bluuebunny/crossref_metadata_2025 huggingface dataset:
An Audiospectrographic Study of Male Stridulation in the Genus Corixa Geoffr. (Hemiptera, Corixidae)
Authors: Finke Christine , Prager Joachim
Published: August 2018

The stridulation signals of three species of the Genus Corixa were investigated especially with respect to their spectral composition. Thee dominant frequencies are: 2.7 kHz for C. panzeri, 2.2 kHz for C. dentipes and 2.0 kHz for C. punctata. For C. punctata the threshold frequency responses, especially for one (A1) of both receptor units of the mesothoracic tympanic organ, correspond well to the frequency spectrum of the emitted sounds.
The Para-O-Methylation of Apigenin to Acacetin by Cell-Free Extracts of Robinia pseudoacacia L.
Authors: Kuroki Gary , Poulton Jonathan E.
Published: August 2018

Crude extracts from young Robinia pseudoacacia seedlings, shoots, and callus tissue catalyze the para-O-methylation of apigenin to acacetin using S-adenosyl-ʟ-methionine as methyl donor. Optimum activity was exhibited at pH 9.0, and Mg2+ was not required for maximum activity. EDTA (10 mᴍ) did not affect the reaction rate, but 47% inhibition was observed with SAH (100 μᴍ). β-Mercaptoethanol (5 mᴍ) was required in the homogenization medium for optimum O-methyltransferase activity. Apigenin (Km, 50 μᴍ) was the best substrate, but significant activity was shown towards caffeic acid, 5-hydroxyferulic acid, naringenin, and quercetin. Paracoumaric, ferulic, and sinapic acids were not methylated. The Km for S-adenosyl-ʟ-methionine was 31 μᴍ. Our demonstration of a para-O-methyltransferase activity methylating apigenin, but not para-coumaric acid, strongly supports the conclusion that the B-ring methylation pattern of acacetin is determined at the C15-level in Robinia pseudoacacia.
Influence of Crystal Packing Forces on Molecular Structure in 4-Thiouridine. Comparison of anti and syn Forms
Authors: Lesyng Bogdan , Saenger Wolfram
Published: August 2018

4-thiouridine crystallizes from butyric acid in the form of yellow needles, monoclinic space group P21 with a = 10.136 (3), b = 4.843 (2), c = 11.257 (3) Å, β = 93.91 (5) °. The crystal structure was solved on the the basis of 895 X-ray counter data using direct methods and refined to a reliability index of R = 5.6%. 4-thiouridine is in the anti conformation, the torsion angle O(1′)-C(1′)-N(1)-C(6) being 26.5°. Pseudorotation parameters τmax = 41.1° and P = 15.7° refer to C(3′)-endo (3E) envelope form of the ribose. The conformation about the C(5′)-O(5′) bond is gauche, gauche.

The present structure is compared with the previous one, crystallized from water as sesquihydrate and existing as the syn conformer (W. Saenger and K. H. Scheit, J. Mol. Biol. 50, 153-169 (1970). The influence of crystal packing forces on flexible molecules such as nucleosides is discussed.
Effect of Vanadate and Iron Stress on the Pigment Composition of Chlorella fusca
Authors: Becker Ludwig J. M. , Meisch Hans-Ulrich
Published: August 2018

The pigment composition of Chlorella fusca has been investigated in the absence and in presence of vanadate and during iron stress.

1. Fe-deficiency generally decreases algal pigment content without change of the ratio chlorophyll a/b.

2. A twofold vanadate induced increase of the chlorophylls is accompanied by a similar enhancement of several xanthophylls, while lutein remains unaffected.

3. Vanadate stimulates the formation of β-carotene up to 5 fold, the effect being less obvious during iron stress
Radiation Damage to Polypeptides and Proteins in the Solid State: Changes in Amino Acid Composition *
Authors: Seredynski J. , Söylemez T. , Baumeister W.
Published: August 2018

Thin layers of synthetic homopolypeptides (poly-α-Ala, -Arg, -Asn, -Asp, -Glu, -His, -Lys and -Tyr) and proteins (myoglobin, concanavalin A, trypsin-inhibitor) were irradiated under solid state conditions in an electron microscope with 100 keV electrons. Radiolytic changes were investigated by amino acid analysis. The results are discussed in terms of the relative radiosensitivities of the constituent amino acids, and possible topochemical effects on the sensitivity pattern emerging. An attempt is also made to trace at least some of the predominant pathways of amino acid transformation, namely the production of alanine and a-aminobutyric acid
Anpassung von Kleinwinkelröntgenspektren durch eine nicht-lineare Regressionsanalyse
Authors: Schilling V. , Jonak R. , Nemetschek Th. , Riedl H. , Pöppe Chr. , Schwander E.
Published: August 2018

A method for fitting of background-based curves is described whereas, with it’s aid, the peakpositions and areas in fitted spectrum sought, are easily located
Mammalian pheromone studies, IV*. Terpenoid Compounds and Hydroxy Esters from the Dorsal Gland of the Springbok, Antidorcas marsupialis
Authors: Burger B. V. , Roux Maritha le , Spies H. S. C. , Truter Verona , Bigalke R. C.
Published: August 2018

Acyclic terpenoid compounds, aldehydes, ketones, hydroxy esters, and dimethyl sulphone were identified in the dorsal exudate of the antelope Antidorcas marsupialis. The novel diterpenes α- and β-springene, found in this exudate, were synthesised from famesyl acetone
Mammalian Pheromone Studies, V*. Compounds from the Preorbital Gland of the Grysbok, Raphicerus melanotis
Authors: Burger B. V. , Roux Maritha le , Spies H. S. C. , Truter Verona , Bigalke R. C. , Novellie P. A.
Published: August 2018

A series of straight chain ketones, saturated, unsaturated, and doubly unsaturated alcohols, saturated and unsaturated formiates, hexanal, formic acid, and a number of long chain fatty acids have been identified in the preorbital secretion of the grysbok, Raphicerus melanotis
Light-Induced Accumulation and Stability of Chlorophylls and Chlorophyll-Proteins during Chloroplast Development in Radish Seedlings
Authors: Lichtenthaler H. K. , Burkard G. , Kuhn G. , Prenzel U.
Published: August 2018

Illumination of 3 day old etiolated radish seedlings with continuous white light results in a progressive accumulation of chlorophyll a and b. Both pigments are bound in a different way to the thylakoid chlorophyll-proteins, which appear parallel to the formation of chlorophylls. By applying the SDS-PAGE method to SDS-digested chloroplasts, it was possible to show that the chloroplasts of radish cotyledons contain the typical chlorophyll proteins LHCP1-3, CPa, CPI and CPIa which have been found in other plants. Between LHCP1 and CPI an additional chlorophyll protein is detected with the spectral properties of a LHCP; it is termed here LHCPy.

When the green plants are transferred to continuous darkness, chlorophylls and the chlorophyll-proteins are progressively degraded. At an early stage of greening chlorophyll b is destroyed at a much higher rate in darkness than chlorophyll a, which yields high chlorophyll a/b ratios. This is paralleled by a faster decrease in the level of the corresponding chloro­phyll a/b-protein LHCP3 than of CPI. At a later stage of greening, after the end of the logarithmic chlorophyll accumulation, the chlorophylls a and b and also the LHCP3 and CPI are destroyed in continuous darkness at equal rates; the a/b ratios and the LHCP3/CPI ratios are then little different from the light control.

The data indicate that at an early stage of greening the light-harvesting chlorophyll a/b-protein LHCP3 is less stable than the other chlorophyll-proteins (CPI, CPIa, CPa), which contain pre­ dominantly chlorophyll a.

The ratio chlorophyll a to β-carotene (a/c ratio) of CPIa, CPI and CPa is about 10, while that of the LHCP1-3 is found to be between 150 to 300. We therefore propose using the a/c ratio to define the chlorophyll-proteins which, besides the absorption spectra, is the most suitable parameter.
The Kok Effect and Its Relationship to Photorespiration in Tobacco
Authors: Ishii Ryuichi , Schmid Georg H.
Published: August 2018

The Kok effect of photosynthesis was investigated in different tobacco mutants. It was found that the breaks in the light intensity curve were always at or around 1000 lux in all plants tested regardless of the unit sizes which differed by a factor of 10. It was concluded that the photo­ receptor responsible for the effect must be present in the wild type and the chlorophyll deficient mutants in the same amount and is probably not chlorophyll. Due to the fact that the light dependency of the Hill reaction in isolated tobacco chloroplasts also shows a break at or around the “Kok intensity” it was concluded that probably a structural change of the photochemical apparatus around 1000 lux contributes to the effect. Measurement of 180 2-uptake by mass spectrometry at low light intensity shows at low CO2-concentration an enhancement of 180 2-uptake again at/around 1000 lux indicating that photorespiration starts to function at the “Kok intensity”. Due to the fact that 180 2-uptake remains constant at high CO2-concentrations the break in the photosynthetic light intensity curve cannot be due to an inhibition of “dark respiration” at low light intensities.
Stoffwechselprodukte des 1.2.4-Trihydroxybenzols aus Fruchtkörpern von Gomphidius maculatus und G. glutinosus (Boletales) [1] / Metabolites of 1,2,4-Trihydroxybenzene from Fruiting Bodies of Gomphidius maculatus and G. glutinosus (Boletales) [1]
Authors: Jägers Erhard , Steffan Bert , Ardenne Renata von , Steglich Wolfgang
Published: August 2018

From fruiting bodies of Gomphidius 2,2′,4,4′,5,5′-hexahydroxybiphenyl (7) and a red pigment, gomphilactone (1), have been isolated. The latter may be derived biogenetically from 1,2,4-trihydroxybenzene (6) via oxidative dimerization to 3,5′-dihydroxydibenzoquinone (8) followed by Postemak rearrangement.
Electroreceptors and Direction Specific Arrangement in the Lateral Line System of Salamanders?
Authors: Fritzsch Bernd
Published: August 2018

The arrangement of the lateral line afferents of salamanders as revealed by transganglionic staining with horse­ radish peroxidase is described. Each lateral line organ is supplied by two fibers only. In the medulla these two afferent fibers run in separate fiber bundles. It is suggested, that only those fibers contacting lateral line sensory cells with the same polarity form together one bundle. Bundles formed by anterior or posterior lateral line afferents are also clearly separated. Beside the lateral line organs smaller pit organs are described. These organs are supplied by one afferent only which reveals an arrangement in the medulla different from that of the lateral line afferents. Based on anatomical facts, these small pit organs are considered to be electroreceptors. Centrifugally projecting neurons, most probably efferents, are described in the medulla.
18O-Exchange by Hydrolyzing Enzymes: An ab initio Calculation
Authors: Rösch Paul , Kalbitzer Hans Robert , Goody Roger S.
Published: August 2018

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

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

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

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

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

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

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

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

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.
Energy Transfer Inhibition Induced by Nitrofen
Authors: Huchzermeyer Bernhard
Published: August 2018

The herbicide nitrofen was shown to act as an energy transfer inhibitor. The results proved nitrofen to act by inhibiting nucleotide exchange on the chloroplast coupling factor. A strong correlation was found between the inhibition of phosphorylation, ATPase activity, and nucleotide exchange. These results are discussed in terms of a regulatory effect of tightly bound ADP on the enzymatic activity of the chloroplast coupling factor.
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.
Chemical Aspects of the Mutagenic Activity of the Ascorbic Acid Autoxidation System
Authors: Kalus Werner H. , Filby William G. , Münzner Ruth
Published: August 2018

It has been proposed that the mutagenic activity associated with the ascorbic acid autoxidation system may involve hydrogen peroxide and peroxide radicals. We report here that the mutagenic effect may also partially reside in as yet unknown secondary products. The observed mutagenicity of 2,3-diketogulonic acid, one of the main oxidation products, reflects its ability to form hydrogen peroxide.
Investigation of Large Intramolecular Movements within Metmyoglobin by Rayleigh Scattering of Mössbauer Radiation (RSMR)
Authors: Krupyanskii Yu. F. , Parak F. , Goldanskii V. I. , Mössbauer R. L. , Gaubman E. E. , Engelmann H. , Suzdalev I. P.
Published: August 2018

This paper reports Rayleigh scattering experiments on metmyoglobin crystals and freeze dried myoglobin which was exposed to air with different partial pressure of water vapor. While dry myoglobin shows no fluctuations between conformational substates such “breathing modes” are rearly seen in water covered myoglobin. Larger amounts of water increase the average mean square displacements. In crystals the dynamic behaviour is hindered by the crystal packing. The results are analysed by a theory describing the motion within the molecule by a Langevin equation with restoring forces corresponding to a square well potential.
On the Free Radical-Induced Aggregation of Ribonuclease — A Pulse Radiolysis Study Using the Light Scattering Detection Method
Authors: Seki H. , Schnabel W.
Published: August 2018

The aggregation of bovine ribonuclease (RNase) induced by either ·OH or Br•̅
2 radicals has been studied. These radicals, which were generated by pulse radiolysis of aqueous solutions with 16 MeV electrons, readily attack the enzyme thus producing RNase-radicals which subsequently combine. At initial radical concentrations low enough (≤ 0.1 radical per enzyme molecule) to prevent multimerizations other than dimerization, rate constants for the latter process were determined from the increase of the light scattering intensity after the pulse: 2 k2 = (2.2 ± 0.3) 106 l/mol s (Br•̅
2 initiated dimerization) and (5.4 ± 0.4) 106 l/mol s (·OH initiated dimerization). The G-values for dimerization are: 1.3 (Br•̅
2)and 0.85 (·OH). Transient optical absorption measurements revealed the existence of phenoxyl radicals of tyrosine (TyrO·) that decayed with a rate constant of 2 k2 (total) = (5.5 ± 0.7) 106 l/mol s (Br•̅
2 )-case). The difference between k2 and k2 (total) presumably indicates the occurrence of disproportionation.
Dark Oxidation of Unsaturated Lipids by the Photoxidized 8-Methoxypsoralen
Authors: Potapenko A. Ya. , Moshnin M. V. , Krasnovsky A. A. , Sukhorukov V. L.
Published: August 2018

8-Methoxypsoralen (8-MOP) in ethanol, acetone, benzene, or CCl4 is photoxidized under UV- irradiation (320-400 nm). Photoxidized 8-MOP (O2-8-MOP) is stable in the organic solvents, but it is destructed in water or in liposome suspension. The destruction rate constants are 0.04 s-1 in water and 0.004 s-1 in liposome membranes as estimated by the kinetics of the chemilumin­escence accompanying the destruction. In course of O2-8-MOP destruction the residues of phospholipid unsaturated fatty acids are oxidized. Generation of the singlet oxygen (1⊿g) by excited 8-MOP is observed neither in acetone, nor in ethanol. Quantum yield of 1⊿g formation in CCl4 is less than 3%. A pattern is proposed for 8-MOP-sensitized oxidation of unsaturated lipids proceeding without direct attack of lipids by singlet oxygen.
Studies on 18O2-Uptake in the Light by Entire Plants of Different Tobacco Mutants
Authors: Ishii Ryuichi , Schmid Georg H.
Published: August 2018

Photorespiratory activity was measured in entire plants of five tobacco variants. These tobacco variants are: the green type N. tabacum var. John William’s Broadleaf (su/su Aur/aur or su/su Aur/Aur) the chlorophyll-deficient tobacco mutant Su/su (Su/su Aur/Aur) and the chlorophyll- deficient mutant Su/su var. Aurea (Su/su Aur/aur). Furthermore, two recently characterized phenotypes originating from N. tabacum var. Consolation namely “consolation green” (Aa Bb) and “consolation yellow-green” (aa bb). In entire plants of these phenotypes photorespiration was measured as 18O2-uptake in the light. This uptake was compared with the enhancement of CO2- fixation in the Warburg effect i. e. when the oxygen partial pressure is lowered from 21% Oz to 3% O2. The principal conclusion from these measurements is firstly that under the assay conditions which are identical for all 5 phenotypes (330 ppm CO2, 14000 lux white light and 25 °C) all five phenotypes yield considerable differences in photorespiratory activity. Furthermore, we were able to show that in the different phenotypes the global O2-uptake in the light is repartitioned to different degrees among different metabolic pathways. Thus, in JWB which is under the assay conditions the only fast growing species, only half of the measured 18O2-uptake belongs to glycolate metabolism or photorespiration proper, the other half belongs to a Mehler type reaction in which excess reducing power is eliminated apparently already at the level of photosynthetic electron transport. In the chlorophyll-deficient mutant Su/su, however, the observed 18O2-uptake in the light belongs under the assay conditions exclusively to glycolate metabolism (no Mehler type reaction). The chlorophyll-deficient mutant Su/su var. Aurea behaves more like JWB, that is, part of its 18O2-uptake is due to a Mehler type reaction and only the remainder is involved in CO2- metabolism, which has been already found out previously by genetic analysis. In addition photorespiration depends in Su/su more on the temperature than in the other phenotypes tested. One of the implications of our results could be that it makes a difference to the plant whether excess reducing power is disposed of at the level of the photosynthetic electron transport chain (via a Mehler type reaction) or at the level of CO2-metabolism.
Flavonol 3-O-MethyItransferase in Plant Tissues
Authors: De Luca Vincenzo , Brunet Gunter , Khouri Henry , Ibrahim Ragai , Hrazdina Géza
Published: August 2018

Flavonol 3-O-methyltransferase activity has been de­tected in Calamondin orange peel and root tissue, tobacco cell culture and young shoots of Chrysosplenium americanum. The enzyme was purified from the latter tissue by precipitation with ammonium sulphate, ion-exchange chro­matography and finally by chromatofocusing on Poly- buffer exchanger at pi 4.8. The focused enzyme exhibited strict stereospecificity towards quercetin, MW of 65000 daltons and pH optimum of 7.5-8.5. The apparent Km values for quercetin and S-adenosyl-ʟ-methionine were 1.4 and 70 μM, respectively.
Degradation of the Isoflavone Biochanin A by Fusarium javanicum
Authors: Willeke Ulrike , Barz Wolfgang
Published: August 2018

After a lag-phase of 1 h a mycelial Suspension of Fusarium javanicum completely degraded 5,7-dihydroxy-4'-methoxyisoflavone (biochanin A) to a series of transiently accumulating catabolites. The compounds were elucidated by spectroscopic techniques and are arranged in the first known degradative pathway for an isoflavone: biochanin A → dihydrobiochanin A → 3-(p-methoxyphenyl)-4,6-diketo-5,6-dihydro-4H-pyran → p-methoxyphenylacetic acid → p-hy- droxyphenylacetic acid → 3,4-dihydroxyphenylacetic acid → CO2. The carbon atoms of bio­chanin A not accounted for by this sequence are discussed in relation to microbial flavonoid pathways.
Effect of Aging on the Fluorescence Lifetime of Chloroplasts
Authors: Brody S. S.
Published: August 2018

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

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

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

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

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.
B-Decachloro-o-carborane Derivatives Suitable for the Preparation of Boron-Labeled Biological Macromolecules
Authors: Gabel Detlef , Walczyna Rita
Published: August 2018

B-decachloro-o-carborane derivatives in which one of the carbon atoms was substituted by -CH2CH2CO2H (I), -CH2CHOHCH2-O-CH2CH=CH2 (II) and -CH2CHOHCH2-O-p-C6H4NHCOOC(CH3)3 (III) were prepared from decachloro-o-carborane and the corre­sponding bromo (I) or epoxi (II and III) derivatives under alkaline conditions. II could be epoxidized and bound to dextran, Concanavalin A, and human IgG, with a boron content of 4.3, 4.8. and 4.9% (w/w), respectively. III could be converted to the corresponding amine and further to the isothiocyanate. Such boron derivatives could be suitable compounds for neutron capture therapy of tumors, as they are well water soluble and could be attached to tumor spe­cific antibodies.
"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

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

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

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

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

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.
Tetrapyrrol Derivatives Shown by Fluorescence Emission and Excitation Spectroscopy in Cells of Rhodopseudomonas capsulata Adapting to Phototrophic Conditions
Authors: Beck Jürgen , Drews Gerhart
Published: August 2018

Aerobically in the dark grown cells were incubated semiaerobically (30 min) and afterwards 180 min anaerobically in the light During phototrophic induction the bacteriochlorophyll concentra­ tion increased from 0.26 to 2.10 nmol/mg cell protein.

In samples taken at different times after lowering of oxygen partial pressure the following tetrapyrrol derivatives were identified by fluorescence emission and excitation spectroscopy at 1.7 K: Mg-protoporphyrin EX-monomethylester, Mg-2,4-divinylphaeoporphyrin a5-monomethylester, 2-de-vinyl-2 -hydroxyethyl-chlorophyllide, 2 -devinyl-2 -hydroxyethyl-pheophorbide, chlorophyllide a, pheophorbide, bacteriopheophorbide, bacteriopheophytin, bacteriochlorophyllide and bacte­ riochlorophyll a in different pigment complexes. The highest relative concentrations of bacte­ riochlorophyll precursors normalized to the total amount o f bacteriochlorophyll a were found in cells during the first hour of adaptation at 0.5 μg Bchl/mg cell protein or less.
On the Occurrence of Monoacylglycerol Derivatives in Lipid Metabolism of Chloroplasts
Authors: Sauer Andreas , Heise Klaus-Peter
Published: August 2018

The aim of this investigation was to elucidate the rapid synthesis o f monogalactosyl mono­ glycerides and their role as intermediary acyl-acceptors in galactolipid synthesis of spinach chlo­ roplasts. The problem was attacked by studying the incorporation o f sn-[14C]glycerol-3-phosphate and [l-14C]acetate into the lipid fraction o f gently shocked and reconstituted preparations. The data revealed: 1 . a concurrent accumulation o f both monoglycerides and monogalactosyl monoglycerides under acidic incubation conditions, with C16-fatty acid species predominating, 2 . similarities in the fatty acid incorporation of both monoacyllipids, 3. the occurrence o f two isomeric forms viz. 1 -and 2-O-acyl-isomers o f these lipids. Thus, it appears that monogalactosyl monoglycerides are synthesized by galactosylation o f mo­ noglycerides rather than by galactolipase hydrolysis. Both monoacyllipids are likely to be derived from the corresponding lysophosphatidic acids by dephosphorylation. Their fatty acid incorporation pattern therefore may contribute to an under­ standing of the specific esterification o f different fatty acids at the Ct-and exp osition of the gly­ cerol moiety of galactolipids. Analysis o f the specific acylation o f monoglycerides and monogalac­ tosyl monoglycerides as well as the nature of the acyl donors involved in this fatty acid transfer yielded the following observations: 5. The position of the fatty acids within the monoacyllipids seems to depend on whether acyl-ACP or acyl-CoA is the primary acyl donor. 6 . The characteristics of the fatty acid incorporation into monoglycerides and their galactosylated derivatives support the notion that a successive acylation o f sn-glycerol-3-phosphate occurs first in the C2-and then in the Q-position. 7. In contrast, the chain length o f the fatty acids incorporated seems to be determined by such fac­ tors as pH and the concentration o f sn-glycerol-3-phosphate. This observation suggests that these parameters may act by controlling the elongation o f ACP-bound C16-fatty acids to their C18-species.
Possible Models of Murein and Their Fourier Transforms
Authors: Formanek Helmut
Published: August 2018

Murein, Models, Fourier Transforms Murein, the rigid layer of the cell walls of almost all bacteria can be regarded as derivative of chitin. Within the sterically allowed region its polysaccharide chain can perform conformations with two-to threefold screw axes. Two dimensional Fourier transforms calculated from different possible conformations have been compared with data of density measurements, X-ray and electron diffraction. The Fourier transform of murein with a chitin-like conformation of the poly­ saccharide chain and an elementary cell of 4.5 × 10.4 × 21.5 Å3 provides the best agreement with the experimental results.