Search Results (526)

Tuna peptides possess significant bioactivity but are limited by their persistent fishy odor. This study employed mild oxidation with medical-grade hydrogen peroxide (3% H₂O₂) to deodorize tuna peptides. The optimal parameters determined through single-factor and orthogonal experiments were 798 mmol/L H₂O₂, 35 °C, and 20 min. Under these conditions, the sensory score decreased markedly from 5 (very strong odor) to 2.48 (slight odor). Solid-phase microextraction and gas chromatography/mass spectrometry (SPME-GC/MS) analysis confirmed the complete removal of key odorants such as octanal and heptanal, along with a 44.8–54.7% reduction in other volatile compounds. Importantly, the treated peptides retained substantial antioxidant activity, with 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging rates of 91.5% and 78.3%, respectively. Successful incorporation of the deodorized peptides into a moisturizer demonstrated effective and lasting odor reduction. The proposed method offers an efficient, mild, and industrially viable strategy to expand the application of tuna peptides in functional cosmetics and foods. Full article

Copper(II) compounds exhibit interesting magnetic properties due to halide–halide, copper–halide, and intermolecular hydrogen bond interactions. In this study, seven new copper(II) bromide complexes were synthesised, six of which contain Dabco (1,4-diazabicyclo[2.2.2]octane) as a ligand. Single-crystal X-ray diffraction data were refined using both conventional spherical-atom models and a non-spherical-atom approach implemented in NoSpherA2. Magnetic properties were investigated by temperature-dependent magnetic susceptibility and field-dependent magnetisation measurements, analysed using a molecular field approximation. Crystallographic analysis shows that NoSpherA2 significantly improves the description of hydrogen atom positions, yielding C–H and N–H bond lengths closer to neutron diffraction values than conventional refinement. Magnetic measurements indicate that interactions between mononuclear copper(II) centres are determined primarily by the nature of intermolecular exchange pathways rather than copper–copper separations alone. Despite comparable Cu···Cu distances, complexes lacking N–H···Br hydrogen bonds exhibit only weak antiferromagnetic interactions, whereas stronger coupling, effective up to 150 K, is observed when such hydrogen bonds connect neighbouring complexes. These results highlight the importance of hydrogen-bond topology and three-dimensional connectivity in governing magnetic behaviour in mononuclear copper(II) systems. Full article

In this investigation, the local mode model for C-H overtone transitions in hydrocarbons and the thermal lens (TL) technique are used to obtain vibrational overtone spectra and subsequent analysis of hydrocarbon impurities in liquid solutions. The experimental thermal lens design enables the detection of hydrocarbon solutes in trace amounts within a hydrocarbon solvent by exciting two distinct vibrational overtones. To exemplify the method, we present the thermal lens signal corresponding to the (Δυ = 6) overtone of benzene or naphthalene as impurities in solvents such as n-hexane or iso-octane. The lowest composition recorded for benzene in n-hexane was 0.005%, while for naphthalene in n-hexane it was 0.001%. Additionally, we explore more sensitive experiments where the (Δυ = 5) transition of the impurity is detected concurrently with the (Δυ = 6) transition of the solvent. This analytical method can also be adapted for use with saturated alcohols in solution contaminating hydrocarbon solvents. Full article

The hydroisomerization reaction of light alkanes was used to improve their octane value. Industrial light alkane feeds usually contain a certain amount of cycloalkanes and aromatics (known as hydrocarbon impurities). In this study, the influence of hydrocarbon impurities on the isomerization activity of n-alkanes over Pt/SO₄²⁻/ZrO₂/Al₂O₃ (PSZA) was investigated in a continuous flow fixed-bed reactor, TPSR, and pulse reactor. The reason for the influence of hydrocarbon impurities on the isomerization activity of n-alkanes was also discussed by using in situ adsorption–desorption and temperature-programmed reactions. The catalyst was characterized by XRD, PyIR, N₂ adsorption–desorption, TEM, and XRF. The results showed that the prepared catalyst contained mainly tetragonal zirconia and possessed a large amount of strong B and L acid sites. A certain amount of hydrocarbon impurities obviously inhibited the isomerization conversion of n-alkanes. The extent of the inhibition was very dependent on the kind of hydrocarbon impurities, n-alkane carbon number, and reaction temperature. Lighter n-alkane isomerization conversion was influenced to a greater extent. And the increase of reaction temperature could weaken its inhibitory effect. The results provided a reference and base for the industrial application of light alkane hydroisomerization over PSZA. Full article

Lung cancer (LC) remains the leading cause of cancer-related death worldwide, largely due to late-stage diagnosis and the limited performance of current screening strategies. In this preliminary study, headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME/GC-MS) was used to comprehensively characterize the urinary volatilome of LC patients and healthy controls (HCs), with the dual aim of defining an LC-associated volatilomic signature and identifying volatile organic metabolites (VOMs) with discriminatory potential. A total of 56 VOMs spanning multiple chemical classes were identified, revealing a distinct metabolic footprint between groups. LC patients exhibited markedly increased levels of terpenoids and aldehydes, consistent with heightened oxidative stress, including lipid peroxidation, and perturbed metabolic pathways, whereas HCs showed a predominance of sulphur-containing compounds and volatile phenols, likely reflecting active sulphur amino acid metabolism and/or microbial-derived processes. Multivariate modelling using partial least squares-discriminant analysis (PLS-DA, R² = 0.961; Q² = 0.941; p < 0.001), supported by hierarchical clustering, demonstrated robust and clearly separated group stratification. Among the detected VOMs, octanal, dehydro-p-cymene, 2,6-dimethyl-7-octen-2-ol and 3,7-dimethyl-3-octanol displayed the highest discriminative power, emerging as promising candidate urinary biomarkers of LC. These findings provide proof-of-concept that HS-SPME/GC-MS-based urinary volatilomic profiling can capture disease-specific molecular signatures and may serve as a non-invasive approach to support the early detection of LC, warranting validation in independent cohorts and integration within future multi-omics diagnostic frameworks. Full article

Medium-milled rice is increasingly valued for its health benefits and distinctive aroma, which differs from that of white rice because differences in milling degree modify the content of lipids and other aroma precursors. However, its aroma profile remains underexplored. This study aimed to systematically analyze aroma differences among four Simiao rice cultivars after medium milling (8% degree of milling) and to elucidate the chemical basis underlying consumer preference. Odor sensory evaluation identified Xiangzhuxiang as the cultivar with the highest aroma acceptance. Subsequently, gas chromatography–olfactometry–mass spectrometry and odor activity value analysis characterized the volatile profile, identifying 45 volatile compounds across the four cultivars, including 17 key odor-active components. Multivariate statistical analysis pinpointed the discriminating key odor-active compounds responsible for the superior aroma quality of Xiangzhuxiang. The results showed that (E,E)-2,4-decadienal and indole (VIP > 1.0, FDR-adjusted q < 0.05, FC > 1.2, OAV > 1.0, confirmed by GC-O) significantly increased the aroma scores of Xiangzhuxiang; imparted nutty, fatty, and sweet notes; and thus played a decisive role in shaping its characteristic aroma. Moreover, the moderate levels of hexanal and octanal in Xiangzhuxiang facilitated its characteristic aroma expression. These findings provide a basis for developing premium fragrant Simiao rice cultivars optimized for medium milling. Full article

This work describes the lead optimization of a promising class of antibacterial compounds, derived from a previously reported N-[4-(4-fluorophenoxy)phenyl]-6-(methylsulfonyl)-2,6-diazaspiro [3.4]octane-8-carboxamide (LK1819), through systematic scaffold simplification. A novel series of amide derivatives were designed and synthesized, exploring key structural variations, including the replacement of the diphenyl ether core with a biphenyl system. All compounds were evaluated for in vitro antibacterial activity against the ESKAPE panel of pathogens. The most potent simplified analogs demonstrated exceptional, broad-spectrum activity, with minimum inhibitory concentrations (MICs) that were 10 to 100 times lower than the control antibiotic ciprofloxacin against many strains. Mechanistic studies using a reporter system and enzymatic assays revealed that the compounds do not inhibit protein synthesis but disrupt DNA replication, exhibiting a dose-dependent inhibitory effect on bacterial topoisomerase I and DNA gyrase. The compounds showed moderate toxicity against human cell lines, consistent with their DNA-targeting mechanism, but cytotoxicity assays indicated a sufficient selectivity window. We conclude that scaffold simplification successfully yielded highly potent antibacterial agents with a defined mechanism of action, presenting a promising foundation for further development as antibiotics and potentially as anticancer agents. Full article

In this study, the singlet oxygen photosensitization potential of three natural African plant extracts was investigated using the photooxygenation of α-terpinene (1). Utilizing visible light, the Carpolobia lutea extract achieved high conversions towards the anthelmintic ascaridole (2) of >60% after 90 min of irradiation, while the extracts of Hibiscus sabdariffa and Justicia secunda failed to induce significant photoreactivity. Quenching using 1,4-diazabicyclo[2.2.2]octane (DABCO) confirmed a singlet oxygen pathway for irradiation with the C. lutea extract. Further separation of the C. lutea extract and subsequent photooxygenation screening established several active fractions for ascaridole generation. Advanced HPLC–MS analyses of these active fractions revealed several photosensitizing constituents. These findings establish C. lutea extract as a sustainable and effective photosensitiser with comparable performance to commercial dyes. Full article

The Sumaco volcano in Ecuador, which has a distinct geological origin from the Andes and is located in the Amazon basin, offers an opportunity to study untouched microbiomes. We explored comparative patterns of abundance from predicted functional profiling in soil samples collected along the elevation and sulfur gradients on its slopes. Using 16S rRNA gene metabarcoding, we inferred metagenome functional profiles, contrasting sample groups by altitude or soil sulfur concentration. We inferred that high-altitude communities may have higher predicted abundance for anaerobic metabolism (crotonate fermentation), coenzyme B12 synthesis, and degradation of diverse carbon sources (sugars and octane). High-sulfur soils were associated with an inferred enrichment of pathways for degrading complex organic compounds and nitrogen metabolism, reflecting adaptation to unique geochemical conditions. In contrast, low-sulfur soils are consistent with a higher predicted abundance of glycerol degradation. Within the limitation imposed by the potential weak associations of the applied predicted functional profiling to actual gene content, we propose that the inferred metabolic changes represent different ecological strategies for resource acquisition, energy generation, and stress tolerance, and they are optimized for varying conditions in this unique volcanic ecosystem. Our findings highlight how environmental gradients shape soil microbiome functional diversity and offer insights into microbial adaptation in Sumaco’s exceptional geochemistry within the Amazon. Further efforts linking functional predictions back to specific taxa will offer a complete ecological perspective of the microbiome exploration in the Sumaco volcano. Full article

Food packaging is the largest segment of the global plastics market, yet its low degradability and limited performance in preserving perishable goods highlight the need for more sustainable alternatives. This study investigates the use of industrial softwood kraft lignin, a renewable polyol, and γ-valerolactone (GVL), an excellent green lignin solvent, to synthesize bio-based polyurethane (PU) coatings for recycled linerboard. PU was synthesized with hexamethylene diisocyanate (HDI), GVL, and 1,4-diazabicyclo[2.2.2]octane (DABCO) as a catalyst and applied to recycled linerboard (166.6 g/m²) at three coating weights: 13.5, 16.5, and 23.5 g/m². The coating enhanced water resistance, as shown by the reduced water vapor transmission rate (WVTR) and Cobb₁₈₀₀ values. Oil resistance was also significantly improved, reaching a Kit rating of 11 at the highest coating weight. Mechanical performance was maintained or enhanced, with increases in ring crush strength (RCT) and tensile index. These findings confirm the effectiveness of lignin-based PU in improving both the barrier and mechanical properties of packaging paper. Additionally, this approach presents an environmentally responsible alternative to petroleum-based coatings, adding value to lignin as a byproduct of the pulp and paper industry and supporting the transition toward more circular and sustainable packaging materials. Full article

In response to Ecuador’s need for sustainable and locally sourced transport fuels, this study evaluates the energetic and environmental performance of a biofuel (bioethanol-based) derived from the mucilage of the CCN51 cocoa variety, analyzed under controlled operating conditions in an internal combustion engine. Bioethanol obtained from this feedstock was blended with Ecuador’s commercial Extra gasoline to produce an E5 formulation, experimentally compared with Extra (85 RON) and Super (92 RON) fuels. Physicochemical analysis following NTE INEN 2102 revealed a research octane number of 85.8 and a lower heating value of 45.22 MJ/kg. Static tests performed on a Hyundai i10 engine (2021) at 700 and 2500 rpm showed that the E5 blend achieved higher energy and exergy efficiencies (21.17% and 64.12%, respectively) than Extra gasoline, approaching Super performance. Environmentally, the E5–CCN51 blend reduced carbon monoxide (CO) by ~10–15% and unburned hydrocarbons (HC) by ~5–8%, while maintaining λ ≈ 1. Variations in O₂ and CO₂ confirmed enhanced oxidation and more complete combustion. Overall, these findings demonstrate the technical feasibility and environmental relevance of CCN51 cocoa mucilage as a sustainable ethanol source, contributing to cleaner combustion, circular bioeconomy promotion, and energy resilience in tropical developing regions. Full article

Studies were conducted on the hydrogen-free processing of model alkanes, straight-run gasoline, and catalytic cracking gasoline using a new synthesized Co-Mo-Ce/ZSM + Al₂O₃ nanocatalyst, which demonstrated high activity in desulfurization. Thus, the mass fraction of sulfur in the resulting gasoline was reduced by almost three times compared to the initial value of 0.0776% to 0.0354% as a result of hydrogen-free processing of straight-run gasoline. The amount of sulfur in the resulting product was reduced by almost an order of magnitude with hydrogen-free processing of catalytic cracked gasoline: from 0.1650 in the original gasoline to 0.0123%. The octane number of the refined straight-run gasoline was 77.9–80.9 according to the research method (RM) and 61.13–65.8 with the motor method (MM). Physical and chemical methods of analysis (BET, TPD-NH₃, TEM, SEM, and XRD) revealed that nano-structured acid sites coexist with nano-dispersed metallic sites on the surface of the Co-Mo-Ce/ZSM + Al₂O₃ catalyst. The functioning of these two types of nano-active sites (metallic and acidic) ensures the polyfunctionality of the catalytic action of the nanoparticles. The following reactions occur simultaneously in the hydrogen-free processing: isomerization, dehydrogenation, dehydrocyclization. Hydrogen-free processing of low-octane gasoline fractions on nanosized zeolite-containing catalysts is one of the most promising methods to obtain high-octane motor gasoline. Full article

The synthesis of VO_x/MgO catalysts by solution combustion synthesis was investigated using varying molar ratios of glycine to oxidant. The effect of varying the fuel amount on morphology, phase composition, surface area, crystallite size, elemental distribution, and coordination environment around V was investigated. The results showed that the morphology, surface area, and crystallite size are all dependent on the flame temperature during the combustion process, which is dependent on the amount of fuel added. Results also suggested that adding glycine in excess lowers the combustion temperature. The catalysts were tested for the ODH of n-octane. The catalyst with superior catalytic properties was the stoichiometric sample, in which equal molar ratios of the fuel and oxidizer were added. The better catalytic performance was related to the contribution of the VO_x species from the magnesium vanadate phase. This is the only sample in which vanadates were detected. Catalysts synthesized under fuel-lean and fuel-rich conditions were characterized by large crystallites and the absence of detectable magnesium vanadates, using XRD. Full article

Storage time significantly influences the aroma quality of peanut oil. In this study, gas chromatography–mass spectrometry (GC-MS) and gas chromatography–ion migration spectrometry (GC-IMS) were used to analyze the volatile flavor compounds of hot-pressed peanut oil baked at two temperatures (140 °C and 160 °C, denoted as OPO and RPO, respectively) during storage. The two methods detected 80 and 76 volatile flavor compounds, respectively, and principal component analysis (PCA) revealed clear distinctions between OPO and RPO during the storage period. Ten key aroma compounds were identified based on relative odor activity value (ROAV) analysis, including 3-methylbutanal, hexanal, heptanal, octanal, benzeneacetaldehyde, 3-ethyl-2,5-dimethylpyrazine,2-ethyl-6-methylpyrazine, acetylpyrazine, 2-methoxy- 4-vinylphenol, and acetic acid. During storage, the degradation and transformation of flavor compounds were more pronounced in RPO than in OPO. Physicochemical analyses showed increased acid and peroxide values, concomitant with decreased vitamin E and phytosterol content. Notably, these parameters changed more slowly in OPO than in RPO, confirming that OPO maintained superior quality over time. Correlation analysis suggested that changes in the aldehyde and pyrazine contents are key indicators of flavor and quality evolution in peanut oil during storage. This study provides insights into how baking temperature and storage time affect peanut oil aroma, elucidating the mechanisms of flavor variation and offering a theoretical basis for optimizing the flavor and quality of hot-pressed peanut oil. Full article

Risdiplam is the first approved small-molecule therapy for spinal muscular atrophy (SMA), a severe, progressive neuromuscular disorder. In addition to its clinical significance, risdiplam is of a great interest for organic and medicinal chemistry due to its complex molecular architecture. Its structure incorporates three highly substituted heterocyclic fragments—imidazo[1,2-b]pyridazine, pyrido[1,2-a]pyrimidin-4-one, and 4,7-diazaspiro[2.5]octane—that serve as both versatile synthetic building blocks and critical pharmacophoric elements for drug design and discovery. The increasing scientific interest in risdiplam has led to numerous publications and patent applications that describe alternative synthetic methodologies. Recently, our group has also developed and introduced efficient, scalable manufacturing routes for the preparation of the target substance and the key intermediates of its synthesis. This mini-review systematically analyzes a plethora of risdiplam assembly strategies and synthetic approaches, covering developments from 2013 to the present. Full article