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1.
Metabolites of hydrocortisone were isolated from rat liver on a preparative scale, fractionated by column chromatography on Sephadex LH-20 and silica gel and tested for biological activity. Apart from the well known neutral metabolites, steroid glucuronides and sulfates, we obtained metabolite fractions containing non-conjugated steroidal carboxy acids and acid metabolites of unknown structure. One of these fractions induced tyrosine aminotransferase (EC 2.6.1.5) in adrenalectomized female rats but not trptophan oxygenase (EC 1.13.11.11), whereas another one mainly increased activity of tryptophan oxygenase. The doses necessary to significantly induce both enzymes were much lower in case of these metabolites than in the case of hydrocortisone itself. The active fractions eluting from silica gel column were analyzed by thin-layer chromatography in two different solvent systems. Absence of hydrocortisone in these fractions could be clearly demonstrated. Furthermore, the active fractions eluting from the silica gel column were characterized by treatment with an extract from Helix pomatia and/or diazomethane and subsequent analysis by thin-layer chromatography. We conclude, considering the biological activity of some synthesized derivatives of hydrocortisone, that the biologically active components are acid metabolites of hydrocortison which are not identical to any of the known metabolites.  相似文献   

2.
After administration of [3H]hydrocortisone to adrenalectomized rats, hormone-protein complexes were isolated from liver cytosol by DEAE-cellulose chromatography. After application of biologically active and inactive doses of hydrocortisone five binding components were detected eluting at the same salt concentrations as the hormone-protein complexes observed after incubation of cytosol with [3H]hydrocortisone in vitro. The isolated hormone-protein fractions were acidified and extracted with ethylacetate and the steroids were analyzed by thin-layer chromatography. No significant amount of hydrocortisone could be detected in any of the complexes formed in vivo 5–60 min after administration of biologically active doses of hydrocortisone. 3ξ,11β,17α,20ξ, 21-Pentahydroxypregnane, steroidal carboxy acids, glucuronides and a very polar conjugate of hydrocortisone were found in the different fractions. After an in vivo dose of hydrocortisone of about 1/5000th of the minimal dose required for enzyme induction, hydrocortisone could be found in all cytoplasmic hormone-protein complexes formed. In contrast to the cytoplasmic hormone-protein complexes, hydrocortisone could be readily demonstrated in nuclei isolated after the administration of biologically active doses of hormone, although acid metabolites were found to represent the main part of the radioactive compounds present in the nuclei. These acid metabolites were located in ronide on the basis of its chromatographic behavior. The biological significance of this conjugate of hydrocortisone as well as that of the extremely polar conjugate found in fraction DE-3 cannot be understood on the basis of the published data pertaining to biological functions and metabolism of glucocorticosteroids.Our finding that no ‘classical’ glucocorticosteroid receptor can be detected in rat liver cytosol raises again the question of the way in which hydrocortisone and its active metabolites enter the nucleus. On the basis of the published data, the possibility cannot be ruled out that glucocorticosteroids are transported via the endoplasmic reticulum. A transport by this way has been inferred for the uptake of sodium and inulin by liver nuclei [40–42].  相似文献   

3.
Lipid components obtained from Salmonella typhosa O-901 endotoxin by acid hydrolysis were separated into neutral, polar-I and polar-II lipid fractions by silica gel column chromatography. These lipids were further separated by silica gel column and/or thin-layer chromatography. The subfractions were analyzed by thin-layer chromatography, gas chromatography and infrared spectrophotometry. Seven subfractions obtained from the neutral lipid fraction contained lauric, myristic, palmitic, 3-OH-myristic acid, artificial products of 3-OH-myristic acid, or a small amount of two unidentified fatty acids. These fatty acids and glucosamine were commonly detected in six subfractions obtained from the polar-I lipid fraction. Fatty acids, glucosamine, and O-phosphorylethanolamine were detected in all of the 13 subfractions obtained from the polar-II lipid fraction. Chick embryo lethal activity, rabbit pyrogenicity and in vitro interferon inducing activity were found in three polar-I lipid subfractions and five polar-II lipid subfractions, but not in neutral lipids. The activities were highest in a polar-II lipid subfraction, which contained smaller amounts of O-phosphorylethanolamine and glucosamine than the other subfractions. However, no particular chemical constituent (s) related to the biological activities could be found. Prolonged acid hydrolysis of the polar-II lipids gave rise to neutral and polar-I lipids. Chemical and biological aspects of the lipid constituents of endotoxin are discussed.  相似文献   

4.
Isolation and identification of substances having an activity to stimulate the fruiting body formation of Schizophyllum commune were attempted. The active principles in its mycelia were divided into four fractions by sequential purification with silica gel column and reverse-phase HPLC column chromatography. By infrared spectra and thin-layer chromatography, the active substances in these four fractions were revealed as cerebrosides. About 0.1 μg of the cerebroside fractions showed a discriminative stimulating activity on S. commune when tested by the method these authors adopted. The active substance in the fraction II was N-2′-hydroxypalmitoyl-1-O-glucosyl-nonadecasphingadienine. The cerebrosides from pea seeds and Fusicoccum amygdali showed the similar activity on S. commune, but some commercial synthetic cerebrosides and cerebrosides from bovine and porcine brains exhibited no stimulating activity. Only definite cerebrosides with special structures seem to be able to induce the fruiting of S. commune.  相似文献   

5.
Peptide inhibitors of angiotensin I-converting enzyme (peptidyldipeptide hydrolase, EC 3.4.15.1) were produced by digesting gelatin with bacterial collagenase. The inhibitors were isolated from the digests with a combination of alcohol fractionation, treatment with Amberlite CG-50 column, gel filtration through Sephadex G-25, and Dowex 50 column and paper chromatography. Nine peptide fractions were purified to apparent homogeneity judging by thin-layer and ion-exchange column chromatography, and amino acid composition. Amino acid sequences of the peptides were determined: 2 were found to be mixtures of peptides and the sequence of another was only partially determined. Six of the peptides were potent inhibitors of the converting enzyme, while the other three were less active. 6 peptides were substrates for the enzyme. The enzyme released a dipeptide, Ala-Hyp from one peptide and was strongly inhibited by this dipeptide. The remainder of the parent peptides was a less effective inhibitor.  相似文献   

6.
Sezik E  Aslan M  Yesilada E  Ito S 《Life sciences》2005,76(11):1223-1238
Hypoglycemic effect of Gentiana olivieri Griseb. (Gentianaceae) flowering herbs on oral administration were studied using in vivo models in normal, glucose-hyperglycemic and streptozotocin-induced diabetic rats. Through in vivo bioassay-guided fractionation processes isoorientin, a known C-glycosylflavone, was isolated from the ethylacetate fraction by silica gel column chromatography as the main active ingredient from the plant. Isoorientin exhibited significant hypoglycemic and antihyperlipidemic effects at 15 mg/kg b.w.dose. Isoorientin concentration of the extracts and fractions were determined by HPLC in order to establish a correlation between the hypoglycaemic activity.  相似文献   

7.
【目的】研究稀有放线菌——雷公藤内生小单孢菌(Micromonospora sp.M66)的次级代谢产物,为微生物药物或农用生物制剂开发提供结构多样的化合物资源。【方法】利用薄层层析、正(反)相硅胶柱层析、凝胶层析、液相色谱等技术对M66菌株中次级代谢产物进行分离纯化,利用波谱技术对化合物进行结构鉴定。【结果】最终分离纯化了7个单体化合物,结合质谱与核磁技术对这7个化合物进行了结构解析和鉴定,它们属于一组吲哚生物碱。化合物2是重要的植物生长调节剂,化合物3对淋巴细胞性白血病细胞P388、枯草芽孢杆菌和酿酒酵母的增殖有抑制作用,化合物6对金黄色葡萄球菌有很好的抑制作用。【结论】化合物3-7首次从小单胞菌中鉴定出来,表明该小单孢菌具有较强的利用吲哚或色氨酸合成次级代谢产物的能力和挖掘生物碱类药物的潜力。  相似文献   

8.
福寿螺(Pomacea canaliculata)不同生长发育阶段(螺苗、仔螺、中螺、成螺)的软体匀浆物用乙酸乙酯进行提取.提取物分别用硅胶柱进行柱层析,并分别用不同极性的有机溶剂进行洗脱,分离出不同极性组分:非极性组分(石油醚洗脱组分)、弱极性组分(苯洗脱组分)、强极性组分(乙醇洗脱组分).然后用11种细菌对不同极性组分进行抗菌活性检测.结果表明,不同生长发育阶段组分抗菌作用的共同点是:强极性组分的抗菌活性最强,弱极性组分次之,非极性组分无抑菌作用.将不同生长发育阶段抗菌活性最强的乙醇洗脱组分分别进行薄层层析(TLC)分析并进行抗菌实验.薄层层析所用的展层剂不同,分离出条带数不同,各条带抗菌活性也存在差异.将抗菌活性最强的条带用气相色谱.质谱法进行化学成分鉴定,结果表明,各不同生长发育阶段抗菌物质的化学成分大部分是酸类物质,相同的化学成分在不同生长发育阶段的含量及相似度都不一样.  相似文献   

9.
An improved apparatus and a procedure are described by which the migration of sample components in column chromatography is accelerated by centrifugal force, thereby making it possible to use beds of densely packed gel prepared with ultrafine silica. This technique was used to resolve components of certain lipid mixtures where other methods have failed, and it has been found generally useful as an adjunct to other methods for the fractionation of lipids. Biologically active phosphoglycolipids from Mycobacterium tuberculosis and a phosphatidylglycerol-like substance from Mycoplasma pneumoniae which formed single spots on thin-layer chromatographic plates were each found to contain a major and several minor components by centrifugal chromatography. The method enabled us to isolate individual components of Wax D from M. tuberculosis rather than a spectrum of components. Minor components were resolved which, although present in insufficient quantity to influence results of chemical analyses, may be responsible for biological activity. The apparatus provides an essentially closed system which reduces highly volatile solvents to minimal evaporation during the chromatographic process. Samples are applied in solution and are not allowed to dry on the columns until after separation has been achieved. Consequently, polar, labile microbial lipids can be resolved without the use of harsh reagents which destroy some of their properties. Single components may be harvested by cutting and removing appropriate segments of the larger chromatograms or by eluting them from the columns.  相似文献   

10.
Characterization of vitamin K from bovine liver   总被引:1,自引:0,他引:1  
Concentrated fractions of vitamin K from bovine liver were purified by thin-layer chromatography and fractions were analyzed by UV spectroscopy and mass spectrometry. The chromatographic behavior of the purified vitamins was compared with that of known compounds on thin layers of silica gel, either untreated or impregnated with silver nitrate or paraffin. The principal forms of vitamin K recovered from bovine liver were highly lipophilic. Two fractions were obtained which collectively gave identifiable mass spectra of menaquinone-10, menaquinone-11, and menaquinone-12.  相似文献   

11.
The red pigment uroerythrin, a chromophore known to be adsorbed by the amorphous urate sediments (sedimentum lateritium), has been isolated from human urine and further purified as its trimethyl derivative. Urine was applied to a column of Amberlite XAD-2 resin on which uroerythrin and other pigments were adsorbed. The pigments were eluted with methanol and uroerythrin was further purified by extraction with ether at pH 4.0, repeated chromatography on lipophilic Sephadex LH-20 and thin-layer chromatography on silica gel. For optimal purification uroerythrin was converted into the trimethyl derivative and chromatographed on silical gel thin-layer plates. The structure of the pigment has been studied by chromate degradation followed by identification of the imide products by thin-layer chromatography. From these results and from infrared, mass spectral and nuclear magnetic resonance data a tripyrrole structure for uroerythrin is concluded. The proposed structure for the chromophore is related to that of the bile pigment biliverdin consisting, however, only of the rings A, B and C.  相似文献   

12.
Acyl-coenzyme A:cholesterol acyltransferase (ACAT) assays are usually performed by incubation of the enzyme with a labeled substrate followed by thin-layer chromatography separation and subsequent quantification of cholesteryl esters (CE) formed. Herein, a method is described for rapid separation of CE from other lipids, by elution from a silica gel column with a solvent mixture of petroleum ether/diethyl ether (98:2, v/v). Silica gel column chromatography is reliable and more rapid and safer than TLC. The best results were obtained when the reaction was stopped by Dole extraction followed by CE separation on a silica gel column. Assays for ACAT from rat intestinal microsomes showed that the specific activity values obtained using this method were reproducible and in good agreement with those obtained by conventional TLC method.  相似文献   

13.
Gangliosides were isolated from human milk fat and purified by silica gel column chromatography and high performance liquid chromatography (HPLC). Low amounts of the ganglioside GM1, detected by high performance thin layer chromatography (HPTLC)-immunoassay, were found in all fractions with enterotoxin-inhibitory activity, while fractions without GM1 were inactive. It is concluded that GM1 is responsible for enterotoxin-inhibitory activity in the ganglioside fraction from human milk.  相似文献   

14.
Lipogenesis in vitro from acetate-1-(14)C was studied in human preputial skin and abdominal skin. Radioactive lipids were separated by column chromatography on Florisil and by thin-layer chromatography on silica gel. Radioactivity was incorporated chiefly into the triglyceride, sterol, and polar lipid fractions, while lesser amounts of (14)C were found in the hydrocarbon, wax, diglyceride, monoglyceride, and fatty acid fractions; labeling of steryl esters was minimal. On thin-layer chromatography, the radioactive polar lipids had mobilities similar to lysolecithin, phosphatidyl choline, phosphatidyl ethanolamine, and phosphatidic acid. The radioactive fatty acids of the different lipid fractions were separated by gas-liquid chromatography. The major (14)C-labeled acids were 16:0 and 18:0. Radioactivity was also detected in acids 14:0, 15:0, 16:1, 18:1, 18:2, 20:0, 20:1, 22:0, 24:0, 24:1, and 26:0. No radioactivity could be detected in arachidonic acid, although this fatty acid comprises 9% of the chromatographed fatty acids. The pattern of incorporated (14)C was different from the percentage mass composition of the fatty acids. Skin is therefore active in the biosynthesis of a wider variety of lipids than previously demonstrated.  相似文献   

15.
两种水溶性抗菌活性物质的分离提取   总被引:2,自引:0,他引:2  
对水溶性、不解离的极性物质分离时,一般采用吸附层析和凝胶层析等途径。实验通过硅胶柱层析、葡聚糖凝胶柱层析以及硅胶GF254制备型薄板层析,从发酵液样品中分离出两种有抗菌活性的纯物质。薄层层析的展开剂为二氯甲烷-四氢呋喃-甲醇-水(25:30:2),分离出的组分中Rf=0.7和Rf=0.8两种物质有抗菌活性。硅胶柱层析洗脱过程为梯度洗脱,先用150ml上述展开剂洗脱,再用二氯甲烷-甲醇(20:80)  相似文献   

16.
Isozymes of pyridoxine (pyridoxamine)-5′-phosphate oxidase (EC 1.4.3.5) were isolated from the extract of wheat seedlings by column chromatographies. From DEAE-Sephadex A-50, two fractions having pyridoxine-5′-phosphate oxidase activity were separated by eluting with ~0.075 and ~0.125 m phosphate buffers (pH 8.0). These fractions were further fractionated on a Blue-Sepharose CL-6B column, from which again two activities were eluted by 1.0 m KCl solution. One fraction, designated as E-I, used only pyridoxine 5′-phosphate as substrate, whereas the other, designated as E-II, oxidized not only pyridoxine 5′-phosphate but also pyridoxamine 5′-phosphate with approximately equal rates. The mobility on polyacrylamide disc gel electrophoresis and the substrate specificity of these two fractions were different. Therefore, they were concluded to be isozymes.  相似文献   

17.
The nucleotides from a trichloroacetic acid extract of mature strawberry leaves were separated into ten main fractions by chromatography on a Dowex 1 (formate form) column with ammonium formate as the eluting agent. One of these fractions, which was suspected to contain not only ADP but also GDP-sugars, was separated into a number of subfractions by further chromatography on a Dowex 1 (formate form) column with the formic acid system as the eluting agent. One of these subfractions was identified from its ultraviolet spectra, from its position on the two ion-exchange columns and by thin-layer chromatography as a GDP-sugar. Mild acid hydrolysis gave GDP and a mixture of sugars. The sugars, after a preliminary separation on a paper chromatogram, were identified by an isotope-dilution method. The sugars were condensed with sodium [(14)C]cyanide, the [(14)C]nitriles were hydrolysed and one of the epimeric acids was isolated, either as lactone or amide, by co-crystallization with a non-radioactive carrier. This method distinguishes between enantiomorphic sugars. d-Mannose, d-xylose, d-glucose and d-galactose were present in the proportions 40:10:1:1 respectively. The total amount of the GDP-sugars was approx. 0.1mumole/100g. of fresh leaves.  相似文献   

18.
Sobeslavsky, O. (National Institute of Allergy and Infectious Diseases, Bethesda, Md.), B. Prescott, W. D. James, and R. M. Chanock. Isolation and characterization of fractions of Mycoplasma pneumoniae. II. Antigenicity and immunogenicity. J. Bacteriol. 91:2126-2138. 1966.-Chemical and chromatographic fractions of disrupted Mycoplasma pneumoniae organisms were examined for serological and immunogenic activity. Complement-fixing activity was associated with lipid components, whereas precipitin activity was chiefly associated with polysaccharide components. When chemically extracted lipids were separated by thin-layer silica gel chromatography, only three of the nine fractions exhibited complement-fixing activity. Although lipids were highly active serologically, they were only weakly immunogenic. However, lipids combined with protein in lipoprotein complexes were highly immunogenic, stimulating high levels of complement-fixing, indirect-hemagglutinating, and growth-inhibiting antibodies. The specificity of these antibodies was directed chiefly against the serologically active lipid constituents of the organism. It was suggested that these serologically active lipids are present at the sites on the limiting membrane of M. pneumoniae at which antibody acts to inhibit growth of the organism. Only protein fractions adsorbed to tanned erythrocytes. The main function of protein in the indirect-hemagglutination reaction appeared to be that of serving as a carrier for the serologically active lipids.  相似文献   

19.
Purification and study of the antibiotic substances produced byLentinus squarrosulus have been carried out. The substances, excreted in the culture medium, were extracted withn-butanol. The butanolic extract inhibited growth ofRigidopurus lignosus, the agent of white rot ofHevea brasiliensis, and also ofMucor ramannianus, Rhodotorula mucilaginosa, Saccharomyces cerevisiae, andBacillus subtilis. The antibiotic fractions were purified by silicic acid column chromatography, then by reversed-phase (C18) high performance liquid chromatography (HPLC) followed by preparative adsorption thin-layer chromatography on silica gel. Two purified compounds were obtained: Ls1, which was active againstB. subtilis, and Ls2, which in addition was also active againstR. lignosus, M. ramannianus, and yeasts. Only the Ls2 compound is analyzed in this work. It was characterized by chemical reactions, ultraviolet spectroscopy, infrared spectroscopy, and proton nuclear magnetic resonance spectroscopy, which indicated the hydrophilic character of the molecule and the presence of alcoholic functions as well as a glycosidic moiety. The properties differed from those of already known antibiotics produced by different species ofLentinus.  相似文献   

20.
Gas chromatographic estimation of acidic urinary metabolites after separation on prepacked silica gel columnsThe acidic ethylacetate extracts of 24-h urine specimens are evaporated and redissolved in chloroform—methanol—acetic acid. The resulting solution is transferred to a prepacked silica gel column. Elution takes 160 min using a specially designed chloroform—methanol—acetic acid gradient. The eluate is divided into fractions (16 min each) which are evaporated to dryness. The residues are silylated and determined quantitatively by gas chromatography. The capacity of the silica gel column allows analysis of 30% of a 24-h urine specimen. In consequence, metabolites can be quantitated at concentrations less than 1 mg per 24 h. The method is suitable to obtain more detailed metabolic profiles of the carboxylic acids in urine.  相似文献   

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