Electromigration methods in the determination of synthetic food dyes

Conditions were optimized for separating synthetic food dyes E 102, E 110, E 122, E 124, E 128, E 129, and E 133 by two-dimensional thin-layer chromatography (TLC) on Sorbfil plates using the mobile phase methanol-2-propanol-ethyl acetate-water (1: 1: 2: 2) in both the first (high-performance TLC) and second (electroosmotic TLC) directions. Conditions were selected for separating E 122, E 124, and E 133 by capillary zone electrophoresis; a borate buffer solution with pH 9.2 containing 10 vol % of acetonitrile was used. The time of separation was 16 min.     

胶束电动毛细管色谱法测定硫酸多粘菌素E药物中的多粘菌素E1和E2

采用胶束电动毛细管色谱法(MECC)对硫酸多粘菌素E药物中的主要成分多粘菌素E1和E2进行了分离,并测定了多粘菌素E1、E2的含量。分别考察了电泳电压、表面活性剂种类、Brij-35(月桂醇聚氧乙烯醚)浓度、乙腈含量、磷酸盐缓冲液的pH值、氯化钠浓度等实验参数对实验结果的影响,从而确定了最佳的分离条件: 电泳电压为10 kV,运行缓冲液为含有30 mmol/L Brij-35、5%(体积分数)乙腈、0.167 mol/L氯化钠的磷酸二氢钠缓冲液(0.01 mol/L,pH 4.1)。在优化的实验条件下,E1和E2得到了较好的分离,分离度达到1.94。以多粘菌素E1为例,柱效和峰面积的日间及日内测定的相对标准偏差(RSD)均小于5%。E1和E2在硫酸多粘菌素E药物中的含量分别为67%和32%。该方法简便、快速、准确、重现性好。     

The synthesis of key intermediates in cembranolides

Two key intermediates of cembranolides- (2E,6E,10E)-3,7,11,15-tetramethyl-9-phenylsulfonyl-2,6,10,14-tetraen-1-hexadecanol (1) and (2E,6E,10E,14E)-2,6,10,14-tetramethyl-8-phenylsulfonyl-2,6,10,14-tetraen-1,16-hexadecanediol (2) were synthesized starting from geraniol and linalool and some improved synthetic methods were used.     

Studies on the formation of aliphatic aldehydes in the plasma and liver of vitamin E-deficient rats

The effects of vitamin E (E) deficiency on the formation of aliphatic aldehydes in rat plasma and liver were studied. Three-week-old Wistar male rats were fed either an E supplemented diet (2-ambo-alpha-tocopheryl acetate 20 mg/kg diet, designated as E supplemented diet group) or an E deficient diet (E deficient diet group). After 8 weeks, n-hexanal and (E)-4-hydroxy-2-nonenal (4-HN) in the plasma of the E deficient diet group were found to be 2.0 and 2.5-fold greater than those of the E supplemented diet group, respectively. The contents of aldehydes such as n-pentanal, n-hexanal, 4-HN in the liver were also significantly higher in the E deficient diet group than in the E supplemented diet group. These results indicate that some aldehydes, arising possibly from lipid peroxides, are produced and detected in the plasma and liver of rats under the condition like E deficiency. In this study we further found that the activity of the liver aldehyde dehydrogenase (ALDH, EC 1.2.1.3) was significantly changed; 5 and 8 weeks after the start it was lower in the E deficient diet group when compared to that in the E supplemented diet group. The decrease of enzyme activity was related to the increase of aldehydes such as n-hexanal in the liver. the aldehyde increase in the plasma of the E deficient diet group was thought to raise the injury of cells, namely, a strong hemolysis on erythrocytes prepared from the blood of rats fed the E deficient diet.     

Quantitative measurement of 17 beta-estradiol and estriol in river water by time-resolved fluoroimmunoassay.

A sensitive method for detecting 17 beta-estradiol (E2) and estriol (E3) in river water has been developed, based on the time-resolved fluoroimmunoassay by using a fluorescent europium chelate label, 4,4'-bis(1",1",1",2",2",3",3"-heptafluoro-4",6"-hexanedion-6"-yl)- chlorosulfo-o-terphenyl (BHHCT)-Eu3+. In the E2 assay, microtiter plates were coated with the E2-bovine serum albumin (BSA) conjugate. The anti-17 beta-estradiol antibody, the biotinylated goat anti-rabbit IgG antibody and the BHHCT-Eu3+ labeled streptavidin (SA)-BSA conjugate were used. In the E3 assay, the goat anti-rabbit IgG antibody was coated on a microtiter plate. The anti-estriol antibody and the BHHCT-Eu3+ labeled E3-BSA conjugate were used. The detection limits for E2 and E3 were 2.3 pg/ml and 4.3 pg/ml, respectively, and the analytical recoveries were 95-120%. Quantitative measurement of estrogens in river water was carried out for Kanda River (Tokyo, Japan) by using the method. The E2 and E3 levels were 32 pg/ml and 5.5 pg/ml, respectively. The detection limits of the present method are in the same orders of magnitude as those of ELISA for E2, and are 1-2 orders of magnitude better for E3.     

Photochemical behavior of some p-styrylstilbenes and related compounds: spectral properties and photoisomerization in solution and in solid state

The spectral properties and Z,E-photoisomerizations of three 4-styrylstilbenes, a 4,4'-bis(P-methylstyryl)benzene and a 4,4'-distyrylstilbene were investigated in solution and in the solid state. Some notable features of the absorption and fluorescence spectra due to the structures and the phases (solution or solid) were observed, especially the Stokes shifts. Interesting photochemical behaviors in solution and in the solid state were also found. While the (E,Z)-4-styrylstilbenes undergo a one-way photoisomerization to their E,E-isomers with almost equal rates in solution, their quantum yields in the solid state decrease with increasing substituent size at the terminal aromatic rings. On the other hand, the 4,4'-bis(beta-methylstyryl)benzene undergoes a mutual photoisomerization in solution, but its E,Z-isomer isomerizes in a one-way manner to the E,E-isomer in the solid state. Additionally, the (Z,E,Z)-4,4'-styrylstilbene was found to undergo a one-way photoisomerization to the E,E,E-isomer via the E,E,Z-isomer in solution and the crystalline E,E,Z-isomer to the E,E,E-isomer in the solid state.     

Purification and Characterization of <Emphasis Type="Italic">Aspergillus terreus</Emphasis> α-Galactosidases and Their Use for Hydrolysis of Soymilk Oligosaccharides

α-Galactosidases has the potential to hydrolyze α-1-6 linkages in raffinose family oligosaccharides (RFO). Aspergillus terreus cells cultivated on wheat bran produced three extracellular forms of α-galactosidases (E1, E2, and E3). E1 and E2 α-galactosidases presented maximal activities at pH 5, while E3 α-galactosidase was more active at pH 5.5. The E1 and E2 enzymes showed stability for 6 h at pH 4–7. Maximal activities were determined at 60, 55, and 50°C, for E1, E2, and E3 α-galactosidase, respectively. E2 α-galactosidase retained 90% of its initial activity after 70 h at 50°C. The enzymes hydrolyzed ρNPGal, melibiose, raffinose and stachyose, and E1 and E2 enzymes were able to hydrolyze guar gum and locust bean gum substrates. E1 and E3 α-galactosidases were completely inhibited by Hg²⁺, Ag⁺, and Cu²⁺. The treatment of RFO present in soy milk with the enzymes showed that E1 α-galactosidase reduced the stachyose content to zero after 12 h of reaction, while E2 promoted total hydrolysis of raffinose. The complete removal of the oligosaccharides in soy milk could be reached by synergistic action of both enzymes     

In vitro fluorescence, toxicity and phototoxicity induced by delta-aminolevulinic acid (ALA) or ALA-esters

Synthesis of delta-aminolevulinic acid (ALA) derivatives is a promising way to improve the therapeutic properties of ALA, particularly cell uptake or homogeneity of protoporphyrin IX (PpIX) synthesis. The fluorescence emission kinetics and phototoxic properties of ALA-n-pentyl ester (E1) and R,S-ALA-2-(hydroxymethyl) tetrahydrofuranyl ester (E2) were compared with those of ALA and assessed on C6 glioma cells. ALA (100 micrograms/mL), E1 and E2 (10 micrograms/mL) induced similar PpIX-fluorescence kinetics (maximum between 5 and 7 h incubation), fluorescence being limited to the cytoplasm. The 50% lethal dose occurred after 6 h with 45, 4 and 8 micrograms/mL of ALA, E1 and E2, respectively. ALA, E1 and E2 induced no dark toxicity when drugs were removed after 5 min of incubation. However, light (25 J/cm2) applied 6 h after 5 min incubation with 168 micrograms/mL of each compound induced 85% survival with ALA, 27% with E1 and 41% with E2. Increasing the incubation time with ALA, E1 and E2 before washing increased the phototoxicity, but E1 and E2 remained more efficient than ALA, regardless of incubation time. ALA-esters were more efficient than ALA in inducing phototoxicity after short incubation times, probably through an increase of the amount of PpIX synthesized by C6 cells.     

Conjugated ketonic fatty acids from Pleurocybella porrigens

Three novel conjugated long-chain fatty acids (1-3) were obtained from aqueous methanol extracts of Pleurocybella porrigens together with nine known constituents including (8E,10E)-7,12-dioxo-8,10-octadecadienoic acid (ostopanic acid) (4). The structures of the new fatty acids were characterized as (14RS)-(10E,12E)-14-hydroxy-9-oxo-10,12-octadecadienoic acid (1), (12RS)-(8E,10E)-12-hydroxy-7-oxo-8,10-octadecadienoic acid (2), and (10E,12E)-9,14-dioxo-10,12-octadecadienoic acid (3) by spectroscopic methods.     

Synthesis of novel 1,3,5-tris(arylazo)benzenes via Pd-catalyzed couplings and Cu(I)-mediated direct oxidations

A series of novel 1,3,5-tris-azobenzenes were prepared from 1,3,5-trihalobenzene via Pd-catalyzed couplings of N-Boc aryl hydrazines and subsequent Cu(I)-mediated direct oxidations. The oxidation of tris-arylhydrazide provided the azobenzene as a mixture of all four of the possible E/Z-isomers; [E,E,E]-, [E,E,Z]-, [E,Z,Z]-, and [Z,Z,Z]-1,3,5-tris-azobenzenes. A slow removal of the solvent in the dark transformed the isomers into the all-trans, [E,E,E]-isomer.     

Highly stereoselective synthesis of (E)- and (Z)-alpha-fluoro-alpha,beta-unsaturated esters and (E)- and (Z)-alpha-fluoro-alpha,beta-unsaturated amides from 1-bromo-1-fluoroalkenes via palladium-catalyzed carbonylation reactions

The highly stereoselective synthesis of (E)- and (Z)-alpha-fluoro-alpha,beta-unsaturated esters and (E)- and (Z)-alpha-fluoro-alpha,beta-unsaturated amides is described. 1-Bromo-1-fluoroalkenes (E/Z approximately 1:1), which are readily available starting materials, have been found to isomerize to high E/Z ratios after storage at -20 degrees C for 1 week or by photolysis at 254 nm. Since the (E)-isomers have been found to react faster than the corresponding (Z)-isomers at room temperature in Pd(0)-catalyzed reactions, the palladium-catalyzed carboalkoxylation of high E/Z 1-bromo-1-fluoroalkenes lead to a high Z/E (Z/E >/= 98:2) ratio of the alpha-fluoro-alpha,beta-unsaturated esters. When 1-bromo-1-fluoroalkenes (E/Z approximately 1:1) were reacted with HCOOH/NBu(3)/Pd(II)/DMF, the (E)-isomer was selectively reduced, and the remaining (Z)-1-bromo-1-fluoroalkenes were recovered in essentially pure isomeric form. The resulting mixture of (Z)-1-bromo-1-fluoroalkenes and the reduced products underwent similar palladium-catalyzed carboalkoxylation reactions at 70 degrees C, and the (E)-alpha-fluoro-alpha,beta-unsaturated esters were stereospecifically obtained. This methodology was also successfully applied for the stereospecific synthesis of (Z)- and (E)-alpha-fluoro-alpha,beta-unsaturated amides: the palladium-catalyzed carboamidation reaction of high E/Z and (Z)-1-bromo-1-fluoroalkenes lead to pure (Z)- and (E)-alpha-fluoro-alpha,beta-unsaturated amides, respectively.     

Eleutherosides in aerial parts of Eleutherococcus species cultivated in Poland

Many Eleutherococcus species grow in Siberia, China, Korea, Japan, and the Philippines. The most well known is Eleutherococcus senticosus, which contains pharmacologically active compounds, such as eleutherosides, flavonoids, vitamins, and complex polysaccharides. E. senticosus owes its medicinal properties mainly to eleutherosides. The objective of this study was to determine eleutherosides B, E, and E1 in the aerial parts of different Eleutherococcus species. The eleutherosides were extracted with ethanol, and the extracts were cleaned by SPE on C18 columns, and then analyzed by HPTLC. Silica gel plates with fluorescence indicator, designated F254, were used with chloroform-methanol-water (70 + 30 + 4, v/v/v) and chloroform-methanol-toluene-ammonium hydroxide (9 + 6 + 3 + 2, v/vv/v) mobile phases. Two-step elution with these mobile phases was used for the development of chromatograms. Eleutherosides were visualized by derivatization with Liebermann-Burchard reagent. This reagent was used for the first time to detect eleutherosides. Eleutherosides B, E, and E1 were detected in the fruits of the investigated species. E. senticosus contained three of the investigated compounds, and E. sessiliflorus, E. gracilistylus, and E. divaricatus two compounds each.     

Temperature investigations of E/Z isomers in ketimines based of p-dibenzoylobenzene with aniline and 2,6-dimethylaniline by infrared spectroscopy

The reaction of aniline with p-dibenzoylobenzene (K1) can lead to Z/Z, Z/E and E/E isomers however the only Z/Z and E/E were formed. At room temperature these isomers may be separated, thus the corresponding FTIR spectra could be recorded. The observed bands were assigned and temperature investigations were lead to monitor the structural changes during heating Z and E forms of K1 from 20 to 240 degrees C. FTIR spectroscopy showed that the bigger changes of the Z form was observed with an increase of temperature. Similar experience was lead with the ketimine synthesized from 2,6-dimethylaniline and p-dibenzoylobenzene (K2) investigated as a mixture of isomers.     

Simultaneous LC Analysis of Food Dyes in Soft Drinks

Liquid chromatography with diode-array detection has been used for simultaneous analysis of eight water-soluble synthetic colorants (E102, E104, E110, E122, E124, E129, E131, and E133) in non-alcoholic beverages. The colors were separated in 15 min on a C₁₈ reversed-phase column with a linear mobile phase gradient prepared from tetrabutylammonium hydrogen sulfate, methanol, and deionized water. The analytical characteristics of the separation were evaluated. Good linearity (r ² = 0.9988–0.9999), adequate limits of quantification, and high recovery (from 96.3 to 98.5%) were achieved. The method was used for analysis of 57 samples of soft drinks. The experimental results showed the colorants were present in 34 of the samples, and confirmed the method is sensitive, rapid, precise, and suitable for routine analysis of synthetic organic dyes.

     

Characterization of (E,E)-farnesol and its fatty acid esters from anal scent glands of nutria (Myocastor coypus) by gas chromatography-mass spectrometry and gas chromatography-infrared spectrometry

Several volatile compounds, including terpenoids, fatty alcohols, fatty acids and some of their esters, were identified from solvent extracts prepared from anal scent glands of nutria (a.k.a. coypu), a serious rodent pest ravaging wetlands in the USA. The major terpenoid constituents were identified as (E,E)-farnesol and its esters by a comparison of their gas chromatographic retention times, and electron-ionization (EI) and chemical-ionization (CI) mass spectra with those of authentic compounds. EI mass spectra of the four farnesol isomers are very similar, however, the ChemStation (Agilent) and GC-MS Solution (Shimadzu) software algorithms were able to identify the natural compound as the (E,E)-isomer, when a high-quality mass spectral library was compiled from reference samples and used for searching. Similarly, the esters were identified as those of (E,E)-farnesol. In contrast to EI spectra, the CI spectra of the (E,E)- and (E,Z)-isomers are distinctly different from those of the (Z,E)- and (Z,Z)-isomers. The intensities (I) of the peaks for the m/z 137 and 121 ions in the CI spectra offer a way of determining the configuration of the C-2 double bond of farnesols (for 2E isomers I(137)>I(121), whereas for 2Z isomers I(137)相似文献   

Construction of ribosome display library based on lipocalin scaffold and screening anticalins with specificity for estradiol

A new anticalin against estradiol (E(2)), a kind of endocrine disruptor, was obtained in the present study to detect E(2) levels. A member of the lipocalin family from Pieris brassicae called bilin-binding protein (BBP) was employed for the preparation of a random library to specifically complex E(2). Sixteen amino acid residues at the center of the binding site, which were formed by four loops on top of an eight-stranded β-barrel, were subjected to targeted random mutagenesis. Estradiol-binding BBP variants so-called 'anticalins', which exhibit binding activity for compounds, such as E(2), were selected from the resulting library by combining both ribosome display and screening techniques. Four variants of complex E(2) with high affinity were identified. These variants exhibited dissociation constants (KDs) as low as 54.265 nM. ELISA showed that ribosome displayed anticalin (E(2)-A) specifically bound E(2). The 50% inhibition concentration (IC(50)) for E(2) was 50 ng mL(-1) and the limit of detection (LOD:IC(10)) was 0.071 ng mL(-1). The experimental results suggest that E(2)-A can be used as a potential anticalin to detect E(2) in animals.     

HPV E6 antisense induces apoptosis in CaSki cells via suppression of E6 splicing

Cervical cancer is known to be highly associated with viral oncogene E6 and E7 of human papilloma virus. Down-regulation of oncogene expression by antisense-based gene therapy has been extensively studied. To investigate the effect of HPV 16 E6 antisense nucleic acid (AS) on cervical cancer cells, human cervical cancer cell lines, CaSki and SiHa cells harboring HPV 16 genome were transfected with plasmid containing E6(AS). The decreased viability and the apoptotic morphology were observed in E6(AS)-transfected cervical cancer cell lines. By 6 h after transfection, inhibition of E6 splicing, rapid upregulations of p53 and a p53-responsive protein, GADD45, were displayed in E6(AS)-transfected CaSki cells. Furthermore, E6(AS) induced loss of mitochondrial transmembrane potential, release of mitochondrial cytochrome c into the cytoplasm, and subsequent activation of caspase-9 and caspase-3. These results indicate that HPV 16 E6(AS) induces apoptosis in CaSki cells via upregulation of p53 and release of cytochrome c into cytoplasm, consequently activating procaspase-9 and procaspase-3.     

Bioactive saponins and glycosides. XXIII. Triterpene saponins with gastroprotective effect from the seeds of Camellia sinensis--theasaponins E3, E4, E5, E6, and E7

The saponin fraction from the seeds of the tea plant [Camellia sinensis (L.) O. KUNTZE (Theaceae)] was found to exhibit potent protective effects on ethanol- and indomethacin-induced gastric mucosal lesions in rats. Five new triterpene saponins, theasaponins E3 (1), E4 (2), E5 (3), E6 (4), and E7 (5), were isolated together with 11 known saponins from the saponin fraction. The chemical structures of 1-5 were elucidated on the basis of chemical and physicochemical evidence. Among the isolated saponins, theasaponins E1 (6), E2 (7), and E5 (3) and assamsaponin C (10) showed an inhibitory effect on ethanol-induced gastric mucosal lesions at a dose of 5.0 mg/kg, p.o. and their activities were stronger than that of omeplazole. With regard to the structure-activity relationships of theasaponins, the following structural requirements for a protective effect on ethanol-induced gastric lesions were suggested; 1) the 21- and/or 22-acyl groups are essential for the activity, 2) acetylation of the 16-hydroxyl group reduce the activity.     

高硒情况下维生素E对幼龄大鼠抗氧化作用的研究

研究了高Se或高维生系E下,幼龄大鼠体内抗氧化活性的变化以及高Se下,维生素E对其体内抗氧化水平的影响。将三月龄Wistar大鼠32只随机分成4组：正常饲料组、高Se高维生素E饲料组、高Se饲料组和高维生素E饲料组。饲至十周末,处死大鼠,按试剂盒要求分别取其血液、心、肝、肾制成标本测SOD、CAT活性及MDA、GSH含量。结果表明,高Se或高维生素E下饲养下的大鼠与对照组比较,血液中SOD活性明显下降;维生素E能明显抑制高Se大鼠血液中SOD活性的下降。结论：单独高Se或高维生素E会降低幼龄大鼠的抗氧化活性,而维生素E能明显提高高Se下幼龄大鼠体内抗氧化活性。