Synthesis and evaluation of some amine compounds having surface active properties as H2S scavenger

In this work three H₂S scavengers were prepared by reacting monoethanolamine with formaldehyde in different ratios (1:1, 2:1 and 2:3) to give MF1, MF2 and MF3, respectively. The chemical structures of the prepared scavengers were confirmed by FT-IR spectroscopy. The effect of reaction time (the time required for completing the reaction between the scavenger and the H₂S gas) has been studied for the three prepared scavengers. The effects of concentration and temperature have been studied on the scavenging efficiency of H₂S using three prepared products and two commercial products EPRI-710 and EPRI-730. The surface and thermodynamic parameters of the prepared scavengers were determined at 25 °C including, surface tension (γ), and effectiveness, maximum surface excess (Γ_max) and minimum surface area (A_min). Also, the standard free energy of micellization and adsorption was recorded. The results show that the efficiency of scavengers increased with increasing reaction time up to 50 min. Also, as concentration of scavengers and temperature increased, the removal efficiency of the scavengers increased. By comparing the efficiency of the prepared products with the commercial products EPRI-710 and EPRI 730, it was found that, MF3 exhibited a similar efficiency comparing with the commercial scavenger EPRI 730 (currently used in the field) at different concentrations and temperatures.     

Chemical Effects of Radiation Emitted from 10B(n, γ)7Li Reaction on Mixture of n-Propylamine and n-Propanol

The long term variation of the mean dose due to natural radiation in Japan received by an individual person was investigated. The mean exposure rate in each prefecture obtained by in-situ measurements was adopted as a basis of the radiation level. Population data were taken from both the resident registration and the census taking into account the essential difference of their meanings. It was revealed that the per capita dose due to outdoor natural radiaiton in Japan has been decreasing in the last approximate 30 yr. It will be due to the population movement from countrysides towards urban areas. That is because countrysides generally consist of stable mountainlands where granitic rocks distribute though urban areas generally consist of alluvial plains where volcanic ash or humus dominates. Although the contribution of low radiation level (below 9.0μR/h) areas to the nation-wide collective dose still remains under 50%, its relative importance has certainly been increasing in the last three decades. It is expected that human population will be the dominating factor which eventually controls the mean dose due to natural radiation in Japan.     

Tribochemical behaviour and lubrication characteristics of aromatic compounds

Radical scavenger, radical anion scavenger, and peroxide decomposer were added to aromatic hydrocarbons and phosphates in aromatic rings with and without side chain, and the effect of these inhibitors on tribopolymerisation and the lubrication characteristics of the aromatic compounds were investigated, in various atmospheres, in order to clarify the reaction mechanism. The aromatics of both hydrocarbons and phosphates with a methyl group in aromatic rings react readily at the rubbing surfaces to form polymer or polymer-like products, improving the lubricating characteristics. The tribochemical reactions of alkylaromatic compounds is shown to differ from those of trialkyl or triarylphosphates. It was concluded that the reaction proceeds through the radical or radicalanion and via peroxide to cause polymerisation.     

高LET的7Li离子致DNA损伤的直接和间接作用研究

在HI-13串列加速器加速的具有高LET值的7Li离子辐照不同浓度的pUC19质粒DNA水溶液、加自由基清除剂(甘露醇)的DNA水溶液以及干状DNA样品,利用高分辨的原子力显微镜技术,研究7Li致DNA损伤的直接作用和间接作用.结果显示,在相同剂量下,7Li离子比低LET辐射能诱发更多的双链断裂,形成更多的集团损伤,使DSB的分布更局部和更密集.对于水溶液DNA,7Li离子的水辐解产生的自由基的间接作用在DNA分子链断裂的产生方面发挥着重要作用,而且自由基清除剂甘露醇能有效地保护DNA分子.     

Antioxidant properties,radical scavenging activity and biomolecule protection capacity of flavonoid naringenin and its glycoside naringin: a comparative study

BACKGROUND: This study was designed to evaluate and compare antioxidant capacity and radical scavenging activity of naringin and its aglycone by different in vitro assays. The effects of flavanones on lipid peroxidation, glutathione (GSH) oxidation and DNA cleavage were also assessed. RESULTS: The results showed that naringenin exhibited higher antioxidant capacity and hydroxyl and superoxide radical scavenger efficiency than naringin. Our results evidenced that glycosylation attenuated the efficiency in inhibiting the enzyme xanthine oxidase and the aglycone could act like a more active chelator of metallic ions than the glycoside. Additionally, naringenin showed a greater effectiveness in the protection against oxidative damage to lipids in a dose‐dependent manner. Both flavanones were equally effective in reducing DNA damage. However, they show no protective effect on oxidation of GSH. CONCLUSION: The data obtained support the importance of characterizing the ratio naringin/naringenin in foods when they are evaluated for their health benefits. Copyright © 2010 Society of Chemical Industry     

毛竹春笋提取物抗氧化活性研究

分别对毛竹春笋甲醇、己烷、氯仿、乙酸乙酯和水提取物的抗氧化活性和总多酚含量进行了测定.结果表明,乙酸乙酯提取物具有最强的抗氧化活性(DPPH和ABTS)和最高的总多酚含量.5种提取物的抗氧化活性与其总多酚化合物含量有显著的相关性.GC-MS图谱分析表明乙酸乙酯萃取物包含多种多酚化合物,HPLC图谱证实多酚化合物主要有邻苯三酚、邻苯二酚、阿魏酸和p-香豆酸等.     

Activity-guided isolation and identification of radical scavenging components in Gao-Cha tea

Gao-Cha is a traditional Chinese health tea made from Acer ginnala. We performed a components and radical scavenging activity analysis to identify any medicinal components in this tea. High performance thin layer chromatography (HPTLC)-1,1-Diphenyl-2-picryhydrazyl (HPTLC-DPPH) assay showed that the methanolic extract contained strong radical scavengers. Quantitative analysis revealed that the IC(50) of the extract against 1 mM DPPH was 52.7 ± 0.6 μg/mL. Bioactive-guided isolations led to procurement of 3 radical scavengers with IC(50)s of 17.5 ± 2.1, 29.3 ± 2.5, and 21.6 ± 1.7 μg/mL, respectively. Analysis of the high resolution-electric spray ionization-mass spectrometer and (1)H, (13)C, distortionless enhancement by polarization transfer at 135°, heteronuclear quantum coherence, correlating spectroscopy coupling, and heteronuclear multiple bond coherence (HMBC) data revealed that the compounds were methyl 3, 4, 5-trihydroxybenzoate (1), quercetin-3-O-α-rhamnopyranoside (2), and 2,6-bis (3,4,5-trihydroxybenzoyl)-aceritol (3). Bioactive combined components analysis revealed that, apart from compounds 1, 2, and 3, the tea possibly contained radical scavengers: ginnalin A (4) and B (5), 2″-O-Galloylquercitrin (6) and 3″-O-Galloyl-quercitrin (7). Compounds 2, 6, and 7 were isolated from Acer ginnala for the first time. The positions of the 2 galloyl moieties in compound 3 were unambiguously established by the HMBC spectrum for the first time.     

Active Packaging Applications for Food

The traditional role of food packaging is continuing to evolve in response to changing market needs. Current drivers such as consumer's demand for safer, “healthier,” and higher‐quality foods, ideally with a long shelf‐life; the demand for convenient and transparent packaging, and the preference for more sustainable packaging materials, have led to the development of new packaging technologies, such as active packaging (AP). As defined in the European regulation (EC) No 450/2009, AP systems are designed to “deliberately incorporate components that would release or absorb substances into or from the packaged food or the environment surrounding the food.” Active packaging materials are thereby “intended to extend the shelf‐life or to maintain or improve the condition of packaged food.” Although extensive research on AP technologies is being undertaken, many of these technologies have not yet been implemented successfully in commercial food packaging systems. Broad communication of their benefits in food product applications will facilitate the successful development and market introduction. In this review, an overview of AP technologies, such as antimicrobial, antioxidant or carbon dioxide‐releasing systems, and systems absorbing oxygen, moisture or ethylene, is provided, and, in particular, scientific publications illustrating the benefits of such technologies for specific food products are reviewed. Furthermore, the challenges in applying such AP technologies to food systems and the anticipated direction of future developments are discussed. This review will provide food and packaging scientists with a thorough understanding of the benefits of AP technologies when applied to specific foods and hence can assist in accelerating commercial adoption.     

润滑油自由基捕捉剂型抗氧剂作用机理研究

酚型抗氧剂和胺型抗氧剂作为自由基捕捉剂型抗氧剂,已被广泛地应用于各类润滑油中。分析研究了自由基捕捉剂型抗氧剂的作用机理,对于有效地改善润滑油的氧化安定性能、延长润滑油的使用寿命以及研制新型润滑油抗氧剂具有重要意义。