Full article

A new deconvolution strategy, reverse curve fitting, was developed to determine peak positions and independent intensities of overlapping Fourier transform (FT) nuclear magnetic resonance (NMR) bands. From the third-order derivative of the overlapping band, the peak position was estimated from its zero-crossing point and the peak intensity was quantitated by partial curve matching with its primary maxima. Every matched peak in the overlapping band was dismembered in turn to weaken the overlap until an independent peak was filtered out. The deconvolution can be refined progressively by manually tuning the peak positions and peak widths. In a simulation study, a closely overlapped ¹³C NMR triplet (overlapping degrees between 0.5 and 1.0) at a signal-to-noise ratio (SNR) of 20:1 was quantitatively deconvoluted by our reverse curve fitting procedure with a routine denoising technique. The noise interference and denoising technique were also studied in the simulation. A real FT-NMR overlapping band of Ethylbenzene (300 MHz) was satisfactorily deconvoluted and compatible with higher resolution literature spectral data. A more complicated overlapping NMR band of Tetraphenyl porphyrin was studied as well. This new approach to the deconvolutions is applicable to other FT spectroscopies. Full article

In this study, novel fluorescent 5-aryl-2-styryl-3H-indole derivatives were efficiently synthesized from 4-bromophenylhydrazine hydrochloride using the microwave-accelerated one-pot technique, which includes Fischer synthesis, Suzuki cross-coupling, and Knoevenagel condensation. The structural assignments of the synthesized compounds were based on ¹H, ¹³C, ¹⁵N, and ¹⁹F NMR; IR spectroscopy; and HRMS spectral data. The optical properties of the newly obtained styryl-indole dyes were studied using UV-vis and fluorescence spectroscopy, which clearly demonstrated that the derivatives substituted with electron-donating or -withdrawing groups exhibited varying emission shifts and quantum yields ranging from negligible to high. Full article

An efficient protocol has been developed for the synthesis of a new bioactive sulfonylphthalimide under environmentally friendly conditions. Ultrasonic energy was used to achieve the desired products with excellent yields and high purity, all in solvent-free conditions. The synthesis of this sulfonylphthalimide was carried out using sulfamide and phthalic anhydride. The structure of the synthesized compound was confirmed by 1H, 13C NMR and MS spectral data as well as IR spectroscopy. Full article

Two new decalin-tetramic acid hybrid metabolites, zopfiellamides C (1) and D (2) were isolated from the marine-derived fungus Aspergillus sp. NF666. The structure determination was accomplished on the basis of HRESIMS and NMR spectral data analyses including COSY, HSQC, HMBC, and NOESY experiments. Both isolated metabolites (1 and 2) exhibited significant growth inhibition against four clinically relevant bacterial strains with minimum inhibitory concentration (MIC) values of about 12.5 μΜ. Moreover, we proposed a plausible biosynthetic pathway of zopfiellamide D (2) in this work. Full article

A highly novel method for the preparation of benzyl 2-phenyl-1H-pyrrole-1-carboxylate has been developed. The intramolecular reaction of benzyl (E)-(4-oxo-4-phenylbut-2-en-1-yl)carbamate with oxalyl chloride provided title compound in good yields. The structure of the newly synthesized compound was determined using ¹H-, ¹³C-NMR, IR, and mass spectral data. Full article

The Thymus vulgaris and Origanum vulgare essential oils (contained thymol and carvacrol in a range of 35–80%) are used in various products in the fields of medicine, cosmetics, and foods. Molecular hybridization between benzothiazole (BT) and phenolic monoterpenoids is a promising method for the development of biologically active compounds. New benzothiazole–monoterpenoid hybrids were synthesized through a regioselective α-amidoalkylation reaction of thymol and carvacrol with high yields (70–96%). This approach is both simple and cost-effective, employing easily accessible and inexpensive reagents to produce target molecules. The structure of the synthesized compounds was characterized spectrally using ¹H-, ¹³C-NMR, FT-IR, and HRMS data. The newly obtained compounds are structural analogues of the UVB filter PBSA, which is used in cosmetics. The spectral properties of the aromatic products thymol hybrid (2-(4-hydroxy-5-isopropyl-2-methylphenyl)benzo[d]thiazole) and carvacrol hybrid (2-(4-hydroxy-2-isopropyl-5-methylphenyl)benzo[d]thiazole) were successfully examined, using a validated spectrophotometric method. SPF values varied from 31 to 36, compared to the PBSA (30), and were observed at concentrations of 1–0.25 mM. 2-Hydroxyphenylbenzothiazoles are known antimicrobial and antioxidant agents that have potential applications in the food industry and cosmetics as preservatives and antioxidants. In this context, antimicrobial activity of the hybrid compounds was evaluated using the agar diffusion method against E. coli, S. aureus, P. aeruginosa, and C. albicans. Compounds of methyl-2-(4-hydroxy-2-isopropyl-5-methylphenyl)benzo[d]thiazole-3(2H)-carboxylate containing carvacrol fragments showed high activity against Staphylococcus aureus ATCC 25923 (with 0.044 μmol content). The radical scavenging activity was determined using ABTS and DPPH assays, the highest activity was exhibited by the thymol hybrids ethyl-2-(4-hydroxy-5-isopropyl-2-methylphenyl)benzo[d]thiazole-3(2H)-carboxylate (IC₅₀—133.70 ± 10 µM) and methyl-2-(4-hydroxy-5-isopropyl-2-methylphenyl)benzo[d]thiazole-3(2H)-carboxylate (IC₅₀—157.50 ± 10 µM), defined by ABTS. The aromatic benzothiazole–monoterpenoid hybrids are classified using in silico analyses as non-mutagenic, with low toxicity, and they are non-irritating to the skin. These compounds were identified as new hit scaffolds for multifunctional molecules in cosmetics. Full article

Introduction: NMR spectroscopy is a powerful technique for studying metabolism, either in metabolomics settings or through tracing with stable isotope-enriched metabolic precursors. MetaboLabPy (version 0.9.66) is a free and open-source software package used to process 1D- and 2D-NMR spectra. The software implements a complete workflow for NMR data pre-processing to prepare a series of 1D-NMR spectra for multi-variate statistical data analysis. This includes a choice of algorithms for automated phase correction, segmental alignment, spectral scaling, variance stabilisation, export to various software platforms, and analysis of metabolic tracing data. The software has an integrated help system with tutorials that demonstrate standard workflows and explain the capabilities of MetaboLabPy. Materials and Methods: The software is implemented in Python and uses numerous Python toolboxes, such as numpy, scipy, pandas, etc. The software is implemented in three different packages: metabolabpy, qtmetabolabpy, and metabolabpytools. The metabolabpy package contains classes to handle NMR data and all the numerical routines necessary to process and pre-process 1D NMR data and perform multiplet analysis on 2D-¹H, ¹³C HSQC NMR data. The qtmetabolabpy package contains routines related to the graphical user interface. Results: PySide6 is used to produce a modern and user-friendly graphical user interface. The metabolabpytools package contains routines which are not specific to just handling NMR data, for example, routines to derive isotopomer distributions from the combination of NMR multiplet and GC-MS data. A deep-learning approach for the latter is currently under development. MetaboLabPy is available via the Python Package Index or via GitHub. Full article

Cathinone and its synthetic derivatives belong to organic compounds with narcotic properties. Their structural diversity and massive illegal use create the need to develop new analytical methods for their identification in different matrices. NMR spectroscopy is one of the most versatile methods for identifying the structure of organic substances. However, its use could sometimes be very difficult and time-consuming due to the complexity of NMR spectra, as well as the technical limitations of measurements. In such cases, molecular modeling serves as a good supporting technique for interpreting ambiguous spectral data. Theoretical prediction of NMR spectra includes calculation of nuclear magnetic shieldings and sometimes also indirect spin–spin coupling constants (SSCC). The quality of theoretical prediction is strongly dependent on the choice of the theory level. In the current study, cathinone and its 12 fluorinated derivatives were selected for gauge-including atomic orbital (GIAO) NMR calculations using Hartree–Fock (HF) and 28 density functionals combined with 6-311++G** basis set to find the optimal level of theory for ¹H, ¹³C, and ¹⁹F chemical shifts modeling. All calculations were performed in the gas phase, and solutions were modeled with a polarized-continuum model (PCM) and solvation model based on density (SMD). The results were critically compared with available experimental data. Full article