bluuebunny/crossref_metadata_2025_split huggingface dataset:
DNA Content and Fragmentation of the Egg Nucleus of Trichoplax adhaerens
Authors: Ruthmann A. , Grell K. G. , Benwitz G. 
Published: August 2018

Abstract
Under culture conditions the egg nucleus of Trichoplax adhaerens reaches an unusually high and variable DNA content. Before the "fertilization membrane" is formed, the nucleus undergoes fragmentation. It is assumed that culture conditions differ from natural conditions by preventing the switch-over from the S-phase to the G 2-phase of the cell cycle: DNA replication continues and nuclear division is impossible. Cleavage ceases at an earlier or later stage.
Intracelluläre Wirkung von Hydroxyalkenalen auf tierische Tumoren / Intracellular Effect of Hydroxyalkenals on Animal Tumors
Authors: Khoschsorur G. , Schaur R. J. , Schauenstein E. , Tillian H. M. , Reiter M. 
Published: August 2018

Abstract
When incubated for 30 min in vitro, 4-hydroxyalkenals in a 5 x 1 0 ~ 3 m solution react with SH-groups of soluble cytoplasmic and nuclear proteins (ProtL-SH) of Morris hepatomas 9618 A and 5123 tc, and of Ehrlich ascites tumor (EAT) cells. The extent of the reaction strongly increases with decreasing doubling time of the respective tumors. Former experiments with EAT cells have shown that the reaction with cytoplasmic ProtL-SH causes inhibition of respiration, glycolysis, and probably of other SH-controlled processes associated with cell division. The intranuclear reaction leads to an inhibition of DNA-and RNA-synthesis. In a 2 x 10-4 M solution of hydroxyalkenals, however, the reaction with cytoplasmic ProtL-SH diminishes almost completely so that no mea­ surable inhibition of respiration and only 3% inhibition of glycolysis are observed, while 20 to 30 percent of the nuclear ProtL-SH are still blocked. This corresponds well with a previous obser­ vation that a 2 x 10-4 m solution of hydroxypentenal inhibits DNA-synthesis by 90 percent.
In vivo Evidence for a Functional Glycolytic Compartment in Synchronous Yeast Cells
Authors: Postius Stefan 
Published: August 2018

Abstract
The different metabolic behaviour of endogenously produced [1-14C] pyruvate derived from [3,4-14C]glucose and of exogenously added [1-14C]pyruvate were studied with synchronous yeast cell populations, under conditions which differentially influenced the activities of pyruvate decarboxylase in the cytoplasm and pyruvate dehydrogenase in the mitochondria. Endogenously produced [1-14C]pyruvate is decarboxylated almost exclusively by PDC under anaerobic condi­ tions, in contrast to added [1-14C]pyruvate which is decarboxylated under aerobic conditions by the action of PDH mainly. Whereas 14CO 2 evolution from exogenous [l-14C]pyruvate can be diluted proportionally by addition of pyruvate, this is not the case for 14CO 2 evolution from endogenous [1-14C]pyruvate. It is suggested that glycolysis or at least some constituents of it might be arranged in such a manner that the resulting complex behaves as a functional compartment, meaning that it is almost inaccessible to exogenously added pyruvate.
Iridoide aus Clerodendrum thomsonae Balf. f., Verbenaceae / Iridoids in Clerodendrum thomsonae Balf. f., Verbenaceae
Authors: Lammel Gabriele , Rimpler Horst 
Published: August 2018

Abstract
Iridoids, 8-O-Acetylmioporosid, Clerodendrum, NMR, MS Clerodendrum thomsonae Balf. f. has been examined for iridoids. Besides the known compounds melittoside, aucubin, 8-O-acetylharpagide, reptoside and ajugoside a new iridoid, 8-O-acetylmioporoside, has been isolated using SC and HPLC. The structure and relative configuration of the new compound have been determined by spectroscopic methods (1H-NMR, 13C-NMR, MS) and by correlation with mioporoside.
The Effect of Clotrimazole and Triadimefon on 3-Hydroxy-3-Methyl-Glutaryl-CoA-Reductase-[EC 1.1.1.341]- Activity in Saccharomyces cerevisiae
Authors: Berg Dieter , Draber Wilfried , Hugo Hasso von , Hummel Werner , Mayer Dieter 
Published: August 2018

Abstract
Clotrimazole and triadimefon are known as potent inhibitors of ergosterol synthesis in pathogenic yeasts and fungi, respectively. As their mode of action generally the inhibition of sterol desmethylation reactions is accepted. We report about a second effect, a "feed-back" inhibition of 3-hydroxy-3-methyl-glutaryl (HMG)-CoA-reductase by accumulation of ergosterol precursors. Addition of lanosterol to intact cells leads to an inhibition of HMG-CoA-reductase as well, but not to fungistatic effects. From the reported data the influences of clotrimazole and triadimefon have to be considered as an inhibition of desmethylation reactions involved in ergosterol synthesis of yeasts and fungi with a concomitant decreased production of mevalonate.
Ascorbate Oxidase and Its Possible Involvement in Cancer
Authors: Lohmann Wolfgang 
Published: August 2018

Abstract
The electron spin resonance (ESR) spectrum of erythrocytes of a healthy male volunteer exhibited 2 min after intravenous administration of 1 g of ascorbic acid a considerable increase in spin concentration and a new signal at about g = 2.005 which we previously had found to correlate to the semidehydroascorbate (SDA) radical and which is not identical with the O j radical. Moreover, the vitamin C concentration in erythrocytes and plasma was considerably higher than in comparable samples of other volunteers treated identically. In the latter cases, the ESR spectrum of the erythrocytes was not modified at all. These findings suggest that there must be a substance which reacts with ascorbic acid specifically. It can be assumed that the enzyme ascorbate oxidase plays this decisive role in the ascorbic acid metabolism. For this reason, different amounts of ascorbate oxidase have been added to healthy erythrocytes treated in vitro with ascorbic acid and to tissue samples of lung cancer. As expected, the vitamin C effect as expressed by the appearance of the SDA signal and the increase in spin concentration could be reversed. It is suggested, therefore, that in special types of cancer, such as acute lymphatic leukemia and lung cancer, the concentration of ascorbate oxidase or of an enzyme acting like it is, primarily, diminished, while in other types it might be enlarged.
Hydrogen-Deuterium Exchange in Adenosine 5'-Monophosphate Detected by Surface Enhanced Raman Scattering (SERS)
Authors: Koglin E. , Séquaris J. M. , Valenta P. 
Published: August 2018

Abstract
The enhanced Raman effect from 5'-AMP adsorbed on the roughened silver surface is used to characterize hydrogen-deuterium exchange. SERS spectra of 5'-AMP present in H2O and D2O solutions at rather low concentrations were recorded in the spectral range of 2000 to 3500 cm-1. Surface enhanced Raman bands in this spectral range are found to increase in intensity, relative to bands of normal Raman solution spectra. In addition, one notes that the CH and CD stretching vibrations, almost obscured by H2O2 or D2O scattering, now stand out clearly.
Effect of Lectins and Chemical Modification on the Hemagglutinin Activity of Human Plasma Fibronectin
Authors: Vuento Matti , Salonen Eija 
Published: August 2018

Abstract
Purified hum an plasm a fibronectin has been shown to agglutinate protease-treated red cells [Vuento, Hoppe-Seyler's Z. Physiol. Chem. 360, 1327-1333, (1979)]. The present report shows that the activity is inhibited by low concentrations of lectins and by macrom olecular serum factors. Chemical m odification of carboxyl groups of fibronectin strongly inhibited the activity, but modification of am ino groups or guanidinium groups had little effect on the activity. The results suggest that fibronectin receptors on erythrocyte surface are carbohydrate-containing molecules. Humoral m acrom olecular factors may control the interaction of fibronectin with cell surfaces. Chemical m odification studies indicate that the parts of the fibronectin molecule responsible for the hem agglutinin activity are different from those mediating the binding of fibronectin to collagen.
Red Light Induced Change in the Saponin Content of Prolamellar Bodies in Avena sativa
Authors: Müller Mechthild 
Published: August 2018

Abstract
Exposure to red light of high intensities leads to saponin and prolam ellar body degradation in etiolated Avena sativa seedlings. Exposure to red light of low intensities increases the saponin percentage found in prolam ellar bodies w ithout changing the overall saponin content. Proto­ chlorophyllide is assumed to act a decisive p art in the phototransform ation of the PLB as expressed by their saponin content. This is indicated by the action spectrum of this stim ulation as well as by experiments with long-wave red (729 nm) and A LA /LA treatment. In weak light the pchlide phototransformation is decelerated-probably due to lack of energy. The PLB are inter­ preted to be modified by the increased pchlide concentration so that more saponin can be incorporated.
In further experiments a barley m utant (albina f 17) lacking the capacity to esterify phytol as well as the capacity to degrade the PLB during the greening process was investigated. The results substantiate our hypothesis, as PLB transform ation — indicated by PLB saponin concentration — is decelerated with increasing pchlide concentration in greening etioplasts.
Pannarsäure und Porphyrilsäuremethylester — Sekundärstoffe der Flechtengattung Psoroma / Pannaric Acid and Prophyrilic Acid Methyl Ester Lichen Substances in the Genus Psorma
Authors: Renner B. , Henssen A. , Gerstner E. 
Published: August 2018

Abstract
The novel liehen substance porphyrilic acid methyl ester and pannaric acid are reported the first time in the lichen genus Psoroma. They are constituents in the two varieties of the new species Psoroma tenue as well as in members of the Psoroma hypnorum/paleaceum aggr. and in a hitherto underscribed species from the southern hemisphere. Both dibenzofuranes are characterized by mass spectrometry and UV/VIS spectroscopy. A third compound of unknown structure (Ut) has been found additionally in the two varieties of P. tenue and in some specimens of the P. hypnorum/paleaceum group.
Carotenoid Composition of Chlorophyll-Carotenoid-Proteins from Radish Chloroplasts
Authors: Lichtenthaler Hartmut K. , Prenzel Ursula , Kuhn Gertrud 
Published: August 2018

The uneven distribution of carotenoids and chlorophylls between several chlorophyll- carotenoid-proteins isolated from radish chloroplasts by SDS-polyacrylamide-gel electrophoresis is described.
Lutein and neoxanthin are enriched in the light-harvesting chlorophyll a/b-protein LHCP3, which exhibits low chlorophyll a/b ratios (1.1-1.3) and high values for the ratio chloro­phyll a/β-carotene (a/c = 60-180).
β-carotene is bound not only to the chlorophyll a-protein CPI + CPIa of photosystem I, but also to the chlorophyll a-protein CPa. Both chlorophyll a-proteins are characterized by high values for the ratio a/b and low values for the ratio a/c.
Hydroxyrutacridon-Epoxid, ein neues Acridon-Alkaloid aus Ruta graveolens / Hydroxyrutacridone Epoxide, a New Acridone Alkaloid from Ruta graveolens
Authors: Eilert U. , Wolters B. , Nahrstedt A. , Wray V. 
Published: August 2018

Abstract
Hydroxyrutacridone epoxide was isolated from roots and callus tissue cultures of Ruta graveolens L. and identified by spectroscopic methods by comparison to rutacridone epoxide.
Über die Biogenese von Aromastoffen bei Pflanzen und Früchten, XVII* Anabole Leistung von Erdbeerfruchtgewebe bei der Biosynthese von Aromastoffen / On the Biogenesis of Aroma Compounds in Plants and Fruits, XVII * Anabolic Properties of Strawberry Fruit Tissue for the Biosynthesis of Aroma Compounds
Authors: Drawert Friedrich , Berger Ralf G. 
Published: August 2018

Abstract
Slices from ripe strawberry fruit (in shape of segments) metabolize exogenous ʟ-alanine, acetate, pyruvate, n-butyrate, 2-ketovalerianate, n-butanal, n-hexanoate or d,l-mevalonic acid-δ-lactone to yield fruit-typical aroma compounds and some of them to considerable extent. Employing standard-controlled aroma separation by liquid-liquid-extraction, as well as prefrac­tionation on silica gel, the aroma components were determined by GC and GC-MS. Alkyldonors were converted more quickly and selectively than acyldonors, the former resulting in twenty-to thirtyfold increase in some of the concentrations of fruit-esters under specific conditions. The increase in ester biosynthesis ʟ-alanine is directly proportional to the concen­ tration of substrate up to 3 mmol/1. After addition of the above mentioned precursors the con­ centration of (+)-nerolidol, a terpenoid compound o f strawberry aroma, is increased.
The Triton X-100 and High Salt Resistant Residue of Saccharomyces cerevisiae Nuclear Membranes
Authors: Mann Karlheinz , Mecke Dieter 
Published: August 2018

Abstract
Saccharomyces cerevisiae nuclear membranes were prepared from isolated nuclei by digesting chromatin with deoxyribonuclease after an initial treatment of nuclei with very diluted buffers. When the nuclear membranes were treated with 5% Triton X-100 and 1 ᴍ NaCl an insoluble fibrous net was obtained which consisted mainly of protein with Mr values of 85000, 48000, 45000, 39000 and 31000. Lamins, a set of proteins with Mr = 65000-75000, which were shown to be the major proteins of the insoluble nuclear membrane residue of higher eukaryotes, were not found.
Alanine Dehydrogenase from Bacteroids and Free Living Cells of Rhizobium japonicum
Authors: Müller Peter , Werner Dietrich 
Published: August 2018

Abstract
Alanine dehydrogenase (E.C. 1.4.1.1.) from nitrogenase repressed free living cells of Rhizobium japonicum 61-A-101 was purified 370 fold to a specific activity o f 30.4 (μmol pyruvate · min-1 · mg protein-1. The same enzyme from effective bacteroids from nodules of Glycine max var. Mandarin, infected with the same strain was purified 150 fold to a specific activity of 35 units. The enzyme from both preparations was identical in the molecular weight of about 168 kD with four identical subunits of 42 kD. The alanine dehydrogenase is, therefore, different from the same enzyme from Bacillus subtilis (molecular weight 228 kD) and from Anabaena cylindrica (molec­ ular weight 270 kD). The Kᴍ data for the enzyme from Rhizobium japonicum are: 4.7 mmol/l for NH+
4 0.68 mmol/l for pyruvate and 44 μmol/l for NADH. Specific activity of the enzyme in total cell extracts from eight other strains of Rhizobium japonicum (3 effective strains, 5 ineffective strains) was only 20 to 30% o f the activity with strain 61-A-101. No correlation between alanine dehydrogenase activity and nitrogenase activity in these other eight strains was observed. The function of alanine dehydrogenase in Rhizobium japonicum in ammonium assimilation and cell wall differentiation is discussed.
Further Observations on the Source of Nitrogen in Phenazine Biosynthesis
Authors: Römer A. , Herbert R. B. 
Published: August 2018

Abstract
It is concluded from experiments with (S)-[CO15NH2]glutamine and [15N]ammonium sulphate that the biosynthesis of iodinin (1), in Brevibacterium iodinum, and of phenazine-1-carboxylic acid (7), in Pseudomonas aureofaciens, is primarily from a single nitrogen source (glutamine) and that the phenazines are constitued by combination of two units of the same precursor, as. 5. Some observations are made on the inhibition and triggering of iodinin biosynthesis.
Photosynthetic Adaptation in Synechococcus Cells
Authors: Döhler Günter , Leclerc Jean-Claude 
Published: August 2018

Abstract
The cyanobacterium Synechococcus (Anacystis nidulans, strain L 1401-1) grown under different light conditions showed variations in pigmentation. Ratios of photosynthetic pigments and the effect on quantum requirement and oxygen evolution were studied. An increase in the ratio of chlorophyll a forms with absorption maxima in the far red regime to total chlorophyll a forms was observed in cells grown in strong white light. The quantum efficiency of orange light (637 nm) - absorbed by phycocyanin - was higher after growth of Synechococcus in white than
Interrelationship between Quinolizidine Alkaloid Producing Legumes and Infesting Insects: Exploitation of the Alkaloid- Containing Phloem Sap of Cytisus scoparius by the Broom Aphid Aphis cytisorum
Authors: Wink Michael , Hartmann Thomas , Witte Ludger , Rheinheimer Joachim 
Published: August 2018

Abstract
Aphids (Aphis cytisorum) which infest broom plants (Cytisus scoparius) accumulate up to 500 μg alkaloid/g fr. wt. The alkaloids, which are similar to those of the plants, consist of 17-oxo-sparteine, sparteine, 12,13-dehydrosparteine, and lupanine. Infested plants contain > 50% less alkaloids than aphid-free plants. In Lupinus aphid resistance which is due to their high alkaloid content is more expressed: Whereas bitter varieties are free from aphids, only the sweet alkaloid-free plants are susceptible to aphid infestation. The accumulation of alkaloids in aphids indicates that the quinolizidine alkaloids are translocated via the phloem in legume plants. This assumption is supported by direct evidence: analysis of phloem sap from Lupinus contains up to 5 mg alkaloid whereas xylem sap is virtually free of alkaloids. The interrelationship between quinolizidine alkaloids and hervivores is discussed.
Multicomponent Mandibular Gland Secretions in Three Species of Andrena Bees (Hym., Apoidea)
Authors: Bergström Gunnar , Tengö Jan , Reith Wolfgang , Francke Wittko 
Published: August 2018

Abstract
50 volatile constituents of the mandibular gland secretions in males and females of three species of Andrena bees, A. wilkella (Chr.), A. ovatula (K .) and A. ocreata (K .), have been identified. The secretions are made up of a series of spiroacetals of four different systems together with mono-terpenes and unbranched acyclic compounds. Many of the components, particularly several of the dominant ones, occur in both sexes of all three species, so that the volatile secretions are qualita­tively very similar. Females contain about 100 μg per individuum , which is 3-5 times the amount of the males’ secretions. Major spiroacetals are E,E- and Z ,E-2,8-dimethyl-1,7-dioxa-spiro[5.5]undecane and E,E-and Z,E-2-ethyl-7-methyl-1,6-dioxaspiro[4.5]undecane, while prominent monoterpenes are geraniol and citronellol. Straight chain hydrocarbons C17, C19, C21 and C23 occur in fairly large amounts, mostly with increasing concentrations. With respect to the quantitative distribution of components of minor concentration, the bouquet of A. wilkella is clearly distinguishable from A. ovatula and A. ocreata which from the morphological and ethological point of view are more closely related. Behaviour tests with A. wilkella indicate high biological activity of the main spiroacetal.
Conformational Analysis of Benzyloxycarbonyl-Protected Peptides
Authors: Knack Ingo 
Published: August 2018

Abstract
The benzyloxycarbonyl (Z-) residue, an important protecting group in peptide synthesis, was introduced into the input data set of the “Empirical Conformational Energy Program for Peptides” (ECEPP) developed by Scheraga and coworkers. With additional modifications ECEPP is now prepared for conformational analysis of peptides containing this amino end group. Preferred conformations of the Z-residue were studied by performing calculations on Z-Gly methylamide. The results obtained may be applied to the conformational analysis of Z-protected peptides.
Immunochemical Characterization of Porphyridium cruentum B-Phycoerythrin: Proof of Cross-Reaction between Chromophore-Free Apoprotein and Holoprotein-Specific Antibodies
Authors: Sepp Eva , Wanner Gerhard , Eder Jörg , Köst Hans-Peter 
Published: August 2018

Abstract
Antibodies against phycobilisom es of Porphyridium cruentum immunoreact with B-phycoerythrin from the same organism. A strong antigen-antibody complex is not only formed with the native B-phycoerythrin but also when the chromophore is chemically reduced, split or even degraded with chromic acid. Characteristics of precipitations and dissolutions in the presence of the chaotropic reagents urea and potassium rhodanide are discussed for the immunocomplex with native B-phycoerythrin. A sandwich-type immunoadsorbent column appropriate for antigen-isolation is described; its binding properties are investigated biochem ically and by electron microscopy.
Release of K+ and H+ from Poly U in Aqueous Solution upon γ and Electron Irradiation.Rate of Strand Break Formation in Poly U
Authors: Bothe Eberhard , Schulte-Frohlinde Dietrich 
Published: August 2018

Abstract
Conductivity changes were found which followed the reaction of radiolytically generated OH radicals with the potassium salt of polyuridylic acid (poly U) in aqueous solution. After 60Co-γ-irradiation the observed increase of conductivity at pH = 6.8 was shown to consist of the liberation of K+ ions from the stock of K+ ions electrostatically bound to the polyanion. The initial G(K+) is 36 and hence 6 times higher than the G value of OH radicals in N2O saturated solutions. At a poly U concentration of 60 mgl-1 half of the ion release occurred at 12 J kg-1 and nearly all ions are released at 40 J kg-1. The liberation of K+ is explained to be a consequence of the formation of chain breaks leading to an increase of the degree of dissociation.
The rate of the ion release was studied under pulse radiolysis conditions. Because of the high G-vlaue of counterion liberation and the use of conductivity as analytical quantity the method is very sensitive. With 6 mgl-1 poly U the rate could be measured even at a dose per pulse of 0.25 J kg-1. The kinetics of the ion release can be described in terms of two parallel first order reactions of comparable contribution with an average rate constant of 0.8 s-1 at 20 °C, 60 mgl-1 poly U and pH = 6.8 with a small contribution of slower components. In more acidic solutions, besides K+ ions H+ are also liberated since at low pH values bound K+ is replaced by H+. The rate of the ion release was found to increase with increasing replacement of K+ by H+ (kobs = 100 s-1 at pH = 3.4, 60 mgl-1 poly U and T = 18 °C). With potassium ion free poly­ uridylic acid the corresponding rate constant amounted to 220 s-1, nearly independent of pH. From the temperature dependence activation parameters for the ion release were derived (Ea = 57 kJ mol-1, A = 1.0 x 1010 s-1 at pH = 6.8). Addition of p-benzoquinone at pH = 3.7 and dithiothreitol (DTT) at pH 6.8 were found to decrease the size of the conductivity changes and to increase the rate. The results show that p-benzoquinone and DTT react with poly U radicals and that these reactions prevent chain breaks and ion liberation.
It is concluded that the rate determining step of the conductivity increase is the formation of strand breaks by a cleavage of poly U radicals and that this reaction is pH dependent. The pH dependence and the observed value for the activation energy was found to be in agreement with the behaviour of a model system for the earlier postulated C-4′ mechanism for strand break formation of polynucleotides and DNA.