首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
A single oral administration of phenoxy herbicides, viz. 2,4-dichlorophenoxyacetic acid (2,4-D), amino salt, sodium salt, diethylene glycol, iso-octyl and octyl ethers in a dose of LD16, was found to produce a pronounced suppressive effect on humoral immunity on day 5. The 2,4-D derivatives under study, administered in the same dose, stimulated the manifestations of delayed-type hypersensitivity in mice immunized with sheep red blood cells. The effect of the inhibition of antibody formation to thymus-dependent antigen ranged in the order of the increase in the toxicity of substances: amino salt, diethylene glycol ether, 2,4-D, sodium salt, iso-octyl and octyl ethers. On the contrary, the intensity of delayed-type hypersensitivity was more pronounced with regard to substances having greater toxicity.  相似文献   

2.
Mutagenicity testing of some commonly used dyes.   总被引:8,自引:2,他引:6       下载免费PDF全文
Seventeen commonly used dyes and 16 of their metabolites or derivatives were tested in the Salmonella-mammalian microsome mutagenicity test. Mutagens active with and without added Aroclor-induced rat liver microsome preparations (S9) were 3-aminopyrene, lithol red, methylene blue (USP), methyl yellow, neutral red, and phenol red. Those mutagenic only with S9 activation were 4-aminopyrazolone, 2,4-dimethylaniline, N,N-dimethyl-p-phenylenediamine, methyl red, and 4-phenyl-azo-1-naphthylamine. Orange II was mutagenic only without added S9. Nonmutagenic azo dyes were allura red, amaranth, ponceau R, ponceau SX, sunset yellow, and tartrazine. Miscellaneous dyes not mutagenic were methyl green, methyl violet 2B, and nigrosin. Metabolites of the azo dyes that were not mutagenic were 1-amino-2-naphthol hydrochloride, aniline, anthranilic acid, cresidine salt, pyrazolone T,R-amino salt (1-amino-2-naphthol-3,6-disulfonic disodium salt), R-salt, Schaeffer's salt (2-naphthol-6-sulfonic acid, sodium salt), sodium naphthionate, sulfanilamide, and sulfanilic acid. 4-Amino-1-naphthalenesulfonic acid sodium salt was also not mutagenic. Fusobacterium sp. 2 could reductively cleave methyl yellow to N,N-dimethyl-p-phenylenediamine which was then activated to a mutagen.  相似文献   

3.
In order to investigate the effect of the fixation of the orientations of the two long chains, three types of novel derivatives of scavenger receptor inhibitor 1 were synthesized, and their biological activities were evaluated. Among the novel derivatives, 2,4-bis(octadecanoylamino)benzenesulfonic acid sodium salt (4d) showed the most potent inhibitory activity against the incorporation of 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate-labeled acetyl-LDL (DiI-acetyl-LDL) into macrophages. 2,5-Bis(octadecanoylamino)benzenesulfonic acid sodium salt (4c), a regioisomer of 4d, did not exhibit as potent an inhibitory activity as 4d, meaning that the substitution pattern of two long chains on the benzene ring must be important. Compound 4d exhibited 10 times more potent inhibitory activity against the binding of 125I-labeled acetyl-LDL to the surface of macrophages than compound 1.  相似文献   

4.
Summary Hypocotyl protoplasts of four different Helianthus annuus genotypes were cultivated for 22–28 days in agarose droplets covered with liquid medium. In the first week, supplementation of the medium with plant growth regulators was at a 0.8/1 ratio of cytokinin and auxin followed by a high auxin concentration in the second week and a cytokinin to auxin ratio of 8/1 in the third and fourth week. Following transfer onto solid medium containing cytokinin and auxin in a proportion of 40/1 morphogenic callus started to form globular structures that developed into leaf primordia. Subsequent shoot elongation and rooting were obtained on hormone free medium after dipping the cut shoots into high auxin solution. Thirteen weeks after protoplast isolation, plantlets could be transferred to the greenhouse. Shoot regeneration was obtained for all four cultivars (Florom-328, Cerflor, Euroflor, Frankasol) at different rates reflecting their regenerative potential.Abbreviations BAP 6-benzylaminopurine - 2,4-D 2,4-dichlorophenoxyacetic acid - FeNaEDTA ethylenediamine tetraacetic acid ferric sodium salt - IAA indole acetic acid - MES morpholinoethane sulfonic acid - NAA 1-naphtalene acetic acid  相似文献   

5.
Abstract A natural isolate, designated BSA56, which was originally selected for growth with benzene sulfuric acid as sole carbon and energy source, was identified as a strain of Pseudomonas maltophila . Strain BSA56 grew on a wide range of aromatic sulfonic acids and was shown to release sulfite from benzene sulfonic acid and 2-napthalene sulforic acid. Although it also grew on toluene sulfonic acid and pyridine sulfonic acid, no significant sulfite release was observed with these substrates. Release of sulfite from benzene sulfonic acid was greatly promoted by the presence of glycerol. The ability to release sulfite was induced by growth in the presence of benzene sulfonic acid and was repressed almost entirely by substrates allowing rapid growth such as acetate. Strain BSA56 grew better at 30°C than 37°C on most aromatic substrates, but the reverse was true for most aromatic sulfonates. Several mutants of BSA56 were isolated with defects in benzoate, salicylate, or gentisate metabolism. However, all these mutants retained the ability to degrade the aromatic sulfonates.  相似文献   

6.
Effects of humic acid on removal of hydroxy polychlorobiphenyls (PCBs) with laccase from Trametes versicolor were studied. In the absence of humic acid, hydroxy PCBs were rapidly degraded by laccase. However, the rate constants decreased with increasing humic acid concentration, the reactions being completely inhibited at 150 mg l-1 of humic acid. Peroxidase from Arthromyces ramosus was not inhibited by the same treatment. The activity of humic acid-deactivated laccase was completely restored by copper ions (500 M of Cu2+ in 150 mg l-1 of humic acid), but not by other metal ions (Zn2+, Fe2+ and Hg2+). Humic acid-deactivated laccase purified by gel permeation chromatography (GPC) showed no activity against 2,2-azino-bis(3-ethylbenzthiazoline sulfonic acid) diammonium salt and 3,5-dichloro-4-hydroxybiphenyl, but its activity was restored by copper ion treatment. Humic acid-deactivated laccase showed similar properties, such as GPC retention time and copper ion requirements for activity, to those of laccase deactivated by nitrilotriacetic acid. The extent of humic acid inhibition, expressed as activity non-recoverable by copper ion treatment, increased over time more rapidly than that of the humic acid-free control. These results suggest that short-term inactivation of laccase, i.e., less than 1 day, is attributable to a depletion of copper ion.  相似文献   

7.
Fourteen mono-azo dyes were used to study the effects of substitution patterns on the biodegradability of dimethyl-hydroxy-azobenzene 4(prm1)-sulfonic acids by Streptomyces chromofuscus A11. Two substitution patterns were analyzed: (i) all possible substitution patterns of the two methyl and hydroxy substitution groups, 2-hydroxy (3,5; 4,5; 5,6) dimethyl and 4-hydroxy (2,3; 2,5; 2,6; 3,5) dimethyl isomers of azobenzene 4(prm1)-sulfonic acid; and (ii) replacement of the sulfonic group with a carboxylic group in these sulfonated azo dyes. The structural pattern of the hydroxy group in para position relative to the azo linkage and of two methyl substitution groups in ortho position relative to the hydroxy group was the most susceptible to degradation. Replacement of the sulfonic group with a carboxylic group enhanced overall dye degradability by S. chromofuscus A11.  相似文献   

8.
中度嗜盐菌Bacillus alcalophilus DTY1分离自晋西北黄土高原盐碱土壤, 能够产生耐盐相关的相容性溶质四氢嘧啶。为了研究四氢嘧啶的功能, 克隆了DTY1菌株四氢嘧啶合成基因簇ectABC。ectA、ectB和ectC分别编码169、428和132个氨基酸的肽链, 分别与B. halodurans C-125中的二氨基丁酸乙酰基转移酶(EctA)、二氨基丁酸氨基转移酶(EctB)、四氢嘧啶合成酶(EctC)同源性达59%、81%和81%。将携带该基因簇的4.0 kb片段转入蜡质芽孢杆菌B. cereus Z后, 芽孢杆菌的耐盐度显著提高。HPLC检测发现, 在1.0% NaCl浓度下, 转化菌B. cereus Z-E菌株生成70.1 mg/g四氢嘧啶, 而在5.0%的NaCl浓度下四氢嘧啶的产量高达118.6 mg/g, 显著高于B. alcalophilus DTY1的四氢嘧啶产量。而且随着盐浓度的提高, 四氢嘧啶的合成量也随之提高。由此证明四氢嘧啶参与中度嗜盐菌重要的渗透调节, ectABC的表达受盐诱导。  相似文献   

9.
中度嗜盐菌Bacillus alcalophilus DTY1分离自晋西北黄土高原盐碱土壤, 能够产生耐盐相关的相容性溶质四氢嘧啶。为了研究四氢嘧啶的功能, 克隆了DTY1菌株四氢嘧啶合成基因簇ectABC。ectA、ectB和ectC分别编码169、428和132个氨基酸的肽链, 分别与B. halodurans C-125中的二氨基丁酸乙酰基转移酶(EctA)、二氨基丁酸氨基转移酶(EctB)、四氢嘧啶合成酶(EctC)同源性达59%、81%和81%。将携带该基因簇的4.0 kb片段转入蜡质芽孢杆菌B. cereus Z后, 芽孢杆菌的耐盐度显著提高。HPLC检测发现, 在1.0% NaCl浓度下, 转化菌B. cereus Z-E菌株生成70.1 mg/g四氢嘧啶, 而在5.0%的NaCl浓度下四氢嘧啶的产量高达118.6 mg/g, 显著高于B. alcalophilus DTY1的四氢嘧啶产量。而且随着盐浓度的提高, 四氢嘧啶的合成量也随之提高。由此证明四氢嘧啶参与中度嗜盐菌重要的渗透调节, ectABC的表达受盐诱导。  相似文献   

10.
11.
Glycosidation of 2,5-anhydro-1,6-di-O-benzoyl-D-mannitol with methyl(2,3,4-tri-O-acetyl-alpha-d-glucopyranosyl-1-O-trichloroacetimidate)uronate in the presence of trimethylsilyl triflate afforded the corresponding 3-O-beta-glycoside, which after deprotection was converted into its hexa-O-sulfate with DMF x SO3 to give after treatment with sodium acetate and subsequent saponification of the methyl ester with sodium hydroxide the hepta sodium salt of 2,5-anhydro-3-O-(beta-d-glucopyranosyl uronate)-D-mannitol hexa-O-sulfate. Glycosidation of the same acceptor with the alpha-thiophenylglycoside of methyl 2,4-di-O-acetyl-3-O-benzyl-L-idopyranosyl uronate in the presence of NIS/TfOH afforded the corresponding 3-O-alpha-glycoside in very low yield, therefore the alpha-thiophenylglycoside of 2-O-acetyl-2,4-O-benzylidene-3-O-benzyl-L-idopyranose was used as donor. The terminal hydroxymethyl group of the obtained disaccharide was subsequently oxidised with NaOCl/TEMPO and the obtained iduronic acid derivative was converted into the hepta sodium salt of 2,5-anhydro-3-O-(-alpha-L-idopyranosyluronate)-D-mannitol hexa-O-sulfonate with DMF x SO3 and subsequent treatment with sodium acetate.  相似文献   

12.
An assay method for the quantification of the cytotoxicities of various agents toward cultured human endothelial cells was developed using Earle's solution as an incubation medium. By this method, the cytotoxicities of a linoleic acid hydroperoxide (LOOH) and its related aliphatic aldehydes toward human umbilical vein endothelial cells were investigated. Saturated aldehydes, pentanal, hexanal and 9-oxononanoic acid, are nontoxic; alpha, beta-unsaturated aldehydes, 2-hexenal, 2-heptenal, 2-octenal and 2-nonenal, are toxic only at high concentrations; LOOH and alpha, beta-unsaturated aldehydes with a hydroxy group or an additional double bond, 4-hydroxy-2-nonenal, 2,4-nonadienal and 2,4-decadienal, are highly toxic. In particular, 2,4-decadienal, whose 50% lethal concentration is 9 microM, is the most injurious. The cytotoxicities of LOOH and its related aldehydes were found to be much reduced in growth medium containing serum, growth factors, heparin, amino acids and vitamins.  相似文献   

13.
Four different amino-reactive reagents, 4-acetamido-4'-isothiocyano-stilbene-2,2'-disulfonic acid (SITS),1 1-fluoro-2,4-dinitrobenzene (FDNB), 2,4,6-trinitrobenzene sulfonic acid (TNBS), and 2-methoxy-5-nitrotropone (MNT) decrease the anion permeability of the human red blood cell, as measured by sulfate fluxes, whereas the sulfhydryl agent, parachloromercuriphenyl sulfonic acid (PCMBS), does not. In contrast, PCMBS increases the cation permeability as measured by K+ leakage, whereas SITS does not. Of the other agents, FDNB increases the cation permeability to the same extent as PCMBS but MNT and TNBS produce smaller increases. PCMBS does not protect against FDNB as it does against other sulfhydryl agents (X-irradiation) and the FDNB effect on cations is attributed to amino groups. Studies of the binding of SITS indicate that it does not penetrate into the membrane and its failure to influence cation permeability is attributed to its inability to reach an internal population of amino groups. It is concluded that two ion permeability barriers, both involving proteins, are present in the red blood cell. The more superficial barrier contains amino groups and controls anion flow; the more internal barrier contains sulfhydryl and amino groups and controls cation flow. The amino groups contribute to the control of permeability by virtue of their positive charges, but the role of sulfhydryl groups is not clear. Only a small fraction of the membrane protein amino and sulfhydryl is involved in the barriers.  相似文献   

14.
Summary Three bacterial strains, one ofF. peregrinum (Stapp and Spicher) and two Achromobacter strains, have been isolated from soil and shown to decompose either 2,4-D, MCPA orp-chlorophenoxyacetic acid. Aerobic conditions are essential for the bacterial decomposition of 2,4-D. Pretreatment of soil with one of the three chlorophenoxyacetic acids accelerated the rate of breakdown of either of the other two. In a liquid medium, growth of theF. peregrinum strain caused breakdown of 2,4-D and liberated 76% of the chlorine in 2,4-D in ionic form. An unknown acidic substance, colourless in acid solution but forming a yellow sodium salt has been detected in cultures ofF. peregrinum or an MCPA-decomposing Achromobacter strain growing inp-chlorophenoxyacetate medium. The bacterial oxidation of chlorophenoxyacetic acid herbicides was attributed to adaptive enzyme formation. Respiration experiments showed that the oxidation of 2,4-D or ofp-chlorophenoxyacetic acid is incomplete. 4-Chloro-2-hydroxyphenoxyacetic acid and 4-chlorocatechol may be metabolic intermediates in the case ofp-chlorophenoxyacetic acid, but no intermediary metabolites have as yet been established for 2,4-D.  相似文献   

15.
1-O-Glucosyl esters of 2,4-dichlorophenoxyacetic acid (2,4-D) were easily prepared from 4,6-O-benzylideneglucose. The configuration of 1-O-ester linkage was affected by pH at the end of the reaction, that is, β-type was a major product at a neutral or acidic condition and α-type at an alkaline condition. Both of the anomers showed the same biological activities as sodium salt of 2,4-D.  相似文献   

16.
The sulfonic acid function was introduced into chitosan by reacting it with 5-formyl-2-furansulfonic acid, sodium salt, under the mild conditions of the Schiff reaction, thus avoiding polymer degradation and O-substitution. The reaction of chitosan (degree of deacetylation 0·58) with 5-formyl-2-furansulfonic acid, sodium salt produced a viscous solution that, upon hydrogenation, yielded N-sulfofurfuryl chitosan sodium salt. Infrared spectrometry, alkalimetry and elemental analysis provided evidence that the degree of substitution was 0·26. Circular dichroism measurements on solutions showed multiple Cotton bands in the pH interval 7·1–8·3, while at lower and higher pH values just one negative band was observed, thus providing indication of the polyampholyte nature of N-sulfofurfuryl chitosan. The 13C-NMR and FTIR spectra showed typical signals of furane carbons. Metal ion solutions at concentrations in the range 0·1–5·0 m , pH 6, promoted precipitation of metal ion complexes of N-sulfofurfuryl chitosan, with most effective removal from the solutions for Cu(II), Pb(II) and Ni(II). Sulfoethyl N-carboxymethyl chitosan was also synthesized from 2-chloroethanesulfonic acid in organic media: the sulfur content was similar (3·7%) in both polymers.  相似文献   

17.
The effects of herbicides with different primary modes of action were examined on the growth of photoautotrophic, photomixotrophic, and heterotrophic cultures of tobacco cells. These responses were compared with those of tobacco seedlings to the same herbicides. Herbicides, which primarily inhibit or disturb photosynthetic processes, suppressed the growth of photoautotrophic cells most strongly, as compared to photomixotrophic and heterotrophic cells (atrazine, diuron, paraquat). Herbicides having a primary mode of action other than the inhibition of photosynthetic processes, suppressed the growth of all types of cultured cells at similar concentrations (2,4-D, diphenamid, glyphosate, dinoseb, sodium chlorate, bialaphos, DTP), but the photoautotrophic cells were still the most sensitive to all kinds of herbicides except sodium chlorate. Furthermore, photoautotrophic cells responded to most of the herbicides as did the seedlings, with the exception of glyphosate and diphenamid. The possibility of photoautotrophically cultured cells as a model system to study the effects of herbicides are discussed.Abbreviation bialaphos (2-amino-4-methylphosphinobutyryl)alanylalanine sodium salt - diuron 3-(3,4-dichloro-phenyl)-1,1-dimethyl-urea - 2,4-D 2,4-dichlorophenoxy-acetic acid - DTP 1,3-dimethyl-4-(2,4-dichlorobenzoyl)-5-hydoxy-pyrazolate - dinoseb 2-secbutyl-4,6-dinitrophenol  相似文献   

18.
Ester synthesis catalyzed by polyethylene glycol-modified lipase in benzene   总被引:4,自引:0,他引:4  
Lipoprotein lipase, which catalyzes hydrolysis of emulsified triglycerides or water-insoluble esters, was modified with 2,4-bis(o-methoxy-polyethylene glycol)-6-chloro-s-triazine(activated PEG2). The modified lipase, in which 55% of the total amino groups in the lipase molecule, was soluble in organic solvents such as benzene, toluene, chloroform and dioxane. The modified lipase could catalyze ester synthesis reaction in benzene. When very hydrophobic substrates of lauryl alcohol and stearic acid were used, the ester synthesis reaction proceeded efficiently in the transparent benzene solution with the maximum activity of approximate 5.0 mumoles/min/mg of protein. Ester exchange and aminolysis reactions were also conducted with the modified lipase in benzene.  相似文献   

19.
Garcia MA  Graham EF 《Theriogenology》1989,31(5):1021-1028
The effect of N-TRIS(hydroxymethyl)methyl-2-aminoetane sulfonic acid (TES); N,N BIS (2 hydroxvethyl)-2 aminoethane sulfonic acid (BES), N-2(hydroxyethyl)piperazine-N-2-ethane sulfonic acid (HEPES), morpholinopropane sulfonic acid (MOPS), and piperazine-N-N-BIS(2-ethane sulfonic acid (PIPES) solutions on dialyzed semen was studied. Each was titrated to pH 7.0 with TRIS-(hydroxymethyl)-amino methane (TRIS) solution and the osmotic pressure was adjusted to between 320 to 325 mOsm/kg. The new solutions were identified as TEST, BEST, HEPEST, MOPST and PIPEST, respectively. The solutions were used 1) alone, 2) in a composite with equal parts (V/V) of each solution and 3) in a 1:1 (V/V) combination with isosmotic trisodium citrate solution. Later, TRIS and sodium hydroxide (NaOH) were compared as titration bases for piperazine-N-N-BIS (2-ethane sulfonic acid) (PIPES) and N-Tris(hydroxymethyl)methyl-2-aminoethane sulfonic acid (TES). Ejaculates were diluted 1:10 (V/V) in extenders containing buffer, 20% egg yolk and 5% glycerol (V/V). The samples were dialyzed (1:50) during cooling for a period of 2 h. Each sample was dialyzed against the same buffer system containing 5% glycerol without egg yolk and later it was frozen in pellets. The treatments were evaluated by observation of sperm motility in fresh and thawed semen samples. The latter were also analyzed by electronic count of cells that passed through the Sephadex column. Sperm survival was higher in PIPEST (PIPES titrated with TRIS) or the composite buffer, and the inclusion of 50% sodium citrate (Na citrate) improved significantly (P<0.05) sperm motility in fresh and frozen-thawed semen samples. There was no difference (P>0.05) between the titration bases. In the second experiment, sperm survival was superior in extenders containing PIPEST (P<0.05) than in those containing TEST independently of the inclusion of Na citrate.  相似文献   

20.
The structure of the glucuronide of sulphadimethoxine formed in man   总被引:12,自引:12,他引:0       下载免费PDF全文
1. The major metabolite of 2,4-dimethoxy-6-sulphanilamidopyrimidine (sulphadimethoxine) in urine in man is a non-reducing glucuronide, which has been isolated and characterized as its S-benzylthiouronium salt. 2. The same compound was made synthetically by standard methods from sodium sulphadimethoxine and methyl 2,3,4-tri-O-acetyl-1-bromoglucuronate. 3. On hydrolysis with acid, the glucuronide yielded sulphanilic acid, glucuronic acid and barbituric acid, and with beta-glucuronidase it slowly yielded sulphadimethoxine and glucuronic acid. 4. Evidence based on infrared spectra and other data showed that the urinary and synthetic glucuronide was 1-deoxy-1-[N(1)'-(2',4'-dimethoxypyrimidin-6' -yl)sulphanilamido-beta-d-glucosid]uronic acid or sulphadimethoxine N(1)-glucuronide. 5. N(1)-Methyl- and N(ring)-methyl derivatives of sulphadimethoxine and 4-methoxy-6-sulphanilamidopyrimidine were prepared and their infrared and ultraviolet spectra determined for comparison.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号