Search Results (1,587)

NMR spectroscopy enables the study of complex mixtures, including plant extracts. The interpretation of specific ranges of ¹H NMR spectra allows for the determination of polyphenolic compound, sugar, amino acid, and fatty acid profiles. The main goal of ¹H NMR analyses of plant extracts is to identify the unique “fingerprint” of the material being studied. The aim of this study was to determine the metabolomic profile and antioxidant activity of various Lavandula angustifolia (Betty’s Blue, Elizabeth, Hidcote, and Blue Mountain White) and Lavandula × intermedia cultivars (Alba, Grosso, and Gros Bleu) grown in Poland. Modern green chemistry extraction methods (supercritical fluid extraction (SFE) and ultrasound-assisted extraction (UAE)) were used to prepare the lipophilic and hydrophilic extracts, respectively. The secondary metabolite profiles were determined using the diagnostic signals from ¹H NMR and HPLC-DAD analyses. These metabolomic profiles were used to illustrate the differences between the different lavender and lavandin cultivars. The HPLC-DAD analysis revealed that both lavender species have similar polyphenolic profiles but different levels of individual compounds. The extracts from L. angustifolia were characterized by higher phenolic acid and flavonoid contents, while the extracts from L. × intermedia had a higher coumarin content. Diagnostic ¹H NMR signals can be used to verify the authenticity and origin of plant extracts, and identify directions for further research, providing a basis for applications such as in cosmetics. Full article

In the present study, Dipteryx odorata seeds (tonka beans) were extracted via the Soxhlet method to acquire ethanolic (TBSE) and hexane (TBSH) extracts. Both extracts were characterized using Gas Chromatography–Mass Spectrometry (GC-MS). The antimicrobial activity was evaluated against two Gram-positive (Bacillus licheniformis, Staphylococcus epidermidis) and two Gram-negative (Escherichia coli, Pseudomonas aeruginosa) human pathogens using the disc diffusion test (DDT), followed by the determination of Minimum Inhibitory Concentrations (MIC). The Cytokinesis-Block Micronucleus (CBMN) assay was applied in human lymphocytes (0.1, 0.2, 0.5 µL/mL), to investigate the cyto-genotoxic activity of both extracts, while their antigenotoxic potential was evaluated against mitomycin C (MMC) (0.5 μg/mL). Coumarin was the major constituent in both extracts. TBSE exhibited remarkable antimicrobial activity, whereas TBSH was not equally potent. Cytotoxicity was reported for higher doses, while no genotoxicity was observed, except for 0.2 µL/mL for TBSE. A considerable antigenotoxic activity was shown by the lowest dose of TBSE, which was not present at the two highest concentrations. However, TBSH did not diminish the MMC mediated genotoxicity, while at the same time led to an increase in genotoxic potency. To our knowledge, this is the first comprehensive evaluation of the cyto-genotoxic and antigenotoxic profiles of tonka bean extracts. Full article

Tropical almond tree (Terminalia catappa L.), belonging to the Combretaceae family, is an unfurling tree with different edible parts. This review discussed the nutritional content, ethnopharmacological applications, main bioactive components, biological effects and economic potential of T. catappa. T. catappa shows essential applications in medicine, cosmetics and pharmaceutics. The nutritional values of T. catappa are associated with its contents of carbohydrates, minerals, proteins, lipids, vitamins and amino acids. It is used in many ethnopharmacological applications, including a heart stimulator, anti-diarrhoeal, bactericidal, anti-parasitic and anti-stress. T. catappa is used to treat angina pectoris, asthma attacks and bronchitis. The main reported biological activities for T. catappa were antioxidant, antidiabetic, anti-atherosclerosis, antitumor, antimicrobial, anthelmintic, antimalaria, hepatoprotective, insecticidal, anti-inflammatory and antihyperlipidemic activities. The main bioactive components reported in T. catappa encompassed phenolic compounds, alkaloids, diterpenes, fatty acids, galloyl glucose and derivatives, steroids and coumarins. T. catappa shows great economic opportunities which need to be expanded and diversified, taking into account its sustainability. Full article

The development of new photoinitiators for photocurable systems has gained increasing interest in response to regulatory and environmental requirements, including efficient absorption in the UV/Vis range and reduced toxicity. Among emerging light-sensitive compounds, oxime esters have attracted growing attention as efficient radical photoinitiators. In this paper, five series of oxime esters based on carbazole, coumarin, carbazole–coumarin, phenothiazine, and triphenylamine scaffolds were described. Their high performance in photopolymerization processes was presented, demonstrating their ability to act as both type I and type II photoinitiators, as confirmed by high monomer conversion degrees. These data highlight oxime esters as versatile photoinitiating systems and provide a basis for further structural optimization aimed at improving water solubility and enabling comprehensive cytotoxicity assessment. Full article

A novel series of benzoxazole-derived iminocoumarins was synthesized via a Knoevenagel condensation and fully characterized using NMR, UV–Vis spectroscopy, and computational methods. Their photophysical properties were systematically examined in solvents of varying polarity, revealing pronounced effects of both substituents and solvent environment on absorption maxima and intensity. Derivatives bearing electron-donating substituents on the coumarin core exhibited distinct and reversible pH-responsive spectral shifts, confirming their potential as optical pH probes. Experimental pK_a values derived from absorption titrations showed excellent agreement with DFT-calculated data, validating the proposed protonation-deprotonation equilibria and associated electronic structure changes. Structure–property relationships revealed that electron-donating groups enhance intramolecular charge transfer, while electron-withdrawing substituents modulate spectral response and stability. In parallel, the compounds were evaluated for antiproliferative, antiviral, and antifungal activities in vitro. Strong electron-donating substituents were associated with potent but non-selective cytotoxicity, whereas derivatives bearing electron-withdrawing groups displayed moderate and more selective antiproliferative effects against leukemia cell lines. Antifungal screening revealed moderate inhibition of phytopathogenic fungi, particularly for compounds with electron-withdrawing or methoxy substituents. Overall, these findings demonstrate that benzoxazole iminocoumarins represent a promising class of multifunctional heterocycles with potential applications as optical pH sensors and scaffolds for bioactive compound development. Full article

This review summarizes recent advances (2023–2025) in coumarin-based fluorescent probes, highlighting their structural modularity, tunable VIS–NIR photophysics, and broad applicability in detecting metal ions, biothiols, ROS/RNS, organelle-specific microenvironments, and amyloid-β aggregates. Particular emphasis is placed on multifunctional and organelle-targeted probes, as well as emerging NIR-emissive and theranostic systems enabling deep-tissue imaging and modulation of pathological processes. The perspectives section outlines current limitations and future directions toward clinically relevant coumarin-based imaging tools. A though the review focuses on literature published from 2023 onward, several earlier studies are cited selectively to clarify fluorescence mechanisms, illustrate reaction pathways, or provide essential photophysical benchmarks necessary for contextual understanding. Full article

Copper(II) complexes have great potential as antitumor and antimicrobial agents, and their coumarin derivatives bearing histamine substituents possess versatile structural and biological properties. The present article describes the synthesis of novel copper(II)–coumarin–histamine complexes and ligands and their characterization by IR, NMR, X-ray diffraction, and elemental analysis. Their antimicrobial activity (MIC, MBC/MFC) was tested against 11 reference strains. Cytotoxicity was evaluated using the MTT assay against 15 selected cancer cell lines and normal HMEC-1 cells. It presents three new ligands and three new complexes with copper(II) ions and selected histamine-containing coumarin derivatives. The new copper(II) complexes demonstrated markedly higher anticancer activity than their corresponding ligands across all evaluated cancer cell lines. The highest anticancer activity against the Hep3B liver cancer cell line was demonstrated by the copper(II) complex (3b), which also showed the strongest inhibition of S. epidermidis ATCC 12228 and S. aureus ATCC 6538. The copper(II) ions play a crucial role in the antitumor activity of these derivatives. Despite limited antimicrobial effects, the tested complexes, particularly 3a and 3b, demonstrate promising anticancer potential, especially against the Hep3B cancer cell line. Only 3b demonstrated antimicrobial activity against S. epidermidis ATCC 12228 and S. aureus ATCC 6538. Full article

Photo-Fenton advanced oxidation processes are promising and sustainable approaches for water treatment, particularly under visible-light irradiation. In this study, Cu-Fe bimetallic catalysts supported on silica and γ-alumina were developed for visible-light-driven photo-Fenton reactions, with emphasis on the influence of metal ratios and support-metal interactions on charge–carrier dynamics and hydroxyl radical formation. Comprehensive characterization (XRD, TEM, UV-Vis DRS, PL, TCSPC, and EPR) revealed stronger metal–support interactions and higher metal dispersion on γ-alumina, while silica-supported catalysts showed CuO aggregation at higher Cu loadings. Catalytic performance was evaluated using coumarin oxidation as both a model reaction and a quantitative probe for ^•OH radical generation. Alumina-supported catalysts exhibited superior activity, and ^•OH production increased with increasing Cu content on both supports. Importantly, iron was found to play a dual role: low Fe loading enhances photo-Fenton activity, whereas higher Fe content promotes charge–carrier recombination, leading to reduced activity under visible-light irradiation. These results highlight how the interplay between Fe/Cu ratio and support material governs charge dynamics and provides clear guidelines for the rational design of efficient heterogeneous photo-Fenton catalysts. Full article

Dengue is a mosquito-borne viral disease transmitted by Aedes aegypti, the main vector in the Americas. The lack of effective antiviral treatments, limited vaccine coverage, and the increasing resistance of mosquitoes to conventional insecticides emphasize the need for alternative vector control strategies. Plant-derived larvicides represent a promising and eco-friendly approach. This study characterized the phytochemical profile of Persea americana Mill. (var. Lorena) and evaluated its larvicidal activity against Ae. aegypti (Rockefeller strain). The phytochemical profile was assessed through qualitative screening, UV-Vis spectrophotometry, and UHPLC analysis. Larvicidal activity was evaluated against third-instar larvae of Ae. aegypti (Rockefeller strain) and the median lethal concentration (LC₅₀) values were determined. Preliminary screening of ethanolic extracts revealed the presence of various secondary metabolites of pharmacological relevance, including alkaloids, coumarins, tannins, flavonoids, saponins, triterpenes/sterols, and quinones. UV-Vis spectra displayed distinct absorption patterns, with a prominent peak near 260 nm, consistent with the presence of aromatic compounds. UHPLC profiling revealed high chemical diversity across different plant parts, with 70, 98, 71, and 52 peaks (above 1 × 10⁵ intensity) detected in seed, flower, pulp, and leaf extracts, respectively. Larvicidal bioassays showed significant activity, particularly in the seed extract, with LC₅₀ values (µg/mL) of 3.8 (3.3–4.1) for seeds, 22.4 (21.8–23.9) for flowers, 23.0 (21.5–24.6) for pulp, and 29.7 (28.1–31.2) for leaves. This study highlights the larvicidal potential of ethanolic extracts from P. americana (var. Lorena), with the seed extract exhibiting the highest chemical diversity and bioactivity against Ae. aegypti larvae. The detection of key secondary metabolites, including flavonoids, alkaloids, and saponins, supports the development of an effective, plant-based larvicide for sustainable vector control strategies. Full article

High-risk neuroblastoma (NB) is an aggressive pediatric tumor characterized by pronounced biological heterogeneity and frequent development of chemoresistance, which critically limits therapeutic efficacy. Identifying novel anti-NB agents remains an urgent unmet need. To address this, we designed and synthesized 17 hybrid molecules by combining natural antioxidant scaffolds (coumarin, vanillin, and isovanillin) through an acyl-hydrazone linker. Several derivatives significantly reduced the viability of MYCN-amplified NB cells (HTLA-230) and their multi-drug resistant counterpart (ER) while not affecting human keratinocytes (HaCat). Among them, compounds 5, 9 and 12 selectively inhibited HTLA and ER growth (10–25%) without affecting HaCat, accompanied by robust ROS overproduction, particularly by 9 and 12 (up to 40%). None of these compounds induced apoptosis or ferroptosis. Instead, their antiproliferative effects were associated with senescence induction and, only for compound 5, with a decrease in clonogenic potential. Moreover, to further characterize compounds 5, 9, and 12, the analysis was extended across other human neuroblastoma cell lines. In parallel, the effects of the compounds on non-malignant cell lines were assessed to obtain an indication of their selectivity toward tumor cells. Compound 17, a structural analog lacking the second aromatic ring in the ex-aldehyde portion, displayed a distinct profile with a limited anticancer activity, underscoring the importance of this structural fragment for antiproliferative efficacy. Full article

Understanding the influence of solvent environments on the excited-state charge transfer process remains a fundamental question in molecular photophysics and photochemistry. While twisted intramolecular charge transfer (TICT) is crucial in determining fluorescence efficiency and photostability, the combined effects of solvent polarity and hydrogen bonding interactions are still elusive. Here, we employ steady-state and femtosecond transient absorption (fs-TA) spectroscopy with density functional theory (DFT) calculations to investigate the excited-state dynamics of 7-(diethylamino)coumarin-3-carboxylic acid (7-DCCA) in different solvents. Our findings reveal that in highly polar solvents with strong hydrogen-donating and hydrogen-accepting capabilities, 7-DCCA undergoes significant TICT formation, resulting in fluorescence quenching. Conversely, in environments with low polarity or weak hydrogen-bonding interactions, this transformation is largely suppressed. Quantitative correlation analysis utilizing the Kamlet–Taft and Catalán four-parameter models further elucidates the synergistic role of solvent polarity and specific hydrogen-bonding parameters in modulating the steady-state spectral behavior of 7-DCCA. This study provides microscopic insights into solvent–charge transfer interactions and establishes a general framework for enhancing the luminescence efficiency and structural robustness of organic optoelectronic materials through strategic solvent engineering. Full article

Background: Recent studies have shown that plant-based dietary extracts can prevent the formation of lipid droplets (LDs) and oxidized lipid droplets (oxLDs) in liver cells. These results indicate that these extracts might be useful in addressing metabolic dysfunction-associated fatty liver disease (MAFLD) and its more severe form, metabolic dysfunction-associated steatohepatitis (MASH). In our ongoing study, we evaluated the potential of various food extracts to inhibit the accumulation and oxidation of LDs in liver cells to prevent metabolic MAFLD and MASH. Methods: The antioxidant activity index was determined using the DPPH assay, cell viability was assessed via cytotoxicity and lipotoxicity, and lipid droplet accumulation inhibition (LDAI) assays were performed. Metabolome analysis was performed using 1D-NMR [¹H, ¹³C, DEPT 90, and 135] techniques. Results: Dietary clove (Syzygium aromaticum) extract exhibited antioxidant properties and inhibited linoleic acid-induced lipid droplet (LD) accumulation (LDA) and oxidized LDA (oxLDA) in HepG2 cells. Additionally, an analysis of the metabolome of dietary clove bioactive LDAI using 1D-NMR showed that clove extract (CE) mainly consists of hydroxybenzoic acids (HBAs) and hydroxycinnamic acids (HCAs), along with minor amounts of carbohydrates, coumarins, polyphenolic compounds, and small quantities of polyols, fatty acyls, small peptides, and amino acids. This suggests that CE could be a promising resource for developing functional foods and nutraceuticals and discovering drugs for treating MAFLD, MASH, and related conditions. Full article

This study reports the microwave-assisted synthesis and surface modification of carbon quantum dots (CQDs) from natural precursors and their evaluation as fluorescent probes for cancer cell visualization. CQDs were obtained using amino-glucose as the carbon source and betaine, marine collagen, or dopamine as surface modifiers. Further functionalization with 7-amino-4-(trifluoromethyl)coumarin enhanced their fluorescence properties. Spectroscopic analyses confirmed successful surface modification, with coumarin-modified CQDs displaying a strong emission peak at ~500 nm and approximately 1.5-fold higher fluorescence intensity compared to unmodified CQDs. Cytotoxicity testing on MG-63 osteosarcoma cells showed cell viabilities above 80% for selected samples, fulfilling ISO 10993-5 criteria for non-toxicity. In vitro bioimaging of astrocytoma 1321N1 cells demonstrated bright and uniform intracellular staining, confirming effective cellular uptake. Compared with the literature reports of green-synthesized CQDs, our results indicate comparable or superior fluorescence performance and similar levels of biocompatibility. These findings highlight the potential of surface-engineered CQDs as biocompatible nanoprobes for cancer diagnostics and represent an initial step toward their application in the detection of circulating tumor cells (CTCs). Full article

This review highlights Artemisia annua, a medicinal plant which grows in the Kingdom of Saudi Arabia, known for its abundant therapeutic properties. A. annua serves as a rich source of various bioactive compounds, including sesquiterpenoid lactones, flavonoids, phenolic acids, and coumarins. Among these, artemisinin and its derivatives are most extensively studied due to their potent antimalarial properties. Extracts and isolates of A. annua have demonstrated a range of therapeutic effects, such as antioxidant, anticancer, anti-inflammatory, antimicrobial, antimalarial, and antiviral properties. Given its significant antiviral activity, A. annua could be investigated for the development of new nutraceutical bioactive compounds to combat SARS-CoV-2. Artificial Intelligence (AI) can assist in drug discovery by optimizing the selection of more effective and safer natural bioactives, including artemisinin. It can also predict potential clinical outcomes through in silico modeling of protein–ligand interactions. In silico studies have reported that artemisinin and its derivatives possess a strong ability to bind with the Lys353 and Lys31 hotspots of the SARS-CoV-2 spike protein, demonstrating their effective antiviral effects against COVID-19. This integrated approach may accelerate the identification of effective and safer natural antiviral agents against COVID-19. Full article

Background/Objectives: Cancer is among the leading causes of mortality worldwide. In 2022 alone, the global cancer death toll stood at 9.74 million. Projections indicate that this figure will rise to 10.4 million by 2025. Methods: A new series of benzimidazolone-bridged hybrid compounds containing thiophene, furan, oxadiazole, piperazine, and coumarin moieties was synthesized and structurally characterized by ¹H-NMR, ¹³C-NMR (APT), and elemental analysis. Their cytotoxic effects were evaluated by MTT assay against human lung (A549), human breast (MCF-7), and human cervical (HeLa) cancer cell lines, and the non-cancerous HEK293 cell line after 48 h exposure over a concentration range of 0.5–250 µM. IC₅₀ values were determined, and Selectivity Indexes (SI) were calculated using HEK293 as the reference normal cell line. Molecular docking studies were carried out using the Glide XP protocol against VEGFR2 (PDB ID: 4ASD) and CDK4–Cyclin D3 (PDB ID: 7SJ3), with sorafenib and abemaciclib as reference inhibitors. Results: The results of anticancer activity were compared with doxorubicin (IC₅₀ ± SD (µM)/SI: 4.3 ± 0.2/1.20 for A549, 6.4 ± 0.37/0.77 for MCF-7, 3.4 ± 0.19/1.54 for HeLa), a drug used for cancer chemotherapy. The structures of the newly synthesized hybrid compounds were identified by ¹H-NMR, ¹³C-NMR (APT), and elemental analysis data. These hybrid compounds represent a promising class of anticancer agents. Several compounds demonstrated marked and concentration-dependent cytotoxicity across all cancer cell lines, with HeLa cells showing the highest overall sensitivity. The introduction of an oxadiazole ring (compound 7) and coumarin substituents (compounds 12b–12d) markedly improved anticancer activity and selectivity, yielding low-micromolar IC₅₀ values in HeLa cells (10.6–13.6 µM) and high Selectivity Indexes (SI = 2.0–3.63). Compound 6 also exhibited balanced potency across A549, MCF-7, and HeLa cells (IC₅₀ = 28.3–31.2 µM) with SI values ≥ 2.0. Compound 9 showed strong cytotoxicity across all cancer cell lines; its moderate SI values indicate lower discrimination between malignant and non-malignant cells. Taken together, these findings identified compounds 7, 12b–12d, 6, and 12c as the most promising benzimidazolone-based candidates, displaying both potent cytotoxicity and favorable selectivity over non-malignant HEK293 cells. Conclusions: Among the synthesized molecules, the oxadiazole derivative (7) and the coumarin-based hybrids (12b–12d) exhibited the strongest combination of cytotoxic activity and selectivity, reflected by their low IC₅₀ values and high SI ratios. Notably, compound 12c combined strong biological activity with the highest predicted VEGFR2 affinity in the series, highlighting it as a particularly promising scaffold. While compound 9 exhibited excellent docking scores toward both VEGFR2 and CDK4, its lower selectivity suggests a need for further structural refinement. Overall, the biological and computational findings converge to identify these benzimidazolone hybrids as credible lead candidates for future anticancer optimization. Full article