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A novel reactive fluorescent hydrogen sulphide (H2S) probe (T-DNBS) consisting of 2,4-dinitrobenzenesulfonyl (DNBS) units has been synthesised from 4,7-dibromo-2,1,3-benzothidiazole. Adding H2S to probe T-DNBS solution resulted in a marked fluorescence increase accompanied by a visual colour change from colourless to pale red. Probe T-DNBS performed excellent sensitivity and selectivity for H2S, substantial fluorescence enhancement, can be detected quantitatively in the concentration range of 0–125 μM and the low detection limit was 77.78 nM. In addition, the probe T-DNBS can track H2S in red wine samples with high accuracy, high recovery and practical value in food analysis. [ABSTRACT FROM AUTHOR]

The effects of sulforaphane on glycolysis and proliferation of SGC7901 and BGC823 gastric carcinoma cell lines were analyzed, and the potential mediating role of the TBX15/KIF2C axis was explored. SGC7901 and BGC823 cells stably over- or underexpressing TBX15 were exposed to sulforaphane, and cell viability was assessed together with the expression of TBX15, KIF2C, and proteins involved in glycolysis, glucose uptake, and lactate production. Overexpressing TBX15 in SGC7901 and BGC823 cells significantly reduced glucose uptake, lactate production, cell viability, expression of KIF2C, and pyruvate kinase M2-mediated (PKM2) glycolysis. These effects were recapitulated by treatment with sulforaphane. The anti-tumor effects of sulforaphane were antagonized by down-regulation of TBX15, up-regulation of KIF2C or addition of a PKM2 agonist. Sulforaphane can reduce cell proliferation and PKM2-mediated glycolysis in gastric carcinoma cells, apparently by activating the TBX15/KIF2C pathway. [ABSTRACT FROM AUTHOR]

A novel 1,2,3-triazole based dansyl fluorophore has been designed and synthesized for detecting Cu2+ as a fluorescent probe (P1). The probe P1 exhibited high sensitivity and selectivity for Cu2+ compared to other selected species in aqueous solution within a wide pH span (5 to 14), which showed that P1 may be applied in the entire alkaline pH window. The limit of detection (LOD) was measured to be as low as 5 × 10−7 mol/L for Cu2+. A 1:2 binding ratio and association constant of 4.6 × 104 M−1 between P1 and Cu2+ were determined. Additionally, rapid response to Cu2+ was demonstrated in less than 3 seconds and the linear concentration range was from 0.5 to 2.5 µmol/L. Moreover, probe P1 showed good biocompatibility and cell membrane permeability and was successfully applied for imaging Cu2+ in water samples and living cells, which demonstrates the application of P1 in complicated environments. [ABSTRACT FROM AUTHOR]

Oolong tea (OT) is a traditional Chinese tea (Camellia sinensis) and is especially popular in south China. This review is to comprehensively summarize the miscellaneous research that has been done towards to the processing, phytochemistry, health benefit, and risk of OT. These literatures were carried out not only from different electronic databases but also from text books written in English, Japanese, and Chinese, including those traditional records tracing back to the Tang Dynasty (A.D. 618-907). The full process OT producing is depicted below in this review. The phytochemistry of OT has been comprehensively investigated. More than 100 chemical compositions have been isolated and identified. In health benefit, OT performs outstandingly in reducing obesity and controlling diabetes explained by modern pharmacological studies. (-)-Epigallocatechin-3-gallate (6) in OT prevention of cancerous cells developing. OT can also improve and reduce on heart and vascular disease, protect teeth and bone, function as anti-oxidative and antibacterial agents. This review also mentioned the risk, summarized briefly on various forms of toxicity and harmful associated with OT. In short, this review can provided a natural product library of OT, gave inspirations for further new garden systems, designed idea on quality, bioactivity-oriented screening. In addition, it is suggested more scientists and education is necessary to guarantee the stability and safety of drinking OT. [ABSTRACT FROM AUTHOR]

Formic acid and formates are often produced by hydrogenation of CO2 with hydrogen over homogeneous catalysts. The present review reports recent achievements in utilization of heterogeneous catalysts. It shows that highly dispersed supported metal catalysts are able to carry out this reaction by providing activation of hydrogen on the metal sites and activation of CO2 or bicarbonate on the support sites. Important advances have recently been achieved through utilization of catalysts using CxNy materials as supports. The high activity of these catalysts could be assigned to their ability to stabilize the active metal in a state of single-metal atoms or heterogenized metal complexes, which may demonstrate a higher activity than metal atoms on the surface of metal nanoparticles. [ABSTRACT FROM AUTHOR]

Introduction: Phenolic compounds have been widely credited as an important part in various human ailments and plants’ disease resistances. Few studies, however, focused on the method to extract and detect the contents of phenolic compounds in the stems of Dendrobium officinale, a prized medicinal plant and functional food in China. Materials and methods: In this work, a very rapid, sensitive and reliable reverse-phase high-performance liquid chromatography (RP-HPLC) method was established for the separation and quantification of two phenolic compounds, i.e., quercetin and erianin in D. officinale stems, but also an optimized extraction process. Result and discussion: Results showed that quercetin and erianin were eluted before around 35 min, providing a time-saving separation. Furthermore, the steeper gradient rate in the range of 2.66-4.85% acetonitrile/min was the best for the elution. Meanwhile, the maceration of 30 min by the extraction solvent should be performed for removing polysaccharides that interfered the detection of phenolic components and resulted in the blockage of the chromatographic column, followed by a shorten ultrasonic-assisted extraction time of 30 min. The solid-liquid ratio was 1:100. Conclusions: This method is broadly applicable for chemical analyses of phenolic components in other Dendrobium species, for which similar problem may emerge. [ABSTRACT FROM AUTHOR]

Aluminum (Al) and copper (Cu) thin tube casings were employed to facilitate the equal channel angular pressing (ECAP) process of wrought AM30 magnesium (Mg) alloy. We covered the Mg rods (diameter, 14 mm) with pure copper (Mg/Cu) and Al-1050 alloy (Mg/Al) sheaths in the form of tubes (thickness, 2.5 mm). We then performed the ECAP processes at 200, 250, and 275°C using the conventional ECAP of AM30 alloy and covered tube casing (CTC) methods with a single pass. We assessed the effect of CTC on ECAP temperature, grain refinement, uniformity of structure, hardness distribution, and strength. The results of Mg/Cu and Mg/Al bimetal sample tests showed that there was a significant decrease in the process temperature when compared with the conventional ECAP of AM30. The sheath resolved the segmented material flow that occurred in a conventional ECAP of material at 250°C, and transformed it to a uniform flow in CTC bimetal samples. Grain sizes of the CTC samples decreased by 20% compared with the conventional ECAP of AM30 samples. Furthermore, grain uniformity, strain distribution homogeneity, tensile yield strength (TYS), and elongation increased. However, we observed a similar trend of deformation twinning in compression test results for the ECAP and CTC methods, and there was no significant variation in material yield asymmetry between the ECAP and CTC samples. [ABSTRACT FROM AUTHOR]

Aluminum (Al) and copper (Cu) thin tube casings were employed to facilitate the equal channel angular pressing (ECAP) process of wrought AM30 magnesium (Mg) alloy. We covered the Mg rods (diameter, 14 mm) with pure copper (Mg/Cu) and Al-1050 alloy (Mg/Al) sheaths in the form of tubes (thickness, 2.5 mm). We then performed the ECAP processes at 200, 250, and 275°C using the conventional ECAP of AM30 alloy and covered tube casing (CTC) methods with a single pass. We assessed the effect of CTC on ECAP temperature, grain refinement, uniformity of structure, hardness distribution, and strength. The results of Mg/Cu and Mg/Al bimetal sample tests showed that there was a significant decrease in the process temperature when compared with the conventional ECAP of AM30. The sheath resolved the segmented material flow that occurred in a conventional ECAP of material at 250°C, and transformed it to a uniform flow in CTC bimetal samples. Grain sizes of the CTC samples decreased by 20% compared with the conventional ECAP of AM30 samples. Furthermore, grain uniformity, strain distribution homogeneity, tensile yield strength (TYS), and elongation increased. However, we observed a similar trend of deformation twinning in compression test results for the ECAP and CTC methods, and there was no significant variation in material yield asymmetry between the ECAP and CTC samples. [ABSTRACT FROM PUBLISHER]

Tea has been widely consumed around the world for thousands of years and drinking tea is a daily habit for people of all ages. Tea is a major source of flavanoids, which have become well known as antioxidants. Tea also contains caffeine and theanine, which have been found to associate with health benefits. Many animal and epidemiological studies have been conducted to investigate the link between tea consumption and human health. However, common questions that arise about tea consumption include: whether all teas are the same, why drinking tea is linked with health benefits, how do the different ways of tea preparation impact on availability of tea components, how much and how long a person should consume tea to obtain health benefits, and whether there is any negative health effect associated with drinking tea. To answer these questions, this paper outlines the tea components and their link to human health, discusses major factors affecting availability of tea components in a tea cup, and reviews the latest epidemiological evidence linking tea consumption to human health. [ABSTRACT FROM PUBLISHER]

The UV light photo-Fenton degradation of oolong tea polyphenols in tea manufacturing effluent that color the wastewater to a dark brown has been examined. In order to elucidate the photo-Fenton degradation mechanism of oolong tea polyphenols and find the optimal dosages of the Fenton reagents, systematic study has been conducted. For the UV light photo-Fenton degradation of oolong tea effluent being 70 mg-(polyphenol) L−1, the optimum dosages of Fenton reagents were found to be 20 mgL−1of total Fe and 500 mgL−1of H2O2. The polyphenol degradation could be divided into two stages. The polyphenols concentration rapidly decreased to around 30% of the initial concentration within 2 min and the degradation rate significantly slowed down in the subsequent stage. After 60 min of UV light irradiation, 97% polyphenol removal was obtained. The initial quick degradation of oolong tea polyphenols suggests that hydroxyl radical generated by the photo-Fenton process might preferentially attack polyphenols having high antioxidant activity by scavenging hydroxyl radicals. Almost complete decolorization of the oolong tea effluent was achieved after 80 min. About 96% mineralization of 63 mgL−1TOC loading was achieved within 60 min and then further mineralization was rather slow. The complete COD removal of 239 mgL−1COD loading was obtained after 100 min. The present results indicate that the UV light photo-Fenton degradation process can treat tea manufacturing wastewaters very effectively. [ABSTRACT FROM AUTHOR]

Processed tea and herbal infusions were studied for their phenol content, antioxidant activity and main flavonoids. Total phenolics were determined by Folin-Ciocalteu method and ranged from N.D. to 46.46 ± 0.44 mg/g GAE. Flavonoids were investigated by HPLC, and myricetin, quercetin, kaempferol were identified in black, green, and chamomile tea. Antioxidant activity was evaluated using two methods: DPPH and β-carotene bleaching test (BCB). Using the BCB, the highest activities were found for infusions of black tea, mate, lemongrass, chamomile, and fennel; whereas fresh herbal infusions presented the lowest activities. Using the DPPH method, fresh herbal infusions presented the highest activities. Processed leaves with the lowest IC50 values were green and black tea (147.63 and 288.60 μg/mL, respectively). The results of this research show that the infusions studied are good source of compounds presenting antioxidant activity in vitro. Resumen Se estudio el contenido de compuestos fenólicos, principales flavonoides y la actividad antioxidante de tés procesados e infusiones herbarias. Los compuestos fenólicos totales fueron determinados por el método de Folin-Ciocalteu y variaron desde N.D. hasta 46,46 ± 0,44 mg/g GAE. Los flavonoides fueron investigados por HPLC y la miricetina, quercetina y kaempferol fueron identificados en té negro, verde y en infusión de manzanilla. La actividad antioxidante fue evaluada usando dos metodologías, DPPH y el método de decoloración del μ-caroteno (DBC). Utilizando el DBC, las actividades más elevadas fueron encontradas en las infusiones del té negro, del mate, de la hierba limón, de la manzanilla y del hinojo, mientras que las infusiones herbarias frescas presentaron las actividades más bajas. Utilizando el método de DPPH las infusiones herbarias frescas presentaron las actividades más altas. Las hojas procesadas con los valores más bajos IC50 fueron el té verde y negro (147,63 y 288,60 μg/mL, respectivamente). Los resultados de esta investigación demuestran que las infusiones analizadas son una buena fuente de compuestos que presentan actividad antioxidante in vitro. Palabras clave: Infusión herbaria, té, fenólicos, flavonóides, DPPH, decoloración del β-caroteno [ABSTRACT FROM PUBLISHER]