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1.
H. DE  HAAN 《Freshwater Biology》1972,2(3):235-241
It this study the use of Sephadex G-25, Sephadex LH-20 and CPG-10-75 for the separation of soluble humic compoutids frotn fresh water is tested. It is shown by Sephadex G-25 gel filtration that differences in molecule-size distribution of soluble humic compounds in one lake at different titnes and between lakes can be predicted by E250 and E365 measurements.  相似文献   

2.
《Insect Biochemistry》1989,19(1):95-101
Six major ecdysteroid conjugates have been isolated from mature ovaries of Bombyx mori by a procedure involving column chromatography on Sephadex G15, silicic acid and Sephadex LH-20, and high-performance liquid chromatography using a reverse-phase column. By analyses including ultraviolet absorption, enzymatic hydrolysis, negative ion fast-atom bombardment mass spectrometry and proton and 31P nuclear magnetic resonance spectrometry, these conjugates were identified as the following: ecdysone-22-phosphate, 20-hydroxyecdysone-22-phosphate, 2-deoxyecdysone-22-phosphate, 2-deoxy-20-hydroxyecdysone-22-phosphate, 2,22-dideoxy-20-hydroxyecdysone-3-phosphate and bombycosterol-3-phosphate.  相似文献   

3.
Summary A strain ofFusarium oxysporum was identified as having an intracellular penicillin V acylase activity (penicillin V amidohydrolase EC 3.5.1.11). Activity was induced by phenoxyacetic acid and had a good tolerance for high substrate and product concentrations. Washed cells could be used repeatedly for the complete hydrolysis of 5% penicillin V solutions. The enzyme was partially purified and concentrated from disrupted cells by fractional precipitation with water miscible solvents.  相似文献   

4.
Locusta adipokinetic hormone (AKH) has been purified from glandular lobes of corpora cardiaca by a series of chromatographic steps that have allowed a 58 to 77% recovery of activity. Methanolic extracts of the glandular lobes were fractionated on Sephadex LH-20 and then on thin-layer plates. The average recovery of AKH activity after separation on Sephadex LH-20 approached 100%, whereas recoveries of between 58 to 77% were obtained after TLC on cellulose plates. In practice, the highest recoveries were obtained with separations of large amounts of the hormone on cellulose plates. In the course of this investigation it was found that AKH activity can be extracted efficiently from aqueous solutions using Florisil. The hormone activity was recovered from the Florisil by eluting with 80% methanol. The purified hormone was found to be homogeneous in composition when subjected to rechromatography on Sephadex LH-20 and to amino acid analysis of the acid hydrolysate. From the amino acid analysis we estimate that one pair of glandular lobes contains on average 188 pmoles of AKH.  相似文献   

5.
E. W. Hewett  P. F. Wareing 《Planta》1973,112(3):225-233
Summary At least seven cytokinins have been detected in mature leaves of Populus x robusta Schneid after chromatography on Sephadex LH-20. Two of these have similar elution volumes to zeatin and zeatin riboside. A third appears to be a cytokinin glucoside. A fourth is a new, unidentified cytokinin, susceptible to mild oxidation, and yielding two cytokinin active products after acid hydrolysis. This cytokinin complex has been found in fully expanded leaves, a tissue in which cell division is completed.  相似文献   

6.
Summary The empirical rate expression previously proposed for the hydrolysis of avicel and tissue paper by Meicelase from Trichoderma viride also held for the hydrolysis of dewaxing cotton, Whatmann CF-11, Solka Floc SW-40, tissue paper and 1% NaOH-pretreated sawdust by Meicelase, Trichoderma reesei QM9414 or Cellulosin from Aspergillus nigar.  相似文献   

7.
Free fatty acids and triglycerides have been separated by elution with chloroform or chloroform + 0.2% (vv) acetic acid from columns of Sephadex LH-20. Loads of up to 10 mg/gm dry weight Sephadex were used, and recovery of artificial and natural mixtures was generally better than 95%.  相似文献   

8.
New glycosidic aroma precursors (1 and 2) of the main volatile constituents, trans- and cis-linalool 3,6-oxides (linalool oxides I and II), were isolated from oolong tea leaves (Camellia sinensis var. sinensis cv. Maoxie). The isolation was guided by an enzymatic hydrolysis with acetone powder prepared from fresh tea leaves (cv. Yabukita) followed by GC or GC-MS analyses. Chromatographic purification of hot water extracts of the tea leaves on active charcoal, Amberlite XAD-2, and Sephadex LH-20 columns as well as HPLC gave two new glycosides, trans- and cis-linalool 3,6-oxide 6-O-β-d-xylopyranosyl-β-d-glucopyra-nosides (1 and 2).  相似文献   

9.
Abstract— Godwin & Sneddon (1975) reported the binding of 5-hydroxy-[3H]tryptamine (5-HT) on a Sephadex LH-20 column to‘proteolipid material’extracted with n-butanol from rat brain stem. An examination of this‘proteolipid material’with TLC showed the main constituents to be cerebroside sulfate (CS), monophosphoinositide (PI), and diphosphoinositide. The elution profiles of [3H]5-HT incubated with purified CS or with a mixture of CS and PI were similar to that of the brain extract on the same column. Because the elution profile of the mixture of CS and PI was more similar to that of the brain extract, it was concluded that what was suggested to be a possible proteolipid‘5-HT receptor’was mainly two acidic lipids. The elution profile of [3H]5-HT incubated with purified PI, however, was similar to [3H]5-HT eluted alone. This suggested that either PI did not bind to 5-HT or that the PI-5-HT complex possesses different Chromatographie behavior than PI. To test this latter possibility, [14C]5-HT and [3H]PI were incubated then eluted on a Sephadex LH-20 column with a continuous gradient of increasing polarity. The gradient first eluted PI, then an apparent PI-5-HT complex, and finally 5-HT. This demonstrated that PI will bind to 5-HT on a Sephadex LH-20 column and that the PI-5-HT complex is probably more polar than PI.  相似文献   

10.
Sephadex LH-20 was tested for a potential application in the enrichment of ubiquinone-9 from a lipid-hydrocarbon-extract. The lipid-hydrocarbon-extract was isolated from yeast grown on gas oil (b. p. 240 to 380°C) as carbon-source. The main components of the lipid-hydrocarbon extract were phosphatides, glycerides, fatty acids, and hydrocarbons of gas oil. By use of Sephadex LH-20 and CHCl3/CH3OH (2:1)as eluent it is possible to concentrate the whole ubiquinone-9 in a special fraction both directly from the lipid-hydrocarbon-extract and from the aceton-soluble part of the extract The concentration of ubiquinone in the special fraction was ten times higher than in the raw-material and the hydrocarbons were separated completely. Ubiquinone-9 can be obtained by a simplified separation from the enriched fraction.  相似文献   

11.
Synthesis of the specific monosulfates of cholic acid.   总被引:1,自引:0,他引:1  
G Parmentier  H Eyssen 《Steroids》1975,26(6):721-729
The three isomeric cholic acid-monosulfates were synthetized and characterized. Cholic acid-3-sulfate was obtained by reacting cholic acid for 2 min with chlorosulfonic acid in pyridine and chromatography of the resulting bile salt mixture on Sephadex LH-20. The 7- and the 12-monosulfate were prepared by sulfation of the corresponding monohydroxy-diacetates followed by removal of the acetyl groups by alkaline hydrolysis and purification by chromatography on Sephadex LH-20. On TLC in n-butanol-acetic acid-water (10:1:1, v/v) the Rf values were 0.59 for cholic acid-3-sulfate, 0.52 for cholic acid-7-sulfate and 0.48 for cholic acid-12-sulfate. The time required for complete solvolysis at 37 degrees C in acid methanol-acetone (1:9) was 3 h for cholic acid-3-sulfate, 12 h for the 12-monosulfate and 18 h for the 7-monosulfate.  相似文献   

12.
Metabolism of the selective herbicide flamprop-isopropyl (isopropyl-N-benzoyl-N-(3-chloro-4-fluorophenyl)-2-aminopropionate) in suspension cultures of the dicotyledons Phaseolus vulgaris, P. multiflorus and Medicago sativa showed general similarities be, but particular variations from, that reported in intact plants of Hordeum vulgare. Hydrolysis of the ester and conjugation were major routes, but some hydroxylation and hydrolysis of the amide was also observed. The implications of these variations are discussed.  相似文献   

13.
A particulate membrane preparation fromSaccharomyces cerevisiae catalyzed the incorporation of mannose from GDP-mannose into lipids that were extractable in chloroform-methanol. One lipid has been previously characterized as dolichyl phosphomannose. Another one was purified by chromatography on silicic acid, DEAE-cellulose and Sephadex LH-20 and found to be alkali unstable. The lipid moiety was shown to be dolichol and the glycosydic part contained mannose, glucose and glucosamine.Radioactive mannose was also incorporated at a slower rate into more polar compounds. They were soluble in chloroform-methanol-water and were seen to liberate neutral oligosaccharides after alkaline hydrolysis.Radioactive mannose was also incorporated into substances which behave chemically as glycoproteins since they were insoluble in organic solvents, water and trichloroactic acid. Pronase treatment of the trichloroacetic acidinsoluble material released water-soluble oligosaccharides.When the particulate preparation which had been extracted with chloroform-methanol at –20 C, was incubated with GDP-(U-14C)mannose, radioactivity was incorporated into glycolipids that were soluble in chloroform-methanol-water and into glycoproteins. This result suggests that at least part of the mannose was transferred to endogenous acceptors independent of dolichyl phosphomannose.  相似文献   

14.
This is the first report not only on the presence of polyprenyl phosphates and their site of synthesis in algae, but also on the formation of their sugar derivatives in this system.

A glucose acceptor lipid was isolated from the nonphotosynthetic alga Prototheca zopfii. The lipid was acidic and resistant to mild acid and alkaline treatments. The glucosylated lipid was labile to mild acid hydrolysis and resistant to phenol treatment and catalytic hydrogenation, as dolichyl phosphate glucose is. These results are consistent with the properties of an α-saturated polyprenyl phosphate.

The polyprenylic nature of the lipid was confirmed by biosynthesis from radioactive mevalonate. The [14C]lipid had the same chromatographic properties as dolichyl phosphate in DEAE-cellulose and Sephadex LH-20. Strong alkaline treatment and enzymic hydrolysis liberated free alcohols with chain lengths ranging from C90 to C105, C95 and C100 being the most abundant molecular forms. The glucose acceptor activity of the biosynthesized polyprenyl phosphate was confirmed.

The ability of different subcellular fractions to synthesize dolichyl phosphate was studied. Mitochondria and the Golgi apparatus were the sites of dolichyl phosphate synthesis from mevalonate.

  相似文献   

15.
Analysis of 35S labled nucleosides prepared from tRNA of Pseudomonas aeruginosa by phosphocellulose column chromatography, thin layer chromatography and Sephadex LH-20 column chromatography revealed the presence of 2-methylthioribosylzeatin in it.  相似文献   

16.
Summary Maximum xylanase production byChaetomium cellulolyticum was obtained in the culture supernatant after 30 h of growth at 37°C in basal medium containing 1% xylan at pH maintained between 6.5 and 7.5. Addition of 0.05% Tween 80 to the medium increased the enzyme production considerably. Xylanase production was found to be growth associated. The optimal conditions for enzymatic hydrolysis of xylan were found to be pH 6.0 and 50°C. During enzymatic hydrolysis, xylose, xylobiose and other xylooligosaccharides were liberated from xylan. The pH values for xylanase production and for xylan hydrolysis were closely related to the utilization of hemicelluloses of aspen wood for fungal protein production by this organism as reported in our earlier work.  相似文献   

17.
Summary The extracellular maltase of the fungusPaecilomyces varioti CMI 16196 was purified by acetone precipitation and Sephadex G-150 gel filtration. The enzyme functioned optimally at pH 3.5–4.0 and 60°C. The maltase hydrolysed maltose and maltotriose preferentially but was inactive on both the aryl-and alkyl--D-glucosides. The Km for maltose was 1.31 mM. End product configuration was maintained and transferase activity was observed.  相似文献   

18.
Summary Enzymatically hydrolysed cassava starch was used for C. utilis cultivation. Highly efficient starch hydrolysis was achieved with a 92% DE syrup obtained after 15–20h. Cyanide content fell during cassava processing to very low levels in the hydrolysate. Comparison of biomass yields and protein of C. utilis using molasses and cassava hydrolysate as substrates demonstrates the potential of the latter for yeast production.  相似文献   

19.
The existence of cytokinins both as a free form and as a constituent of t-RNA was investigated in young fruits of Moringa pterigosperma Gaertn. Purified methanol extract was separated into butanol insoluble and butanol soluble fractions. The cytokinin(s) in the butanol insoluble fraction was tentatively identified as zeatin nucleotide. The butanol soluble fraction contained cytokinins and was chromatographed on Sephadex LH-20 with 35% ethanol. The two active fractions from LH-20 column coincided with zeatin and zeatin riboside. Cytokinin per g tissue was high in early stages of fruit growth and then remained more or less constant. Alkaline phosphatase hydrolysis of t-RNA hydrolysate of fruit tissue showed considerable cytokinin activity.  相似文献   

20.
Summary Three pentose fermenting yeast strains ofCandida shehatae and three ofPichia stipitis were examined for their ability to produce ethanol from cellobiose and from sugars liberated by hydrolysis of lignocellulosic biomass. All of thePichia strains tested produced some ethanol;P. stipitis CBS 5776 gave the highest yield: 10.3 g/L on complete fermentation of 25 g/L cellobiose within 48 hours. This yeast also produced considerably more ethanol from the wood sugar mixture.  相似文献   

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