Search Results (214)

Background/Objectives: The emergence of antimicrobial resistance threatens advances achieved by medicine in the last century. This situation has been exacerbated by the suboptimal outcome of screening campaigns to provide novel antimicrobials. Methods: An alternative strategy was employed to identify new chemical scaffolds with antimicrobial activity. A collection of photoactive compounds originally synthesized for industrial purposes was screened for antibacterial activity. Results: 4H-pyran-4-ylidenes were identified as active against Gram-positive bacteria. Compounds belonging to this family displayed dose-dependent bactericidal activity against both wild-type and methicillin-resistant Staphylococcus aureus. No cytotoxicity was observed in the HepG2 hepatic cell line at the concentrations required for antimicrobial activity against S. aureus. Resistance to 4H-pyran-4-ylidenes in S. aureus was associated with point mutations in the rny locus, which encodes for a ribonuclease that plays a key role in RNA homeostasis. Conclusions: These findings indicate that chemical libraries not originally intended for drug discovery can be an innovative source of chemical diversity for the development of novel antimicrobials. Full article

Spirocyclic compounds are experiencing a research surge due to their unique 3D structure, offering enhanced pharmacological, industrial, and material applications. They are increasingly used in medicinal chemistry to improve drug-like properties, such as solubility and target binding, and are also being utilized for advanced material applications, including electronics and photonics. In this communication, 3-(4-hydroxyphenyl)-1′,3′,6-trimethyl-2′H,3H,4H-spiro[furo[3,2-c]pyran-2,5′-pyrimidine]-2′,4,4′,6′(1′H,3′H)-tetraone was prepared via a two-stage transformation including a tandem Knoevenagel–Michael reaction and NBS-induced cyclization. At the first stage, a previously unknown ionic scaffold, morpholin-4-ium 5-((4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)(4-hydroxyphenyl)methyl)-1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-olate was also isolated. Structures of the newly synthesized compounds were established by ¹H and ¹³C NMR, IR spectroscopy, high-resolution mass spectrometry, and elemental analysis. Full article

The present study addresses the development and characterization of an in-chip laser-induced graphene (LIG)-based sensor that combines optical and electrochemical transduction techniques as a proof of concept for the advancement of novel point-of-care (POC) devices. In recent years, LIG has emerged as a suitable material for next-generation diagnostic devices due to the increasing need for effective and easily accessible biosensing platforms. In this context, the presented sensors were fabricated and tested with an increasing number of laser exposures to understand how the resulting morphology, degree of graphitization, defects, and electrical resistance of LIG electrodes affect the electrochemical and optical sensing performance. To validate the dual sensor, ferrocyanide ([Fe(CN)₆]⁴⁻) was used as a redox probe and [(4-Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran] (DCM) was used as model dye to explore the electrochemical and optical sensing capabilities. Finally, we showcase the sensor’s ability to perform simultaneous optical and electrochemical on-time detection and analysis of the ferrocyanide electro-oxidation process, underscoring its potential to be used as a dual optical/electrochemical POC device. Full article

As a part of an SAR study aimed at testing the antitumor activity of some C₁₅ acetogenins related to mycalin A, we report here the synthesis of the C-1 debromo-derivative of laurenciallene, a substance recently isolated from the red alga Laurencia obtusa. This new substance has been obtained by the selective, reductive debromination of the terminal bromoallene moiety of laurenciallene with Zn/AcOH. Its structure has been fully characterized by spectral methods, including 2D-NMR spectra. Full article

An inorganic–organic hybrid nano-adsorbent was prepared by chemical immobilisation of an organic Schiff base Cu (II) ion receptor, DHB ((E)-N-(1-(2-hydroxy-6-methyl-4-oxo-4H-pyran-3-yl) ethylidene) benzohydrazide), a selective dehydroacetic acid-based chemosensor, onto a mesoporous silica support. In order to prepare the sorbent, the silylating agent was anchored onto the silica. During this procedure, 3-Chloropropyl trimethoxy silane (CPTS) was attached to the surface, increasing hydrophobicity. By immobilising DHB onto the CPTS platform, the silica surface was activated, and as a result the coordination chemistry of the Schiff base generated a hybrid adsorbent with the capability to rapidly sequestrate Cu (II) ions from wastewater, as an answer to combat growing Waste Electrical and Electronic Equipment (WEEE) contamination in water supplies, in the wake of a prolonged consumerism mentality and boom in cryptocurrency mining. The produced hybrid materials were characterised by FTIR, proximate and ultimate analysis, nitrogen physisorption, PXRD, SEM, and TEM. The parameters influencing the removal efficiency of the sorbent, including pH, initial metal ion concentration, contact time, and adsorbent dosage, were optimised to achieve enhanced removal efficiency. Under optimal conditions (pH 7.0, adsorbent dosage 3 mg, contact time of 70 min, and 25 °C), Cu (II) ions were quantitatively sequestered from the sample solution; 93.1% of Cu (II) was removed under these conditions. The adsorption was found to follow pseudo-second-order kinetics, and Langmuir model fitting affirmed the monolayer adsorption. Full article

Achillea fragrantissima is a medicinal herb valued for its essential oils and bioactive compounds. Microalgae, such as Spirulina platensis and Chlorella vulgaris, show considerable promise as natural biostimulants due to their high levels of protein, minerals, vitamins, and fatty acids. The individual or compound effects of S. platensis and C. vulgaris on the growth, photosynthetic pigments, and essential oil composition of A. fragrantissima in vitro were measured in this study. According to chemical analysis, S. platensis contains large amounts of protein and several minerals, including phosphorus, manganese, and iron. Conversely, C. vulgaris showed a higher percentage of carbohydrates, lipids, phytol, aldehydes, and fatty acid esters. The combination of 1.0 g·L⁻¹ S. platensis and 0.5 g·L⁻¹ C. vulgaris tended to stimulate callus formation. Meanwhile, the 0.5 g·L⁻¹ C. vulgaris treatment enhanced shoot and leaf development and increased total photosynthetic pigment content. Analysis of essential oils from A. fragrantissima produced under different treatments demonstrated that combined treatments with S. platensis and C. vulgaris had greatly improved the valuable bioactive substances, such as phytol, oleic acid, 2H-pyran, and thymine. These results show the effectiveness of using S. platensis and C. vulgaris extracts as eco-friendly biostimulants. Full article

Traditional herbal prescriptions composed of multiple botanicals remain central to ethnopharmacological practice; however, their chemical basis and classification remain poorly understood. Non-volatile compound analyses of herbal medicines are well established, but comparative studies focusing on volatile organic compounds (VOCs) across multi-herbal prescriptions are scarce. To enhance the chemical understanding of traditional formulations and clarify prescription-level characteristics, this study applied headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME–GC–MS) to characterize VOC-based chemical signatures in 30 prescriptions composed of 76 herbal ingredients. Multivariate analyses such as principal component analysis, partial least squares discriminant analysis (PLS-DA), and orthogonal PLS-DA (OPLS-DA) enabled systematic differentiation of various prescriptions and identified 25 discriminant VOCs, 9 of which were common among multiple therapeutic categories. These shared compounds, such as 5-hydroxymethylfurfural (5-HMF) and 4H-pyran-4-one derivatives, reflect recurrent chemical patterns associated with broad-spectrum applications, whereas category-specific volatiles (including isopsoralen, senkyunolide, and fenipentol) delineated therapeutic boundaries, even among prescriptions with overlapping botanicals. Capturing both shared and distinct volatile signatures clarified ambiguous boundaries between categories such as cold, inflammation, or diabetes versus kidney disorder prescriptions, thereby linking chemical patterns with ethnopharmacological indications. Together, these findings highlight VOC profiling as a valuable diagnostic and interpretive tool that bridges traditional categorization systems with modern chemical analysis, offering a robust framework for future pharmacological and mechanistic investigations. Such an approach not only substantiates traditional categorization but also provides a practical basis for quality control and pharmacological evaluation of multi-herbal formulations. Full article

Background/Objectives: The development of effective oncologic therapies with fewer adverse effects is often limited by the intrinsic and acquired resistance of tumor cells. Hybrid molecules, rationally designed to combine different pharmacophores, represent a promising strategy by providing synergistic effects, dose reduction, and a lower risk of resistance. In this study, the antitumor potential and mechanisms of action of 22 novel hybrid compounds derived from xanthene and pyran scaffolds (SJ022–SJ103) were investigated. The hybrids were initially evaluated through in vitro screening in four breast, three ovarian, and two prostate cancer cell lines, followed by the selection of T-47D, OVCAR-3, and LNCaP cells for detailed assays assessing cytotoxicity, apoptosis, cell cycle distribution, DNA damage, caspase-3/7 activity, morphology, and PI3K/AKT/mTOR pathway modulation. Methods: Cytotoxicity assays were performed in the selected cell lines, while mechanistic studies included apoptosis and cell cycle analysis by flow cytometry, γH2AX detection, Western blotting for PI3K/AKT/mTOR pathway proteins, and 3D spheroid assays. Combinatorial effects with hormone therapies (tamoxifen, fulvestrant, and letrozole) and the AKT inhibitor MK2206 were evaluated. AKT silencing by esiRNA and molecular docking was performed to confirm target engagement. Results: SJ028 demonstrated broad activity across all tested cell lines, whereas SJ064 and SJ078 exhibited higher selectivity. Treatments induced apoptosis, S/G2-M arrest, and DNA damage, accompanied by decreased phospho-AKT levels and stable PI3K and mTOR expression. In 3D models, the hybrids increased caspase-3/7 activity and necrotic core expansion. Co-administration with hormone therapies resulted in synergistic effects in breast and ovarian cancer cells, reducing IC₅₀ values by more than 50% in both parental and resistant models, while combinations with MK2206 were antagonistic across all tumor subtypes. AKT silencing abrogated cytotoxicity, and docking confirmed SJ028 binding to AKT. Conclusions: Xanthene- and pyran-based hybrids—particularly SJ028, SJ064, and SJ078—showed strong antitumor activity through apoptosis induction, cell cycle arrest, and PI3K/AKT pathway modulation. Their preserved efficacy in resistant models and synergistic interactions with hormone therapies contrasted with the antagonism observed with AKT inhibition, highlighting their potential as promising candidates for the treatment of hormone-responsive and -resistant cancers. Full article

This study explores the Diels–Alder reaction using spilanthol, a natural diene isolated from Heliopsis longipes roots, to synthesize potentially bioactive compounds. Spilanthol was purified through silica gel column chromatography, yielding 16 g/kg of dried roots, and characterized by ¹H NMR spectroscopy. Among the dienophiles tested, only p-anisaldehyde reacted efficiently in the presence of BF₃·OEt₂ as a Lewis acid catalyst. A cyclic adduct was obtained with yields of 9.72% (endo) and 24.32% (exo). ¹H NMR analysis confirmed the formation of a pyran ring, demonstrating the viability of this synthetic pathway for producing functionalized cyclic compounds with potential biological activity. Full article

Microbial detoxification, as an environmentally friendly strategy, has been widely applied for benzo[a]pyrene (BaP) degradation. Within this approach, food-derived microbial strains offer unique advantages in safety, specificity, and sustainability for detoxifying food-borne BaP. In this study, we aimed to explore the potential of such strains in BaP degradation. Bacillus mojavensis TC-5, a strain that degrades BaP, was isolated from kefir grains. Surprisingly, 12 genes encoding dehydrogenases, synthases, and oxygenases, including betB, fabHB, qdoI, cdoA, and bioI, which are related to BaP degradation, were up-regulated by 2.01-fold to 4.52-fold in TC-5. Two potential degradation pathways were deduced. In pathway I, dioxygenase, betaine aldehyde dehydrogenase, and beta-ketoacyl-ACP synthase III FabHB act sequentially on BaP to form 4H-pyran-4-one,2,3-dihydro-3,5-dihydroxy-6-methyl via the phthalic acid pathway. In the presence of the cytochrome P450 enzyme, BaP progressively mediates ring cleavage via the anthracene pathway, eventually forming 3-methyl-5-propylnonane in pathway II. Notably, TC-5 achieved an impressive BaP removal efficiency of up to 63.94%, with a degradation efficiency of 32.89%. These results suggest that TC-5 has significant potential for application in addressing food-borne BaP contamination. Moreover, our findings expand the application possibilities of Xinjiang fermented milk products and add to the available green strategies for BaP degradation in food systems. Full article

This study investigated the enhancement in lipid accumulation in Chlorella sp. using non-thermal atmospheric pressure plasma as a pretreatment strategy for the production of value-added products. The plasma treatment was optimized by varying discharge times (0–16 min) using argon gas at a flow rate of 4 L/min. Lipid productivity was assessed through gravimetric analysis and profiling of fatty acid methyl ester using gas chromatography−mass spectrometry (GC-MS). The growth rate and pH of the treated cells were monitored. The findings demonstrated that the 4-min plasma exposure maximized the efficiency of lipid recovery, achieving a 35% of the dry cell weight and a 34.6% increase over untreated control. However, longer plasma treatment times resulted in a comparative decrease in lipid yield, as the decline is possibly due to oxidative degradation. The findings highlight the role of plasma treatment, which significantly boosts lipid yield and gives complementary optimization of downstream processes to improve biodiesel production. The accumulation of lipids in terms of size and volume in the algal cells was assessed by confocal laser scanning microscopy. The GC–MS results of the control revealed that lipids comprised primarily mixed esters such as 2H Pyran 2 carboxylic acid ethyl esters, accounting for 50.97% and 20.52% of the total peak area. In contrast, the 4-min treated sample shifted to saturated triacylglycerols (dodecanoic acid, 2,3 propanetriyl ester), comprising 85% of the total lipid content, which efficiently produced biodiesel. Thus, the non-thermal plasma-based enhancement of lipids in the algal cells has been achieved. Full article

N,N-Dimethyl N-[4-[[[2-(4-methylphenyl)-6,7-dihydro-5H-benzocyclohepten-8-yl]carbonyl]amino]benzyl]tetra-hydro-2H-pyran-4-aminium chloride (TAK779) has a potent binding affinity for the chemokine receptor CCR5 and low cytotoxicity; however, their interaction remains unknown. We designed and synthesized four fluorescence-labeled TAK779 analogs as chemical probes. Although the binding properties of the fluorescence-labeled TAK779 analogs for CCR5 could not be determined, it was found that they penetrate the cell membranes and localize to the microtubes of HeLa cells. Full article

The aim of this work was to prepare a large set of variously substituted 3-aminophthalates starting from substituted 3-acylamino-2H-pyran-2-ones acting as dienes in Diels–Alder reactions with dialkyl acetylenedicarboxylates having the role of dienophiles. These thermally allowed [4+2] cycloadditions were taking place with normal electron demand due to rather electron-deficient dienophiles and relatively electron-rich dienes; however, they still required quite harsh reaction conditions: heating in closed vessels at 190 °C for up to 17 h was sufficient in most cases (albeit for a few reactions the time needed was up to 58 h) to achieve conversions above 95%. Such conditions, unfortunately, necessitated the use of a larger excess of dienophiles (as undesired polymerization takes place concomitantly); nevertheless, the straightforward isolation procedures enabled access to the target compounds in moderate to high yields (average yield 56%). All products were characterized by standard analytical and spectroscopic methods. With the goal of changing the reaction conditions to be more environmentally friendly, we investigated the effect of various solvents (water, n-butanol, butyl acetate, xylene, para-cymene, n-nonane, etc.) and the temperature applied (130–190 °C) on the conversion. We found that higher temperatures are necessary in most cases (except for the most reactive 2H-pyran-2-ones) regardless of the solvent used. Relative reactivity was determined for both sets of reactants and the experimentally obtained data show good agreement with the computational results. Full article

Two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOF MS) was employed to analyze the volatile flavor compounds (VOCs) of Tricholoma matsutake samples from six different geographical regions: CX (Chuxiong), DL (Dali), DQ (Diqing), JL (Yanji), SC (Xiaojin) and XZ (Linzhi). The result indicate that a total of 2730 kinds of VOCs were identified from the fruiting bodies of six T. matsutake samples. The primary types of volatile organic compounds identified were 349 alcohols, 92 aldehydes, 146 carboxylic_acids, 311 esters, 742 organoheterocyclic compounds, 630 hydrocarbons, 381 ketones, 51 organic acids, and 28 derivatives and organosulfur compounds. Furthermore, PCA and PLS-DA analysis from the GC×GC-ToF-MS showed that samples from different regions could be distinguished by their VOCs. Network analysis revealed that 33 aroma compounds were identified as markers for distinguishing the samples from the six regions. The sensory attributes sweet, fruity, green, waxy, and floral were found to be more significant to the flavor profile of T. matsutake. 1-Nonanol, 2-Nonanone, Nonanoic acid, ethyl ester, 1-Undecanol, 2-Undecanone, Octanoic acid, ethyl ester, 2H-Pyran, and tetrahy-dro-4-methyl-2-(2-methyl-1-propenyl)- primarily contribute to the differences in the aroma characteristics among six T. matsutake samples. The results also provide a theoretical and practical foundation for the flavor compounds of these precious edible fungi in different regions. Full article

Phaeosphaeride A and its analogues have been extensively explored for their potential pharmacological applications, particularly in the development of anticancer agents. In this study, the synthesis of structurally modified phaeosphaeride analogues is reported. The structures of the synthesized analogues bearing the tetrahydro- and hexahydro-2H-furo[3,2-b]pyran-2-one and hexahydropyrano[3,2-b]pyrrol-2(1H)-one moieties were assessed and the new compounds were evaluated for their antiproliferative activity against two cancer cell lines. Despite successful synthesis and structural modification, the majority of the phaeosphaeride analogues exhibited limited bioactivity. Structure-activity relationship studies suggested that specific modifications did not enhance anticancer potency. The hydroxy groups and the alkyl moiety in cyclic or non-cyclic phaeosphaeride analogues contribute to the activity, as shown by the activity of compounds 24 and 25. The presence of double bonds and oxygen or nitrogen heteroatoms in furopyranones or pyranopyrrolones 9, 28, 29 and 33a, does not significantly impact cytotoxic activity. These findings highlight the challenges in optimizing phaeosphaerides for anticancer applications and provide insights into future structural modifications to improve their therapeutic potential. Moreover, our studies open a synthetic route for the development of new phaeosphaeride analogues. Full article