Delta-tocopherol as an antioxidant in lard

Summary Comparison of the antioxidative properties of α-, β,γ-, and δ-tocopherols at concentrations of 0.02% and 0.1% tocopherol in lard have been made by means of a modified Swift Stability Test at 100°C. In order of increasing antioxidative effectiveness, the tocopherols are: α, β, γ, and δ. The subject matter of this paper has been undertaken in cooperation with the Committee on Food Research of the Quartermastor Food & Container Institute for the Armed Forces. The opinions or conclusions contained in this report are those of the authors. They are not to be construed as necessarily reflecting the views or indorsement of the War Department. Contribution No. 653 from the Department of Chemistry, University of Pittsburgh.     

Structure of an antioxidant from fermented soybeans (tempeh)

In an exhaustive investigation of the antioxidative properties of tempeh constituents, the substance at R _f 0.58 (cyclohexane/ethyl ether, 9:1) was isolated and purified. Until now, only the ultraviolet and fluorescence data of the substance were known, and the presence of an OH group was indicated. In the present paper, the structure of the substance at R _f 0.58 was elucidated by the application of spectroscopic methods and found to be 5-(δ-tocopheroxy)-δ-tocopherol. That previous researchers did not confirm antioxidant activity in tempeh oil has been related to the way the tempeh oil was prepared. Previous suggestions regarding the substance at R _f 0.58 as being one of the main tempeh antioxidants could not be proved. The antioxidative effect of tempeh oil seems to be the result of a synergistic effect of tocopherols (present in the soybeans) and amino acids (liberated during the fermentation process with Rhizopus oligosporus).     

Nutritional and antioxidant status of an institutionalized elderly group in Murcia (Spain)

The aging of the population is giving rise to a large number of studies aimed at improving the quality of life, considering diet as a major contributing factor in this life stage. The objectives of the present study were to evaluate the nutritional status of a group of institutionalized elderly in Murcia, Spain, and to relate the diet to anthropometric and biochemical indices, paying special attention to total antioxidant status. The dietary evaluation showed excessive intakes of proteins and lipids, and deficiencies in those of carbohydrates, dietary fiber, zinc, iodine and vitamins A, E and D. The high proportion of overweight observed were not significantly correlated to the energy intakes. Although total plasma antioxidant status was low (0.62 mM eq Trolox and 0.98 mM eq Fe(II)) compared with reference values, estimated oxidative risk in this group of elderly was low according to plasma levels of vitamins C, A & E.     

Fe~(3 )、Zn~(2 )、Mn~(2 )、Cu~(2 )、Ca~(2 )、Mg~(2 )等离子共存体系中Ca~(2 )、Mg~(2 )的测定

叙述了Fe3 、Zn2 、Mn2 、Cu2 、Ca2 、Mg2 等离子共存体系中采用六次甲基四胺 -铜试剂沉淀除去Fe3 、Zn2 、Mn2 、Cu2 等干扰离子 ,用EDTA滴定钙镁的方法 ,该方法钙的回收率在 99.7%～ 10 0 .3 % ;镁的回收率在 10 0 .0 %～ 10 0 .4% ,标准偏差为 0 .0 2 2。     

Surface properties of an anhydride-epoxy resin cured against different mould surfaces

An epoxy resin consisting of diglycidylether of bisphenol A (DGEBA) and methyltetrahydrophthalic anhydride (MTHPA) was cured against moulds with different surface characteristics: poly(ethylene terephthalate) (PET), perfluorinated ethylene propylene copolymer (FEP), and air. The epoxy surfaces were analysed using contact angle measurements and X-ray photoelectron spectroscopy (XPS). The results presented are interpreted in terms of differences in surface energy between the surface of the mould and the epoxy resin. With PET as the mould surface, the surface content of ester groups resulting from the anhydride increased as compared to the average bulk content. With the non-polar FEP mould, the amount of ester groups decreased instead. Shear tests on overlap joints obtained by adhesive bonding with polyurethane and epoxy adhesives showed, however, a high adhesive joint strength, both for epoxy surfaces obtained with FEP as mould, and for ground surfaces with a bulk composition. The surfaces generated in PET moulds yielded only poor adhesive joint strength. These differences in joint strength could be related to the concentration of reactive functional groups (-OH, -COOH) in the outermost surface of the cured epoxy resin.     

EXTRACTION OF ACTINIDES(III), (IV), (V), (VI), AND LANTHANIDES(III) BY STRUCTURALLY TAILORED DIAMIDES

Eleven diamide extractants having the different backbones were synthesized and their extractability for lanthanides(III) and actinides(III), (IV), (V) and (VI) were measured and compared. The diamides investigated include (CH₂) _n ─(CONR₁,R₂)₂, (n = 0, 1, 2, 3), O─((CH₂) _n′─CONR₁,R₂)₂, S─((CH₂) _n″─CONR₁,R₂)₂, and SS─((CH₂)_n′″─CONR₁,R₂)₂, (n′, n″, n′″ = 1, 2). The diglycolamide introducing an ether oxygen into the main frame, O─(CH₂─CONR₁,R₂)₂, exhibited the highest extractability for An(III), (IV) and (VI), as compared with the other bidentate diamides. It is clear from the present results that the thiadiglycolamide, TDGA, which substitutes ether sulfur atom for oxygen in DGA molecule, also enhances the extraction of actinides. The lanthanide pattern, the distribution ratios versus the atomic number, by diglycolamide in HNO₃-n-dodecane system exhibited a gradual increase of distribution ratio with increase in the atomic number, the opposite trend to that obtained by the other diamides.     

Zeolite encapsulated Ru(III), Cu(II) and Zn(II) complexes as effective catalysts for the oxidation of ethylbenzene

Ru(III), Cu(II) and Zn(II) complexes of imidazole (ImzlH) have been synthesized in the supercages of zeolite-Y by flexible ligand method and characterized by spectroscopic (IR and UV?CVis) studies, XRD and thermogravimetric analysis, surface area, and pore volume measurements. These complexes were screened for their catalytic study towards the oxidation of ethylbenzene to a mixture of acetophenone, benzaldehyde and styrene using tert-butylhydroperoxide (TBHP) as an oxidant. A best-suited reaction condition has been optimized for these catalysts by varying the amount of the oxidant and catalyst, reaction time and volume of solvent for maximum transformation of ethylbenzene. Under the optimized reaction conditions, [Cu(ImzlH)]-Y gave 79.3% conversion after 1?h of reaction time. All these catalysts were more selective towards acetophenone formation. Among the prepared catalysts, zeolite encapsulated Cu(II) complex was found to be more active than the corresponding Ru(III) and Zn(II) complexes and all the complexes were stable enough to be reused. The catalytic activities of the neat complexes and metal exchanged zeolites were also compared with the zeolite encapsulated metal complexes.     

Hydrogen-donating mechanism of rosmariquinone, an antioxidant found in rosemary

Rosmariquinone (RQ), an ortho-quinone diterpenoid found in rosemary, was shown to act as a hydrogen-donating antioxidant. The proposed mechanism is based on the isolation of the catechol intermediate arucadiol (AD) in methyl oleate test systems. AD was also observed in a bulk soybean oil oxidation experiment, which supports the observation that RQ is converted to AD during oxidation of the oil. Because AD was found in both light-induced oxidation and autoxidation test systems, the antioxidant mechanism proceeds in a similar manner. The antioxidant activities of RQ and AD were not significantly different in the autoxidation experiments, while AD was a significantly better (P<0.05) antioxidant than RQ in the light-induced oxidation.     

Hydrogen-donating mechanism of rosmariquinone, an antioxidant found in rosemary

Rosmariquinone (RQ), an ortho-quinone diterpenoid found in rosemary, was shown to act as a hydrogen-donating antioxidant. The proposed mechanism is based on the isolation of the catechol intermediate arucadiol (AD) in methyl oleate test systems. AD was also observed in a bulk soybean oil oxidation experiment, which supports the observation that RQ is converted to AD during oxidation of the oil. Because AD was found in both light-induced oxidation and autoxidation test systems, the antioxidant mechanism proceeds in a similar manner. The antioxidant activities of RQ and AD were not significantly different in the autoxidation experiments, while AD was a significantly better (P<0.05) antioxidant than RQ in the light-induced oxidation.     

Effect of antioxidant in an acute lung injury animal model

The objective of this study was to scrutinize the involvement of nitric oxide (NO) and the diagnosis of blood in ARDS in a rat model determined by the sequential exposure to lipopolysaccharide (LPS). Also, the present study was designed to evaluate the effects of taurine and dexamethasone on ARDS induced by LPS. Measurements of nitrite/nitrate were elevated in BAL of LPS challenged rats, indicative of an induction of the NO synthase. Taurine and dexamethasone abrogated the extent of endotoxin-induced ARDS, as evidenced by the decreases BAL nitrate/nitrite, BALF protein and lung pathology. T+L+D-group had higher PaO₂ and lower PaCO₂ values than L-group and T+Lgroup. But, ionized Ca²⁺ and Mg²⁺ both were not shown significant change. Also, T+L and T+L+D-group showed significant increase compared with L-group, but for the other side no significant difference was seen between T+L and T+L+D group. We suggest that taurine and dexamethasone may be a drug of choice for preventing ARDS.     

A new method for the simultaneous determination of Fe(III), Cu(II), Pb(II), Zn(II), Cd(II), and Ni(II) in wine using differential pulse polarography

A new and simple differential pulse polarographic method for the analysis of wine has been established. With this method, it was possible to determine simultaneously six trace elements in wine. There was no need for time consuming extraction and separation procedures with danger of contamination. The polarogram of wet digested wine was taken initially in pH 2 acetate buffer and Pb, Cd, and Zn were determined by standard additions. Ethylene diamine tetraacetic acid (EDTA) was added and pH was increased to six by addition of NaOH. Fe and Cu were determined subsequently. The ammonia buffer, pH 9.5, was identified as the best medium for separation and determination of Ni and Zn. The quantities of trace elements were found as Cu 290 ± 20 μg L⁻¹, Fe 8960 ± 50 μg L⁻¹, Pb 148 ± 17 μg L⁻¹, Cd 16 ± 8 μg L⁻¹, Zn 460 ± 25 μg L⁻¹, and Ni 78 ± 17 μg L⁻¹.     

Update on the pharmacology of Spirulina (Arthrospira), an unconventional food

Spirulina (Arthrospira), a filamentous, unicellular alga, is a cyanobacterium grown in certain countries as food for human and animal consumption. It is also used to derive additives in pharmaceuticals and foods. This alga is a rich source of proteins, vitamins, amino acids, minerals, and other nutrients. Its main use, therefore, is as a food supplement. Over the last few years, however, it has been found to have many additional pharmacological properties. Thus, it has been experimentally proven, in vivo and in vitro that it is effective to treat certain allergies, anemia, cancer, hepatotoxicity, viral and cardiovascular diseases, hyperglycemia, hyperlipidemia, immunodeficiency, and inflammatory processes, among others. Several of these activities are attributed to Spirulina itself or to some of its components including fatty acids omega-3 or omega-6, beta-carotene, alpha-tocopherol, phycocyanin, phenol compounds, and a recently isolated complex, Ca-Spirulan (Ca-SP). This paper aims to update and critically review the results published over the last few years with regards to these properties. The conclusion is that even if this cyanobacterium has been one of the most extensively studied from the chemical, pharmacological and toxicological points of view, it is still necessary to expand the research in order to have more consistent data for its possible use in human beings.     

Poly(perfluoroether) oxadiazole elastomer system cured with terephthalonitrile oxide

The terpolymerization of N,N′-terephthalonitrile oxide (TPNO), 1,3,5-tricyanobenzene, and oligomeric perfluoroalkylene dinitriles derived from the oligomerization of tetrafluoroethylene oxide yields poly(perfluoroether)-1,2,4-oxadiazole polymers which are soluble in Freon TF and bear pendent nitrile groups as curing sites. The polymerization is a two-step, ambient-temperature reaction. Several different perfluoroether dinitriles are shown to polymerize using this procedure. The syntheses and certain structure/property relationships of the polymers are discussed. Increasing the chain length of the perfluoroalkylene oxide dinitriles results in polymers which range from paraffin-like solids through tough elastomers and, finally, to tacky gums. Tough, crepe elastomer gum with a T_g of ?64°C may be obtained in yields of 60–70%. The poly(perfluoroether) oxadiazoles may be milled with additional TPNO and press cured at 95°C (200°F). The following physical properties of the cured polymers are given: compression set, tensile strength, per cent elongation at break, set at break, and Shore A hardness. Thermal stability, moisture stability, and low-temperature flexibility data are also presented for the cured elastomeric polymer.     

含能材料中间体硝仿的研究进展

硝仿是一种重要的含能材料中间体,用于合成硝仿系炸药及硝仿盐类高能氧化剂。详细介绍了国内外在硝仿的制备和分离方面的研究进展情况。其中制备方法主要介绍了乙炔硝化法、四硝基甲烷法、丙酮硝化法、异丙醇硝化法、嘧啶-4,6-二酮衍生物硝化-水解法。分离方法主要介绍了二次恒沸蒸馏法、萃取法、盐析法、萃取-蒸馏结合法。同时分析了各种方法的优劣。     

Epoxy/polyhedral oligomeric silsesquioxane (POSS) hybrid networks cured with an anhydride: Cure kinetics and thermal properties

A new class of organic-inorganic hybrid networks was prepared via copolymerization of octakis(dimethylsiloxybutyl epoxide)octasilsesquioxane (OB), N,N,N′,N′-tetraglycidyl-4,4′-diaminodiphenyl methane (TGDDM) and hexahydrophthalic anhydride (HHPA). Kinetic studies show that even with 1H-imidazole as the catalyst, the rate for the curing of OB/HHPA is still significantly higher than that for TGDDM/HHPA in the temperature range studied. Two-stage reactions were thus carried out to allow OB to react with HHPA first (Stage I). The glass transition temperature (T_g) of the networks was found to be strongly dependent on Stage I reaction since too short a reaction time caused poor bonding of OB to the networks while too long a reaction time led to the formation of OB oligomers that de-homogenized the networks. With 5 mol.% OB, the hybrid prepared via the optimized two-stage reaction displayed a large jump of ∼20 °C in T_g, which was accompanied by slight improvements in thermal degradation temperature and storage modulus, as compared to TGDDM/HHPA.     

Extraction Behavior of Zinc(II), Cadmium(II), Mercury(II), Indium(III), and Thallium(III) as Thiocyanates in High-Molecular-Weight Amines and Some Mutual Binary Separations

Abstract

The extraction behavior of Zn(II), Cd(II), Hg(II), In(III), and Tl(III) has been studied at different NH₄CNS molarities in some commercially available liquid anion exchangers. The effect of such variables as the type of amine, molarity of NH₄CNS, and pH of aqueous phase and organic diluent on extraction has been explored to achieve the best conditions of some mutual binary separations of analytical and radiochemical interest.