Search Results (269)

Although the fumigant activity of the naturally occurring compounds methyl benzoate and its analogues has been extensively evaluated against stored-product insect pests, their contact toxicity when applied as residual surface sprays and grain protectants, as well as their repellent effects, remains poorly studied. The current study evaluated the contact toxicity of methyl benzoate (MB) and a related natural product, acetophenone (AP), on glass surfaces and on wheat grains, along with their repellent activity, against adults of the lesser grain borer, Rhyzopertha dominica, the red flour beetle, Tribolium castaneum, the rice weevil, Sitophilus oryzae, and the khapra beetle, Trogoderma granarium. Both compounds were significantly toxic as residual films on glass surfaces, with S. oryzae and T. granarium being more susceptible to both compounds than R. dominica and T. castaneum. Dose-mortality studies found that the LC₅₀ values for MB were 0.265, 0.233, 0.257, and 0.149 mg/cm², while those for AP were 0.328, 0.156, 0.233, and 0.126 mg/cm² for R. dominica, S. oryzae, T. castaneum, and T. granarium adults, respectively. Furthermore, both compounds were highly toxic to all insect species on wheat grain, achieving complete adult mortality at 2.0 g/kg after 3 days of exposure, with no adults emerging (0.0 adults) after 65 days of treatment and with no reduction in wheat grain weight (0.0% loss). However, MB and AP exhibited negligible to weak repellent or attractive effects toward all tested insect species, even at the highest concentration tested (50 µg/cm²). Overall, these findings suggest that MB and AP could be viable candidates for stored-product protection as residual applications and may serve as alternatives to, or reduce reliance on, synthetic insecticides. Full article

This work presents the synthesis and structural characterization of a previously unknown palladium(II) complex with (2E)-2-[1-(4-aminophenyl)ethylidene]hydrazine-1-carbothioamide, which in the solid state forms a highly symmetric tetrametallic metallamacrocycle. The structure of the synthesized (2E)-2-[1-(4-aminophenyl)ethylidene]hydrazine-1-carbothioamide and corresponding palladium(II) complex was established by ¹H, ¹³C–{¹H}, ¹H–¹³C HMQC, and ¹H–¹³C HMBC NMR spectroscopy; IR and UV spectroscopy; mass spectrometry; TGA/DSC analyses; and single-crystal X-ray diffraction. Full article

Ageing vessels are critical to the sensory maturation of Baijiu, yet the interfacial material processes by which traditional ceramics modulate liquor chemistry remain insufficiently defined. Here, Zisha and ceramic-clay particles with distinct aluminosilicate frameworks, mineral compositions, and pore structures were investigated to elucidate their roles in sauce-flavor Baijiu ageing. Ceramic characterization was combined with elemental and volatile analyses using ICP-MS, GC-MS, and GC-IMS. The results showed that pore development in Zisha was primarily governed by fluxing metal oxides and the Si/Al framework, whereas metal-ion migration into Baijiu was regulated by the SiO₂-rich matrix, pore accessibility, and trace elemental composition. Metal elements exhibited reversible interfacial exchange rather than simple leaching, revealing a dynamic metal-ion cycling process during ageing. This process was associated with selective remodeling of the volatile profile. Compared with ceramic-clay particles, Zisha promoted the accumulation of acetophenone, 3-pentanone, and pyrazine derivatives while reducing dimethyl disulfide and heptanal. Sensory evaluation of Baijiu aged in ceramic jars further validated these findings. These findings identify Zisha ceramics as active material–flavour interfaces and provide a mechanistic basis for the rational design of ceramic ageing vessels to direct Baijiu flavour maturation. Full article

We have prepared two novel tethered (arene)Ru(II)/TsDPEN complexes, one containing a p-OTBS on the η⁶-arene ring, and the other with a p-CO₂Et group at the same position, representing an electron-rich and electron-poor derivative. These have been evaluated in asymmetric transfer hydrogenation (ATH) of acetophenone derivatives and acetylcyclohexane. Both catalysts were effective in ATH and gave alcohols in high ees in most cases (with the exception of acetylcyclohexane reduction), mirroring results previously obtained using Ru(II) tethered catalysts. It was notable that the p-CO₂Et-containing catalyst was more active than the untethered equivalent catalyst containing an ester on the η⁶-arene ring, although it still gave products of high ee. This indicates that N-η⁶-arene ring tethering can compensate for the lower activity of the electron-withdrawing ester group and may be a useful factor to consider for future catalyst design. Full article

Polishing enhances the appearance and market competitiveness of rice. To better understand the effect of polishing on rice flavor, volatile flavor compounds in polished rice (PR), unpolished rice (UR), cooked polished rice (CPR), and cooked unpolished rice (CUR) were examined using headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS). The results revealed fourteen volatile flavor compounds displayed significant differences in abundance, with eight of these compounds potentially contributing to the overall flavor profile based on their volatility and reported odor characteristics. Among these compounds, only eicosane and hexanal were detected in uncooked rice, whereas acetophenone, hexadecanol, dodecane, and octadecane were unique to CUR. Four compounds were associated with aroma notes reminiscent of flowers, wax, and almond, among others. However, nonanal and nerol were common in both cooked rice samples, and they may contribute to a sweet-like aroma in cooked rice. These findings illuminate the changes in volatile composition, offer insights to prevent over-polishing, and inspire further research toward producing rice with potentially improved aroma profiles. Full article

A facile co-precipitation method was employed to synthesize copper(II) ferrite composites with carbon materials (reduced graphene oxide, graphitic carbon nitride, and their mixture), followed by heat treatment at 700 °C. To obtain Fe-Cu-containing catalysts, copper ferrite composites were electrochemically reduced. Structures, compositions, and morphologies of the composites were studied using scanning electron microscopy, X-ray diffraction techniques, and thermogravimetric analysis. The results showed that graphitic carbon nitride had the strongest effect on the phase composition of copper ferrite. Crystalline phases of reduced copper and iron metals appear in the CuFe₂O₄/g-C₃N₄ composite during the annealing process, facilitating further complete electrochemical reduction of copper ferrite and shortening its duration. The resulting Fe-Cu/C composites were used as catalysts in the electrohydrogenation of acetophenone as a model compound. The activation of the cathode with Fe-Cu/C catalysts increases the rate of acetophenone hydrogenation and leads to the selective formation of a single product, 1-phenylethanol, in high yields. Full article

Atraphaxis virgata and Atraphaxis pyrifolia are xerophytic species of the Polygonaceae family that remain insufficiently characterized from pharmacognostic, phytochemical, and toxicological perspectives. This study provides an integrated evaluation of both species through anatomical authentication, sequential extraction of CO₂-extracted residual biomass, GC–MS and LC–MS metabolite profiling, and acute oral toxicity assessment. Anatomical analysis revealed shared xeromorphic traits, including cuticular protection, dorsiventral mesophyll organization, structured vascular bundles, and calcium oxalate druses. It also identified species-specific differences in leaf thickness, mesophyll arrangement, vascular architecture, and druse morphology. GC–MS analysis showed distinct chemical profiles: A. virgata displayed a concentrated profile dominated by acetophenone- and benzofuran-related constituents, whereas A. pyrifolia showed a broader spectrum of carbohydrate-derived, phenolic-related, and oxygenated constituents. LC–MS analysis supported the tentative annotation of diverse polyphenolic classes, including flavonoids, phenolic acids, coumarins, and phenylpropanoid derivatives. Acute oral toxicity testing showed no mortality at doses up to 2000 mg/kg, supporting a low acute oral toxicity classification under the tested conditions. However, histological examination revealed mild to moderate dose-dependent alterations in liver and kidney tissues at higher doses. The novelty of this work lies in linking diagnostic anatomical traits, species-specific metabolite patterns, residual biomass valorization, and preliminary safety evidence within a single comparative framework. These findings provide a basis for pharmacognostic authentication, phytochemical standardization, and future bioactivity-guided evaluation of Atraphaxis species. Full article

Walnut oil is growing in consumer demand due to its rich nutritional profile; however, its fatty acid composition exhibits an imbalanced SFA:MUFA:PUFA ratio (0.13:0.18:1). To improve the fatty acid balance using locally available vegetable oils in Xinjiang, we investigated the effects of blending walnut oil with linseed oil, safflower seed oil, sunflower seed oil, rapeseed oil, peanut oil, and soybean oil on physicochemical indexes, fatty acid composition, and bioactive components. Aroma characteristics were assessed by E-nose and HS-GC-IMS. The results showed that the acid value and peroxide value of the blended oil decreased, while the content of vitamin E and squalene increased inversely. The ratio of ω-6/ω-3 maintain steadily at 4–6:1, and the ratios of SFA, MUFA, and PUFA were close to 0.27:1:1. Significant differences were observed between the aroma characteristics of walnut oil and the blended oil. HS-GC-IMS identified 85 volatile organic compounds (VOCs), among which walnut oil had a higher content of alcohols, aldehydes, and ketones, with 4-hydroxy-5-ethyl-2-methyl-3(2H)-furanone as its characteristic aroma compound. The acetophenone serves as the key aroma component after blending, and the unique flavor components of each base oil (e.g., 4-nonanone in linseed oil, 3-methyl-2-pentanone in rapeseed oil, etc.) exert a synergistic effect after rationing to present a composite aroma characteristic of blended oils, which mainly consists of 3-methylbutyl butyrate and 4-ethylphenol. Full article

A new tert-butyldimethylsilyl-protected polyoxygenated chalcone was prepared by Claisen–Schmidt condensation of suitably protected acetophenone and benzaldehyde derivatives. Treatment of this chalcone with m-chloroperbenzoic acid (mCPBA) afforded β-(3-chlorobenzoyloxy)-α-hydroxyketone 5, which was fully characterized by spectroscopic methods. The structure of 5 is consistent with initial epoxidation of the enone double bond followed by in situ nucleophilic opening of the transient epoxide by m-chlorobenzoate generated in the reaction medium. This work reports the preparation of the chalcone precursor and the characterization of the unexpected oxidation product 5. Full article

Herein we reported on a one-pot nitro reduction/nucleophilic aromatic substitution on 1-(2-fluoro-5-nitrophenyl)ethan-1-one using a mixture of acetic acid and iron powder in ethanol. The resultant target compound, a nitrated N bis-acetophenone, has many reactive handles; as such, it is a novel intermediate that can be deployed for the syntheses of a vast array of compounds not reported before. This compound is fully characterized using ¹H and ¹³C NMR spectroscopy, and HRMS. Full article

The genus Scutellaria (Lamiaceae) is a phytochemically rich and medicinally important group of plants. Scutellaria species have been characterized by biologically active flavonoids such as baicalin, baicalein, and wogonin. In the present study, the essential oils of S. angustifolia, S. baicalensis, S. barbata, and S. lateriflora, cultivated in eastern Oregon, were obtained by means of hydrodistillation and analyzed using gas chromatographic methods. We hypothesize that the essential oils have compositions that may play a role in the traditional uses and biological activities of the genus. The major components in S. angustifolia essential oils were germacrene D (32.5–58.3%), (E)-β-caryophyllene (4.9–29.2%), and β-bourbonene (2.8–9.4%). Scutellaria barbata essential oil was dominated by 1-octen-3-ol (59.9%), with lower concentrations of linalool (9.5%) and (2E)-hexenal (5.1%). The major components in the essential oil of S. lateriflora were 1-octen-3-ol (28.3%), acetophenone (24.8%), benzaldehyde (7.5%), limonene (6.0%), (E)-benzalacetone (5.9%), and β-phellandrene (5.1%). The major components of the essential oil of S. baicalensis were 1-octen-3-ol (22.3%), (E)-β-caryophyllene (22.3%), and germacrene D (28.3%). This study demonstrates that Scutellaria can be cultivated in eastern Oregon. Additionally, S. angustifolia essential oil has been characterized for the first time. Full article

Aging underground pipeline infrastructure across the United States, including systems used for potable water supply, wastewater collection, and stormwater conveyance, has exceeded its intended service life, emphasizing the need for replacement or rehabilitation to maintain reliable service to communities. Among available trenchless technologies, cured-in-place pipe (CIPP) is widely applied because it minimizes surface disruption and is well-suited for use in densely populated areas. Despite these advantages, environmental concerns remain regarding the release of total volatile organic compounds (VOCs) during CIPP installation and curing. This study evaluates total VOC emissions from CIPP liners under field conditions. Air samples were collected at six installation sites across the United States before, during, and after installation and curing to quantify key VOC species. Multiple sampling methods were employed, including photoionization detectors (PIDs), Summa canisters, and personal worker sampling. The measured compounds included styrene, cumene, acetophenone, hexane, toluene, and ethanol. Measured concentrations were compared with occupational exposure limits established by the U.S. Environmental Protection Agency (USEPA), the National Institute for Occupational Safety and Health (NIOSH), and the Occupational Safety and Health Administration (OSHA). The results indicate that styrene was the dominant compound within active CIPP work zones, with peak concentrations reaching 25.5 ppm during curing. In contrast, VOC concentrations decreased substantially within five feet downwind of the work zone. Overall, the findings suggest that potential public exposure risks are limited, while workers directly involved in CIPP operations may experience elevated short-term exposures during installation and curing activities. Full article

Volatile organic compounds (VOCs) are increasingly recognized as metabolic byproducts of viral infection and may serve as olfactory cues detectable by trained scent dogs. This study examined whether dogs could distinguish cell culture samples infected with murine hepatitis virus strain 1 (MHV-1), a biosafety level 2 coronavirus model, from uninfected controls. Parallel chemical analysis using gas chromatography–mass spectrometry (GC-MS) identified 14 VOCs in infected and 12 in control samples. Notably, 3-heptanone and 1-nonanol were unique to infected samples, while others such as acetophenone, nonanal, decanal, and benzaldehyde were significantly elevated—often by 1.5 to 3 times—in infected cultures. Two trained dogs demonstrated high detection sensitivity (0.95) for infected samples compared to a previously trained odor cinnamon group (0.88) and responded with shorter latency (p = 0.04), suggesting perceptual salience of infection-related VOCs. Reliable detection required pooled volumes (~600 µL), suggesting a threshold effect related to VOC concentration. Additionally, a Random Forest-based machine learning classifier trained on the GC-MS-obtained VOC profiles achieved a cross-validated accuracy of 0.82 (SD = 0.25). These findings suggest that dogs use quantitative VOC differences, rather than unique compounds, for detection. The study provides a validated experimental framework for olfactory diagnostics of viral infections and highlights the potential of scent dogs as non-invasive biosensors in both veterinary and public health contexts. Full article

In this study, copper–carbon material composites, Cu/CM (where CM is reduced graphene oxide (rGO), graphitic carbon nitride (g-C₃N₄), their mixture, and N-doped reduced graphene oxide (N-rGO)), were prepared using a simple method of chemical reduction of copper cations in the presence of CM related to molecular-level mixing methods. Additionally, copper cations from its oxides present in the composites were reduced in an electrochemical cell by depositing them on the surface of a horizontally positioned cathode. The structure and morphology of the Cu/CM composites were studied using electron microscopy and X-ray diffraction analysis. The thermal stability and elemental analysis were determined for the carbon materials. The resulting Cu/CM composites were used as electrocatalysts in the electrohydrogenation of the aromatic ketone, acetophenone. Cu/rGO and Cu/N-rGO composites with a 1:1 ratio exhibited catalytic activity in this process, increasing the rate of APh hydrogenation and its degree of conversion with the selective formation of a single product, methyl phenyl carbinol (or 1-phenylethanol), compared to the electrochemical reduction of APh on a cathode without a catalyst. The Cu/N-rGO composite demonstrated the highest electrocatalytic activity. Full article

This study investigates the production of volatile organic compounds (VOCs) in RK-13 cells infected with three equine viruses representing different families: equine arteritis virus (EAV) (Arteriviridae), equine herpesvirus 1 (EHV-1) (Herpesviridae), and equine rhinitis B virus (ERBV) (Picornaviridae). VOCs, which are byproducts of cellular metabolism and potential non-invasive diagnostic markers, were analyzed using headspace solid-phase microextraction (HS-SPME) and gas chromatography–mass spectrometry (GC-MS). Since viruses do not possess intrinsic metabolic activity, the observed changes in the VOC profiles were attributed to host responses, such as metabolic reprogramming, oxidative stress, and apoptosis. We hypothesized that each viral infection induces distinct metabolic changes, resulting in characteristic VOC signatures that mirror the virus type, replication kinetics, and cytopathic effects. Notably, viruses with rapid cytopathic effects (e.g., EHV-1) were anticipated to trigger more pronounced VOC alterations. In our experimental design, RK-13 cells were infected at a multiplicity of infection of 1 and incubated for 24 h, 48 h, or 72 h. Distinct VOC profiles emerged, with significant elevations in compounds like 2-ethyl-1-hexanol, particularly in EHV-1 infections, and selective increases in acetophenone and benzaldehyde. Principal component analysis (PCA) of the VOC concentration data showed the clear separation of data from viruses from different families. These findings support the potential of VOC profiling as a rapid diagnostic tool for viral infections. Full article