bluuebunny/crossref_metadata_2025 huggingface dataset:
The Possible Mode of Herbicidal Action of Atrazine Basing on the Gas Exchange and the Mode of Plant Damage after Treatment
Authors: Bolhàr-Nordenkampf Harald R.
Published: August 2018

Under field conditions atrazine inhibits CO2 fixation but the electron flow seems to be hindered partly only. The remaining capacity of the electron transport chain produces not used reducing electrons. The consequence should be a destructiv photooxidation. This process however is suppressed by photorespiration. When all possible substrats including stored carbohydrates are metabolized by photorespiration photooxidation is not hindered any longer and destroys the plant.
Inhibition of Photosynthetic Electron Flow by Phenol and Diphenylether Herbicides in Control and Trypsin-Treated Chloroplasts
Authors: Trebst A.
Published: August 2018

Alkyl substituted 2-halogen-4-nitro-phenols (like bromonitrothymol) are potent inhibitors of photosynthetic electron flow in chloroplasts. There inhibition site is identical to that of DCMU, though the phenols do not contain their essential chemical element responsible for inhibition nor do they follow their correlation of chemical structure and biochemical function. Binding of labelled metribuzin on the chloroplast membrane and its replacement by the phenol inhibitors support the notion of identical binding sites, however.

In trypsin treated chloroplasts, the primary acceptor of photosystem II becomes accessible to ferricyanide, whose photoreduction is therefore DCMU insensitive. After trypsin treatment also the sensitivity of ferricyanide reduction to phenol inhibitors is lost as is the binding of labelled metri­buzin.

The dinitrophenylethers of bromonitrothymol and of ioxynil and other diphenylethers are potent inhibitors of photosynthetic electron flow. Their site of inhibition is after the function of plastoquinone, i. e. they are DBMIB analogues.
Field Desorption Mass Spectrometry of Physiologically Active Steroid-and Dammarane-Saponins
Authors: Komori T. , Kawamura M. , Miyahara K. , Kawasaki T. , Tanaka O. , Yahara S. , Schulten H.-R.
Published: August 2018

The use of field desorption mass spectrometry is demonstrated not only for molecular weight determination but also for detailed structural analysis of large, underivatized natural products. Owing to cationization by small alkali salt impurities, saponins carrying one to four sugar units gave abundant quasimolecular ions. In addition, the observed sequence-specific fragment ions reflected the complete sequence of the sugar units in the oligoglycosides. This fragmentation of the oligosaccharidic moiety of the natural products was interpreted by analogy with acidic solvolysis, a mechanism well established in solution chemistry. Of particular interest was a first com­parison of the field desorption mass spectra obtained from two different commercially available instruments operated by different groups in order to give an estimate of interlaboratory reproducibility in field desorption mass spectrometry.
Molecular Cloning of the Restriction Fragments Derived from Double EcoRI/PstI Digestion of the Calf Satellite I DNA and Their Restriction Analysis
Authors: Kłysik Jan , Furtak Krystyna , Szymczak Grażyna , Bartnik Ewa , Skowroński Jacek , Panusz Henryk
Published: August 2018

Calf satellite I DNA digested with EcoRI and PstI gives three fragments 643, 621 and 83 bp long. Two of them , the 643 and 621 bp were cloned using pBR 322 vector and analyzed by means of the MspI and Haelll restriction enzymes.
Expression of Aspartokinase, Dihydrodipicolinic Acid Synthase and Homoserine Dehydrogenase During Growth of Carrot Cell Suspension Cultures on Lysine-and Threonine-Supplemented Media
Authors: Matthews Benjamin F. , Widholm Jack M.
Published: August 2018

Reduction in the amounts of activity of the first enzyme, aspartokinase (EC 2.7.2.4) and two branch-point enzymes, dihydrodipicolinic acid synthase (EC 4.2.1.52) and homoserine dehydrogenase (EC 1.1.1.3), located in the pathway for the synthesis of aspartate-family amino acids, occurred when cell suspension cultures of Daucus carota L. var. Danvers were grown in media containing 2 mᴍ threonine or 2 mᴍ lysine, endproducts of the pathway. Activity of the lysine-sensitive form of aspartokinase was decreased when cells were grown in medium containing lysine and the activity of the threonine-sensitive form was decreased when cells were grown in medium containing threonine. Activity of the branch-point enzyme leading to threonine synthesis, homoserine dehydrogenase, was decreased up to 70% in specific activity (units/mg protein) and relative activity (units/g fresh weight) when cells were grown in media containing lysine or threonine. Threonine had no effect on the relative activity of dihydrodipicolinic acid synthase, but decreased its specific activity. Lysine decreased the relative activity of the synthase by up to 40%, but had little effect on its specific activity. The decreased activities of the enzymes were apparently not due to binding of the inhibitory amino acids to the enzymes since homogenization of cells in buffer with 2 mᴍ lysine and threonine did not decrease the measurable enzyme activities. These and other results presented suggest that both forms of the aspartokinase activity and homoserine dehydrogenase activity can be altered by supplementing the growth medium with lysine or threonine.
Rates of de novo Synthesis of Malate Synthase and Albumins during the Very Early Phase of Germination
Authors: Köller Wolfram , Kindl Helmut
Published: August 2018

Malate synthase is synthesized de novo in the very early phase of germination. Its molecular and immunological properties do not differ from those of malate synthase from fully developed cotyledons. Radioactive leucine was administered to dry seeds of cucumber, and its incorporation into proteins of cotyledons was examined after 2 days of germination. The specific radioactivity of malate synthase, purified by immunoprecipitation and electrophoresis on polyacrylamide gel, was only 1/20 the average value of the total albumin fraction. The minimal incorporation documented by the comparatively low specific activity of isolated malate synthase is discussed in relation to the large pool of malate synthase already present in dry seeds.
Protein Subunits of Bacteriochlorophylls B 802 and B 855 of the Light-Harvesting Complex II of Rhodopseudomonas capsulata
Authors: Feick Reiner , Drews Gerhart
Published: August 2018

The light-harvesting antenna complex II of Rhodopseudomonas capsulata is characterized by two prominent IR-absorption maxima at 802 and 855 nm and three polypeptides of 14,000, 10,000 and 8,000 molecular weight (SDS-polyacrylamide gel electrophoresis). Bacteriochlorophyll (Bchl) is associated with the two lower molecular weight polypeptides. The membranes of the mutant Y 5, which lades reaction center and light harvesting complex I (B 875), were treated with trypsin. The 14,000 polypeptide was rapidly digested by trypsin, but the absorption spectrum of the membrane and the activity of the cytochrome c oxidase were not altered. Subsequently the 8,000 polypeptide was degraded. The digestion of the 8,000 polypeptide was concomitant with and proportional to the loss of absorbance at 802 nm. The absorption peak at 855 nm and the content of the 10,000 molecular weight polypeptide were, in contrast, stable for a longer time, but were also lost simultaneously.

These results, in combination with the recent publications of Sauer and Austin (Biochemistry 17, 2011, 1978), and Cogdell and Crofts (Biochim. Biophys. Acta 502, 409, 1978) support the idea that the two molecules of Bchl associated with the 10,000 polypeptide are responsible for the 855 nm peak while the one or two mol of Bchl associated with 8,000 polypeptide result in the 802 nm absorption maximum.
Isolation and Characterization of Flavonol Converting Enzymes from Mentha piperita Plants and from Mentha arvensis Cell Suspension Cultures
Authors: Frey-Schröder Gudrun , Barz Wolfgang
Published: August 2018

Peroxidases from several plants, including horseradish peroxidase, were capable of converting flavonols to the corresponding 2,3-dihydroxyflavanones in presence of H2O2 . Contrastingly, protein extracts from Mentha piperita plants and Mentha arvensis cell suspension cultures perform ed the same enzymatic step in absence of H2O2 , but only with quercetin, not with kaempferol. H2O2-independent, quercetin converting enzymes were isolated and purified from these extracts, and they could be classified in two groups according to the extent of stimulation of the enzyme reaction by H2O2 . Enzymes from group I were stimulated by exogenous H2O2 , and they resembled horse­ radish peroxidase in several aspects. They possessed IAA oxidase activity, but quercetin was the preferred substrate. Enzymes from group II from the plants appeared to be a distinctly different set of enzymes. They were not stimulated by H2O2 , but required molecular oxygen and converted only 3,3′,4′-trihydroxyflavones under aerobic conditions. Also, they showed no Soret-bands and possessed no IAA oxidase activity. These proteins appear to be a new class of enzymes participating in the first step of flavonol degradation in plants.
On the Oligomycin-Sensitivity and Subunit Composition of the ATPase Complex from Rhodospirillum rubrum
Authors: Miiller Hans Werner , Baltscheffsky Margareta
Published: August 2018

Two alternative procedures for isolation of the oligomycin-sensitive ATPase complex (E. C. 3.6.1.3) from R. rubrum chromatophores are compared with respect to ease, rapidity, and yield.

The inhibitory effect of oligomycin on the membrane-bound Ca2+ -ATPase activity is increased during storage of the chromatophores, whereas the effect of oligomycin on the membrane-bound Mg2+ -ATPase activity does not change within a week.

Oligomycin-sensitivity of the solubilized ATPase complex depends on the isolation procedure.

The enzyme complex consists of at least nine different polypeptides with the apparent molecular weights of (1) 67,000, (2) 60,000, (3) 56,000, (4) 35,000, (5) 22,000, (6) 20,000, (7) 17,000, (8) 12,000, (9) 11,000. The polypeptides 2 - 4, 7, and 8 represent subunits of coupling factor 1.
The Molecular Weight of rRNA Precursor Molecules and Their Processing in Higher Plant Cells
Authors: Seitz Ursula , Seitz Ulrich
Published: August 2018

Actively dividing callus cells of higher plants (Petroselinum crispum, Daucus carota, Acer pseudoplatanus) were used to detect the primary gene product of rDNA in vivo. Parsley and carrot cells were labelled with [32P] orthophosphate. Under non-denaturing conditions, in both cases only one high molecular weight rRNA precursor was present on polyacrylamide gels. Its molecular weight did not exceed 2.5 × 106 dalton. Under denaturing conditions, 2.0 - 2.1 × 106 dalton were determined on formamide gels. This rRNA precursor was already present after a labelling period of 5 -10 min. In parsley cells labelled mature rRNA (25S and 18S) arrived in the cytoplasm 45 min after onset of incubation.

In Acer pseudoplatanus incubated with [3H] uridine two rapidly labelled components did emerge from polyacrylamide gels without formamide; their molecular weights were 2.3 and 3.2 - 3.4 × 106 dalton. After electrophoresis in formamide, the larger component disappeared, thus indicating that it would be an intermolecular aggregate of different for the existence of rRNA precursors exceeding the molecular weight of 2.5 × 106 dalton.
Density-Dependent Growth Adaptation Kinetics in 3T 3 Cell Populations Following Sudden [Ca2+] and Temperature Changes. A Comparison with SV40-3T3 Cells
Authors: Bosch Jürgen van der , Sommer Ilse , Maier Heinz , Rahmig Willy
Published: August 2018

Lowered extracellular [Ca2+] causes low growth rates and low stationary cell densities in 3T3 cell cultures as compared to physiological [Ca2+]. Under otherwise constant conditions the extra­ cellular [Ca2+] determines a stable stationary cell density, which can be readied by increase of net cell number or decrease of net cell number, depending on cell density at the time of [Ca2+] adjustment. SV40-3T3 cells do not show this [Ca2+] dependency. At 39 °C 3T3 and SV40-3T3 cell populations show an increased growth rate at low cell densities as compared to cell populations at 35 °C. Approaching the stationary density the growth rate of both cell sorts is reduced faster at 39 °C than at 35 °C, leading to lower stationary cell densities at 39 °C than at 35 °C. A temperature change from 39 °C to 35 °C or in the opposite direction can affect the stationary cell density of 3T3 cell populations only if applied before reduction of growth rate by density-dependent growth-inhibiting principles has taken place.
Notizen: Isolation of Batatasin I from Dioscorea dumetorum Rhizomes
Authors: El-Olemy M. M. , Reisch J.
Published: August 2018

Batatasin I was shown to occur in the fresh rhizomes of poisonous yam (Dioscorea dumetorum Pax.,). It was isolated by column chromatography and identified by chromatographic and spectral evidence. Two other unknown phenanthrenes were shown to occur by thin-layer chromatography.
Notizen: Phytoalexin Production by Species of the Genus Caragana
Authors: Ingham John L.
Published: August 2018

The fungus-inoculated leaflets of 39 Caragana species have been found to variously produce five isoflavonoid phytoalexins including the known pterocarpan derivatives, medicarpin, maackiain, variabilin and pisatin. Small quantities of a previously undescribed C-methylated pterocarpan were obtained from leaflets of C. acanthophylla.
Notizen: Electron Microscopy of Synaptonemal Complexes in Semithin Sections
Authors: Colman Ondina D. , Stockert Juan C.
Published: August 2018

The technique of osmium tetroxide fixation followed by a treatment with p-phenylenediamine was applied to mouse testes in order to analyze pachytene nuclei. Observation of Epon semithin sections (0.25 - 0.5 μm) in conventional elec­tron microscopy revealed the presence of positively stained synaptonemal complexes surrounded by unstained chromatin. The present results show that by using this method a suitable contrast and resolution can be achieved for semithin sections, which facilitates the topographical study of synaptonemal complexes.
Comparison of the Inhibition of Photosynthetic Reactions in Chloroplasts by Dibromothymoquinone, Bromonitrothymol and Ioxynil
Authors: Reimer S. , Link K. , Trebst A.
Published: August 2018

The inhibition of photosynthetic electron flow in broken chloroplasts by dibromothymoquinone and dibromothymohydroquinone (DBMIBH2) is reversed by dithiothreitol (DTT) as well as by serum albumin. The reversal of DBMIBH2 inhibition by DTT shows a time lag, that of DBMIB only, when chloroplasts and DBMIB had been preilluminated. This is to show that chloroplasts reduce DBMIB and that probably DBMIBH2 is the actual inhibitor species.

Bromonitrothymol, ioxynil and related inhibitory phenolic compounds have a different relation­ ship of inhibitory potency to chemical structure than DCMU and the analogous triazinone herbicide metribuzin but nevertheless inhibit photosynthetic electron flow at the same functional site. This is supported by the finding that labelled metribuzin is displaced from the thylakoid membrane by bromonitrothymol and ioxynil indicating identical binding sites. On the other hand inhibition by the phenolic inhibitors bromonitrothymol and ioxynil but not that of DCMU and metribuzin has a time lag of about 4 min.
Fusion of Plant Protoplasts Induced by a Positively Charged Synthetic Phospholipid
Authors: Nagata Toshiyuki , Eibl Hansjörg , Melchers Georg
Published: August 2018

A newly synthesized phospholipid, 1,2-O-Dipentadecylmethylidene-glycerol-3-phosphoryl-(N-ethyl-amino) -ethanolamine, having positive charge was found to exercise fusion activity on plant proto­ plasts. This phospholipid is not found in cells and has an unusal chemical structure with a dioxolane ring. Some properties of this compound are discussed in relation to phospholipid-induced cell fusion.
Die Temperaturabhängigkeit biologischer Prozesse / Temperature-Dependence of Biological Process
Authors: Trindier K.
Published: August 2018

Temperature dependence of biological processes is described by the modified Arrhenius equation, in which the constant is replaced by a temperature-variable coefficient. The theoretical foun­dation for this replacement is given and experimentally verified.
On the Construction of a Phylogenetic Tree
Authors: Tohá José , Soto María Angélica , Pieber María
Published: August 2018

An algorithm for phylogenetic trees’ construction is analyzed.
Antimicrobial Activity of Quaternary Ammonium Salts of Some Saturated Heterocycloalkyl Amines [1]
Authors: Lacko Ivan , Devínsky Ferdinand , Krasnec Ľudovít , Mlynarčik Dušan
Published: August 2018

N,N-Dialkyl Ammonium Salts of Saturated Heterocyclic Amines, Antimicrobial Activity Antimicrobial activity of N-alkyl-N-dodecylpiperidinium bromides and N-ethyl-N-dodecylheterocycloalkyl ammonium bromides (pyrrolidine, morpholine, perhydroazepine) deter­ mined on grampositive and gramnegative bacteria, yeasts and moulds, presented as minimum inhibition concentration (MIC). Comparison of the effect of change of structure: lenghtening of alkyl chain, change of heterocyclic ring. Change in the lenght of alkyl chain markedly affects the antimicrobial activity, change of heterocyclic ring has no substantial effect. The most active compounds were N-heptyl-and N-hexyl-N-dodecylpiperidinium bromides.
Studies on the Chemistry of Lichens, XIX. New Amino Compounds from Anaptychia fusca and Several Stereocaulon Species
Authors: Solberg Yngve
Published: August 2018

The lichen Anaptychia fusca and several Stereocaulon species have been chemically investigated with regard to their content of unknown ninhydrin-positive com pounds. New aliphatic and alicyclic, amino components isolated from water extracts of these lichen species have been characterised as aminopentitol, am inohexitol and aminocyclitetrol. To our knowledge, this is the first time that com pounds such as these have been found in lichen material. Aminopentitol and amino­ cyclitetrol appear to be characteristic constituents of Anaptychia fusca, whereas aminohexitol has been found in several species of Stereocaulaceae.
The Chemical Composition of Cuticular Lipids from Dragonflies (Odonata)
Authors: Jacob Jürgen , Hanssen Hans-Peter
Published: August 2018

The cuticular lipids of 4 species (Aeschna grandis, A. mixta, Sympetrum sanguineum, S. danae) of the insect order Odonata (dragonflies) have been analysed. Alkanes, triglycerides, and free fatty acids predominate and minor amounts of monoester waxes have been detected. Among the hy­drocarbons unbranched odd-numbered (56 - 66%) predominate, followed by monometnyl-alkanes with the branch in the middle of molecule (11 - 19%), 3-methylalkanes (7 - 15%), and 2-me­thyl-alkanes (1 - 13%). Moreover, alkanes (1 - 12%) were detected. The composition of triglyceri­des and free fatty acids were very similar with 14 : 0, 16 : 0, 18 : 0, 16 : 1. 18 : 1 and 18 : 2 being main constituents. Ester waxes were composed of unbranched and predominantly even-numbered fatty acids and alcohols with chain lengths C14- C30. The results are discussed from a chemotaxonomic viewpoint. Similarities of the integumental lipjids from Odonata and Plecoptera were found.
Inhibition of the Nitrate Reductase Complex by Dibromothymoquinone
Authors: Jawali N. , Ramakrishna J. , Sainis J. K. , Sane P. V.
Published: August 2018

The plastoauinone antagonist 2,5-dibromothymoquinone was found to inhibit NO3
- reduction from NADH by the nitrate reductase complex from wheat. It accepts electrons from NADH through the NADH dehydrogenase activity of the nitrate reductase. However, it does not inhibit the reduction of 2,6-dichlorophenol-indophenol by the enzyme. This suggests that the two com­pounds may be accepting electrons at different places from the enzyme. Further it was observed that reduced DCIP could be oxidized by DBMIB in the absence of NADH indicating that the electron flow in the nitrate reductase complex may take place in a unidirectional way.
γ-Bestrahlte Ribosomen von Micrococcus radiodurans in einem System der zellfreien Proteinsynthese / γ-Irradiated Ribosomes from Micrococcus radiodurans in a Cell-Free Protein Synthesizing System
Authors: Süssmuth Roland , Widmann Annette
Published: August 2018

γ-irradiation inactivation of isolated ribosomes of Micrococcus radiodurans was studied by ex amining poly U directed synthesis of polyphenylalanine. Ribosomes of M . radiodurans did not show significant y-radiation sensitivity up to a dose of approx. 11.6k Gy. Cells of M . radiodurans take up more magnesium than E. coli cells unter the same conditions. The magnesium content of ribosomes of M . radiodurans was 18% higher than that of E. coli ribosomes. A possible relation between Mg2+-content and γ-resistance is discussed.
Hypermetabolic Response Induced by Juvenile Hormone Analogues in an Insect
Authors: Sláma Karel , Kryspin-Sørensen Ilona
Published: August 2018

Some synthetic analogues of insect juvenile hormone cause tremendous rise of respiratory me­tabolism in the last larval instar of Dermestes maculatus. The O2 consumption values occasionally found in these hypermetabolic larvae (20 ml/g/h) can be classified among the most intensive res­piratory rates ever recorded in living organisms. The phenomenon is directly related to the dose of juvenile hormone activity and it is dependent on nutrition. The mechanism of such specific meta­bolic action of juvenile hormone is based on complete oxidation of the dietary fatty acids, provid­ing metabolic water for larval somatic growth. The excessive amounts of energy created by hy­permetabolism are partly converted to heat, suggesting uncoupling of phosphorylation. Some other specific endocrmological features associated with hypermetabolism have been discussed.
On the Analysis of Competitive Binding of Various Ligands to Cooperative and Independent Binding Sites of Macromolecules
Authors: Kalbitzer Hans Robert , Stehlik Dietmar
Published: August 2018

The paper deals with the practical evaluation of multiple binding equilibria of macromolecules and different ligands competing for the same binding sites. The necessary formalism is reviewed and set up for the equilibria involving a macromolecule with various classes of independent binding sites and/or a class of cooperative sites and up to three different ligands in competition for them. In particular, it was necessary to extend the Hill approximation to treat simultaneous competition for cooperative as well as independent binding sites, while earlier at­tempts are shown to be inadequate.

Criteria are developed for a qualitative analysis of complex binding patterns using the Scatchard-plot of the experimental data in order to obtain a model of the binding structure and an adequate set of input parameters for the numerical analysis. Numerical examples refer to the binding of calcium and magnesium to the sarcoplasmic reticulum as studied by competitive re­placement of manganese ions [3].
High Sensitivity in CID Mass Spectrometry, Structure Analysis of Pyrolysis Fragments
Authors: Louter G. J. , Stalmeier P. F. M. , Boerboom A. J. H. , Haverkamp J. , Kistemaker J.
Published: August 2018

Collision Induced Dissociation (C ID),C ollisional Activation (CA), Pyrolysis, Mycobacterium, Mass Spectrometry An apparatus is described for Collision Induced Dissociation Mass Spectrometry, where es­ sential increase in sensitivity in the detection of the fragment spectrum is obtained by simultaneous detection. Decrease in resolution due to kinetic energy release on dissociation is prevented by post-acceleration of the fragment ions.

The instrument was used to investigate the structure of the mass m/z= 59 com pound in the pyrolysis products of Mycobacterium cells. This mass is a key mass in the pyrolysis mass spectrometric identification of dangerous mycobacterial strains.
Insulin und Glukagon im Blutplasma teilhepatektomierter Ratten / Insulin and Glucagon in the Blood Plasma of Partial Hepatectomized Rats
Authors: Strecker Wolf , Silz Siegfried , Ruhenstroth-Bauer Gerhard , Böttger Ingolf
Published: August 2018

Up to 4 weeks after partial hepatectomy the concentrations of immunoreactive insulin and glucagon in the blood plasma of rats were determined. Furtherm ore we m easured the activity of acid phosphatase in the serum, the concentration of cyclic AMP in liver cells, the activities of acid phosphatase in whole liver cells and in the cytosol of liver cells after partial hepatectomy.

2 h after partial hepatectom y there was a decline of the concentration of insulin in the plasm a to about 13% of the initial value. 12 h after surgery a 5-fold increase of glucagon was found in the plasma. Shortly after this cyclic AMP reached its highest concentration.

The activity of acid phosphatase in the whole liver cells and in the cytosol decreases slightly in the first 24 h after surgery whereas there is an increase of the activity of acid phosphatase in the serum.
Effect of 5-Aza-2′-deoxycytidine on Antibody Formation and DNA Synthesis in Rat Spleen
Authors: Čihák A. , Madar J. , Veselý J.
Published: August 2018

5-Aza-2′-deoxycytidine which is preferentially taken up by the lymphatic tissue and is in­ corporated into D NA strongly affects the ability of the immune system to synthesize IgG anti­ bodies against sheep red blood cells without affecting IgM antibody formation. A single dose of the drug results in a prolonged inhibition persisting 14 days after the secondary immunization. The inhibitory effect is dose-dependent and is maximal when 5-aza-2′-deoxycytidine is given 2 days after sheep erythrocytes. The drug affects the utilization of thymidine for the synthesis of DNA in the spleen; under certain conditions the enhancement of the rate of DNA synthesis in the spleen has been observed.
Separation of Alphavirus Nucleocapsids from Envelope Fragments
Authors: Enzmann P.-J. , Weiland F.
Published: August 2018

Methods for the preparation of alphavirus nucleocapsids and envelope fragments for bio­ chemical, electron microscopical and serological investigations are described. Difficulties which have been encountered previously in attempts to isolate viral nucleocapsids for morphological studies, namely disruption of the fragile particles, have been overcome by treatment with formaldehyde.
A High Potential Iron Sulfur Protein of the Purple Sulfur Bacterium Thiocapsa roseopersicina
Authors: Fischer Ulrich
Published: August 2018

Thiocapsa roseopersicina, High Potential Iron Sulfur Pro­ tein (HIPIP), Phototrophic Bacteria High potential iron sulfur protein (HIPIP) from the purple sulfur bacterium Thiocapsa roseopersicina was isolated in the oxidized and reduced form by DEAE-and Sephadex column chromatography (best purity index A 282 nm red/A 385 nm red. = 3.78). The enzyme contains non-heme iron and acid-labile sulfide in an equimolar ratio. The enzyme shows no aconitase activity.
Method for the Selective 2′-O-Substitution of Nucleosides
Authors: Sauer C. , Schwabe U.
Published: August 2018

This paper presents a new method for selective reactions of predetermined sugar hydroxyls of nucleosides. Suc-cinylated nucleosides were investigated as examples for the use of the cyclic phosphate group for protecting purposes. Starting from cyclic AMP the 2′-O-group was selectively succinylated yielding 93% 2′-O-succinyl cyclic AMP. The cyclic phosphate was enzymatically dephosphorylated in a one step procedure under neutral conditions and 2′-O -succinyl adenosine containing a small amount of the 3′-O-isomer was produced in 91% yield. When establishment of equilibrium of the 2′-O-and 3′-O-isomers was allowed, 54% yield of crystallized 3′-O-succinyl adenosine was prod­ uced. The results suggest that the easily accessible cyclic monophosphates are good protecting groups for the pro­ duction of nucleoside derivatives, especially at the 2′-O-position under neutral conditions.
Quantitative Investigations on the Diaplacental Transfer of Thallium by Field Desorption Mass Spectrometry
Authors: Ziskoven R. , Achenbach C. , Bahr U. , Schulten H.-R.
Published: August 2018

The placental transfer of thallium cations in pregnant mice was investigated by determining the thallium concentrations in fetal and maternal tissue 0.5 to 24 h after application of thallium. The maternal dose of thallium was 8 mg/kg body weight throughout. Uterus and fetus were found not to differ from other organs like heart and liver in time course and magnitude of thallium uptake with an initial surge during the first few hours of exposure to thallium and a rapid decrease to steady 12 and 24 h values somewhat lower than those found in the kidney. Diaplacental transfer is therefore assumed comparatively rapid and a specific placental barrier for thallium does not seem to exist. For the determination of thallium concentrations Field Desorption Mass Spectrometry was utilized as a reliable, fast, and sensitive method for the analysis of metal cations in biological material. This method does not require extensive pretreatment of the tissue and total sample amounts in the range of milligrams and less are sufficient for quantitative analysis.
Tectorigenin, a Phytoalexin of Centrosema haitiense and Other Centrosema Species
Authors: Markham K enneth R. , Ingham John L.
Published: August 2018

A phytoalexin isolated from the fungus-inoculated leaflets of Centrosema haitiense, C. pubescens (3 accessions) and C. virginianum has been identified as 5,7,4′-trihydroxy-6-methoxy-isoflavone (tectorigenin). This compound is variously accompanied by other isoflavones includ­ ing the previously described phytoalexin, cajanin (5,2′,4′-trihydroxy-7-methoxyisoflavone). Sub­ stantial quantities of aesculetin were obtained when C. haitiense leaves were submerged for 48 h in water or fungal spore suspensions. The taxonomic position of Centrosema within the legume tribe Phaseoleae is discussed.
Enzymatic Preparation of 14C-Labeled Phytoene, Squalene, and Geranylgeranyl Pyrophosphate from [2-14C]Mevalonic Acid
Authors: Sandmann Gerhard , Hilgenberg Willy , Böger Peter
Published: August 2018

Methods are described for an enzymatic preparation of 14C-labeled terpenoids. With a cell-free system of a white mutant of Phycomyces blakesleeanus (Mucoraceae) [14C]squalene and [14C- cis]phytoene can be synthesized from [2-14C]mevalonate. The application of norflurazon, a phenyl- pyridazinone herbicide, helps to increase the yield of squalene. Furthermore, the liquid endosperm of Echinocystis lobata (Cucurbitaceae) was used for the formation of either [14C(-)]kaurene from [14C]mevalonic acid or [14C-/ra/w]geranylgeranyl pyrophosphate in the presence of Amo 1618.

The hydrocarbons formed were purified by alumina-column chromatography and preparative thin-layer chromatography (TLC). Geranylgeranyl pyrophosphate was separated by DE-column chromatography followed by TLC.
Effects of ʟ-Methionine-S-sulfoximine on Growth and Glutathione Synthesis in Tobacco Suspension Cultures
Authors: Rennenberg Heinz , Uthemann Rolf
Published: August 2018

Tobacco cells grown photoheterotrophically with high ammonium and sulfate concentrations are able to cope with small amounts of methionine-sulfoximine. The observed methionine-sulfoximine tolerance of tobacco suspensions is due to an extracellular glutathione and an intra­ cellular glutamine reservoir, both reservoirs are considerably reduced by treatment with methionine-sulfoximine concentrations that do not affect the growth of the cells. In tobacco suspension cultures grown with nitrate as sole nitrogen source that do not contain high amounts of glutathione and glutamine, growth inhibition by methionine-sulfoximine can be prevented by addition of these substances to the growth medium. These data indicate that synthesis of glutathione and glutamine are both inhibited by mentionine-sulfoximine; furthermore they show evidence that - in contrary to animal cells -the whole glutathione molecule is taken up by tobacco cells. Synthesis of glutathione from the consisting amino acids is inhibited by methionine-sulfoximine in crude cell homogenates to a similar extent than observed in tobacco suspensions in vivo; therefore, the activity, and not the amount of enzymes of glutathione syn­ thesis seems to be reduced by treatment with methionine-sulfoximine. As tobacco suspensions are able to recover from methionine-sulfoximine treatment with respect to accumulation of glutathione in the medium as well as with respect to growth, detoxication of methionine-sulf­ oximine has to be assumed.
Sinapine Esterase. II . Specificity and Change of Sinapine Esterase Activity During Germination of Raphanus sativus
Authors: Strack Dieter , Nurmann Gerhild , Sachs Gesine
Published: August 2018

Following a 20 to 24 h lag-phase after sowing, the onset of both rapid degradation of sinapine (sinapolycholine) and rapid increase in sinapine esterase activity in cotyledons of Raphanus sativus was observed. After 2 days of germination maximal enzyme activity was reached and declined in subsequent germination stages as rapidly as it had appeared. Esterases, active against indophenyl acetate, showed highest activity in dry seeds, declining to more than 50% between the 1st and 3rd day of germination.

Starch gel electrophoresis showed that all protein extracts contained a multiplicity of esterases, active against α-naphthyl acetate. When gels were incubated with sinapine, one new band appeared, stainable with diazotized ρ-nitroaniline. This band represents sinapine esterase activity. Tests for substrate specificity towards cinnamic acid choline esters showed highest enzyme activity with sinapine.

Studies on the occurrence of sinapine esterase in other Brassicaceae revealed that the enzyme activity coincides with the occurrence and degradation of sinapine.
Zur photosynthetischen CO2-Fixierung von Synechococcus / Photosynthetic CO2 Fixation of Synechococcus
Authors: Döhler Günter
Published: August 2018

The cyanobacterium Synechococcus (Anacystis nidulans strain L 1402-1) was grown at + 37 °C in 3.0 vol.% CO2. The effect of preillumination with white light on the subsequent dark 14CO2 fixation was studied under aerobic conditions at + 30 °C. The radioactive carbon first incoiporated into 3-phosphoglyceric acid was transferred during the later periods of dark 14CO2 fixation to phosphoenolpyruvate and aspartate. No labelling or a very low label in sugar monophosphates could be observed. During the dark/light transients the initial fixation product was mainly aspartate. The pattern of 14C-incorporation into photosynthetic products under steady state conditions (10 min photosynthesis) varied with the temperature during the experiments. The radioactive carbon was firstly incorporated into 3-phosphoglyceric acid. During the later periods of photosynthetic 14CO2 fixation an increased 14C-incorporation into aspartate and glutamate could be observed. Our findings were interpreted with operating of a phospho­enolpyruvate carboxylation besides the Calvin cycle.
In vivo und in vitro Hydroxylierung von Androgenen in Ratten nach Leberschädigung und Nahrungskarenz / In vivo and in vitro hydroxylation of testosterone and dihydrotestosterone in rats after liver damage and starvation
Authors: Wenzel Martin , Lemm Ursula
Published: August 2018

The in vivo C-2-hydroxylation of testosterone and 5-dihydrotestosterone in rats was measured by labilisation of tritium as HTO after injection of [1α, 2α-T]testosterone or [1 α, 2α-T]5α-dihy- drotestosterone (radiospirometry).

After experimental liver damage caused by CCl4 or after starvation for 60 h the hyroxylation of the androgens decreased. Similar results were gained by measuring the C-2-hydroxylation of testosterone, 5 α-dihydrotestosterone and estradiol.
Modulation of Amino Acid Transport in Rat Liver Slices by Tissue Preincubation
Authors: Ehrhardt Volker
Published: August 2018

In rat liver slices, a prolonged preincubation resulted in a stimulation of AIB and alanine uptake. The increase of transport of both amino acids can be ascribed to a reduction of Kt without an alteration of Vt.

The enhancement of transport seems to be restricted to the A mediation as indicated by the findings that only the Na+-dependent, MeAIB-inhibitable portion of AIB transport was increased by the prolonged preincubation, and, furthermore, that the uptake of cysteine, a specific substrate for system ASC in liver cells, was not affected.

The effect of an extended preincubation on AIB transport was abolished by the addition of high concentrations of AIB and alanine to the preincubation medium. Several other amino acids tested did not affect the increase of AIB transport.

The observed stimulation of transport seems not to be due to the derepression of the synthesis of transport proteins, as cycloheximide and 5-azacytidine did not block the increase of AIB uptake.

The enhancement of amino acid transport does not appear to be a result of a release from transinhibition since the uptake of alanine was markedly enhanced after 3 h of preincubation while the alanine concentrations in the incubated liver slices did not change significantly.
Cooperation of Compartments for the Generation of Positional Information
Authors: Meinhardt Hans
Published: August 2018

A mechanism is proposed for pattern formation in developmental subfields. In application to imaginal disks, the compartmentalization appears as a prerequisite for the generation of positional information in the proximo-distal dimension. Cooperation of three or four compartments in the production of a morphogen leads to a cone-shaped morphogen distribution, since a high production rate of the morphogen is possible only at the intersection of compartment borders. The local concentration of the cone-shaped distribution is a measure for the distance from this center and can be used as positional information. In agreement with the experimental observations, the model predicts that (i) the distalmost structures are formed at the intersection of compartment borders; (ii) distal transformation occurs whenever cells of all compartments come close to each other; (iii) distal transformation does not require a complete set of circumferential structures; (iv) mutants exist in which the positional information and not the response of the cells is altered and (v) no distal to proximal intercalation of missing leg segments occur. Regeneration and formation of supernumerary insect legs can be explained as well. Simple molecular reaction can account for this type of pattern formation. The “complete circle rule” of French, Bryant and Bryant (Science 193,969-981 (1976)) for distal transformation may be simplified by a “cooperation of compartments” rule.
The Oocytes of the Goby Pomatoschistus minutus. III. Determination of Amino Acid Component
Authors: Riehl Rüdiger
Published: August 2018

The oocytes of the marine goby Pomatoschistus minutus were analyzed for their amino acid content. Most of the amino acids exist as protein, only a little part is free or peptide-bound. Among the protein-bound amino acids, high levels of glutamic acid, proline, alanine, aspartic acid, valine and leucine were detected. These represent more than 60% of the protein amino acids. Among the free acids, glutamic acid, serine and alanine, are dominant. There are no certain proofs of the occurrence of peptide pools in the oocytes of Pomatoschistus minutus.
The Development of the Static Vestibulo-Ocular Reflex in Xenopus
Authors: Lang Hans-Georg , Horn Eberhard
Published: August 2018

The relation between the amount of the static vestibulo-ocular reflex arc and the developmental stage is characterized by an optimum function. The reflexes occur before the labyrinth is completely developed, but at this time, bilateral connections of the labyrinth with the oculomotor centers are efficient.
Sparticarpin: A Pterocarpan Phytoalexin from Spartium junceum
Authors: Ingham John L. , Dewick Paul M.
Published: August 2018

A new phytoalexin isolated from the fungus-inoculated leaflets of Spartium junceum (Spanish broom) has been identified as (-)-6 aR; 11 aR-2,3-dimethoxy-9-hydroxypterocarpan (sparticarpin). The total synthesis of sparticarpin is described.
Phenylpropanoic Acid Esters in the Essential Oil of Cistus ladanifer L. (Cistaceae)
Authors: Budzikiewicz Herbert , Proksch Peter , Gülz Paul-Gerhard
Published: August 2018

Esters of phenylpropanoic acid with 2-phenyl-ethanol-1 and the homologue, 3-phenyl-propanol-1 as well as geraniol and dehydrogeraniol were found in the essential oil of Cistus ladanifer. The isolation of these esters by chromatographic methods and structural elucidation by NMR and MS are described.
Enzymatic Synthesis of 1-Sinapoylglucose from Free Sinapic Acid and UDP-Glucose by a Cell-Free System from Raphanus sativus Seedlings
Authors: Strack Dieter
Published: August 2018

Protein extracts from seedlings of Raphanus sativus catalyze the transfer of the glucosyl moiety of UDP-glucose to the carboxyl group of phenolic acids. Enzymatic activity was determined spectrophotometrically by measuring the increase in absorbance at 360 nm and/or by the aid of high performance liquid chromatography (HPLC).

From 12 phenolic acids tested as acceptors, sinapic acid was by far the best substrate. The glucosyltransfer to sinapic acid has a pH optimum near 7 and requires as SH group for activity, p-Chloromercuribenzoate (PCMB) inhibits activity, which can be restored by the addition of dithiothreitol (DTT). The formation of 1-sinapoylglucose was found to be a reversible reaction, since the addition of UDP results in a breakdown of the ester.
Ruthenium Red Staining of Chromatin in Epon Sections
Authors: Stockert Juan C. , Paniagua R.
Published: August 2018

After staining with a 50% ethanol solution of ruthenium red, chromatin from onion and mouse cells showed red color and high contrast in the light and electron micro­scope, respectively. When applied to glutaraldehyde-fixed, Epon-embedded tissues, this selective staining technique proved to be dependent on the DNA content of chromatin.
Probable Phase Composition of the Mineral in Bone
Authors: Driessens F. C. M.
Published: August 2018

Formulas proposed for the mineral of bone were reviewed. Literature data were collected where Ca, P, Na, Mg and CO3 are determined in the same samples. These data were analyzed for their conformity to the above mentioned formulas. According to this analysis Mg is contained in a phase having the Ca/P of magnesium whitlockite within the limits of error. Na is contained in a carbonated calcium phosphate phase which in analogy with synthetic systems must have the apatite structure. The Ca/P ratio of the remaining "rest phase" is 2. This is based on the composi­ tion of 101 bone mineral samples taken from fishes, reptiles, amphibians, birds and mammals. The CO3 content of the bone samples agrees with the formula

Ca8 (PO4)4 (CO3) (OH)2 · x H2O

for the "rest phase" within the limits of experimental error. Such a compound has, however, not been found in synthetic systems. Human bone contains about 15% magnesium whitlockite, 25% of the Na and CO3 containing apatite and the rest is the carbonated calcium phosphate with Ca/P = 2. It is presumed that this compound has a structure similar to that of octo calcium phosphate and that most of the citrate ions which always occur in bone mineral samples are in­ corporated in that phase.
Calliphorin, a Protein Involved in the Cuticle Formation of the Blowfly, Calliphora vicina
Authors: Scheller Klaus , Zimmermann Hans-Peter , Sekeris Constantin E.
Published: August 2018

Injections of radioactively labelled calliphorin into Illrd instar larvae of Calliphora indicate that the protein is incorporated into the integument. Immunofluorescence techniques show that the endocuticle is the Final site of deposition of calliphorin. It is concluded that calliphorin is an essen­ tial protein of the tanned cuticle.
Degradation of 3,9-Dimethoxypterocarpan and Medicarpin by Fusarium proliferatum
Authors: Weltring Klaus-Michael , Barz Wolfgang
Published: August 2018

The degradation of 3,9-dimethoxypterocarpan was investigated in selected strains of Fusarium. Fusarium proliferatum (i. e. Gibberella fujikuroi (SAW)WR) degrades this substrate via 3-meth-oxy-9-hydroxypterocarpan, 3,9-dihydroxypterocarpan and 2',4',7-trihydroxyisoflavan. During degradation by this organism medicarpin is first demethylated to 3,9-dihydroxypterocarpan.
The Effect of Phytochrome and Proteinsynthesis-Inhibitors on the Formation of Chlorophylls and Carotenoids in Radish Seedlings Treated with Photosystem II and Bleaching Herbicides
Authors: Grumbach K. H. , Drollinger M.
Published: August 2018

Etioplasts of radish seedlings treated with photosystem II (DCM U, bentazon) and chlorotic herbicides (amitrole, SAN 6706) were tested on their ability to perform the phytochrome mediated chlorophyll and carotenoid biosynthesis. The cytoplasmic influence on the chloroplastic action of herbicides was also investigated by inhibition of protein synthesis either in the chloro­ plast with chloramphenicol or in the cytoplasm with actidion.

In all herbicide treated radish seedlings a phytochrome mediated chlorophyll and carotenoid biosynthesis was obtained as found in control plants. In plants treated with DCM U the bio­ synthesis of carotenoids is enhanced compared to the control plants, while SAN 6706 significantly suppresses the carotenoid formation.

It is concluded, that photosystem II and chlorotic herbicides do not interfere with the primary action of phytochrome but rather do develope their effects on the terpenoid metabolism through phytochrome.

Chloramphenicol applied at the time of sowing very strongly suppresses the formation of chlorophylls and carotenoids in control plants. The sensitivity towards actidion is, however, very much lower. If chloramphenicol and actidion treated plants were also supplied with herbicides, the pigment pattern is completely different In SAN 6706-treated plants chloramphenicol acts synergistic, resulting in an even lower chlorophyll and carotenoid content than in plants supplied only with chloramphenicol. On the other hand SAN 6706 in combination with actidion enhances the formation of pigments, leading to a much higher chlorophyll and carotenoid content as in plants treated only with actidion. A stimulatory effect on the formation of chlorophylls and carotenoids was also found for DCMU-treated plants in combination with actidion.

The observation, that in plants treated with SAN 6706 together with actidion, which inhibits protein synthesis in the cytoplasm, the herbicidal response in the chloroplast is completely abolished, gives evidence that the photooxidative action of SAN 6706 in the chloroplast is developed by the cytoplasm.
Formation of Actin Clusters in Rat Liver Parenchymal Cells on Phalloidin Poisoning as Visualized by a Fluorescent Phallotoxin
Authors: Jahn Wemer , Faulstich Heinz , Deboben Axel , Wieland Theodor
Published: August 2018

By staining of cryo-sections of rat liver with a fluorescent phallotoxin, the distribution of filamentous actin in liver cells could be demonstrated by fluorescence microscopy. While in untreated livers filamentous actin forms an almost continous layer at the cell periphery, the poisoning by phalloidin leads to the formation of actin clusters, preferentially located near the cell membrane.
Influence of Lithium Ions on Human Circadian Rhythms
Authors: Johnsson Anders , Engelmann Wolfgang , Pflug Burkhard , Klemke Waldemar
Published: August 2018

Lithium carbonate lengthens the circadian period in humans under temporal isolation (arctic summer four groups.
The Determination of Prolamellar Bodies and Saponins in Etioplasts and Leaves of Avena sativa L.
Authors: Lütz Cornelius
Published: August 2018

Prolamellar body tubules in etioplasts are composed mainly of two saponins. The determination of these saponins in leaves, etioplasts or subfractions of etioplasts is recommended to evaluate the concentration of these tubules in a given fraction. Using a densitometer after TLC-separation of the saponins measurements are carried out in a short time with high accurancy. Also the absolute concentration of these saponins can be determined. Problems in the quantification of the saponins in leaf samples can be overcame with filters of different wavelengths.