bluuebunny/crossref_metadata_2025_split huggingface dataset:
De novo Synthesis and Levels of Cytochrome c and a Biliprotein during Pupal-Adult Development of a Butterfly, Pieris brassicae
Authors: Kayser Hartmut 
Published: August 2018

Abstract
Using a sensitive pH-difference spectroscopic method in combination with a three-column procedure of ion-exchange chromatography (overall yield 94%) the levels of cytochrome c in the large white butterfly, Pieris brassicae, were determined from the last larval instar to the adult insect. In the larva cytochrome concentration reached a maximum at mid instar and sub­sequently decreased to very low values in the pupa. During adult development the level of cytochrome c increased 50-fold in males and 43-fold in females; this sexual difference was expressed only after adult emergence. Biliverdin IXγ which occurs as a specific biliprotein complex was accumulated during the last larval instar and also in young butterflies. De novo synthesis of heme c, biliverdin IXγ and the corresponding apoproteins was demonstrated in newly emerged butterflies by injections of radiolabeled 5-aminolevulinate, lysine, leucine, and succinate, respectively. Cycloheximide inhibited labeling of both apoproteins and of heme c to 90% but that of the bilin to only 25%. This suggests that in cytochrome c but not in the biliprotein formation of the holoprotein depended on a coordinated synthesis of both constituents. In­corporation of 5-aminolevulinate into the biliprotein exceeded that into cytochrome c sevenfold indicating that biliverdin IXγ is the major product of the heme pathway in P. brassicae. The results are discussed in relation to the formation of mitochondria and flight muscles during postembryonic development of insects.
Surface Pressure Hysteresis of Mixed Lipid/Protein Monolayers: Applications to the Alveolar Dynamics
Authors: Mutafchieva Rada , Panaiotov Ivan , Dimitrov Dimiter S. 
Published: August 2018

Abstract
Mixed Lipid/Protein Monolayers, Alveolar Surfactant, Monolayer Models Experimental data on surface pressure-surface area hysteresis of mixed serum albumin/dipal-mitoyl lecithin/sphingomyelin monolayers in the Langmuir trough are presented. Several possible physicochemical mechanisms of the hysteresis are discussed: Marangoni effect, surface pressure relaxations, bulk-to-surface diffusion interchange, and collapse. Depending on the concrete conditions each of these mechanisms can be important. Possible applications of these results to the alveolar dynamics are presented and discussed on the basis of the balloon model of the alveolus. The main conclusions of biological importance are that 1) the alveolar stability depends on the DPL/SM ratio as well as on the protein content. Under normal breathing conditions the surface pressure hysteresis is small and does not play a decisive role in the alveolar dynamics. 2) At large extent of compression the collapse predominates in determining the hysteretic behavior of the alveolar surface.
Produktion pflanzlicher C6-Wundgase und ihre Wirkung auf einige phytopathogene Pilze / Production of C6-Wound Gases by Plants and the Effect on Some Phytopathogenic Fungi
Authors: Urbasch Irene 
Published: August 2018

Abastract
The production of C6-wound gases by cultivated and wild tomato plants (Lycopersicon esculenium Mill., L. hirsutum Humb. et Bonpl., L. peruvianum (L.) Mill., L. pimpinellifolium Mill., L. glandulosum C. H. Muller) and the tree tomato (Cyphomandra betacea (Cav.) Sendtn.) was investigated. The genuine mixture of compounds and the single compounds showed antifungal properties against the phytopathogenic fungi Botrytis cinerea Pers., Rhizoctonia solani Kühn, Fusarium oxysporum f. sp. lycopersici (Sacc.) Snyder & Hansen, Didymelia lycopersici Kleb, and Cladosporium fulvum Cooke.
Absorption Spectra of Phytochrome Intermediates
Authors: Eilfeld Peter , Rüdiger Wolfhart 
Published: August 2018

Native phytochrome (124 kdalton) was isolated from etiolated seedlings of Avena sativa L. cv. Pirol (Baywa, Munich). From low temperature spectra (0°C to - 165 °C) of phytochrome samples irradiated either with red or far-red light, spectra of intermediates were calculated. Both absorption bands of the phytochrome chromophore were reported. On the pathway Pr → Pfr, native phytochrome does not form a bleached intermediate (meta-Rb) in contrast to degraded phytochrome.
An additional intermediate, meta-Rc (λmax = 725 nm), is formed instead. On the reverse pathway only two intermediates were found, lumi-F and meta-F. Oscillator strengths′ values were calculated and interpreted in terms of chromophore conformation. A scheme of intermediates for native phytochrome is presented.
Biochemical Characterization of Propylglyoxal Bis(guanylhydrazone). Facile Synthesis of Monoalkylglyoxal Bis(guanylhydrazones)
Authors: Elo Hannu , Laine Raija , Alhonen-Hongisto Leena , Jänne Juhani , Mutikainen Ilpo , Lumme Paavo 
Published: August 2018

Abstract
Propylglyoxal Bis(guanylhydrazone). Ethylglyoxal Bis(guanylhydrazone), Adenosylmethionine Decarboxylase Inhibition. Tumor Cells, Cellular Uptake Propylglyoxal bis(guanylhydrazone) sulfate, a novel analog of the well-known antileukemic drug methylglyoxal bis(guanylhydrazone), has been prepared from 2,2-dibromopentanal, and the compound has been characterized biochemically. Although it is a powerful inhibitor of S-adenosylmethionine decarboxylase, its Ki, value (0.2 μᴍ) is considerably higher than that of ethylglyoxal bis(guanylhydrazone) (0.06 μᴍ). The compound is only poorly taken up by tumor cells, and its accumulation is not stimulated by a prior exposure of the tumor cells to di-fluoromethylornithine, a compound that causes polyamine depletion. Thus, the uptake charac­ teristics of the compound are similar to those of ethylglyoxal bis(guanylhydrazone), but in striking contrast to those of methylglyoxal and glyoxal bis(guanylhydrazones). Since the configuration of the double bonds in glyoxal, methylglyoxal and propylglyoxal bis(guanylhydrazones) has been shown to be identical, the different uptake characteristics are probably only due to differences in side chain size and/or hydrophobicity.
Further Observations on Periodicities of Nucleotide Occurrences in Natural DNA's
Authors: Furlong N. Burr , Marien Koenraad 
Published: August 2018

Abstract
There are non-random features in the occurrences of nucleotides in the DNA’s of certain organisms which are detectable by statistical analyses of the entire sequence. Earlier, using the bacteriophage Phi-X 174 DNA sequence, we had reported that the self-information values for one type of dinucleotide association showed a marked periodicity when their autocorrelation coefficients were graphed. A similar, but computationally simpler, analysis has been developed which gives a comparable indication of periodicity. The difference, in average autocorrelation coefficients obtained with this analysis, between the peak values and all others has been used as an index to compare the extent of periodic non-randomness for a series of natural DNA sequences and for various artificial sequences. Calculations show that triplet periodicity, the relationship between dinucleotides separated by a single nucleotide, is characteristic only of the natural sequences of certain filamentous phages and is not found prominently in any other DNA analyzed (including sequences of similar length from plasmids, yeast, bacteria and higher animals). By shuffling nucleotides in a given sequence or by substituting selected nucleotides to alter various positions in both periodic and aperiodic sequences, we have found that an excess or deficiency of a given nucleotide at one of the three positions in a triplet reading frame can simulate the periodic characteristic. Thus, it appears that this global statistical analysis detects the tendency for single­ strand phages to utilize a specific nucleotide, rather than one randomly selected, to constitute codons.
Seasonal Variation of Free Flavone Aglycones from Sideritis leucantha (Lamiaceae)
Authors: Barberán F. A. T. , Tomás F. , Núñez J. M. 
Published: August 2018

Abstract
A quantitative and qualitative study of the seasonal variation of free flavone aglycones from Sideritis leucantha (Lamiaceae) has been carried out by means of HPLC. The flavonoid pattern remained unvariable with seasonal varia­ tion supporting flavonoid aglycones as idoneous taxonomic markers. Quantitative variations were observed, being the summer months which yielded a higher content in these compounds. These highly methylated flavone aglycones are located in the leaves surface as part of the excretion mate­ rial.
The UV Absorption Spectra of the C(5) and C(6) OH Adduct Radicals of Uracil and Thymine Derivatives. A Pulse Radiolysis Study
Authors: Deeble David J. , Sonntag Clemens von 
Published: August 2018

Abstract
Using pulse radiolysis the UV spectra of the C(6) OH adduct radicals of 1,3-dimethyluracil and 1,3-dimethylthy-mine were obtained by reacting the formate radical with the corresponding 5-bromo-5,6-dihydro-6-hydroxy derivatives. In the reaction of the pyrimidines with OH radicals a mixture of C(5) and C(6) OH adduct radicals is formed. From the known ratios in which these two radicals are formed and the spectra of the C(6) OH adduct radicals, the spectra of the C(5) OH adducts were calculated.
Specificity of Sexual Attractants in Xestia triangulum Hufn. and X. ditrapezium Schiff. (Lepidoptera: Noctuidae)
Authors: Priesner E. 
Published: August 2018

Abstract
Electrophysiological analysis of male antennal Sensilla trichodea in Xestia triangulum and X. ditrapezium showed that they contain the same five types of receptor cells in both species. These cells responded specifically to the (Z)-alkenyl acetates Z7-12:Ac, Z5-14:Ac, Z7-14:Ac, Z9-14:Ac and Z 11-14:Ac. Yet, in field trapping tests, male X. triangulum were highly attracted to pure Z5-14:Ac as a single compound, whereas male X. ditrapezium responded specifically to a ternary combination of Z5-/ Z7-/ Z9-14: Ac with the Z7 isomer as the major constituent. The four other “key compounds” in X. triangulum, and the other two in X. ditrapezium, inhibited trap captures. The results are considered in view of the close taxonomic relationship of the two species and their potential reproductive isolation from other, pheromonally-related noctuid moths.
Ingibitors of Sexual Attraction in the Moth Agrotis exclamationis
Authors: Priesner E. 
Published: August 2018

Abstract
The sex-attractant system of the dart moth Agrotis exclamationis (L.) (Noctuidae) was re-investigated with electrophysiological and field trapping tests. The identified pheromone components (Z)-5-tetradecenyl acetate and (Z)-9-tetradecenyl acetate elicited maximum trap captures when combined in a Z5-/Z9-mixture ratio of between 100/10 and 100/20, in contrast to an earlier reported mixture optimum of 100/5. Each compound activated a particular type of receptor cell located in the male antennal hair sensilla. Three further cell types discovered in these sensilla responded specifically to the non-pheromonal compounds (Z)-7-dodecenyl acetate and (Z)-7-and (Z)-11-tetra-decenyl acetate. These latter compounds did not show attractive or synergistic properties in field trapping tests but rather reduced captures when added to the binary pheromone blend as a third component. The biological functions of these three “attraction-inhibitors” remain unidentified.
Isoceroptene, a Novel Polyphenol from Pityrogramma triangularis
Authors: Markham Kenneth R. , Vilain Christian , Wollenweber Eckhard , Dietz Volker H. , Schilling Gerhard 
Published: August 2018

Abstract
Isoceroptene, a polyphenol isolated in trace amount from the farinose frond exudate of Pityro­gramma triangularis, is shown by spectroscopic means to possess the structure of one of the two possible “flavanone” isomers formed by ring closure of the “chalcone” ceroptene. The tautomeric structures best representing ceroptene and a related dihydrochalcone from Myrica gale are defined by 1H-NMR spectroscopy.
Are Spinach Chloroplasts Involved in Flavonoid O-Methylation?
Authors: Thresh Kim , Ibrahim Ragai K. 
Published: August 2018

Abstract
Intact spinach chloroplasts, which were isolated on a cushion of Percoll and purified on discon­tinuous sucrose gradients, were found to adsorb appreciable amounts of high specific activity, cytosolic O-methyltransferases. The latter activity was readily eliminated after washing the chloroplast pellet with 0.1 ᴍ phosphate in sucrose gradient buffer and finally with 0 .1% nonidet. Furthermore, the OMT activity of spinach leaves was resolved by chromatography on DEAE-Sepharose CL-6B into caffeic acid (COMT) and flavonoid (FOMT) O-methyltransferase ac­tivities, and purified to 30-and 50-fold, respectively. The similarities between the FOMT/COMT activity ratios and the methylation patterns of intact chloroplasts and their supernatants, as well as those of purified leaf preparations, suggest non-specific binding of cytosolic OMTs to chloroplast envelopes.
It is concluded, therefore, that spinach chloroplasts are not involved in the methylation of phenylpropanoid or flavonoid compounds. These results call attention for the re-evaluation of the role of this organelle in the biosynthesis or accumulation of plant secondary metabolites.
Isolation of Labeled Lipoprotein from Escherichia coli and Proteus mirabilis after Incubation with [14C]Penicillin
Authors: Gruner Gerhard , Tadros Monier H. , Plapp Roland 
Published: August 2018

Abstract
[14C]penicillin binding experiments and membrane analysis were carried out with cell envelope preparations from Escherichia coli and Proteus mirabilis. After incubation with [14C] penicillin G labeled free lipoprotein could be identified. The analysis of the isolated lipoprotein by SDS polyacrylamide gel electrophoresis indicates that there is only one protein with an apparent molecular weight of 7000. The amino acid composition of isolated labeled free lipoprotein from E. coli was identical to the lipoprotein already found in E. coli. It is a point of interest that the amino acid composition of the isolated labeled free lipoprotein from P. mirabilis D52 differs from that found in other mutants of this strain. The free form of lipoprotein from P. mirabilis D52 is composed of 61 amino acids and has glycine, phenylalanine and proline as specific components.
Diversification of Chemoreceptors in Ectocarpus, Sphacelaria, and Adenocystis (Phaeophyceae)
Authors: Müller Dieter G. , Boland Wilhelm , Jaenicke Lothar , Gassmann Günter 
Published: August 2018

Abstract
Ectocarpene, (+)-(6S)-(1Z-butenyl)-2,5-cycloheptadiene, is the mating pherom one of the three distantly related seaweeds Ectocarpus siliculosus, Sphacelaria rigidula and Adenocystis utricularis. Analogu es of this pheromone, dif­fering in position and π-electron density of the double bond in the C4-side chain, were synthesized and assayed for biological activity. The results suggest, that the fundamen­tal molecular recognition process is conservative in all species, while receptor dynamics and -topologies have been modified by individual developments and expressions dur­ing plant phylogeny.
Nature of Yeast Cells Immobilized by Radiation Polymerization Activity Dependence on the Molecular Motion of Polymer Carriers
Authors: Fujimura Takashi , Kaetsu Isao 
Published: August 2018

Abstract
Higher activity of ethanol production due to higher density of yeast cells, was observed in yeast cells immobilized with artificial polymer carriers of higher molecular motion. These polymer carriers were prepared by radiation-induced polymerization below 0 °C. Yeast cells were­ immobilized with these carriers by adsorption method during multiplication. Molecular motion of polymer carriers in swollen state was evaluated by the line width of nuclear magnetic resonance spectrum. A possible reason for higher activity was discussed. This study of relation between molecular motion of polymer carriers and activity of yeast cells immobilized with these carriers, is very useful to design the chemical and physical structure of polymer carriers for immobilization of microorganisms.
Chicoree-Säure und deren Derivate aus Echinacea-Arten / Chichoric Acid and Its Derivatives from Echinacea Species
Authors: Becker H. , Hsieh W. Ch. 
Published: August 2018

Abstract
Echinacea angustifolia and E. purpurea contain in all plant parts chichoric acid as well as chichoric acid derivatives: chichoric acid methyl ester and chichoric mono and dimethylether.
Degradation of Bacteriochlorophyll a in Rhodopseudomonas sphaeroides R26
Authors: Haidl H. , Knödlmayr K. , Rüdiger W. , Scheer H . , Schoch S. , Ullrich J. 
Published: August 2018

Abstract
A series of pigments of the bacteriopheophytin a spectral type have been isolated from ageing cultures of Rhodopseudomonas sphaeroides strain R26. These pigments are formed in varying amounts, and can be most readily analyzed in vivo by their absorption in the 530 nm spectral range. They are enriched in sedimenting cells, but their formation is not affected by light. By chromatographic comparison with authentic pigments and chemical correlation, the following pigments have been identified: bacteriopheophytin a, bacteriopheophorbide a (which is the predominant product), pyrobacteriopheophorbide a and a fourth, very polar bacteriopheophytin a-type product of unknown structure. The major portion of these newly formed pigments is present in the cells in a state, in which the near-infrared absorption band is shifted to longer wavelengths. As shown by low temperature fluorescence spectroscopy, these forms are very similar to bacteriopheophorbide a aggregates.
Water Relations in Young Growing Wheat Leaves after Application of (2-Chloroethyl)trimethyl- ammoniumchloride (CCC) to the Roots of Wheat Seedlings
Authors: Bode Jutta , Wild Aloysius 
Published: August 2018

Abstract
The influence on the water relations of the third developing leaf of (2-chloroethyl)trimethylammoniumchloride, a synthetic growth regulator, applied to the roots of young wheat plants (Triticum aestivum L.) has been investigated. The tissue water potential and the pressure potential were found to be reduced by several bars in comparison to the untreated controls, whereas the osmotic potential remained unchanged. The content of soluble reducing sugars was considerably increased in the cell sap of CCC-treated leaves. With this accumulation, however, the turgor was not maintained. Additionally, CCC-treated leaves showed considerably lower transpiration rates and higher diffusive resistance than the controls. Thus, the application of CCC to the roots causes alterations in the water relations of developing wheat leaves, which resemble those induced by water deficiency.
Tyrosine Biosynthesis in Sorghum bicolor: Isolation and Regulatory Properties of Arogenate Dehydrogenase
Authors: Connelly James A. , Conn Eric E. 
Published: August 2018

Abstract
The conversion of prephenic acid to tyrosine can occur by two different routes: (a) oxidative decarboxylation (prephenate dehydrogenase) followed by transamination (aromatic aminotrans­ ferase); (b) transamination of prephenate forming the non-aromatic amino acid arogenic acid (prephenate am inotransferase) followed by oxidative decarboxylation (arogenate dehydrogenase).
High activity of arogenate dehydrogenase was found in extracts of etiolated sorghum seedlings, while no evidence of prephenate dehydrogenase was observed. Arogenate dehydrogenase from sorghum eluted, with high recovery of activity (93%), as a single peak on DEAE-cellulose chromatography. The enzyme was strongly inhibited by tyrosine but was unaffected by phenylala­nine, prephenate, or tryptophan. Kinetic analysis showed that tyrosine inhibition was competitive with arogenate and that the Ki for tyrosine (61 μm) was much smaller than the Km for arogenate (350 μm).
The properties of arogenate dehydrogenase indicate that this enzyme is important in the regula­tion of tyrosine biosynthesis in sorghum. Strong inhibition of the enzyme by tyrosine may indicate that arogenate is a branch point in the shikimate pathway in plants and therefore arogenate may be a precursor to phenylalanine and the numerous phenylpropanoid secondary metabolites deriv­ed from phenylalanine.
High Performance Liquid Chromatography Coupled with Radioactivity Detection: A Powerful Tool for Determining Drug Metabolite Profiles in Biological Fluids
Authors: Vollmer K.-O. , Klemisch W. , Hodenberg A. von 
Published: August 2018

Abstract
High performance liquid chromatography coupled with continuous radioactivity detection rep­resents an advancement in drug metabolism research. Using radioactive substances labelled in biologically stable positions, all metabolites can be specifically detected by radioactivity measure­ment. Thus no clean-up of biological fluids is required prior to HPLC. This can prevent artefact formation from unstable metabolites, reduces recovery problems and facilitates quantitation. Separation of highly polar and unpolar metabolites is possible in a single chromatographic run using gradient elution and reversed phase materials. This technique is also well-suited for prepara­tive isolation and purification of metabolites for subsequent structure elucidation.
Various metabolite profiles of drugs labelled with carbon-14 or tritium are shown. Metabolites of the following drugs are presented: norfenefrine, etozolin, thymoxamine, naloxone, and levobunolol. We review the general methodology and report our experience with this technique. In principle, this technique may be useful for all biological systems in which tracer techniques are applied.
Cyanophora paradoxa: Fatty Acids and Fatty Acid Synthesis in vitro
Authors: Kleinig Hans , Beyer Peter , Schubert Carmen , Liedvogel Bodo , Lütke-Brinkhaus Friedhelm 
Published: August 2018

Abstract
The fatty acid pattern of Cyanophora paradoxa membrane lipids is highly unusual with 16:0, 20:3 and 20:4 as the main acids. The 20:4 acid is preferentially distributed among the cyanelle lipids. In isolated cyanelles a relatively low in vitro synthesis of only saturated and monounsatu­rated fatty acids from [l-14C]acetate was observed which corresponds to the relatively low photo­synthetic oxygen evolution.
Phosphoenolpyruvate Carboxylase from Maize Leaves. Studies Using β-Methylated Phosphoenolpyruvate Analogues as Inhibitors and Substrates
Authors: Gonzalez Daniel H. , Andreo Carlos S. 
Published: August 2018

Abstract
1. The phosphoenolpyruvate analogues phosphoenol-α-ketobutyrate and phosphoenol-α-ketoisovalerate are linear competitive inhibitors of maize leaf phosphoenolpyruvate carboxylase with respect to phosphoenolpyruvate. Phosphoenol-α-ketobutyrate is an excellent inhibitor (Ki: 18 μm in the presence of 5 mM MgCl2). The inhibition constant for phosphoenol-α-ketoisovalerate is 0.38 mᴍ under the same conditions. For both compounds, the inhibition is greater in the presence of Mn2+ than with Mg2+. 2. The analogues are dephosphorylated, but apparently not carboxylated, by the enzyme. For the reaction with phosphoenol-α-ketobutyrate, α-ketobutyrate and inorganic phosphate are the reaction products. Bicarbonate and a divalent cation are required for the dephosphorylation reaction. 3. The dephosphorylation reaction is activated by glucose-6-phosphate and the Vmax has the same pH dependence as that of the carboxylation of phosphoenol­ pyruvate. The Km for phosphoenol-α-ketobutyrate is reduced in the presence of 5 mᴍ MnCl2 (55 μᴍ versus 140 μᴍ with 5 mM MgCl2). The Vmax is essentially the same in the presence of either MgCl2 or MnCl2. These results suggest that the dephosphorylation of the analogues occurs by a mechanism which is similar to that of the carboxylation of phosphoenolpyruvate, and that both reactions have a common rate-determining step.