Isolation of Cerebroside from Pea Seeds

Cerebroside was isolated from pea (Pisum sativum L.) seeds by solvent extraction, mild alkaline hydrolysis and silicic acid column chromatography. The purified material was identified as cerebroside by thin-layer chromatography and infrared spectrometry. Hydrolysates of the cerebroside were divided into fatty acid, sphingosine base and sugar fractions, and analysed, mainly by gas-liquid chromatography. The major fatty acid components were hydroxytricosanoic, hydroxydocosanoic and hydroxytetracosanoic acids. Dihydrosphingosine was the predominant sphingosine base. Only glucose was detected in the sugar fraction. Based on these results, one of the major species of pea cerebroside is suggested to be N-hydroxytricosanoyl-glucopyranosyl-dihydrosphingosine.     

Isolation of a Neuroactive Substance,l-Leucine,from the Blood of Silkworm Poisoned with DDT

A neuroactive substance was isolated in colorless crystalline state from body fluid of silkworm larvae which had been poisoned with DDT. It increased a spontaneous activity on the isolated abdominal nerve cord of American cockroaches, and resembled to the Sternburg’s unknwon neuroactive substance in some respects. This compound was, however, not aromatic amine but was identified as l-leucine by mass spectra, infrared absorption spectra, ultraviolet absorption spectra, and paper chromatography. Authentic l-leucine also showed a high neuroactivity.

Various kinds of other amino acids were also tested on the isolated nerve cord of cockroach, and they did not show any increase of spontaneous discharge except l-alanine, which appeared to have a weak neuroactivity.     

Isolation of Permethylated Dicarbonyl Sugar Derivatives from Polysaccharides

Oxidation of methyl trimethyl glucopyranosides which were obtained by methanolysis of permethylated cellulose, laminarin, and dextran, was performed with dimethyl sulfoxide (DMSO)-phosphorus pentoxide to afford the corresponding ulose derivatives, methyl 2,3,6-tri-O-methyl-d-xylo-hexopyranosid-4-ulose, methyl 2,4,6-tri-O-methyl-d-ribo-hexopyranosid-3-ulose, and methyl 2,3,4-tri-O-methyl-d-gluco-hexodialdo-l,5-pyranoside, respectively, in good or moderate yields. As a new type of derivatives for the linkage analysis of polysaccharides the chromatographic and spectrometric properties of 2,4-dinitrophenylhydrazone of the ulose derivatives were investigated.     

Sugar Composition of O-Antigenic Lipopolysaccharides Isolated from Vibrio parahaemolyticus

Vibrio parahaemolyticus, a causative bacterium of food poisoning unique for its particular primary association with sea products, is now divided serologically into 11 or 12 O-forms based on agglutination and agglutinin-absorption tests. We determined the sugar composition of the somatic O-antigens, i.e., lipopolysaccharides (LPS), of representative strains of each O-form. Of particular interest is the absence of evidence for the presence of 2-keto-3-deoxy-octonic acid (KDO), a regular sugar component of gram-negative bacterial LPS, in any LPS examined, with the exception of 06. Furthermore, 07 and 012 LPS contained a KDO-like compound that is, however, not identical with KDO. Glucose, glucosamine, and L-glycero-D-mannoheptose were found as common sugar constituents. Three unidentified amino sugars, designated here as P1, P2, and P3, were found. Various combinations of each of these unidentified amino sugars, and of galactose, fucose, arabinose, D-glycero-D-mannoheptose, galactosamine, KDO, and the KDO-like substance were detected in accordance with the O-form of LPS. On the basis of the sugar composition, LPS of the 12 O-forms of V. parahaemolyticus can be classified into nine chemotypes, because 03, 05, and 011 LPS belong to the same chemotype and 07 and 012 to another chemotype.     

Isolation and Characterization of Isolectins from Talisia esculenta Seeds

Four isolectins (TEL-I, TEL-II, TEL-III and TEL-IV) were isolated from seeds of Talisia esculenta by reverse-phase high-performance liquid chromatography. RP-HPLC was performed on a u-Bondapack C18 column (0.78 cm × 30 cm) (Waters 991-PDA system) at room temperature. Rechromatography of the four fractions on a C18 column under the same conditions yielded lectins with two dissimilar subunits (M_r 20 kDa and 40 kDa) bound noncovalently. The isolectins showed very similar characteristics, such as molecular masses, N-terminal sequences, and hemagglutinating activity, but differed in their isoelectric points and in inhibition by carbohydrates.     

Effect of Gibberellin on Mature Euonymus europaeus L. Seeds

The release from dormancy of Euonvmus europaeus L embryos bya brief treatment with GA₃ has been studied During 48 h incubationof dormant embryos in GA-free medium, phospholipid levels increasedat first, then declined sharply over the last 6 h When the embryoswere placed in GA₃ medium during this 6 h period levels of totalphospholipids as well as of phosphatidylethanolamine increasedwhilst phosphatidylinositol and phosphatidylcholine declinedslightly Fine structural changes stimulated by a brief GA₃ treatmentwere of different character depending on tissue region (1) ‘destructive’changes occurred in the superficial procortical parenchyma onthe hypocotyl/radicle boundary, involving autolysis and decompartmentationof organelles, (2) ‘positive’ changes occurred inregions close to root and shoot apical meristems, involvingdegradation of protein bodies and their conversion into vacuoles,and the proliferation of various organelles A number of differenceswere noted when the changes in GA₃-treated embryos were comparedwith those induced by low temperature, which also overcomesdormancy The results suggest that germination is accompaniedby different cytological events depending on whether it is inducedby cold or GA₃ The growth of embryos in which dormancy was overcomeby GA3 was due to the activation of the apical root meristemclose to the quiescent centre, whilst in embryos in which germinationwas induced by low temperature, the periphery of hypotocotyl/radicleboundary was the site of activation Euonymus europaeus L, dormant embryo, fine structure, phospholipids, GA₃ and cold treatments     

高纯度大豆种子线粒体的分离

利用不连续Percoll梯度分离得到高纯度的大豆（Glycine max）种子线粒体.线粒体制剂中没有检测到胞液、过氧化物体和叶绿素的污染.线粒体的完整性达到97%以上,在0～4℃下至少稳定2小时.     

Postmortem Blood Sugar and Blood Urea Nitrogen Determinations

Glucose and urea nitrogen determinations were made on blood and cerebrospinal fluid samples collected during 160 postmortem examinations in order to determine the usefulness of such tests in diagnosing diabetes and uremia at the time of autopsy. The results indicated that: (1) Blood is unsuitable for postmortem glucose determination, and no postmortem normal can be established. (2) Cerebrospinal fluid gave more uniform but very low glucose values. (3) Diabetics as a group had very high postmortem glucose levels but showed a marked overlap with non-diabetics. (4) Infants less than 3 months of age showed high postmortem glucose values. (5) Postmortem blood urea nitrogen and cerebrospinal fluid urea nitrogen levels were within normal limits in previously healthy persons who died suddenly from accidental causes. (6) Hospital autopsy cases had high urea nitrogen levels. (7) Postmortem urea nitrogen levels higher than 100 mg.% were indicative of uremia.     

Isolation and Structures of Gibberellins from Immature Seeds of Calonyction aculeatum

A deoxyribonuclease was purified about 500 times from a Rhizopus product “Gluczyme.” The enzyme attacks native DNA and produces oligonucleotides terminated with pG, pA, or pC at the 5′ end and with G at the 3′ end. A small amount of mononucleotides was found in the digestion products when the hydrolysis was continued for a long period. The pH and temperature optima for the action were found to be 7.8~8.0 and 50°C, respectively, and the enzyme was activated three fold in the presence of 5 × 10^?3 m Mg²⁺ or Mn²⁺. This enzyme was named DNase Rh.     

Amino Acid Composition of Elm Seeds

In the biosynthetic pathway of aromatic amino acids of Brevibacterium flavum, ratios of each biosynthetic flow at the chorismate branch point were calculated from the reaction velocities of anthranilate synthetase for tryptophan and chorismate mutase for phenylalanine and tyrosine at steady state concentrations of chorismate. When these aromatic amino acids were absent, the ratio was 61, showing an extremely preferential synthesis of tryptophan. The presence of tryptophan at 0.01 mM decreased the ratio to 0.07, showing a diversion of the preferential synthesis to phenylalanine and tyrosine. Complete recovery by glutamate of the ability to synthesize the Millon-positive substance in dialyzed cell extracts confirmed that tyrosine was synthesized via pretyrosine in this organism. Partially purified prephenate aminotransferase, the first enzyme in the tyrosine-specific branch, had a pH optimum of 8.0 and Km’s of 0.45 and 22 mM for prephenate and glutamate, respectively, and its activity was increased 15-fold by pyridoxal-5-phosphate. Neither its activity nor its synthesis was affected at all by the presence of the end product tyrosine or other aromatic amino acids. The ratio of each biosynthetic flow for tyrosine and phenylalanine at the prephenate branch point was calculated from the kinetic equations of prephenate aminotransferase and prephenate dehydratase, the first enzyme in the phenylalanine-specific branch. It showed that tyrosine was synthesized in preference to phenylalanine when phenylalanine and tyrosine were absent. Furthermore, this preferential synthesis was diverted to a balanced synthesis of phenylalanine and tyrosine through activation of prephenate dehydratase by the tyrosine thus synthesized. The feedback inhibition of prephenate dehydratase by phenylalanine was proposed to play a role in maintaining a balanced synthesis when supply of prephenate was decreased by feedback inhibition of 3-deoxy-D-arabino-heptulosonate 7-phosphate (DAHP*) synthetase, the common key enzyme. Overproduction of the end products in various regulatory mutants was also explained by these results.     

Isolation of a Specific Potato Tuber-Inducing Substance from Potato Leaves

Potato tuberization is induced by an unidentified "tuberizationstimulus" which is produced in the leaves. Recently, we confirmedthe occurrence of two acidic substances in the leaves whichappear to be the stimulus (Koda and Okazawa 1988). We reporthere the isolation of one of the substances from potato leaves.The molecular weight of the substance is 388. The substanceis active in inducing tuberization in vitro at a concentrationof 0.01 mg- liter^-11 (ca. 3 ? 10^-8 M). (Received April 15, 1988; Accepted June 28, 1988)     

Isolation of a New Root Growth-stimulating Substance from a Fungus

In the last few decades, enzymatic production of 3,4-dihydroxyphenyl-L-alanine (L-dopa) using tyrosine phenol-lyase (Tpl) has been industrialized. This method has an intrinsic problem of tyrosine contamination because Tpl is synthesized under tyrosine-induced conditions. Herein, we constructed a hyper-L-dopa-producing strain by exploiting a mutant TyrR, an activator of tpl. The highest productivity was obtained for the strain grown under non-induced conditions. It was 30-fold higher than that obtained for tyrosine-induced wild-type cells.     

Isolation of Bacteriophages from Group H Streptococci

Temperate phages were isolated from 5 of the 17 strains of group H streptococci tested.