Search Results (635)

The nucleating agents with different alkyl chain lengths sodium 4-[(benzyl)amino] benzoate (SAB-Be), sodium 4-[(heptanoyl)amino] benzoate (SAB-7C), and sodium 4-[(stearoyl)amino] benzoate (SAB-18C) were synthesized via chemical to improve the crystallization and mechanical properties of recycled polyethylene terephthalate (rPET) that had been damaged during mechanical recycling. The rPET/nucleating agent blends were prepared by melt blending. The molecular structure and thermal stability of the nucleating agents were characterized using the utilization of fourier transform infrared (FTIR) and thermogravimetric analysis (TGA). The differential scanning calorimetry (DSC) results showed that the crystallization properties of the rPET had been improved. In addition, the glass transition temperatures (T_g) of rPET, rPET/SAB-Be, rPET/SAB-7C, and rPET/SAB-18C were 80.3 ± 0.3 °C, 80.4 ± 0.9 °C, 77.0 ± 1.2 °C, and 69.7 ± 0.9 °C, respectively, demonstrating that the length of the alkyl chain in the nucleating agents was essentially proportional to the lubrication effect on rPET. Meanwhile, the rheological properties also supported the conclusion. The isothermal thermodynamic analysis indicated that the compatibility between nucleating agents and rPET was related to the length of the alkyl chain in the nucleating agents. The scanning electron microscopy (SEM) results of the fracture surfaces of the rPET/nucleating agent blends showed that the longer the alkyl chain in the nucleating agent, the greater the compatibility with rPET. Furthermore, the rPET/SAB-18C exhibited the best mechanical properties of the samples used in this research, with flexural strength and impact strength increased by 5.1% and 58.9%, respectively, compared to rPET. Overall, this work provided the new approach for rPET upcycling by combining molecular design strategies. Full article

The red imported fire ant, Solenopsis invicta Buren, is a eusocial insect that relies on a sophisticated chemical communication system for colony organization and function. Its olfactory system is vital for detecting semiochemicals in the environment. This study utilized single sensillum recording (SSR) to assess the olfactory neuronal responses of female alates and workers from basiconica sensilla exposed to a panel of 62 individual pheromones and general odorants, including terpenes, terpenoids, pyrazines, pyridines, ketones, aldehydes, alcohols, acids, aliphatic and aromatic acetates, benzoates, benzyl esters, and three essential oils. Basiconica sensilla, which contain multiple olfactory receptor neurons (ORNs), exhibited moderate to strong responses to most of the tested compounds, demonstrating a broad sensitivity to all odorants elevated. Comparative analysis of the two castes revealed that ORNs had similar responses to 47 odorants; however, workers showed stronger responses to nine specific compounds, while female alates responded more strongly to six others. These differences underscore the caste-specific olfactory tuning, likely reflecting their distinct roles within the colony. This study presents the first comprehensive mapping of basiconica sensilla responses to general odorants in S. invicta female alates and workers, enhancing our understanding of the S. invicta chemical ecology and potentially contribute to more effective fire ant management strategies. Full article

The rapid evolution of insecticide resistance in Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) threatens effective pest management in key crops. This study characterized B. tabaci populations from cotton and tomato fields in Kashgar (September–October 2024) using mtCOI-RFLP for cryptic species identification, leaf-dip bioassays with 13 insecticides, and PCR detection of tomato yellow leaf curl virus (TYLCV). All analyzed individuals belonged to the Mediterranean (MED) cryptic species. Extreme resistance was observed to imidacloprid (RR = 320.65) and pyridaben (RR = 331.29), while nitenpyram (RR = 1.77) and the emamectin benzoate–chlorantraniliprole mixture (RR = 2.13) remained effective. TYLCV was detected in 97.5% of adults from tomato greenhouses. These findings provide a concise assessment of resistance status, species identification, and virus prevalence in B. tabaci, informing sustainable management strategies in cotton and tomato production. Full article

Injecting chemical agents into tree trunks is a key method for preventing pine wilt disease (PWD). However, the long-term use of conventional trunk injection agents such as emamectin benzoate (EB) and avermectin (AVM) may lead to nematode resistance. Therefore, it is crucial to evaluate the potential of new-generation nematicides, including fluopyram (FLU) and its compound formulations, as alternatives to EB and AVM in PWD prevention. In this study, four trunk injection agents, i.e., 5% FLU microemulsion (ME), 2% AVM + 6% FLU ME, 5% EB ME, and 5% AVM emulsifiable concentrate (EC), were injected into Pinus massoniana trunks, and their residual dynamics over time and preventive effects on PWD were compared. Results showed that all agents were transported to various parts of the trees within 90 days post-injection, with FLU showing significantly stronger translocation compared with EB and AVM. At 660 days post-injection, the active ingredient levels of 5% FLU ME in apical branches remained significantly higher than those of the other three agents at both tested doses (30 and 60 mL). Artificial inoculation with 10,000 Bursaphelenchus xylophilus nematodes per tree at 90 days post-injection showed that trees injected with 5% FLU ME and 2% AVM + 6% FLU ME had nearly 100% disease prevention rates at both doses, outperforming 5% EB ME and 5% AVM EC. A second nematode inoculation at 480 days post-injection showed that 2% AVM + 6% FLU ME showed 50% efficacy, outperforming 5% EB ME (25% efficacy). These findings offer a foundation for developing alternative trunk injection strategies for future PWD management in China. Full article

Vitamin C is a small water-soluble molecule primarily cleared by the kidneys. Therefore, its plasma concentration would be expected to increase as kidney function declines. However, studies in patients with chronic kidney disease (CKD) and kidney transplant recipients have shown the opposite: a positive correlation between kidney function and plasma vitamin C levels. In this review, we discuss potential explanations for this counterintuitive finding and suggest alternative mechanisms influencing vitamin C bioavailability in this population. We also explore the hypothesis that this phenomenon may be linked to benzoic acid (benzoate) exposure. Benzoic acid is a widely used food preservative that, like vitamin C, is water-soluble and renally excreted. In individuals with impaired kidney function, reduced clearance may lead to elevated circulating benzoic acid levels, which could increase the likelihood of an in vivo chemical reaction between benzoic acid and vitamin C, resulting in the formation of benzene, which is a known toxic and carcinogenic compound. We summarize experimental evidence demonstrating the vitamin C–benzoic acid reaction in vitro, along with preliminary animal studies suggesting it may also occur in vivo. We also discuss the potential clinical consequences of benzene exposure in the context of patients with kidney function impairment. Given the widespread use of benzoic acid as a food preservative and the ongoing discussion around vitamin C supplementation in patients with kidney disease, this review invites further investigation to evaluate whether this reaction represents a health hazard for this population. Full article

The Citrus limon (L.) Burm. f. industry suffers significant losses due to fungal diseases. Therefore, this study aimed to evaluate the effectiveness of sodium benzoate (SB) and potassium sorbate (PS) on the incidence of fungal decay and fruit quality when used as preharvest treatments on Fino lemon trees over two consecutive seasons (2021–2023). Lower concentrations of SB and PS (0.1% and 0.5%) applied in one or two treatments successfully controlled fungal decay. On average, SB achieved a greater reduction in decay, ranging from 45% to 60%, compared to PS’s reduction of 25% to 50%. This approach minimised the negative impact on lemon fruit quality, in contrast to the highest doses (more than 1%) and the greatest number of applications (more than three times), which increased lemon susceptibility to decay. Furthermore, lemons treated with 0.5% SB twice enhanced antioxidant systems, showing a 35% increase in total phenolic content in the flavedo at harvest compared to the control. Consequently, the application of 0.5% SB twice at preharvest emerges as a promising and potential alternative to conventional fungicides for effective fungal decay control and maintenance of acceptable lemon quality traits during cold storage. Full article

Introduction: We previously showed that baboon offspring born to mothers deprived of estrogen during the second half of gestation exhibited insulin resistance prior to and after the onset of puberty. Moreover, the size of skeletal muscle myofibers and the number of microvessels important for delivery of insulin/glucose to myofibers were lower in near-term fetuses deprived of estrogen during pregnancy, and myofiber capillarization remained reduced in post-pubertal offspring deprived of estrogen in utero. However, it remains to be determined whether skeletal muscle size is restored to normal in animals deprived of estrogen in utero after the onset of puberty/gonadal estrogen production. Methods: To answer this question, the current study quantified the size and number of slow and fast fibers in biopsies of vastus lateralis skeletal muscle obtained from post-pubertal female baboon offspring 9–12 years old, born to mothers who were untreated (n = 7) or treated during the second half of gestation with letrozole (n = 6; suppressed maternal and fetal estrogen by >90%) or letrozole plus estradiol benzoate (n = 3). Results: Results indicated that skeletal muscle slow and fast fiber growth in female offspring appeared to occur by hypertrophy and that respective size of fibers after the onset of puberty was similar in offspring born to mothers who were untreated or deprived of estrogen in utero. Conclusions: Postnatal myofiber hypertrophy likely reflects the impact of the pubertal surge in and continued exposure of offspring myofibers to ovarian estrogen and is restored to normal in post-pubertal female offspring deprived of estrogen in utero. Full article

A novel 3,6-dicarbonyl-substituted derivative of 2-chloropyrazine has been synthesized for the first time via regioselective dilithiation using lithium 2,2,6,6-tetramethylpiperidide (LiTMP) and subsequent trapping with methyl benzoate. The structure was unambiguously confirmed through Sonogashira coupling and diagnostic NMR analysis, establishing selective substitution at both the 3- and 6-positions. This result demonstrates that symmetrical 3,6-functionalization of 2-chloropyrazine is feasible under mild conditions, overcoming long-standing limitations of multiple metalations in electron-deficient heterocycles and opening new pathways for the synthesis of polyfunctional pyrazine frameworks. Full article

Phalaenopsis is one of the most economically valuable genera in the Orchidaceae family. However, the common varieties of Phalaenopsis in the market rarely have fragrance, greatly limiting the sustainable development of the Phalaenopsis industry. Here, an integrated investigation was conducted on the patterns and determinants of aroma release in Phalaenopsis. GC-MS/MS analysis revealed that the primary volatile organic compounds (VOCs) in 10 fragrant Phalaenopsis cultivars are consistent. Terpenoids, alcohols, ketones, and esters collectively accounted for an average of 66.59% of the total VOCs across these 10 varieties. By performing metabolomic and transcriptomic analyses, we investigated the variation in 1532 VOCs in four different developmental stages of Phalaenopsis Formosa Sweet Memory. Metabolite analysis revealed that the levels of total volatiles, terpenoids, esters, and heterocyclic compounds were significantly upregulated during the flowering stages, and Linalool, β-Ocimene, and Methyl Benzoate were selected as key metabolites. While analyzing the correlation network between aroma components synthesis and differentially expressed genes, 33 key structural genes were detected and regulated by transcription factors. PAXXG356500_TPS, PAXXG333030_4CL, and PAXXG061420_SAM were key genes in the terpenoids and esters’ biosynthetic pathway, and they were co-expressed with aroma release. In summary, this study characterized the key metabolic pathways involved in aroma formation in Phalaenopsis and constructed the corresponding transcriptional regulatory network. These results laid a theoretical foundation for the subsequent research on aroma of Phalaenopsis and genetic engineering technology breeding. Full article

This study presents the synthesis, crystal structure determination and luminescence properties of three novel mononuclear europium (III) complexes constructed from sodium benzoate and the three different isomers of biphenylcarboxylic acid (2-, 3-, and 4-). All complexes share a common structural core; consisting of a single europium (III) ion coordinated by three bidentate benzoate ligands and two monodentate biphenylcarboxylate ligands. The synthesis followed a two-step strategy: first, a benzoate-based precursor complex was prepared by displacing the chloride and water molecules from europium (III) chloride hexahydrate with sodium benzoate by chelating process. The remaining water ligands were substituted with each biphenylcarboxylic acid isomer yielding solvent-free luminescent complexes. The structural characterization involved thermogravimetric analysis (TGA) to confirm the complete elimination of water molecules. The crystal structures of the europium (III) complexes were solved from X-ray powder diffraction data using the EXPO2014 software; and were deposited in the Cambridge Crystallographic Data Centre (CCDC) under deposition numbers 2477668, 2477667 and 2476992. The photoluminescence properties, including excitation, emission, decay time, and color purity, were studied. The influence of each biphenylcarboxylate isomer on the symmetry of the europium coordination sphere was assessed by calculating the asymmetry ratio, R = (I⁵D₀ → ⁷F₂/I⁵D₀ → ⁷F₁), revealing clear differences in emission intensity and symmetry distortion, directly correlated to the ligand isomer used. These findings demonstrate the antenna effect and tunable luminescence enabled by ligand design, offering potential applications in optoelectronics, bio-imaging and others. Full article

Two diruthenium(II,II) naphthyridine complexes coordinated with 4-trifluoromethylbenzoate (O₂CPh-4-CF₃) and 3,5-bis(trifluoromethyl)benzoate (O₂CPh-3,5-diCF₃) ligands, formulated as [Ru₂(npc)₂(O₂CPh-4-CF₃)₂] (4; npc = 1,8-naphthyridine-2-carboxylate) and [Ru₂(npc)₂(O₂CPh-3,5-diCF₃)₂] (5), respectively, were synthesized and structurally characterized. Single-crystal X-ray diffraction analysis revealed that both 4 and 5 form a direct metal–metal bond between the two Ru ions (2.2893(8) and 2.2896(7) Å, respectively) and adopt a paddlewheel-type structure in which two npc and two trifluoromethyl-substituted benzoate ligands are coordinated to a Ru₂⁴⁺ core with a cis-2:2 arrangement. The temperature dependence of the magnetic susceptibility measurements of 4 and 5 exhibited very large zero-field splitting (D = 242 and 246 cm⁻¹, respectively) of the triplet ground state of the Ru₂⁴⁺ core, similar to that of [Ru₂(npc)₂(O₂CPh)₂] (3; D = 238 cm⁻¹). Owing to the effects of the trifluoromethyl substituents, compared with 3, 4 and 5 showed (i) a significant blue shift of the absorption bands in the visible region and (ii) a positive shift of the redox potentials, with both shifts becoming more pronounced as the number of trifluoromethyl substituents increased. These experimental results are in good agreement with the electronic structure results obtained from density functional theory calculations. Full article

Plant endophytic fungi, which colonize plant tissues and form symbiotic relationships with their hosts, are known for their high diversity and wide distribution. These fungi often influence plant growth and development through the emission of volatile organic compounds (VOCs), whose effects can extend beyond host plants to non-host species. In this study, we isolated two endophytic fungi, Trametes hirsuta RR1 and Talaromyces pinophilus RR2 from healthy rice roots. The VOCs mixtures produced by strains RR1 and RR2 were both able to promote rice growth when these strains were co-cultured with rice seedlings. Specifically, strain RR1 and RR2 increased rice shoot fresh weight by 44.22% and 26.69%, root fresh weight by 58.24% and 41.76%, shoot length by 30.35% and 25.07%, and root length by 29.11% and 4.23%, respectively. They significantly enhanced the contents of chlorophyll a and carotenoids, which increased by 18.61% and 17.04%, and by 18.73% and 31.55%, respectively. Gas chromatography–mass spectrometry (GC-MS) was applied to analyze the VOCs emitted by the two strains. The analysis successfully identified a total of 13 major compounds. Among them, at appropriate concentrations, 1-pentanol, methyl DL-2-methylbutyrate, ethylbenzene, 2-ethyl-p-xylene, ethyl benzoate and dimethyl phthalate, can promote rice growth and alter the contents of photosynthetic pigments and hydrogen peroxide to varying degrees. This study provides an important basis for the in-depth research and development of biofumigants for promoting crop growth. Full article

Propolis is a resinous natural product produced by honeybees from plant exudates and beeswax. Its complex chemical composition varies significantly with geographical origin and seasonal factors. This study aimed to characterize the chemical composition of propolis samples collected from different regions of Latvia using gas chromatography–mass spectrometry (GC-MS). In total, 47 metabolites were identified, with chemical profiles dominated by phenolic acids and their esters—compounds typical of European propolis. Regional variations reflected differences in local vegetation, and two samples exhibited flavonoid constituents indicative of poplar-type botanical sources. The Daugavpils sample, which showed a particularly rich chemical profile, was further fractionated chromatographically, leading to the isolation of twelve metabolites: 2’,4’,6’-trihydroxy-4-methoxy dihydrochalcone, 2’,6’,4-trihydroxy-4’-methoxy dihydrochalcone, 2’,6’-dihydroxy-4,4’-dimethoxy dihydrochalcone, 2’,6’-dihydroxy-4’-methoxy dihydrochalcone, 2’,4’,6’-trihydroxy dihydrochalcone, palmitic acid, benzyl benzoate, cinnamyl cinnamate, pinostrobin, pinostrobin chalcone, pinocembrin, and pinobanksin. Given the limited prior research on Latvian propolis, this study provides valuable insights into its chemical diversity and the influence of regional flora on its composition. Full article

Wuyi Mingcong (WYMC) is a distinctive tea germplasm resource from Wuyi Mountain, known for its unique aroma and quality characteristics. However, the aroma quality of WYMC has been insufficiently studied. In this study, the aroma profiles of seven characteristic tea plant resources WYMC tea samples were characterized using sensory evaluation combined with headspace solid-phase microextraction and gas chromatography–mass spectrometry (HS-SPME-GC-MS). The results revealed that “floral,” “fruity,” “clean and refreshing,” “woody,” and “sweet” were the main aroma characteristics. A total of 37 volatile compounds were found to contribute significantly to the aroma profiles of the seven WYMC tea samples, with dihydrolinalool and (E)-β-ionone likely being the key contributors to their floral and fruity notes. Ten key volatile markers were identified as responsible for aroma differences between the Fujian Shuixian (SX) and seven WYMC tea samples. Phenylethyl alcohol, cis-3-hexenyl benzoate, δ-cadinene, nerol, and β-myrcene may be critical for the formation of WYMC’s characteristic aroma. cis-3-hexenyl benzoate and nerol may act as “broad-spectrum” aroma contributors, enhancing the overall intensity or layered nature of WYMC’s scent. The results of this study enrich the understanding of the aroma characteristics of WYMC and provide a theoretical foundation for the development and utilization of tea germplasm resources in the Wuyi Mountain. Full article

Broad bean paste (BBP), a traditional Chinese fermented condiment, often suffers from inconsistent quality during spontaneous fermentation. In this study, Weissella confusa KUST3424 and Bacillus subtilis KUST4527 were isolated from BBP and evaluated as starter cultures, either individually or in combination. Flavor characteristics were analyzed using an electronic nose, electronic tongue, and GC–MS combined with odor activity value (OAV) calculations. Results showed that 13 key flavor compounds with OAVs greater than 1 were identified as major contributors to the overall aroma of fermented BBP juice (FBPJ). Moreover, inoculated groups exhibited distinct flavor profiles compared with natural fermentation, with the co-culture producing the most pronounced improvements. The mixed fermentation markedly enhanced desirable alcohols and esters, including significant increases in isoamyl alcohol (125.87%), 2-furanmethanol (128.91%), phenethyl alcohol (354.06%), and 4-vinylguaiacol (150.99%). In addition, compounds such as acetoin, guaiacol, ethyl hexanoate, and ethyl benzoate were newly generated in the co-culture group, while the diversity and total content of esters increased significantly from 0.52% to 9.69%. These findings demonstrate that the combined use of W. confusa KUST3424 and B. subtilis KUST4527 as starter cultures can effectively enhance the complexity and overall quality of BBP flavor. This co-culture strategy shows promise for enhancing flavor control and consistency in industrial-scale BBP production. Full article