bluuebunny/crossref_metadata_2025 huggingface dataset:
Struktur-Reaktivitäts-Beziehungen und verzögerte Neurotoxizität organischer Phosphor-Verbindungen / Structure-Reactivity Relationships and Delayed Neurotoxicity of Organophosphorus Compounds
Authors: Reinhardt Hans-Georg
Published: August 2018

A correlation has been found between the reactivity in the alkaline hydrolysis reaction of a new series of organophosphates and their ability or disability to produce the clinical manifestation of delayed neurotoxicity in hen. At a dose of 1000 mg/kg only compounds exceeding a lower limit of reactivity (about 6×10-2м-1s-1) are active.
Verteilung von [3H]Thiopyronin in Hefezellen (Saccharomyces cerevisiae) / Distribution of [3H]Thiopyronine in Yeast Cells (Saccharomyces cerevisiae)
Authors: Lochmann Ernst-Randolf , Herrmann Cornelia , Pietsch Ingrid , Micheler Astrid
Published: August 2018

After incubation of Saccharomyces cells in [3H] thiopyro­ nine solution the photodynamically high effective dye was detected only to about 1% in the nucleus of the cell. 99% of the dye is distributed in the cytoplasm.
Detachment of Segments from DNA Double Strands as Detected by Time Resolved Rayleigh Light Scattering
Authors: Lindenau D , Hagen U , Schnabel W
Published: August 2018

Calf thymus DNA was irradiated in oxygen saturated 0.01 N NaCl solution with 2 μs pulses of 15 MeV electrons. By monitoring the decrease of light scattering intensity after the pulse, two modes of decrease were detected: The fast decrease (τ½ ≈ 0.8 ms) is ascribed to the separation of DNA fragments produced by double strand breaks at positions directly opposite to each other. The slow decrease (τ½ ≈ 8s) is attributed to the detachment of segments generated by single strand breaks at sites on the alternate strands being separated by about 10 nucleotide units.
β-Cyclocitral and Alkanes in Microcystis (Cyanophyceae)
Authors: Jüttner Friedrich
Published: August 2018

A tobacco-like odorous compound isolated from a bloom of the blue-green alga Microcystis wesenbergii and a laboratory culture of M . aeruginosa was analysed by gas-liquid chromatography and mass spectrometry. Its structure was determined as β-cyclocitral. No other monoterpenes have been detected in these and in other blue-green algae. The hydrocarbon content was 0.10 - 0.18% of the dry weight. n-Hexadecane, n-heptadecane, 4-methylheptadecane and n-octadecane constituted the main components. The relation of the different alkanes to each other, especially 4-methylheptadecane and n-octadecane, revealed marked differences in the two organisms.
The Influence of Oxygen on Nitrite Reduction in a Reconstituted System
Authors: Spiller Hartmut , Bookjans Gerhard , Böger Peter
Published: August 2018

Data regarding the role of oxygen in nitrite reduction are presented. In an NADPH-generating system including homogeneously purified ferredoxin-NADP reductase, ferredoxin (or flavodoxin) and nitrite reductase from the alga Bumilleriopsis filiformis, oxygen and nitrite can be reduced simultaneously. In air, rates of 1.2 μmol nitrite reduced· min-1· mg -1 nitrite reductase are ob­tained, which are physiologically feasible. Ferredoxin is inhibited non-competitively by oxygen during nitrite reduction. Oxygen uptake due to the oxidase reaction of ferredoxin-NADP reductase mediated by flavodoxin from Chlorella fusca and ferredoxin from Bumilleriopsis involves superoxide and is inhibited by the nitrite reducing system.
Effect of an Antiserum to a Thylakoid Membrane Polypeptide on the Primary Photoreaction of Photosystem II
Authors: Schmid Georg H. , Renger Gernot , Gläser Michael , Koenig Friederike , Radunz Alfons , Menke Wilhelm
Published: August 2018

As was described previously, an antiserum to polypeptide 11000 inhibited photosynthetic elec­tron transport on the oxygen evolving side of photosystem II. The effect of the antiserum on chloro­plasts from two tobacco mutants also clearly showed that the inhibition site is on the photosystem II-side of the electron transport chain. One of the two tobacco mutants lades the oxygen evolving capacity but exhibits some electron transport with tetramethyl benzidine, an artificial donor to PS II. In this mutant electron transport was barely inhibited. The effect of the antiserum on the primary photoevents showed that the initial amplitude of the absorption change of chlorophyll an at 690 nm and that of the primary electron acceptor X320 at 334 nm both diminished in the presence of the antiserum. Both signals were restored upon addition of diphenylcarbazide another artificial donor to photosystem II. Comparison of the degree of inhibition on the amplitudes of the fast and slow components of the 690 nm absorption change with the manometrically measured inhibition of electron transport shows that besides a full inactivation of a part of the reaction centers of photosystem II another part apparently mediates a fast cyclic electron flow around photosystem II as reported by Renger and Wolff earlier for tris-treated chloroplasts. Moreover, the antiserum affects the low temperature fluorescence in a way which is opposite to Murata’s effect of the Mg2+ -ion induced inhibition of energy spill-over from photosystem II to photosystem I. The antiserum under the condition in which the Hill reaction is inhibited lowered the 686 nm emission and enhanced the 732 nm emission which indicates an enhanced energy spill-over to photosystem I.
Spurenanalytik von p-Benzochinon-und Hydrochinon-Derivaten mit Gaschromatographie und Gaschromatographie/Massenspektrometrie. Identifizierung von Wehrsekret-Komponenten europäischer Juliden / Trace Analysis of p-Benzoquinone-and Hydroquinone Derivatives by Gas-Liquid Chromatography and Gas-Liquid Chromatography/Mass-Spectrometry. Identification of Defensive Secretion Components from European Julids
Authors: Röper Harald , Heyns Kurt
Published: August 2018

Substituted p-benzoquinones (= quinones) and substituted hydroquinones [bis-trimethylsilyl- ethers or bis-trifluoroacetates] can be separated by gas-liquid chromatography using 50 meter long thinfilm capillaries (inner diameter: 0.25 mm) coated with silicone OV 17 (50% phenyl, methyl) or silicone DC 550 (25% phenyl, methyl).

Total retention times of various derivatives of p-benzoquinone and hydroquinone were deter­mined.

Complex model mixtures of these derivatives can be separated by gas-liquid chromatography with temperature programs and the individual components can be clearly identified by their mass spectra in the sub microgram range by using combined gas-liquid chromatography/mass-spectrometry. This microanalytical technique was applied to identify the defensive secretion components from members of the diplopod order Julida (Arthropods). Julus nitidus produces a defensive secretion that consists exclusively of 2-methyl-3-methoxyquinone. The expelled defensive secretions of Unciger foetidus, Cylindroiulus coeruleocinctus (Iondinensis), Cylindroiulus punctatus, Cylindroiulus luridus and Ophyiulus psilosus consist of a 2-methylquinone and 2-methyl-3-methoxyquinone mixture. The presence of the corresponding hydroquinones-2-methyl-hydroquinone and 2-methyl-3-methoxyhydroquinone-was also determined in all cases.
Reconstitution of a System for H2 Evolution with Chloroplasts, Ferredoxin, and Hydrogenase
Authors: Fry Ian , Papageorgiou George , Tel-Or Elisha , Packer Lester
Published: August 2018

Continuous light-dependent H2 production was studied in a reconstituted in vitro system using Spinacea oleracea chloroplasts, Clostridium pasteurianum hydrogenase and Spirulina maxima ferredoxin. PhotosystemII dependent production at 30 0C is 60 -70 μmol H2/mg chlorophyll. At 15 0C, this reaction proceeds for up to 20 h producing 1O μmol H2/mg chlorophyll. O2 (glucose, glucose oxidase) and peroxide (ethanol, catalase) traps do not extend the lifetime but enhance the rate of H2 production. Stoichiometry of the coupled system for H2 production in this system is 2 H2 formed : 1 glucose consumed. A conversion efficiency of water photolysis for H2 evolution of 70% was determined from the O2 produced, measured as the amount of glucose consumed, during the first 2 h of continuous illumination.

Cessation of H2 production by the reconstituted system involves inactivation of photosystem II and a limitation in the coupling of low potential electrons to hydrogenase. Increasing ferredoxin leads to more rapid H2 evolution but longevity of the system remains unchanged. When H2 evolution ceases due to inactivation of water-splitting activity of photosystem II, about 40% of the hydro­genase and 25% of photosystem I activity are still present; inactivation is unclear when photo­system I is used to drive H2 production since when H2 production ceases, hydrogenase and photo­system I still retain activity. This may suggest that coupling between low potential reducing equivalents from photosystem I to hydrogenase is impaired.
Notizen: Fluorescence and Membrane-Action of Tetracaine
Authors: Elferink J. G. R.
Published: August 2018

Tetracaine, Fluorescence, Erythrocyte Membrane The fluorescence of tetracaine depends on the micro-environment of the molecule and increases with increasing hydrophobicity. The presence of erythrocyte membranes strongly enhances tetracaine fluorescence. The results support the view that the alkyl chain and aromatic part of tetracaine is embedded in apolar regions of the lipid or protein phase of the membrane.
Notizen: Ribosome Crystals in the Oocyte of Gerris najas (Heteroptera)
Authors: Choi Won Chul , Nagl Walter
Published: August 2018

Oocytes of the pond skater, Gerris najas, display ribosome tetramers that are arranged in the form of sheets in the vicinity of the nucleus. This is the first finding of ribosome crystals in an insect and suggests that ribosome crystallization may be a common phenomenon of cells that are inactive in protein synthesis.
Schadstoff-Untersuchungen an datierten Sedimentkernen aus dem Bodensee / Pollution Research on Dated Sediment Cores from Lake Constance
Authors: Müller German
Published: August 2018

The vertical distribution of eight heavy metals (Hg, Cu, Zn, Cr, Co, Ni, Pb, Cd) in dated sediments of four sedimentary profiles from the central part of Lake Constance was examined. From 1900 to about 1960 - 1970, a general increase of all heavy metals was observed. After this time, the concentrations of most of the metals decreased.

As compared with pre-1900 “natural” metal concentrations, Cd and Pb have been enriched the strongest (enrichment factors 4.0 and 3.8 resp.), whereas Ni and Co exhibit least civilizational influences (enrichment factors 1.5 and 1.9 resp.). Cu, Cr, Zn and Hg were enriched by a factor between 2 - 3. Elements which were not influenced by anthropogenic processes - such as K and Li - remained unaffected over the whole vertical sequence. Polycyclic aromatic hydrocarbons (PAH) which were also studied in the same sediment material by Grimmer and Böhnke show a similar pattern. Within a sedimentary profile the concentration ratio benzo (a) pyrene: cadmium remained about constant.

Combustion of coal is believed to be the common source of both heavy metals and PAH and seems to be responsible for the general distribution pattern of both groups of pollutants. In addition, local sources - both domestic and industrial - are assumed to have delivered additional heavy metal pollution.
The Quaternary Structure of Yeast Aminopeptidase I
Authors: Marx Ruth , Metz G. , Röhm K.-H
Published: August 2018

Aminopeptidase, Yeast, Electron Microscopy, Quaternary Structure Electron micrographs of native aminopeptidase I and of isolated subfragments were taken after negative staining with uranyl formate. From these studies and from the chemical evidence sum­ marized in the preceding paper it is concluded that the active enzyme is a dodecamer possessing pseudo-D3 symmetry with the dimer as the smallest symmetric unit.
Characterization of a Soluble NADH-Independent Nitrate Reductase from the Photosynthetic Bacterium Rhodopseudomonas capsulata
Authors: Alef Kasem , Klemme Jobst-Heinrich
Published: August 2018

The assimilatory nitrate reductase was purified 60-fold from a newly isolated, nitrate assimilating strain of the photosynthetic bacterium Rhodopseudomonas capsulata. The enzyme had a molecular weight of about 180 000 dalton and was typically prokaryotic in that it was not active with reduced pyridine nucleotides but rather with reduced flavins.
On the Correlation between the Amplitude of the Electrochromic Absorption Changes and the Number of Bulk Pigments
Authors: Renger Gernot , Schmid Georg H.
Published: August 2018

Electrochromic Absorption Changes, Photosynthetic Unit A correlation between the amplitude of the electrochromic absorption changes measured at 480 nm and 520 nm and the size of the photosynthetic unit is found. Three tobacco mutants which differ with respect to their photosynthetic unit size exhibit decreased amplitudes of the electrochromic absorption changes which parallel the size of the photosynthetic units. Under these conditions the ATP-yield per flash is unaffected by the photosynthetic unit size. From this it is deduced that the correlation between the amplitude of the electrochromic absorption change and the photosynthetic unit size is due to the fact that the number of pigments undergoing an electro­ chromic bandshift is proportional to the total pigment content. As the influence on the electro­ chromic effect at 520 nm is too pronounced as to be simply explainable by the variation of the carotenoid content in the different mutants it is inferred that either structural effects leading to a modification of the carotenoid orientation in the mutants or an indirect influence of chlorophyll on the electrochromic bandshift which depend on the number of chlorophyll molecules are responsible.
Chemische und biochemische Charakterisierung von α-Benzyl-α-brommalonitril (BBMD) als Oxidationsmittel / Chemical and Biochemical Characterization of α-Benzyl-α-bromo-malononitrile (BBMD) as Oxidizing Agent
Authors: Rieser J. , Höckendorf A. , Abou-Elenien G. , Wallenfels K.
Published: August 2018

The behaviour of α-benzyl-α-bromo-malononitrile (BBMD) as oxidizing agent was characterized. The dependence of the electrochemical reduction potentials of BBMD on the pH-values of the solutions was examined. BBMD is reduced in a two-electron wave with half-wave potentials between + 230 and + 312 mV vs. Ag/AgCl/Cl-. BBMD is able to oxidize different organic compounds with OH-, SH-, NH- and CH- groups as well as a series of biological reducing agents as ubihydroquinone, plastohydroquinone, dihydro-lipoic acid, FADH2, NADPH and NADH. In all these cases BBMD is reduced to benzylmalononitrile. Kinetic investigations of this reduction process using NADH as reducing agent and also NMR-investigations using deuterated NADH-models showed that BBMD is directly reduced to benzylmalononitrile without producing benzylidenemalononitrile as intermediate. The reduction of BBMD with reduced pyridine nucleotides as well as that of benzylidene­ malononitrile were accelerated by an enzyme which was concentrated from human erythrocytes, using 2-chloro-benzylidenemalononitrile (CS) as substrate.
Chemical Investigation of the Lichen Species Alectoria ochroleuca, Stereocaulon vesuvianum var. pulvinatum and Icmadophila ericetorum
Authors: Solberg Yngve
Published: August 2018

Lichens, Lipids, Phenols The three lichen species Alectoria ochroleuca, Stereocaulon vesuvianum var. pulvinatum and Icmadophila ericetorum have been chemically investigated with regard to their content of aliphatic and aromatic compounds. Tetrahydroxy fatty acids were isolated in all three species. A mono-acetylated pentol, higher fatty acids and an unsaturated triglyceride were detected as new con­ stituents of A. ochroleuca and I. ericetorum. S. vesuvianum and I. ericetorum both contained phenolic components which not previously have been discussed in literature. Chemical and spectro­ scopic evidences are presented in these studies.
Labelling Experiments on the Origin of Hexa-and Octa- decatrienoic Acids in Galactolipids from Leaves
Authors: Siebertz H. P. , Heinz E.
Published: August 2018

Young leaves from three plants which accumulate hexadecatrienoic acid rather specifically in the sn-2-position of monogalactosyl diglyceride (MGD) were incubated with radioactive CO2 or acetate to investigate the origin of this specificity. Labelled glycerolipids were extracted and analyzed for time-dependent changes of radioactivity in their fatty acids. The investigation of labelled MGD and digalactosyl diglyceride (DGD) included determination of radioactivity in hydrolysis products, separation of molecular species by argentation chromatography and analysis of the positional distribution of fatty acids. The results agree with previous observations on the accumulation of radioactive oleic acid in phosphatidyl choline (PC) and formally with the possibility of a PC-coupled desaturation to linoleic acid. They do not support the proposed function of PC as donator of polyenoic acids. Instead the radioactivity patterns may be interpreted as pointing to a relation between fatty acid desaturation and many if not all glycerolipids, although a different interpretation is also possible.

Fatty acid patterns in lipids and their labelling indicate the existence of several pools for

1) MGD, from which only that without C16-unsaturated fatty acids is accessible for galactosylation to DGD ;

2) palmitic acid, from which one part is accessible to desaturation via C16:0 and C16:2 to C16:3 . Since these acids are found labelled in the sn-2-position of MGD, the specific positioning may be related to this separation of C16:0pools. Desaturation of C16:0 seems to be the major source of C16:3;

3) linolenic acid, from which those parts present in the sn-2-position of galactolipids or in PC are characterized by a strikingly slow labelling.
Biflavones from the Leaves of Araucaria rulei F. Muell. and a Survey on Biflavanoids of the Araucaria Genus
Authors: Ilyas M. , Seligmann O. , Wagner H.
Published: August 2018

Eleven biflavones have been isolated from the leaves of Araucaria rulei and identified by NMR spectroscopy and via the permethylated and peracetylated products. The biflavones found until now in the Araucaria genus are summarized in a table.
Inhibition of Human Prolyl Hydroxylase as Common Biochemical Denominator of the Non-Sedative Effects of Thalidomide in Man
Authors: Hanauske-Abel Hartmut , Günzler Volkmar
Published: August 2018

The two main non-sedative effects of thalidomide (2-phtalimido-glutarimide) in man are the embryopathy, which finally forced termination of its use as a sedative, and the excellent efficacy in leprosy reactions, alone for whose prevention and treatment the drug is still available. Both effects can be explained on a molecular level by assuming that a non-sedative metabolite of thalidomide mediates inhibition of human prolyl hydroxylase, as suggested by steric considerations and correlation to known data. This metabolite may well be a suitable model compound for drugs designed for selective fibrosuppression and selective immunosuppression.
Competition between Oxalate and Phosphate during Active Calcium Accumulation by Sarcoplasmic Vesicles
Authors: Beil Frank-Ulrich , von Chak Dorothee , Hasselbach Wilhelm , Weber Hans-Hermann
Published: August 2018

Sarcoplasmic Calcium Uptake, Oxalate and Phosphate Uptake, Oxalate-Phosphate Competition, Calcium Turnover

1. During ATP supported active calcium uptake oxalate as well as phosphate are accumulated with calcium. The uptake of calcium exceeds that of both anions by a small quantity - accounting for calcium binding to vesicular proteins and lipids.

2. From assay media containing phosphate and oxalate - nearly exclusively either oxalate or phosphate are taken up together with calcium by the sarcoplasmic reticulum vesicles. The mutual exclusion occurs in a very narrow concentration range of the anions.

3. In solutions containing phosphate and oxalate, calcium phosphate or calcium oxalate pre­ cipitates are formed according to their solubility properties.

4. When phosphate prevents oxalate from being taken up, calcium transport is inhibited. In­ hibition occurs, because the concentration of ionized calcium inside the vesicles rises approximately 100-fold when oxalate is replaced by phosphate. The activity of the calcium dependent ATPase parallels the calcium uptake activity.

5. It is excluded that the inhibition of calcium uptake produced by phosphate is caused by an enhanced permeability of the sarcoplasmic reticulum membranes for calcium in the presence of phosphate.
Identification of Essential Histidine Residues of Aminoacylase by Photooxidation and by Reaction with Diethylpyrocarbonate
Authors: Kordel Werner , Schneider Friedhelm
Published: August 2018

State and function of the histidine residues of aminoacylase were investigated by photooxidation in the presence of methylene blue and by chemical modification with diethylpyrocarbonate. Complete inactivation of the enzyme was observed after oxidation of 4 histidine residues. From the pH dependence of the photooxidation it becomes evident that the inactivation of the enzyme is not a consequence of the simultaneous oxidation of tryptophan residues. The enzyme is also inctivated by chemical modification of histidine residues with diethylpyrocarbonate. Activity is restored by treatment with hydroxylamine. Zn2+-ions which are essential for the activity of amino­ acylase protect the available histidine molecules against photooxidation and attack by diethyl­ pyrocarbonate. It is suggested that histidine is involved in the binding of the essential Zn2+-ions.
The Biosynthesis of Phenylacetic Acids in the Blue-Green Alga Anacystis nidulans: Evidence for the Involvement of a Thylakoid-Bound ʟ-Amino Acid Oxidase
Authors: Löffelhardt W.
Published: August 2018

Phenylacetic acid and p-hydroxyphenylacetic acid are formed upon incubation of photosynthetic membranes from the prokaryotic alga Anacystis nidulans with ʟ-phenylalanine and ʟ-tyrosine, respectively. The corresponding phenylpyruvic acids act as intermediates as shown by trapping them as the stable oximino acids. The first step in this reaction sequence appears to be catalyzed by a thylakoid-bound ʟ-amino acid oxidase. Already existing evidence concerning phenylacetic acid formation at thylakoid membranes of higher plants via an ʟ-amino acid oxidase and the results obtained with A. nidulans give another example of aromatic amino acids between chloroplasts and blue-green algae.
Notizen: Visual Fixation in Freely Flying Bees
Authors: Wehner R. , Flatt I.
Published: August 2018

A foraging bee approaching a food source visually fixates the food source before it lands on it. During this process of fixation the bee adjusts its rotatory and translatory flight components to fixed values with respect to all six degrees of freedom.
Photochemically Reversible Dimer Electroreduction Product of 2-Oxopurine
Authors: Czochralska Barbara , Fritsche H. , Shugar D.
Published: August 2018

The electrochemical reduction of 2-oxopurine in buffered aqueous medium was found to proceed via two successive one-electron additions. The initial one-electron step involves the addition of a proton, leading to formation of a free radical which rapidly dimerizes. At more negative potentials, reduction leads to formation of 1,6-dihydro-2-oxopurine. The product of reduction on wave I was isolated and identified by various spectroscopic techniques as the dimer 6,6′-bis-(1,6-dihydro-2-oxo-purine). In neutral aqueous medium this dimer reduction product (but not the product of reduction on wave II, 1,6-dihydro-2-oxopurine) underwent quantitative photochemical dissociation to the parent 2-oxopurine, with a quantum yield at 254 nm of 0.03. The dimer reduction product also quantitatively regenerated the parent monomer in an alkali-catalyzed reaction at room temperature. The proposed mechanism of the reduction reaction, and susceptibility of the reduction product to photodissociation, is compared with the corresponding behaviour of other purine, and pyrimidine, derivatives.
Zur Totalsynthese des Human-Big-Gastrins I und seines 32-Leucin-Analogons (Vorläufige Mitteilung) / Total Synthesis of Human Big Gastrin I and the 32-Leucine Analogue (Preliminary Communication)
Authors: Wünsch E. , Wendlberger G. , Hallett A. , Jaeger E. , Knof S. , Moroder L. , Scharf R. , Schmidt I. , Thamm P. , Wilschowitz L.
Published: August 2018

A new total synthesis of the tetratriacontapeptide amide corresponding to the proposed primary structure of human big gastrin I is described. The synthetic route was based on the preparation of six suitably protected fragments, related to sequence 28 - 34, 23 - 27, 21 - 22, 15-20, 9 - 14, and 1 - 8, to be used as building blocks for the total synthesis. The protecting groups were selected according to the Schwyzer-Wünsch strategy of maximum side chain protection based on tertiary alcohols, also for the imidazol function of histidine. Subsequent assembly of the six fragments by three different pathways using the highly efficient Wünsch-Weygand condensation procedure to ensure minimum racemization, followed by deprotection of the synthetic products via exposure to trifluoroacetic acid and final purification by ion-exchange chromatography on DEAE-Sephadex A-25 and partition chromatography on Sephadex G-25, led to human big gastrin I, homogeneous within the limits of the analytical methods used. The biological activity of the synthetic product proved to be 50 percent higher than that of human little gastrin I. The 32-leucine analogue of human big gastrin I was prepared in the same way.
Conformational Studies on C-Phycocyanin from Spirulina platensis
Authors: Scheer Hugo , Kufer Werner
Published: August 2018

The chromophore-protein interactions of C-phycocyanin (C-PC) from Spirulina platensis have been studied by following the partial and complete denaturation with UV-Vis spectroscopy. From comparison with published MO calculations, an elongated conformation of the chromophore is suggested for native C-PC, a cyclic one for denatured C-PC. By means of partial denaturation, a step­ wise unfolding of the protein has been demonstrated. The presence of at least two sets of spectro­ scopically different diromophores is suggested from the partial denaturation and low temperature experiments.
Pilzpigmente, XXXII 3-Methylriboflavin aus Panellus serotinus (Agaricales) / Pigments of Fungi, XXXII. 3-Methylriboflavine from Panellus serotinus (Agaricales)
Authors: Steglidi Wolfgang , Zechlin Lothar
Published: August 2018

The isolation and identification of 3-methylriboflavine from the toadstool Panellus serotinus is described.
Immunological Reaction of UV-Induced Radiation Damage in Coliphage DNA
Authors: Fink Angelika , Hotz Gerhart
Published: August 2018

Denatured DNA of coliphage Tl, poly-dT and dTpT were UV-irradiated (2537 Å) and con­jugated to methylated bovine serum albumin. These molecules act as haptens after injection into rabbits. Antibodies are predominantly formed against UV-induced cyclobutane-type of cis-syn thymine dimers. They belong to the IgG-type of antibody molecules. Antigen-antibody complexes were detected by means of the CsCl-density gradient method. Denaturation of the DNA strongly influences the amount of specific antibodies bound to the antigen. In native DNA thymine dimers are masked concerning their reaction with antibodies. Photoproducts of UV-irradiated dTpT induce a specific production of antibody. Our results indicate that the cyclobutane type of thymine dimers is the relevant antigenic determinant group in UV -irradiated DNA.
Eigenschaften der [ω-(3-Acetylpyridinium)-n-alkyl]-adenosin-pyrophosphate als Strukturanaloge des Coenzyms NAD / The Properties of [ω-(3-Acetylpyridinio)-n-alkyl] Adenosine Pyrophosphates, Structural Analogs of the Coenzyme NAD
Authors: Jeck Reinhard
Published: August 2018

[ω- (3-Acetylpyridinio) -n-alkyl] adenosine pyrophosphates are coenzyme analogs of NAD⊕. The adenosine pyrophosphate moiety and the 3-acetylpyridine ring of the analogs are connected by n-alkyl chains of different lengths (ethyl -hexyl). The analogs form strong dissociating complexes with lactate dehydrogenase. The complex formation is predominantly achieved by interaction of the ADP moiety with its respective binding domain at the active site.

The redox potentials of the analogs and NAD are of similar magnitude. The coenzyme function of the analogs depends upon the length of the hydrocarbon chain. Lactate dehydrogenase and alcohol dehydrogenases from yeast and horse liver do not catalize hydrogen transfer from their substrates to any other alkyl analog but [4- (3-acetylpyridinio)-n-butyl] adenosine pyrophosphate, aldehyde dehydrogenase from horse liver catalizes hydrogen transfer from acetaldehyde to the pentyl derivative and glyceraldehyde-3-phosphate dehydrogenase catalizes hydrogen transfer to both analogs. In no case, hydrogen transfer from or to one of the 3-acetylpyridine-n-alkyl analogs proceeded with a velocity comparable to NAD or its 3-acetylpyridine analog. The results show that the nicotinamide bound ribose in NAD is involved in the binding and the activation of the coenzyme.
Binding of Antibodies onto the Thylakoid Membrane II. Distribution of Lipids and Proteins at the Outer Surface of the Thylakoid Membrane
Authors: Radunz Alfons
Published: August 2018

The number of antibody molecules which stroma-freed chloroplasts can bind out of the mono-specific antisera to monogalactosyl diglyceride, tri-and digalactosyl diglyceride, sulfoquinovosyl diglyceride, phosphatidyl glycerol, sitosterol, plastoquinone, lutein and neoxanthin was determined. This number was compared to the number of antibody molecules which stroma-freed chloroplasts can maximally bind. The result is that the antibodies to the individual lipids cover at most 17 per cent of the accessible thylakoid membrane surface.

From a serum which contains both antibodies to the proteins and lipids of the thylakoid membrane, not more antibody molecules are bound than from a serum to the proteins. This means that antibodies to proteins are able to cover up the entire accessible surface of the thylakoids whereas a mixture of antibodies to the lipids, listed above, cover only one forth of the surface. Consequently, antibodies which are bound to proteins can cover up the lipid areas entirely and in turn antibodies which are bound to lipids cover up parts of the protein areas. From this it follows that the portion of the surface, which is made up by lipids must be considerably smaller than 24 per cent. Furthermore, it follows from these experiments that the lipid areas are small and that lipids probably only fill up the gaps between the protein molecules.
The Degree of CF1 Release and the Reconstituting Capacity of the Depleted Membranes
Authors: Schopf Reinhard
Published: August 2018

Uncoupling of photophosphorylation was shown in chloroplasts from spinach which were iso­ lated in media containing pyrophosphate and thereafter suspended in salt-free solutions. The effective concentration of pyrophosphate to uncouple was determined by the addition of pyrophos­ phate to free thylakoid systems and shown to be dependent on the presence of the completely dissociated species which favoured complex formation with bivalent cations. Higher concentrations of pyrophosphate led to a stabilization of photophosphorylation. The uncoupling is due to the release of the coupling factor. The degree of liberation was shown to be dependent on the chlorophyll concentration. The capacity of extracted membranes to reconstitute photophosphoryla­tion with their corresponding supernatant or with purified CF1 was directly correlated to the amount of the liberated coupling factor.
Dissociation and Reassociation of Poliovirus II. Protein Components Obtained by Urea Treatment of the Virus Particle
Authors: Yamaguchi-Koll Ursula , Wiegers K. J. , Drzeniek R.
Published: August 2018

Dissociation of poliovirus by 9 ᴍ urea in 0.015 ᴍ NaCl at 25 °C resulted in the liberation of 35S RNA and of polypeptides sedimenting at 2S in sucrose gradients containing 9 ᴍ urea. However. a ribonucleopolypeptide (RNPP) complex sedimenting at 45S and oligomers of the viral polypeptides sedimenting at 7 -8S were found in addition to the monomers sedimenting at 2S when the urea concentration was lowered to 5 M after the dissociation procedure. Ribonuclease treatment prevents the appearance of the RNPP-complex. The amount of the RNPP-complex de­ creased, when the dissociation was performed at higher ionic strength. Under these conditions small amounts of empty capsids were detected.

Polyacrylamide gel electrophoresis showed that the RNPP-complex contained the polypeptide VP1. The oligomers (7 -8S) contained the polypeptide VP3 and small amounts of VP2. The bulk of VP2 and some VP3 were found in the 2S position together with VP4.

The molecular weight of the dissociation products in urea and phosphate buffer was determined by gel filtration to be about 30,000 for the monomeric polypeptides containing predominantly VP2 and about 70,000 for the oligomeric polypeptides containing predominantly VP3.

Our results demonstrate that the oligomers and the RNPP-complex are not primary products obtained by dissociation of the virus particle by urea but are due to a reassociation of the poly­ peptides or of VP1 and RNA.
On the Influence of Aromatic Residues on the Interaction of Copper (II) with Small Peptides Containing Aromatic Amino Acids: ESR and Optical Studies
Authors: Sportelli Luigi , Neubacher Harald , Lohmann Wolfgang
Published: August 2018

The complexation behaviour of Cu(II) with di- and tri­peptides containing the aromatic amino acids phenylalanine or tryptophan has been investigated at different pH-values and compared with results obtained with di- and triglycine. The results obtained by means of ESR and optical absorp­tion spectroscopy show an influence of the two different aromatic entities on the magnetic and optical parameters. A significant decrease of the g‖-value and, concomittantly, an increase of the energy of the d-d transition was measured when an aromatic entity is present in the peptide. A possible explanation for this observation is given.
Aerobic Oxidation of p-Hydroquinone by Horse Radish Peroxidase in the Presence of a Thiol and MnCl2
Authors: Esterbauer Hermann , Schwarzl Elisabeth
Published: August 2018

In the presence of MnCl2 and a thiol (glutathione, cysteine, 2-nitro-5-thiobenzoic acid) horse radish peroxidase oxidizes ρ-hydroquinone to ρ-benzoquinone which in turn immediately adds the thiol present yielding 2-S-substituted ρ-hydroquinone.
Biologically Active Constituents of Leaves and Roots of Aloe arborescens var. natalensis
Authors: Hirata Toshifumi , Suga Takayuki
Published: August 2018

Several biologically active substances, such as aloenin (1), magnesium lactate, aloe-emodin (4), barbaloin (5), and succinic acid, were found to be contained in the leaf juice of Aloe arborescens Mill. var. natalensis Berger, which has widely been used in domestic medicines. Aloenin (1) and magnesium lactate were elucidated to exhibit an inhibitory action on the gastric juice secretion of rats. Various constituents other than the above bioactive substances were found in the leaves and the roots of the plant.
Assimilatory Sulfate Reduction by Chloroplasts: The Regulatory Influence of Adenosine-mono-and Adenosine-diphosphate
Authors: Schwerin Jens-Dirk , Depka Brigitte
Published: August 2018

The first three enzymatic steps of assimilatory sulfate reduction in chloroplasts of higher plants have been investigated with emphasis on the influence of adenosine-mono-and -diphosphate upon the formation of APS, PAPS and bound sulfite.

The data show that the activation process is governed by the energy charge of the chloroplast. The regulatory step is localized at the ATP-sulfurylase reaction. It was found that this enzyme is inhibited by low concentrations of AMP and ADP, with apparent KiAMP = L8mм and KiADP=0.5 mм for the chloroplast preparations. The isolated purified ATP-sulfurylase is inhibited by the nucleotides accordingly, with KiAMP=0.2mм and KiADP=0.4mм. The results are interpreted as a regulatory mechanism for the complete process of assimilatory sulfate reduction in the chloro­ plast.
Hill-Activity and P700 Concentration of Chloroplasts Isolated from Radish Seedlings Treated with -Indoleacetic Acid, Kinetin or Gibberellic Acid
Authors: Buschmann Claus , Lichtenthaler Hartmut K.
Published: August 2018

The Hill-activity (reduction of DCPIP or methylviologen) and the concentration of P700 were studied in chloroplasts isolated from cotyledons of radish seedlings (R aphanus sativu s L. Saxa Treib), which had been grown with the addition of β-indoleacetic acid (IAA), kinetin, or gibberellic acid.

1) The photosynthetic activity of young chloroplasts from 3 day old Raphanus seedlings is very high (c. 180 μmol O2/mol chlorophyll × h) and decreases continuously thereafter with increasing age. The steady state Hill-activity is readied after 8 to 10 days (values of 55 to 50 μmol 02/mg chlorophyll × h).

2) Chloroplasts from plants treated with IAA or kinetin not only exhibit higher plastoquinone levels 1,2, but also a higher P700-content and a higher Hill-activity. The promotion effect is more pronounced with kinetin (+ 36 to 40%) than with IAA (+ 12 to 17%).

3) Gibberellic acid has a different effect on composition and activity of chloroplasts. In younger seedlings the Hill-activity appears to be somewhat stimulated, without promotion effect on plasto­ quinone 2 or P700 concentration. After 10 days GA3-treated plants show signs of chlorosis combined with a strong decrease in photosynthetic activity.

4) The data clearly demonstrate that the composition and activity of the photosynthetic ap­ paratus are under phytohormone control. IAA and even better kinetin promote the light induced formation of pigment systems and electrontransport chains. GA3 seems to block the rebuilding of the photosynthetic apparatus under steady state conditions.
Localization and Functional Characterization of Three Thylakoid Membrane Polypeptides of the Molecular Weight 66000
Authors: Koenig Friederike , Menke Wilhelm , Radunz Alfons , Schmid Georg H.
Published: August 2018

Three polypeptide fractions with the apparent molecular weight 66 000 were isolated from stroma-freed Antirrhinum chloroplasts which were solubilized with dodecyl sulfate. Antisera to these fractions affect electron transport in distinctly different ways. For the characterization of the three antisera photochemical reactions of chloroplast preparations with artificial electron donors and acceptors as well the analysis of fluorescence rise curves were used. Antiserum 66 000 PSI-96 inhibits electron transport apparently on the acceptor side of photosystem I, provided the antibodies are adsorbed onto the outer surface of the thylakoid membrane. Antiserum 66 000 PSI-88 probably acts directly on the reaction centre I or on its immediate vicinity, if the antibodies are adsorbed at the inner surface of the thylakoid membrane. Antiserum 66 000 PSII-42 inhibits electron trans­ port in the region of photosystem II. The antigen towards which the antiserum is directed appears to belong to the reaction centre II, as also in the condition of high inhibition degrees, the fluorescence intensity remains unchanged. The antigenic determinants are located at the outer surface of the thylakoid membrane.
Genetic Information Analysis of Bacteriophage Φx 174
Authors: Figueroa R. , Sepúlveda A. , Soto M. A. , Tohá J.
Published: August 2018

The genetic information of Φx 174 genome (genes and intermediate segments) is analyzed in terms of its independent (D1 index) and dependent information (D2 and D3 Markovian indexes), as well as of its ability to generate secondary structure.

Genes B and E, enclosed in A and D respectively, have: 1) values of D1 and D3 indexes closer to the theoretical random distribution curves than those of (A -B) and (D -E) gene fractions, and 2) in the ability for secondary structure generation minor differences with genes A and D.

F → G and mRNA start → A intermediate segments differ from randomness in their D1 and D2 indexes, but not so much in the D3 values.

All these data point out the use of code degeneracy for increasing the genetic information density of the virus.
Polarization, Isopotential Maps and Tunneling in Guanine, Cytosine, and Tautomeric Forms
Authors: Marañon Julio , Sorarrain Oscar M.
Published: August 2018

We have used the CNDO/2-CI method to calculate the isopotential maps for the fundamental state and the direction of the polarizations corresponding to several singlet transitions in the mole­ cules of guanine, cytosine and tautomeric forms. We have also calculated the times for proton tunneling and equilibrium constants between both conformers corresponding to the fundamental and some excited states. The results have been compared with the available experimental data.
Isolierung und Charakterisierung Antipyrin-abbauender Bakterien / Isolation and Characterization of Antipyrine-degrading Bacteria
Authors: Blecher Hartmut , Blecher Renate , Müller Rudolf , Lingens Franz
Published: August 2018

Five different strains of bacteria ultilizing antipyrine as sole source of carbon were isolated from soil. It was shown by morphological and physiological examinations, that the new isolates are closely related to strains selected with the herbicide chloridazon. A ll of these bacteria are charac­ terized by special features and cannot be classified according to Bergey’s Manual of Determinative Bacteriology.

Part of the strains which were selected with antipyrine not only grow with antipyrine but also with chloridazon. The others cannot be grown on chloridazon. However, resting cells of the latter group convert chloridazon to its catechol derivative (5-amino-4-chloro-2 (2,3-dihydroxyphenyl) -3 (2H)-pyridazinone). In these bacteria a catechol-2,3-dioxygenase (catechol: oxygen 2,3-oxido-reductase, EC 1.13.11.2) was found which readily catalyzes the cleavage of the catechol derivative of antipyrine (2,3-dimethyl-l-(2,3-dihydroxyphenyl)-pyrazolone (5)). The enzyme shows only slight activity with the corresponding derivative of chloridazon.
Antibiotika aus Basidiomyceten, VI [1 ] Merulinsäuren A , B und C, neue Antibiotika aus Merulius tremellosus Fr. und Phlebia radiata Fr./ Antibiotics from Basidiomycetes, VI Merulinic Acids A, B, and C, New Antibiotics from Merulius tremellosus and Phlebia radiata
Authors: Giannetti Bruno Max , Steglieh Wolfgang
Published: August 2018

Three new antibiotics, merulinic acids A, B, and C, have been isolated from fruiting bodies of Merulis tremellosus and Phlebia radiata. They are closely related derivatives of β-resorcylic and salicylic acid, carrying monounsaturated C17-alkyl side chains in 6-position. The merulinic acids are mixtures of the Δ8′-compounds with minor amounts of the corresponding Δ10′-, dehydro, and dihydro derivatives, separable only by means of HPLC. Δ8′-Merulinic acid A (1) was synthesized via a biomimetic cyclization of a linear precursor. The merulinic acids inhibit a variety of bacteria and are not active against fungi. RNA, DNA, and protein synthesis in Bacillus brevis and Ehrlich carcinoma ascites cells are inhibited shortly after the addition of the antibiotics. Almost complete hemolysis of human erythrocytes is caused by 25 μg/ml of merulinic acid B and C or by 73 μg/ml of merulinic acid A.
Purine Nucleosides and Nucleotides Unequivocally in the Syn Conformation: Guanosine and 5′-GM P with 8-tert-Butyl and 8-( α-Hydroxyisopropyl) Substituents
Authors: Pless Reynaldo , Dudycz Lech , Stolarski Ryszard , Shugar David
Published: August 2018

Direct alkylation via a free radical reaction was utilized to prepare 8-tert-butylguanosine-5′- phosphate; this was dephosphorylated with alkaline phosphatase to give the parent nucleoside. The 8- (α-hydroxyisopropyl) derivatives of 5′-GMP and guanosine were prepared in an analogous manner.

The foregoing products, which are necessarily in the syn conformation about the glycosidic bond because of the bulky 8-substituents (van der Waals’ radii 3.5-4 Å), were characterized by elementary analysis, UV spectra and 1HNMR spectroscopy. The changes in chemical shifts of H (1′), H (2′) and H (3′) of each of the foregoing derivatives, relative to those for guanosine and 5′-GMP, were consistent with their being in the syn conformation and, furthermore, pointed to guanosine and 5′-GMP being predominantly anti, in aqueous medium or DMSO. They also demonstrated that, contrary to the prevailing opinion, 8-bromo-5′-GMP and 8-bromoguanosine are not necessarily ex­clusively in the syn conformation in solution.

While 8-bromoadenosine-5′-phosphate was slowly dephosphorylated by snake venom 5′-nucleoti- dase, the 8-tert-butyl and 8-(α-hydroxyisopropyl) derivatives of 5′-GMP were fully resistant to this enzyme.
Calculation of the Circular Dichroism of Chironomus Hemoglobin in the Light of the Quality of Its X-Ray Structure
Authors: Straßburger Wolfgang , Wollmer Axel , Thiele Herbert , Fleischhauer Jörg , Steigemann Wolfgang , Weber Erns
Published: August 2018

For the larval hemoglobin III of the insect Chironomus thummi thummi, the rotational strength of the B (Soret) and Q band is calculated with a monopole/monopole and a dipole/dipole approximation applied to the atomic coordinates of the X-ray structures at 2.5 and 1.4 Å resolution.

In previous calculations using the 2.5 Å coordinates and with perturbing groups being restricted to aromatic side-chains, the dipole/dipole approximation clearly confirmed the negative sign ob­served by experiment. The predominant interactions were those of phenylalanine residues.

Recalculation with X-ray data refined to the present limits of performance corroborates the negativity of the rotational strength, but now the most important contributions are due to the peptide bonds formerly neglected. Also for the 2.5 Å coordinates it is learned that in contrast to earlier expectation the influence of the backbone in this hemoglobin is rather strong. A substantial contribution is further obtained for the perturbation by one of the propionic acid carboxylate groups of the heme.

Perspectives and problems of the approach are outlined.