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1.
《Biochimica et Biophysica Acta (BBA)/General Subjects》1981,677(2):326-329
Labelled shikimic acid was efficiently incorporated into the aniline moiety of , a characteristic aromatic compound of the common mushroom, Agaricus bisporus. Incubations with [3-3H]- and [1,6-14C]shikimic acid clearly proved that the amination of shikimic acid occurs at its 4-position during the biosynthesis of . 相似文献
2.
《Biochimica et Biophysica Acta (BBA)/General Subjects》1985,840(2):287-290
Agaricus bisporus contains the unique aniline derivative, . 14C-labelled chorismic acid was quantitatively incorporated into the 4-hydroxyaniline moiety of this aniline derivative, whereas 14C-labelled prephenic acid and anthranilic acid were not incorporated into 4-hydroxyaniline. These observations indicate the branch point of the biosynthetic route of 4-hydroxyaniline in the shikimic acid pathway to be chorismic acid. Moreover, 4-aminobenzoic acid proved to be an effective precursor of 4-hydroxyaniline. 相似文献
3.
Kei Sasaoka Tadashi Ogawa Hideaki Tsuji Noriko Bando 《Biochimica et Biophysica Acta (BBA)/General Subjects》1980,630(1):137-140
Agaricus bisporus contains novel aromatic compounds. By incubation of the mushroom with [G-14 C] shikimic acid, the radioactivity was incorporated into tyrosine, phenylalanine and several unidentified metabolites. The most radioactive metabolite in the stipe and the cap was identified as . The radioactivity was proved to be localized in the 4-hydroxyaniline moiety of this compound. 相似文献
4.
In vitro stimulation by 2,4-dichlorophenoxyacetic acid of an ATPase and inhibition of phosphatidate phosphatase of plant membranes. 总被引:1,自引:0,他引:1
The auxin herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) was shown to modulate the activities of several phosphatases with membranes isolated from soybean hypocotyls under conditions where degradative changes in the membranes were minimized. The medium for isolation of membranes consisted of 0.1 M Tris/HCl or Tris/acetate, pH 6.5, 0.5 M sucrose, 4% choline () and 4% ethanolamine () to inhibit phospholipase D, 20 mM EGTA [ethyleneglycol-bis- (β aminoethyl ether) N,N-tetracetic acid] and 1 mM nupercaine, to inhibit phospholipase A. In contrast, the inactive auxin analog 2,3-D, did not influence ATPase activity. Endogenous release of inorganic phosphate from an unidentified source was also stimulated 30% by 2,4-D. Phosphatidate phosphatase was inhibited by 2,4-D, whereas hydrolysis of glucose-6-phosphate was not influenced by 2,4-D under the same conditions. These observations may be of relevance to the proton pump hypothesis of growth regulation. 相似文献
5.
Actinomycins of the Z series, synthesized by , contain the unusual amino acid, N-methylalanine, but no proline. Hydrolysates of actinomycin Z5 were investigated using paper, gas and ion-exchange chromatographic procedures. Identification of an unknown amino acid in actinomycin Z5 as 5-methylproline was confirmed by mass spectrometry. Configuration of the imino acid was defined as . 相似文献
6.
R W Fuller H D Snoddy K W Perry B W Roush B B Molloy F P Bymaster D T Wong 《Life sciences》1976,18(9):925-933
Quipazine, 2-(1-piperazinyl)-quinoline, is a drug that has been reported to stimulate serotonin receptors in brain. We therefore studied the effect of quipazine on several parameters of serotonin metabolism in rat brain. Quipazine caused a slight, dose-related elevation of serotonin levels and decrease in 5-hydroxyindoleacetic acid levels for 2–4 hrs after it was administered. The decrease in 5-hydroxyindoleacetic acid levels was probably due primarily to a depression of 5-hydroxyindole synthesis, since quipazine also decreased the rate of 5-hydroxytryptophan accumulation after NSD 1015, the rate of serotonin decline after α-propyldopacetamide, and the rate of 5-hydroxyindoleacetic acid accumulation after probenecid. The elevation of serotonin was probably due to weak inhibition of monoamine oxidase. Quipazine reversibly inhibited the oxidation of serotonin by rat brain monoamine oxidase and protected against the irreversible inactivation of the enzyme . Quipazine also was a potent inhibitor of serotonin uptake into brain synaptosomes and attained concentrations in brain higher than the IC50. However, quipazine did not prevent the depletion of brain serotonin by p-chloroamphetamine . In addition to stimulating serotonin receptors in brain, quipazine may inhibit monoamine oxidase and serotonin reuptake . 相似文献
7.
Leukotriene A: stereochemistry and enzymatic conversion to leukotriene B 总被引:13,自引:0,他引:13
Olof Rådmark Curt Malmsten Bengt Samuelsson David A. Clark Giichi Goto Anthony Marfat E.J. Corey 《Biochemical and biophysical research communications》1980,92(3):954-961
Leukotriene A was assigned the structure 5(S)--5,6-oxido-7,9--eicosatetraenoic acid by the enzymatic conversion of a synthetic product of known stereochemistry into the naturally occurring isomer of 5(S),12(R)-dihydroxy-6,8,10,14-eicosatetraenoic acid in human polymorphonuclear leukocytes. 相似文献
8.
G Tunnicliff 《Biochemical and biophysical research communications》1979,87(3):712-718
The binding of acid to cat cerebellar membranes is inhibited in a competitive manner by pyridoxal-5′-phosphate present during the binding assay. Structural analogues of the inhibitor have no such effect. If, on the other hand, the membranes are preincubated with pyridoxal-5′-phosphate followed by the addition of sodium borohydride, a rapid, inhibition of subsequent γ-aminobutyric acid binding is observed. Since pyridoxal-5′-phosphate is known to inactivate certain enzymes by reacting with essential lysine residues, the present results suggest that such a lysine residue may be present within the γ-aminobutyric acid receptor. 相似文献
9.
A A Qureshi J K Solomon B Eichelman 《Biochemical and biophysical research communications》1978,83(3):1191-1197
When fasted rats were fed a chow or fat-free diet supplemented 5% with L-histidine for three days, the brain adenosine 3′:5′-monophosphate (cAMP) level increased. A 50% increase occurred in rats fed a chow diet and 20% increase in rats fed a fat-free diet. Purification of liver fatty acid synthetase and the isolation of liver apo-, holo- and holo- fatty acid synthetases demonstrated that L-histidine feeding caused changes in the relative amounts of these enzymes. Apo- and holo- fatty acid synthetases increased while the holo- form simultaneously decreased. This effect was observed in rats fed either chow or fat-free diets supplemented with L-histidine. 相似文献
10.
Max O. Funk Alfred W. Alteneder 《Biochemical and biophysical research communications》1983,114(3):937-943
A series of unsaturated and polyunsaturated fatty acids with a sulfur atom substituting for a methylene unit of the chain has been prepared and characterized. The syntheses were accomplished by the Wittig coupling of the ylid derived from the triphenylphosphonium salt of 9-bromononanoic acid with aldehydes containing sulfur. The newly formed double bond had predominately the natural Z geometry even when the starting aldehyde was conjugated with the sulfur atom. The sulfides 13-thia-9(Z)-octadecenoic acid (), 13-thia-9(Z), 11(E)-octadecadienoic acid () and 13-thia-9(E), 11(E)-octadecadienoic acid () were readily converted into their sulfoxide derivatives by treatment with an equivalent amount of m-chloroperoxybenzoic acid. The structures of the novel compounds were confirmed by the application of ir, uv, 1H-nmr, 13C-nmr, and (as methyl esters) chemical ionization mass spectrometry. Two members of this new family of fatty acids ( and ) were found to inhibit the catalysis of the oxygenation of linoleic acid by soybean type-1 lipoxygenase. The analysis of the kinetic data for compound indicated that the type of inhibition was reversible competitive with an inhibition constant of 30 μM. 相似文献
11.
John C. Sih Roy A. Johnson Eldon G. Nidy David R. Graber 《Prostaglandins & other lipid mediators》1978,15(3):409-421
We wish to report here the syntheses of (5, 6)-5-hydroxy-, (5, 6)-5-hydroxy-, (5, 6)-5-hydroxy-, and (5, 6)-5-hydroxy-PGI1 and their methyl ester derivatives. Treatment of (5, 6)-5-epoxy- and (5, 6)-5-epoxy-PFG1α methyl esters with acid washed silica gel afforded (5, 6)-5-hydroxy- and (5, 6)-5-hydroxy-PGI1 methyl esters; correspondingly, silica promoted cyclization of (5, 6)-epoxy- and (5, 6)-5-epoxy- PGF1 methyl esters yielded (5, 6)-5-hydroxy- and (5, 6)-5-hydroxy- PGI1 methyl esters. Alternatively, the 5-hydroxyl group was introduced into the PGI1 skeleton reaction of the 5-mercuric halides with sodium borohydride in the presence of oxygen. Stereochemical assignments were based on their mode of synthesis and 1H nmr shift differences. 相似文献
12.
The presence of 5β-cholanic acid has been detected in the seeds of jequirity bean ( L.) Its structure was unequivocally established by spectroscopic methods. This report provides proof, for the first time, of the occurrence of 5β-cholanic acid in a plant source. 相似文献
13.
A simple micro method for the estimation of urinary pregnanediol (5β-pregnane-3α,20α-diol) is described. Chloroform extracts of acid-hydrolyzed urine are assayed gas chromatographically at 235° using Gas Chrom Z coated with 0.5 gm % NPGA. Thirty urine specimens may be prepared for gas chromatography in 1.5 hr. The rate of hydrolysis of pregnanediol glucuronide is proportional to the concentration of acid, and the rate of decomposition of pregnanediol to the square of acid concentration. Normal pregnant women excreted a mean of pregnanediol in the first trimester, in the second, and in the third. During the luteal phase of the menstrual cycle the excretion of pregnanediol by normal women increased from to . 相似文献
14.
A novel synthesis of 16α-hydroxy-4-androstene-3,17-dione (), 16α-hydroxy-4-androstene-3, 6,17-trione (), 17β-amino-5-androsten-3β-ol () and 17β-amino-4-androsten-3-one (14) is described. 16α-Bromoacetoxy-4-androstene-3, 17-dione (), 16α-bromoacetoxy-4-androstene-3, 6,17-trione () and 17β-bromoacetylamino-4-androsten-3-one () were synthesized as potentially selective irreversible inhibitors of androgen aromatases. 16α-Bromo-4-androstene-3,17-dione () and 16α-bromo-4-androstene-3, 6,17-trione () were converted to compounds and in 80–90% yield by controlled stereospecific hydrolysis using sodium hydroxide in aqueous pyridine. Reductive amination of 3β-hydroxy-5-androsten-17-one and 3-methoxy-3,5-androstadien-17-one () using ammonium acetate and sodium cyanohydridoborate (NaBH3CN) and a subsequent treatment with acid gave the amines and respectively, as a salt. The corresponding 17-imino compounds and were also isolated from the reaction mixtures when methanol was used as a solvent for the reaction. The 16α-hydroxyl compounds and and the 17β-amino compound were con- verted to the corresponding bromoacetyl derivatives, , , and , with bromoacetic acid and N,N'-dicyclohexylcarbodiimide. 相似文献
15.
David A. Clark Giichi Goto Anthony Marfat E.J. Corey Sven Hammarström Bengt Samuelsson 《Biochemical and biophysical research communications》1980,94(4):1133-1139
A slow reacting substance, produced by murine mastocytoma cells, has been shown to have the structure 5(S)-hydroxy-6(R)--glutathionyl-7,9,11- leukotriene C, previously referred to as leukotriene C-2) by ultraviolet spectroscopy, amino acid analyses, lipoxygenase conversion and comparisions with a synthetic compound of known structure and stereochemistry. 相似文献
16.
Malcolm MacCoss Eung K. Ryu Tatsuo Matsushita 《Biochemical and biophysical research communications》1978,85(2):714-723
Recently, 1-β--arabinofuranosylcytosine-5′-diphosphate--1,2-dipalmitin (VIa) was reported to inhibit the growth of L51784 cells in mice and of human colon carcinoma HCT-15 cells, also in mice. This paper describes the synthesis of a single diastereomer by conversion of 1-β--arabinofuranosylcytosine 5′-monophosphate (II) to the nucleoside 5′-phosphomorpholidate (III), followed by reaction with -α-dipalmitoylphosphatidic acid (IV) to give 1-β--arabinofuranosylcytosine-5′-diphosphate--1,2-dipalmitin (V) in good yield. The separation of the product is described and its characterization by chromatography, elemental analysis, and spectroscopic methods. The lipophilic nature of V renders it insoluble in aqueous media and a method of sample preparation utilizing sonication techniques is described which provides a clear solution suitable for biological evaluation. In addition, the ability of V to inhibit the growth of L1210 cells and of mouse myeloma MPC 11 cells is desscribed and compared with 1-β--arabinofuranosylcytosine (I) and other lipophilic prodrugs of I. 相似文献
17.
The purpose of this report is to review the current literature on cytochrome 5 in hepatic microsomes and to draw conclusions as to its role in microsomal electron transfer pathways. For details concerning the history of cytochrome 5 the reader is reffered to reviews by C. F. Strittmatter (1) and P. Strittmatter (2). For information on the chemistry of cytochrome 5 the reader is reffered to the papers by Ozols and Strittmatter (3), Kajihara and Hagihara (4), and Ehrenberg and Bois-Poltoratsky (5). For more recent studies on the isolation and properties of detergent solubilized cytochrome 5, which contains a hydrophobic peptide enabling reincorporation into membranes, the reader is referred to references 6-12.For simplicity, this minireview is divided into four parts, reflecting areas of study on the role of cytochrome 5 in the microsomes. One major area is in fatty acid 9 desaturation. Two other areas concern cytochrome 5 involvement in cytochrome P-450 mediated mixed function oxidations. The fourth section deals with other non-cytochrome P-450 pathways in which cytochrome 5 is suggested as being a component. 相似文献
18.
Snake venom phosphodiesterase from and 5′-nucleotide phosphodiesterase from were incubated with the 1-naphthyl ester of 5′-[methyl-3H]thymidylic acid. After short-time incubation the enzymes were denatured by extraction into phenol and chromatographed on Sephadex G-25. Protein fractions containing radioactivity were collected, dialysed and subjected to ultra-thin-layer isoelectric focussing and autoradiography. The results obtained indicate a hydrolytic course via a covalently-bound intermediate. 相似文献
19.
K Werkmeister F Wieland E Schweizer 《Biochemical and biophysical research communications》1980,96(1):483-490
A mixture of two pantetheine-free mutant fatty acid synthetases was dissociated and recombined to form a hybrid apoenzyme complex. the corresponding -mutants exhibit interallelic complementation when crossed with each other and the enzyme synthesized in the resulting diploid contains pantetheine and exhibits overall fatty acid synthetase activity. Accordingly, the hybrid apoenzyme formed could be activated to holo-fatty acid synthetase when incubated with coenzyme A and a partially purified yeast cell extract. The enzyme coenzyme A: fatty acid synthetase apoenzyme 4′-phosphopantetheine transferase has thus been identified in yeast. Further studies on the mechanism of fatty acid synthetase holoenzyme formation will now be possible. 相似文献
20.
Sven Hammarström Bengt Samuelsson David A. Clark Giichi Goto Anthony Marfat C. Mioskowski E.J. Corey 《Biochemical and biophysical research communications》1980,92(3):946-953
Leukotriene C-1, a “Slow Reacting Substance” (SRS), has been shown to possess the molecular Structure depicted by V (5(S)-hydroxy-6(R)--glutathionyl-7,9--11,14--eicosatetraenoic acid) by its identity with a totally synthetic product of known structure and stereochemistry. 相似文献