bluuebunny/crossref_metadata_2025_split huggingface dataset:
Notizen: Isolierung und Strukturaufklärung von 2′-Hydroxy-4′, 6′dimethoxychalkon-4-glukosid aus Viscum album L. / Isolation and identification of 2′-hydroxy-4′, 6′ -dimethoxy-chalkon-4-glucoside of Viscum album L.
Authors: Becker Hans , Exner Joachim , Schilling Gerhard 
Published: August 2018

Abstract
A hitherto unknown chalkon (2′-hydroxy-4′,6′-dimethoxy-chalkon-4-glucoside) of European mistletoe (Viscum album L.) has been isolated and identified.
Notizen: Terpenic Constituents of Asarum
Authors: Hayashi N . , Sdiolichin M. , Komae H. , Sakao T. 
Published: August 2018

Abstract
Terpenic constituents of 23 species of subgenus Heterotropa growing in Japan were analyzed by means of gaschromatograph-mass spectrometer. Thirteen sesquiterpenes were identified from the essential oils together with fourteen monoterpenes. It is found that all species of Heterotropa contain considerable amount of mono- and sesqui-terpenes in the oils.
Notizen: Physical Parameters and Possible Regulation of ζ-Aminolevulinic Acid Synthetase
Authors: Nandi Dhirendra L. 
Published: August 2018

Abstract
Physical measurements were made on the ζ-aminolevulinic acid synthetase from Rhodopseudomonassph eroides. These include a Stokes radius of 3.8 nm, determined by gel filtration, and sedimentation coefficient of 5.46 S by sucrose density gradient centrifugation. From these measurements and the value of partial specific volume of 0.732 ml/g deter­mined from the amino acid composition, the following physical constants were calculated: molecular weight, 88000; diffusion coefficient, 5.65 × 10-7 cm2 s-1 ; frictional ratio, 1.30; axial ratio, 5.0. The enzyme is inhibited by more than 50% by glyceraldehyde 3-phosphate (1 mᴍ) , pyruvate (0 .02 ᴍ) , α-ketoglutarate (0.02 ᴍ) , urea (0 .8 ᴍ) , CoCl2 (0.2 mᴍ) and hemin (5 µᴍ). The effect of these inhibitors on the possible regulation of this enzymic activity is discussed.
Stained Native Collagen: Interpretation of the Small Angle X-ray Scattering and Electron Microscopic Pictures in Terms of the Primary Structure
Authors: Meyer Helmut , Kilian Hanns-Georg 
Published: August 2018

Abstract
The average axial electron-density distribution of stained collagen fibers derived from X-ray small angle pattern, is shown to be substantially related to the projection of the polar amino acid residues onto the axis of the microfibril taking into consideration the staggering of neighbouring molecules. In order to arrive ultimately at a quantitative representation of the experimental data, an additional periodic fluctuation of the density in necessity of this regular microphase structure for an of collagen fibers will be indicated .
Acetylcholinesterase aus dem Gift von Bungarus multicinctus. Reinigung und Eigenschaften/The Acetylcholinesterase of Bungarus multicinctus Venom. Purification and Properties
Authors: Großmann H. , Weinert M. , Liefländer M. 
Published: August 2018

Abstract
Acetylcholinesterase from Banded krait (Bungarus multicinctus) venom has been purified by CM-Sephadex chromatography and affinity chromatography to a specific activity of 4290 U/mg. The purified enzyme is a glycoprotein. It is free of electrophoretically detectable contaminating proteins. A molecular weight of 140 000 ± 5 000 has been determined by gradient gel electrophoresis for the native enzyme. It is split into two equal-sized subunits (Mr 70 000 ± 2 000) by SDS treatment. The N-terminal amino acid analysis gave glycine and serine. The purified acetyl­ cholinesterase can be resolved by disc gel electrophoresis into four and by isoelectric focusing into six isozymes. The pI value of the main isozyme has been found to be 5.98 ± 0.05.
Assimilatory Nitrate Reductase of Rhodopseudomonas capsulata AD2: A Molybdo-Hemeprotein
Authors: Alef Kasem , Klemme Jobst-Heinrich 
Published: August 2018

Abstract
The assimilatory nitrate reductase of the phototrophic bacterium Rhodopseudomonas capsulata strain AD2 was purified to homogeneity by a combination of ammonium sulfate fractionation, chromatography on DEAE-cellulose and isoelectric focusing (isoelectric point of 4.8). The purified enzyme was active only with reduced viologen dyes or reduced flavin as electron donors. Contrary to other bacterial assimilatory nitrate reductases, the enzyme was not inhibited by chlorate, but rather accepted this substance as an alternate substrate. The molecular weight of the enzyme was 185 000 dalton as determined by gelfiltration. Subunit analysis by sodium dodecyl sulfate (SDS) gel electrophoresis yielded a single protein band with a molecular weight of 85 000 dalton, sug­gesting that the enzyme was composed of two identical subunits. The nitrate reductase contained 0.8 g-atoms molybdenum per 1.85 X 105 g protein and exhibited absorption maxima at 418, 523 and 552 nm in the reduced state (dithionite as reductant). The nitrate reductase of Rps. capsulata AD2 is the first prokaryotic enzyme of the assimilatory type that has been shown to contain heme.
Evidence for the Existence of meta and para Directing O-Methyltransferases in Tobacco Cell Cultures
Authors: Tsang Yun-Fuk , Ibrahim Ragai K. 
Published: August 2018

Abstract
The O-methyltransferase of tobacco cell culture was resolved to its meta and para directing forms by chromatography on DEAE-cellulose. Despite similarities in molecular weights and pi values of the two forms, however, evidence from pH optima, SH-group inhibitors, methylation ratios, SDS-acrylamide gels and mixed substrate experiments indicates the existence of two discrete enzymes acting at the meta and para positions of caffeic acid and quercetin, respectively; though the latter enzyme was less substrate specific than its meta counterpart.
Search for Millimeter Microwave Effects on Enzyme or Protein Functions
Authors: Tuengler P. , Keilmann F. , Genzel L. 
Published: August 2018

Abstract
Recent observations of nonthermal, resonant biological responses to weak millimeter microwave irradiation have led us to investigate whether similar influences exist on enzymatic functions in vitro. We chose (i) the reduction of ethanol in the presence of alcohol dehydrogenase and (ii) the cooperative binding of oxygen on hemoglobin. Using an irradiation intensity near 10 mW/cm2 the frequency was continuously varied from 40 to 115 GHz with a resolution of a few MHz. No micro­ wave influences were detectable within our experimental sensitivity of about 0.1% of the reaction rate in (i), or of the amount of bound oxygen at half saturation in (ii).
Characterization of an Endogenous Transcription Inhibitor from Physarum polycephalum
Authors: Hildebrandt Armin , Mengel Rudolf 
Published: August 2018

Abstract
A substance has been purified from isolated nuclei of Physarum polycephalum by equilibrium and velocity gradient centrifugations, ion exchange chromatography and gel filtration which has a high molecular weight, can be labeled in vivo with 32P, is heat stable and resistant to amylases, proteases, nucleases and phosphodiesterase but is sensitive to phosphatases or hydrolysis. This material consists of phospate and glycerol. It selectively inhibits in vitro transcription of RNA polymerases, predominantly the homologous enzyme A by binding to the enzyme. In the presence of this inhibitor of transcription a stable RNA polymerase-template complex cannot be formed. Binding to and inactivation of RNA polymerase is reversible at high ionic strength.
Die in vitro und in vivo Stabilität des Einschlusses von Methotrexat in negativ geladenen Liposomen nach Sterilfiltration/The in vitro and in vivo Stability of the Entrapment of Methotrexate in Negatively Charged Liposomes after Sterile Filtration
Authors: Freise J. , Magerstedt P. , Schmidt F. W. 
Published: August 2018

Abstract
The preparation of sterile artificial liposomes (phosphatidylcholine: cholesterol: dicethylphos-phate = 5:5:1) by Millipore® filtration is described. Conditions for storing liposome entrapped Methotrexate have been found which allow storage of the drug in the entrapped form over a period of at least 4 months. It is shown that intravenously injected liposome entrapped Metho­trexate is retained for at least 15 hours in the particulate form. During this time no free Methotrexate is detectable in the blood.
Accessibility of Extracellular Space in the Rhabdome of the Living Isolated Retina of the Crayfish
Authors: Schröder W. , Stieve H. , Classen-Linke I. 
Published: August 2018

Abstract
Diffusion of the tracer enzyme horseradish peroxidase (HRP) into the extracellular spaces of living isolated crayfish retinas was monitored by light-and electronmicroscopic identification of the reaction product obtained after immobilisation of the enzyme by fixation. During the incubation in enzyme containing saline (up to 3 hours) the extracellularly recorded electroretinogram (ERG) stayed normal and showed no substantial change. The reaction product of the enzyme HRP was found only extracellularly in the space between the microvilli in the rhabdome.
The results indicate an exchange of substances via extracellular pathways between the extra­ cellular side of the photosensory membrane and the bathing fluid in the living isolated crayfish retina.
Some Properties of the DCMU-Binding Site in Chloroplasts
Authors: Tischer Wolfgang , Strotmann Heinrich 
Published: August 2018

Abstract
Binding of the triazinone derivative metribuzin to thylakoid membranes was studied in depend­ence of temperature and trypsin pre-treatment of the chloroplasts. The temperature curve of the binding constant suggests that the lipid phase of the membrane contributes to inhibitor binding. Trypsin pre-treatment of the membranes removes the receptor sites for the inhibitor, while the trypsin effect on the affinity of the receptor to the inhibitor is marginal. Concomitantly trypsin treatment releases the inhibitory effect of metribuzin on the electron transport from DPC to DCPIP.
The Mode of Action of Photosystem II-Specific Inhibitors in Herbicide-Resistant Weed Biotypes
Authors: Pfister Klaus , Arntzen Charles J. 
Published: August 2018

Abstract
This report reviews studies which provide evidence defining the mode of action and site of action of photosystem II (PS II) herbicides; the involvement of the secondary electron carrier on the reducing side of PS II (called B) is indicated as the target site for these compounds. These studies of the action of PS II-inhibitors were performed in chloroplasts of various weed species in order to define the mechanism which is responsible for herbicide tolerance at the level of chloroplast membranes in newly discovered triazine-resistant weed biotypes. Many species of triazine-resistant weed biotypes have been collected in North America and Europe. Where data is available, these plants have been found to share the following common features:
a) they were discovered in areas where triazine herbicides had been used repeatedly,
b) resistance to the triazines is extreme; it is not due to a minor shift in herbicidal response,
c) no changes in herbicide uptake, translocation or metabolism - as compared to susceptible biotypes - can be detected,
d) resistance is selective for only certain classes of photosynthetic herbicides, and,
e) chloroplasts isolated from triazine-resistant weeds display high preferential resistance to the triazines in assays of photosystem II partial reactions.
To focus on the mechanism which regulates preferential herbicide activity, we have characterized susceptible and resistant chloroplasts in the presence and absence of herbicides. Properties of the PS II complex of chloroplasts from several different triazine-resistant weed biotypes share the following traits:
a) the herbicide binding site (as measured by direct binding of radiolabeled herbicides or by inhibition experiments) is modified such that the affinity for triazines is dramatically reduced.
b) alterations in response to many PS II-herbicides occur such that the triazine-resistant chloroplasts are very strongly resistant to all symmetrical triazines, strongly resistant to assymmetrical triazinones, partially resistant to pyridazones and uracils, only slightly resistant to ureas or amides, and increasingly susceptible to nitrophenols, phenols and the herbicide bentazon (all as compared to susceptible chloroplasts),
c) there is a change in the reaction kinetics of the electron transport step between the primary and secondary electron acceptors (referred to as Q and B ), and
d) in two examples, specific small changes in a membranepolypeptide can be detected in the resistant thylakoids.
We suggest that certain amino acids or segments of the apoprotein of B (the bound quinone which acts as the secondary electron carrier) are modified or deleted in these chloroplasts. Such a polypeptide change could affect both the redox poising of the Q-/B reaction pair, and the specific binding of herbicides.
Ethane Formation and Chlorophyll Bleaching in DCMU-Treated Euglena gracilis Cells and Isolated Spinach Chloroplast Lamellae
Authors: Elstner E. F. , Pils Irene 
Published: August 2018

Abstract
Light dependent chlorophyll bleaching and ethane formation in Euglena gracilis cells at slightly acidic pH values above 5.2 are enhanced by DCMU and other photosystem II blockers. Excited chlorophyll under conditions of limited energy dissipation seems to be the oxidant for ω-3 unsaturated fatty acids, yielding ethane and other (ethylene, “malondialdehyde”) oxidation products, cooxidizing chlorophyll.
Degradation and Metabolization of Lindane and Other Hexachloro- cyclohexane Isomers by Anaerobic and Aerobic Soil Microorganisms
Authors: Haider K. 
Published: August 2018

Abstract
Microbial Metabolization of Hexachlorocyclohexane, Anaerobic and Aerobic Microorganisms, Dechlorination of Hexachlorocyclohexane Microbial degradation of lindane or other hexachlorocyclohexane isomers has been observed to occur more rapidly in flooded than in upland soils. Experiments with a mixed bacterial flora enrich­ ed anaerobically from soils showed a rapid dechlorination and degradation of lindane. Screening studies with pure bacteria indicated that Clostridium spp. and several representatives of Bacillus spp. and Enterobacteriaceac effectively degraded lindane, while representatives of Lactobacillaceae and Propionibacterium were inactive. During degradation organic bound chlorine was released as chloride and nearly chlorine-free, partly volatile metabolites were formed. The chloride formation was promoted by the addition of glucose, pyruvate or formate.
Lindane was the most easily degraded isomer, while α-and especially β-and δ-hexachlorocyclo-hexane was also, but more slowly, dechlorinated. These isomers are relatively frequently observed as environmental contaminants, their occurrence might be caused by their greater persistence or / and by an isomerization of the γ-into α-and other isomers during microbial incubation as it was discussed by several authors. Experiments, however, whether or not this isomerization can be carried out by microbes, were negative or showed that it only can occur to a very minor extent.
Aerobic degradation of lindane proceeded only slowly and chiefly by formation of chlorinated aromatic compounds. One of the main intermediate metabolites seemed to be γ-pentachlorocyclo-hexene which was further transformed by the release of HCl or hydrogen and by addition of water. During anaerobic incubation, γ-tetrachlorocyclohexene intermediately occurred which was further dechlorinated to nearly chlorine-free compounds.
Inhibitory Effects of the Insecticides Allethrin, Lindane, and Jacutin-Fogetten Sublimate on Photosynthetic Electron Transport
Authors: Wild Aloysius 
Published: August 2018

Abstract
The inhibitory effects of the insecticides Allethrin, Lindane, and Jacutin-Fogetten sublimate on photosynthetic electron transport of broken chloroplasts were tested. 50 μmol l-1 Allethrin caused an inhibition of 80% of the benzoquinone and ferricyanide Hill-reactions. 39 μmol l-1 Lindane inhibited the basal, coupled and uncoupled electron transport to ferricyanide up to 35%. The precipitate formed by the sublimation of Jauctin-Fogetten containing Lindane depressed electron transport much more than pure Lindane. 50 μg ml-1 of the sublimate led to an 80% inhibition of ferricyanide Hill-reaction.
The Influence of Different Solvents on the Interaction between Metal Ions and Tetracycline
Authors: Schnarr Manfred , Matthies Michael , Lohmann Wolfgang 
Published: August 2018

Abstract
The interaction of the antibiotic tetracycline with a few metal ions, esp. Cu(II), in different so l­ vents has been investigated by means of IR, ESR, and UV /VIS spectroscopy. It could be shown that the site of complexation depends on the solvent used. In DMSO the interaction occurs mainly via the A ring. In water (pH = 5.7) and octanol, the A chromophore as well as the BCD entity of the molecule are involved in complexation. If the tetracycline concentration exceeds the Cu(II) concentration, a 2 : 1 (antibiotic : Cu(II)) complex seems to be formed, at least in DMSO.
Catalytic Subunit of Adenosine Cyclic 3',5' Monophosphate- Dependent Protein Kinase from Rat Muscle: Basic Properties and Factors Influencing the Activity
Authors: Pyerin Walter , Gagelmann Michael , Kübler Dieter , Kinzel Volker 
Published: August 2018

The catalytic (C) subunit of isoenzyme II of cyclic AMP-dependent protein kinase from rat muscle, purified to apparent homogeneity, was investigated for some of its basic properties and factors that influence its activity. The properties were found to resemble those of C subunits of both isoenzymes I and II from various other tissues of different species. This concerns the molecular weight estimate (about 37 k), ultraviolet light absorption spectrum, isoelectric point (pH 9.0 ± 0.2), the apparent KM values for histone and protamine (for both substrates ≤ 10 μᴍ) and the apparent KM for cosubstrate ATP (3-4 μᴍ). The enzyme is sensitive to the heat- stable inhibitory protein.
The enzyme activity is stable up to 40 °C but becomes destroyed at higher temperatures; the half life at 50 °C is slightly less than 1 min, and at ≥ 60 °C activity is nullified within 1 min. Activity is lost on freezing and thawing. Substrate histone does not improve temperature stability; cosubstrate ATP in absence of Mg2+ decreases, but in presence of Mg2+ increases stability. The optimum pH of enzyme activity is at pH 6.8 for histone and pH 7.8 for protamine phosphoryla­tion. The enzyme becomes irreversibly inactivated at pH values below 5. For activity, the enzyme has absolute requirement for a divalent metal ion, highest activity is found in presence of Mg2+ or Co2+; the optima are at 5-10 mᴍ (half maximum at 0.9 mᴍ) and 0.5-0.8 mᴍ (half maximum at 0.25 mᴍ) for Mg2+ and Co2+, respectively. None of the various other metal ions tested were nearly as effective as these two. Ca2+ antagonized Mg2+. A considerable effect on activity by ionic strength was observed. In dependence on the substrate used, activity is influenced strongly by some anions and zwitterions. E. g. in presence of acetate, histone phosphorylation is by a factor of 3-4 higher than in presence of sulfate, whereas protamine phosphorylation is only half that in presence of sulfate. Roughly the following order of enzyme activity in presence of the respective buffer system was found: MOPS (100%) ≥ TES (95%) ≅ HEPES > MES (65%) ≅ acetate ⪢ ADA (20%) > phosphate (15%) > TRIS • maleate (7%).
Evidence for the Existence of Two β-Carotene Pools and Two Biosynthetic β-Carotene Pathways in the Chloroplast
Authors: Grumbach K. H. 
Published: August 2018

Abstract
Two β-Carotene pools were obtained in the chloroplast. It is concluded that one pool is very small like α-carotene and responsible exclusively for the biosynthesis of β-ionone-xanthophylls. The other β-carotene pool is proposed to be the one, that is located close to photosystem I and is involved in photosynthesis as a light protecting agent for chlorophylls against photo-oxidation. Furthermore evidence is given that both β-carotene pools are synthesized by independent biosyn thetic pathways.
Photosensibilisierung isolierter Mesophyllzellen von Calystegia sepium L. / Photosensibilization of Isolated Mesophyll Cells of Calystegia sepium L.
Authors: Ries P. , Beiderbeck R. 
Published: August 2018

Abstract
Cell division of isolated mesophyll cells of Calystegia sepium can be made sensitive to long-wave UV (LUV) by treatment with 8-methoxypsoralen (8-MP). The inhibition of cell division de­ pends on 8-MP concentration and the length of light exposure. Only the simultaneous presence of 8-MP and LUV gives effective photosensibilization. Cells treated with 8-MP in the dark can be made non-sensitive to LUV by washing out the furocoumarin prior to irradiation. The furocoumarins may offer a means of cell selection.
Inhibition of Photosynthetic Electron Transport in Tobacco Chloroplasts and Thylakoids of the Blue Green Alga Oscillatoria chalybea by an Antiserum to Synthetic Zeaxanthin
Authors: Lehmann-Kirk Ursula , Bader Klaus P. , Schmid Georg H. , Radunz Alfons 
Published: August 2018

An antiserum to synthetic Zeaxanthin inhibits photosynthetic electron transport on the oxygen-evolving side of photosystem II in tobacco chloroplasts and thylakoids of the filamentous blue-green alga Oscillatoria chalybea. The inhibition site lies for both species between the site of electron donation of water or tetramethyl benzidine and that of diphenyl carbazide or manganese II ions. Typical photosystem I reactions are not impaired by the antiserum. The effect of the antiserum concerning the inhibition site is practically identical to that of the earlier described antiserum to violaxanthin. However, the degree of inhibition seems to be generally somewhat lower with the antiserum to Zeaxanthin, than with that to violaxanthin which hints at a lesser accessibility of zeaxanthin, in the tylakoid membrane in comparison to violaxanthin.
In the course of these investigations new evidence was obtained that the oxygen-evolving side of the electron transport scheme is differently organized in Oscillatoria chalybea when compared to tobacco chloroplasts. Thus, the silicomolybdate reduction with water as the electron donor is sen­sitive to DCMU in these algae.
On the Role of Light in the Mating Behavior of Drosophila subobscura
Authors: Pinsker Wilhelm , Doschek Elfriede 
Published: August 2018

Unlike other related species wild flies of Drosophila subobscura require light for successful ma­ting. Two explanations for the influence of light on the reproductive behavior could be suggested:
1)Light increases sexual activity.
2)Light mediates the transmission of visual courtship elements.
In order to decide this question the mating success of wild-type and mutant flies was tested at light of different wave-lengths. It turned out that mutant flies with reduced ommochrome compo­nent of the eye pigment were not able to copulate at wave-lengths above 570 nm whereas the other strains still copulated at wave lengths close to the limit of their spectral sensitivity. Since spectral sensitivity of the photoreceptors is assumed to be the same in all strains tested the difference in mating success must be ascribed to effects caused by the lack of pigment. Thus an investigation of the optomotor response was carried out. It revealed that mating success is clearly correlated with the ability to discriminate contrast. From this result it can be concluded that the exchange of visual signals and not merely the perception of light is essential for the courtship of Drosophila subobscura. Optical stimuli may be important at two different stages of mating behavior: at the begin­ning, when the male is activated by the sight of a female, and during the wing dance, where the movements of the partners are coordinated optically.
The Role of 5-Hydroxymarmesin in the Bioge­nesis of Bergapten
Authors: Dall’Acqua F. , Innocenti G. , Caporale G. , Rodighiero P. , Guiotto A. 
Published: August 2018

Abstract
5-hydroxymarmesin administered to leaves of Ficus carica and to cut ends of Ruta graveolens has been efficaciously and selectively converted into bergapten while no radioactivity was observed in the other isolated furocoumarins.