bluuebunny/crossref_metadata_2025_split huggingface dataset:
18O-Exchange by Hydrolyzing Enzymes: An ab initio Calculation
Authors: Rösch Paul , Kalbitzer Hans Robert , Goody Roger S. 
Published: August 2018

Abstract
Enzymes which hydrolyse ATP cause an exchange of 180 of labelled Pi in the presence of ADP. A theory for the evaluation of rate constants from an observation of the time dependence of the concentration of the various Pi species is presented. Application to the 180 exchange catalysed by myosin SI as observed by 31P-NMR shows excellent agreement with values of the rate constants determined earlier.
Fatty Acid Composition of Eggs during Development of the Cotton Leaf-Worm, Spodoptera littoralis Boisduval
Authors: Boctor I. Z. 
Published: August 2018

Abstract
Fatty Acids, Spodoptera littoralis, Eggs Gas-liquid chromatographic analysis of egg lipids during development of Spodoptera littoralis showed the presence of 13 fatty acids ranging in carbon chain length from caproic (C6:0) to linolenic acid (C 18:3). Palmitic, palmitoleic, stearic, oleic and linoleic acids composed over 90% of the total fatty acids. Palmitic acid was always the predominant fatty acid and oleic acid was the second most abundant.
Dependence of Photorespiration and Photosynthetic Unit Sizes on Two Interdependent Nuclear Gene Factors in Tobacco
Authors: Schmid Georg H. , Bader Klaus P. , Gerster Richard , Triantaphylides Christian , André Marcel 
Published: August 2018

Abstract
A new set of tobacco mutants was obtained by selfing a single variegated plant which emerged in a seed lot of Nicotiana tabacum var. Consolation. The seeds obtained from this mutant give rise to four phenotypes: variegated, yellow, yellow-green, and green seedlings. The green, yellow-green and yellow characters are due to two interdependent nuclear gene factors. The yellow-green phenotype is the homozygous (aabb) true breeding condition, whereas the green and the yellow phenotype are heterozygous (AaBb) with respect to both nuclear factors, the difference in the yellow and green phenotype being the addition of a labile gene factor pair, Cc, in the yellow condition. If photorespiration is measured as the Warburg effect or as 180 2-consumption by mass spectrometry it appears that the heterozygous green phenotype is the defective condition with high photorespiration. The three phenotypes differ with respect to chlorophyll content and photosynthetic unit sizes, the photosynthetic unit size in the yellow phenotype being approxi­ mately 1/10 of that of the green type. The gene expression for photorespiration (measured as 180 2-uptake for example) in the heterozygous green type is suppressed by the addition of the labile gene factor pair Cc in heterozygous condition which leads to the yellow phenotype. In the yellow and green phenotype the photosynthetic unit size is different but not the ratio of photosys­ tem I/photosystem II activity. Moreover, from the present studies it appears that the Warburg effect i. e. an increase of photo­ synthetic rate upon anoxia, can only partly be due to an inhibition of ribulose 1,5-biphosphate oxygenase or glycolate oxidase.
The Permeability Coefficients of the Plasmalemma and the Chloroplast Envelope of Spinach Mesophyll Cells for Phytohormones
Authors: Gimmler H. , Heilmann B. , Demmig B. , Hartung W. 
Published: August 2018

Abstract
The uptake of auxin (LAA), abscisic acid (ABA) the synthetic cytokinin benzylaminopurine (BA), gibberellic acid (GA3) and mevalonic acid (lactone) (MVA) into intact chloroplasts and protoplasts from spinach mesophyll cells was measured and the permeability coefficients Ps of the chloroplast envelope and the plasmalemma were calculated. With all solutes tested uptake and P s values were considerably higher in the chloroplast system than in the protoplast system. At an external pH of 7.0, rates of uptake exhibited the order BA > LAA > MVA > ABA > GA3 in both systems. However, the P s values (corrected for the undissociated species of the solutes) exhibited the order LAA > GA3 > (ABA or BA) > MVA. This corrected sequence indicates the theoretical capacity of penetration under the assumption that preferentially the protonated species of phytohormones are capable of readily penetrating membranes. P s values for phytohormones appeared largely to be determined by the distribution coefficient K d and to a lesser extent by the molecular weight (Mr). In the Collander-plot the relation between the logarithm of Ps values for phytohormones and some other solutes such as acetate, glycerol, glucose, sorbitol and sucrose and the logarithm of K J M T 1.5 approached linearity.
7-Hydroxytropolon aus Pseudomonas sp. [1] / 7-Hydroxy Tropolone from Pseudomonas sp. [1]
Authors: Korth H. , Pulverer G. , Römer A. , Budzikiewicz H. 
Published: August 2018

Abstract
7-Hydroxy Tropolone, Bacterial Constituents, Pseudomonas sp. Structure elucidation and antibiotic activity of 7-hydroxy tropolone -a metabolite from Pseudomonas sp. — is reported.
Inhibition by Cyclic Guanosine 3':5'-Monophosphate of the Soluble DNA Polymerase Activity, and of Partially Purified DNA Polymerase A (DNA Polymerase I) from the Yeast Saccharomyces cerevisiae
Authors: Eckstein Hans 
Published: August 2018

Abstract
Dedicated to Professor Dr. Joachim Kühnau on the Occasion of His 80th Birthday cGMP, DNA Polymerase Activity, DNA Polymerase A, DNA Polymerase I, Baker's Yeast DNA polymerase activity from extracts of growing yeast cells is inhibited by cGMP. Experiments with partially purified yeast DNA polymerases show, that cGMP inhibits DNA polymerase A (DNA polymerase I from Chang), which is the main component of the soluble DNA polymerase activity in yeast extracts, by competing for the enzyme with the primer-template DNA. Since the enzyme is not only inhibited by 3',5'-cGMP, but also by 3',5'-cAMP, the 3': 5'-phosphodiester seems to be crucial for the competition between cGMP and primer. This would be inconsistent with the concept of a 3'-OH primer binding site in the enzyme. The existence of such a site in the yeast DNA polymerase A is indicated from studies with various purine nucleoside monophosphates.
When various DNA polymerases are compared, inhibition by cGMP seems to be restricted to those enzymes, which are involved in DNA replication. DNA polymerases with an associated nuclease activity are not inhibited, DNA polymerase B from yeast is even activated by cGMP. Though some relations between the cGMP effect and the presumed function of the enzymes in the living cell are apparent, the biological meaning of the observations in general remains open.
Photosynthetic Assimilation of 15N-Ammonia and 15N-Nitrate in the Marine Diatoms Bellerochea yucatanensis (von Stosch) and Skeletonema costatum
Authors: Döhler Günter , Roßlenbroich Hans-Jürgen 
Published: August 2018

Abstract
14C-and 15N-Assimilation, 15N-Labelled Amino Acids, M arine D iatom s The marine diatoms Bellerochea yucatanensis and Skeletonema costatum were grown at +20 °C in 0.03 vol.% CO2 with nitrate or ammonia. The 15N -am m onia and 15N -nitrate assim ila­ tion and 15N -incorporation into various amino acids were studied of both diatom s during exponential growth phase in dependence of different nitrogen conditions. In all experiments the 15N -am m onia uptake was lower than the 15N -nitrate assim ilation rate up to 20-40 min photo­ synthesis. N itrate lim itation -cells grown in nitrate followed by growth in nitrogen-free m edium for 24 h — caused a strong 15N-label into aspartate after adding 15NH 4C1 (1 m M). In cells grown in nitrate highest enrichment of 15N was found in glutamine. Results were discussed with reference to the operating of the GS/GOGAT system and glutam ic acid dehydrogenase pathway. Photosynthetic 14CO2 fixation experiments showed a very high labelling of aspartate which was interpreted with a phosphoenolpyruvate carboxylation catalysed by phosphoenolpyruvate carb-oxykinase.
C4-Metabolism in Marine Brown Macrophytic Algae
Authors: Kremer Bruno P. 
Published: August 2018

Abstract
Photosynthesis, D ark Fixation, β-Carboxylation, C 4-M etabolism , Brown Algae Marine brown macroalgae including Macrocystis integrifolia, Nereocystis luetkeana, Lessoniop-sis littoralis, Laminaria saccharina, Fucus serratus and some further representatives of the Laminariales and Fucales (Phaeophyta) have been investigated with respect to their remarkably high potential for β-carboxylation of phosphoenolpyruvate supplem enting photosynthetic CO2 fixation. Kinetic tracer studies indicate that 14C-labelling of C4 acids such as aspartate and malate is not restricted to dark periods, but also occurs during photosynthesis. Rates of carbon fixation into C4 compounds are approxim ately equal in the light and in the dark. Distribution of 14C between C 1 and C4 atoms of aspartate suggests carbon flow from early occurring photosynthates such as 3-phosphoglycerate to C4 compounds including aspartate and malate. In brown macro­ algae dark carbon fixation via β-carboxylation of phosphoenolpyruvate is therefore assumed to be quantitatively and qualitatively integrated into photosynthetic CO2 assimilation thus yielding appreciable 14C-labelling of C4 dicarboxylic acids. The underlying reactions and conversions are basically different from C4 photosynthesis and should preferably be term ed as C4 metabolism.
Nonlinear Polarisationoscillations in a Biophysical Model System II: External Dynamics
Authors: Szabo Z. , Kaiser F. 
Published: August 2018

Abstract
Nonlinear Polarisationoscillations To describe a metastable electric dipole state in a biological system, Fröhlich suggested a nonlinear model potential. In this paper we investigate a system of two nonlinear dipoles, which are coupled by a dipole-dipole interaction. We apply an external field and add linear damping terms. The external drive leads to a phase-locking of the dipoles. Mathematically, the system corresponds to an externally driven anharmonic oscillator with damping. We investigate the system of coupled oscillators and look for the stable and metastable solutions as a function of the internal and external parameters.
Specific Localization of β-ᴅ-Glucoside Conjugates of 2,4-Dichlorophenoxyacetic Acid in Soybean Vacuoles
Authors: Schmitt R. , Sandermann H. 
Published: August 2018

Cell suspension cultures of soybean (Glycine max L.) were incubated with [14C]-2,4- dichlorophenoxyacetic acid (62 h, 27 °C). The cells were converted to protoplasts by use of the cell-wall degrading enzymes, Driselase and pectinase. This procedure resulted in the release of the cellular amino acid conjugates as well as part of the free 2,4-dichlorophenoxyacetic acid and of the β-ᴅ- glucoside conjugates.
A vacuole fraction was obtained by mild osmotic shock in 10% yield, and was characterized by its polypeptide composition. The purified vacuoles were enriched in β-ᴅ-glucoside conjugates, free 2,4-dichlorophenoxyacetic acid being only a minor vacuolar constituent, and amino acid conjugates not being detectable.
Dissociation of FAD from the NAD(P)H-Nitrate Reductase Complex from Ankistrodesmus braunii and Role of Flavin in Catalysis
Authors: De la Rosa Miguel A. , Márquez Antonio J. , Vega José M. 
Published: August 2018

Ankistrodesmus braunii NAD(P)H-nitrate reductase is a complex hemoflavomolybdoprotein composed by eight similar subunits. The flavin prosthetic group, identified as FAD, is essential for the NAD(P)H-dependent activities of the complex, and is located before the heme chromo- phore in the enzyme electron transport chain from reduced pyridine nucleotides to nitrate.
Fluorescence studies indicate that nitrate reductase can dissociate about 80% of its FAD by incubation at room temperature, the flavin dissociation being followed by a parallel decrease of NADH-nitrate reductase activity. Dissociation of FAD from the protein is easily increased by dilution or prolonged dialysis of the enzyme preparations. However, exogenous FAD specifically prevents the dissociation of enzyme-bound flavin, and protects the NAD(P)H-dependent activities. The Km for FAD, as a protector of NADH-cytochrome c reductase activity, is 4 nᴍ. In addition, dithioerythritol also prevents the flavin dissociation, and therefore the presence of free sulphydryl groups in the FAD-domain is suggested.
FAD-depleted nitrate reductase, obtained by several methods, is unable to recover its original activity when incubated in the presence of FAD alone or with thiols.
Effect of Aging on the Fluorescence Lifetime of Chloroplasts
Authors: Brody S. S. 
Published: August 2018

Abstract
The lifetime of fluorescence from pea chloroplasts at room temperature increases with age. The ratio of the fluorescence intensities of the slow to fast decay components, decreases with age o f the chloroplasts. This observation can account for the wide range of lifetimes reported in the literature. The variability of biological material (cultured and prepared with similar procedures) introduces considerable variation in the fluorescence lifetimes measured with pea chloroplasts.
Sonication of chloroplasts results in an increase in both the fast and slow fluorescence lifetimes.
Distribution and Effects of Bentazon in Crop Plants and Weeds
Authors: Lichtenthaler H. K. , Meier D. , Retzlaff G. , Hamm R. 
Published: August 2018

Abstract
The inhibition of photosynthetic CO2-assimilation and of the variable chlorophyll fluorescence as well as uptake and transport of 14C-labelled bentazon and the possibilities for a herbicideinduced shade-type modification of the photosynthetic apparatus were investigated in bentazonsensitive weeds (Galium, Sinapis, Raphanus) and in the tolerant crop plants wheat and maize.
1. In weeds the depression of photosynthetic CO2-assimilation is irreversible, whereas tolerant plants recover due to the metabolization of the active herbicide.
2. A lower rate of uptake and transport of bentazon associated with its fast metabolization is the reason for the tolerance of crop plants towards bentazon.
3. The transport of [14C]bentazon proceeds in the tracheary elements of the xylem. Uptake and transport of bentazon in the weeds are light dependent.
4. The loss of variable fluorescence (Kautsky effect) in the leaves after root application o f bentazon proceeds much faster at high-light than at low light conditions and confirms the light-dependency of the bentazon transport.
5. In the sensitive dicot weeds bentazon not only inhibits photosynthetic electron flow and depresses CO2-fixation but also induces the formation of shade-type chloroplasts which are less efficient in photosynthetic quantum conversion. This bentazon-induced modification of the photosynthetic apparatus (e.g. changes in ultrastructure, pigment ratios, and levels of chloro-phyll-proteins) contributes to the effectiveness of bentazon as a herbicide.
Mechanism of Bleaching in Leaves Treated with Chlorosis-Inducing Herbicides
Authors: Feierabend Jürgen , Winkelhüsener Theresia , Kemmerich Petra , Schulz Ulrike 
Published: August 2018

Abstract
Bleaching of chlorophyll was studied in the leaves of rye seedlings (Secale cereale L.) treated with four chlorosis-inducing herbicides of different potency (weak photodestructions, group 1: aminotriazole, haloxidine; strong photodestructions, group 2: San 6706, difunone). Chlorophyll deficiency and particularly the inactivation of a chloroplast marker enzyme, NADP-dependent glyceraldehyde-3-P dehydrogenase, that occurred in the presence of group 2 herbicides were stronger in red, than in blue, light.
When grown in white light of low intensity (10 lx) herbicide-treated leaves contained chloro­ phyll, 70 S ribosomes and unimpaired activities of NADP-dependent glyceraldehyde-3-P de hydrogenase. At 10 lx only the leaves treated with SAN 6706 and difunone were strongly carotenoid-deficient but not those treated with group 1 herbicides. After all herbicide treatments 10 lx-grown leaf tissue was, however, not capable of photosynthetic O2-evolution indicating some disorder of photosynthetic electron transport. Leaf segments grown at 10 lx were exposed to a high light intensity of 30000 lx at either 0 ° C or 30 °C. In treatments with group 1 herbicides chlorophyll accumulation was stopped in bright light at 30 °C but breakdown was not apparent. Only at 0 °C and in the presence of high, growth-reducing, herbicide concentrations chlorophyll was slightly degraded. The RNAs o f the 70S ribosomes were, however, clearly destroyed at 30000 lx and 30 °C in aminotriazole-treated leaves. In leaves treated with group 2 herbicides chlorophyll was rapidly degraded at 30000 lx both at 0 ° C and 30 °C, however, only in the presence of O2, indicating a true photooxidative and mainly photochemical nature o f the reactions involved. This chlorophyll breakdown was accompanied by the photodestruction of 70S ribosomes and the inactivation of NADP-glyceraldehyde-3-P dehydrogenase.In treatments with group 1 herbicides photoinactivation of the latter enzyme did not occur, although it was clearly localized in the bleached plastids, as demonstrated by gradient separation of organelles.
In the presence of group 2 herbicides the chlorosis was originating from a direct photo­ oxidation of chlorophyll, accompanied by a massive destruction of other plastid constituents and functions. In treatments with group 1 herbicides photodestructions appeared to be much weaker and insufficient to affect chlorophyll directly. Mediated through some photodestructive inter­ ference with obviously more sensitive plastid components, such as their ribosomes, further chlorophyll accumulation was, however, prevented.
Malonate and Krebs Cycle Intermediates Utilization in the Presence of other Carbon Sources by Rhizobium japonicum and Soybean Bacteroids
Authors: Werner Dietrich , Dittrich Walburga , Thierfelder Heidemarie 
Published: August 2018

Abstract
Free living cells of Rhizobium japonicum 61-A-101 and bacteroids from Glycine max var. Mandarin infected with the same strain utilized malonate with a substrate saturation greater than 10-2 mol/l. At low concentrations of malonate (10-5 mol/1) the free living cells were significantly more active in utilizing malonate than bacteroids. In bacteroids two substrate saturation ranges were found, one between 3 x 10-4mol/l and 10-3 mol/l, the other at more than 10-2 mol/l. Utilization of malonate was not affected by 10 to 100 times larger concentrations of either arabinose or xylose. 10-3 mol/l succinate inhibited the utilization of malonate (10-4 mol/l) completely in bacteroids, and by 90% in free living cells. Succinate utilization (10-4 mol/1) was reduced in those cells exposed to 100 times higher malonate concentration only by 20-30% . Utilization and incorporation of pyruvate and 2-oxoglutarate into bacteroids was also only slightly affected by 100 times larger malonate concentration. Citrate utilization by bacteroids however was reduced by more than 70%. The rate of endoxidation of malonate as sole carbon source (14CO2 production from [2-14C] malonic acid)was about 1.5 μmol · h-1 • mg protein-1 and about half the rate with Pseudomonas putida and 70% o f the rate with Pseudomonas fluorescens under the same conditions (pH 6.0, 28 °C).
Coupled Gas Chromatography — Single Cell Recording: a New Technique for Use in the Analysis of Insect Pheromones
Authors: Wadhams Lester J. 
Published: August 2018

Abstract
A method is described for the continuous biological monitoring of the effluent from a high resolution gas chromatographic column using a single cell recording technique. The system can be used to provide precise information on the retention times of compounds with olfactory activity that are not detected with a coupled gas chromatograph - electroantennogram system.
"Memory" of First Interaction with Physiological or Biologically Active Foreign Molecules (Benzpyrene, Gibberelline) in a Unicellular ( Tetrahymena) Model System
Authors: Csaba G. , Németh G. , Vargha P. 
Published: August 2018

Abstract
Gibberelline, prednisolon and benzpyrene stimulated the growth of Tetrahymena at the first interaction, while epinephrine did not. On a second exposure following upon the first 24 h treatment after a rest period of 6 h, epinephrine, too, developed a stimulatory action, and the other three molecules gave rise to a still greater increase in the growth rate. Obviously, imprinting effected by the first interaction accounts for a greater responsiveness to physio­ logical materials (hormones) also if these are indifferent in respect of the given function, and non-physiological, but biologically active materials can also give rise to imprinting in exposed target cells.
Über Nervenwachstumsfaktoren, IX [1] N GF aus menschlicher Glandula submandibularis / On the Nerve Growth Factor (NGF) from Human Glandula submandibularis
Authors: Riemschneider R. , Dembélé F. , Ghouri I. A. K. 
Published: August 2018

Abstract
The properties of human nerve grwoth factor (NGF) from Glandula submandibularis were examined and char­ acterized. The results closely resemble those of NGF from bovine and swine.
Model Reactions for the Degradation of DNA-4′ Radicals in Aqueous Solution. Fast Hydrolysis of α-Alkoxyalkyl Radicals with a Leaving Group in β-Position Followed by Radical Rearrangement and Elimination Reactions
Authors: Behrens Günter , Koltzenburg Günther , Schulte-Frohlinde Dietrich 
Published: August 2018

Abstract
α-Alkoxyalkyl radicals with a leaving group L = Cl or OCOCH3 in β-position are produced by H-abstraction from the corresponding saturated substrates by ·OH, SO·
4
- or (CH3)3CO· radicals. From ESR spectroscopic observations it is concluded that in aqueous solution at pH 5 -9 the following fast hydrolysis reactions take place:

The rate constants of these reactions and for the hydrolysis of CH3O-ĊH-CH2Cl are k ≥ 106 s-1, whereas the rate constant for CH3O-ĊH-CH2OCOCH3 was determined to be ≈ 2 × 103 s-1 at room temperature. The radicals with L = Cl cannot be scavenged by O2 which fact leads to a value of k ≥ 2 × 10-7 s-1. α-Alkoxyalkene radical cations are assumed as intermediates in the hydrolysis reactions. The radicals with L = OCOCH3 and the radical CH3O--ĊH-CH2Cl are observable in acetone solution ESR spectroscopically.
In aqueous solution at pH below 3 proton catalyzed reactions are observed by ESR spectroscopy:

Radicals resulting from H-abstraction at the CH3O-groups of the substrates or at the 5-positions of the cyclic ethers are also observed. The ESR parameters and the pH-ranges of existence of the above radicals are given. Support of the reported reactions comes from quantitative analysis of stable products such as H+, Cl- or CH3OH after 60Co-γ-irradiation of N2O saturated aqueous solutions of the substrates.
The behaviour of the radicals is used as a model to describe a modified version of the degradation of DNA-4′ radicals in aqueous solution in the absence of oxygen.
Composition of Phospholipids in Seed Oil of Jojoba (Simmondsia chinensis [Link], Schneider)
Authors: Gülz Paul-Gerhard , Eich Claudia 
Published: August 2018

Abstract
Phospholipids from Jojoba oil were isolated in amounts of 0.16%. The following phospholipids were identified: phosphatidylcholine 45%, phosphatidylethanolamine 38%, phosphatidylinositol 10% and phosphatidylglycerol 7%. The fatty acid composition is similar in all individual phos­ pholipids. Palmitic acid and oleic acid are the dominating fatty acids.
Das ätherische Öl aus Blüten von Artemisia vulgaris L. / On the Essential Oil Components from Blossoms of Artemisia vulgaris L.
Authors: Michaelis Karl , Vostrowsky Otto , Paulini Hubert , Zintl Robert , Knobloch Karl 
Published: August 2018

Abstract
By use of GC and GC-MS analysis more than 70 compounds, mainly mono- and sesquiterpenes, were structurally identified from the essential oil from blossoms of Artemisia vulgaris L. A distinct seasonal dependence of oil production was observed.