bluuebunny/crossref_metadata_2025_split huggingface dataset:
Verbreitung von Iridoiden in der Gattung Verbena und einigen anderen Verbenoideae / Iridoids in Verbena and Some Other Verbenoideae
Authors: Milz Sabine , Rimpler Horst 
Published: August 2018

Abstract
12 species of the genus Verbena and one Citharexylum species have been examined for iridoids. Besides the known compounds verbenaline, hastatoside, griselinoside, lamiide, ipolamiide and brasoside, two new iridoids, pulchelloside I (1) [2] and pulchelloside II (2) [3] have been isolated from Verbena species. The structures and absolute configurations of pulchelloside I and II have been determined by spectroscopical methods and some chemical reactions. Citharexylum solanaceum has been shown to contain lamiide and durantoside I. The distribution of the iridoids is in excel­ lent agreement with the taxonomic treatment of the genus Verbena by Schauer. The taxonomic significance of our data and some data from the literature regarding the classification of the sub­ family Verbenoideae is discussed.
Incorporation of 5-Bromo-2-deoxyuridine into the Chloroplast DNA of Anemia phyllitidis
Authors: Šonka J. , Schraudolf H. 
Published: August 2018

Abstract
5-Bromo-2-deoxyuridine, DNA, Chloroplasts, Fern 5-Bromo-2-deoxyuridine (BUdR) is incorporated into chloroplast DNA of Anemia phyllitidis. A possible connection between previously published effects of BUdR and on chloroplast ultrastructure and transitions caused by the base analogue in the DNA is referred to.
Complex Influence of Cytochalasin B on Actin Polymerization
Authors: Dancker P. , Low I. 
Published: August 2018

Abstract
In the presence of very low concentrations (about 2 x 10-7 ᴍ) of cytochalasin B (CB) the time course of actin polymerization is much more sigmoidal when followed by viscosity measurements than when followed by light scattering measurements. This suggests that under these conditions actin polymers do not immediately reach their final length but only via short ”bent“ polymers which can be detected only by light scattering but not by viscosity measurements. At higher CB concentrations (about equimolar to those of actin) CB reduces the average degree of polymerization and favors the nucleation step necessary for polymerization.
Eriodictyol-7-glucoside and Other Phenolics in the Blue Fruits of Lasiauthus japonica
Authors: Ishikura Nariyuki , Sugahara Keishin , Kurosawa Kazu 
Published: August 2018

Abstract
Eriodictyol-7-glucoside, a flavanone glycoside, was isolated as cream-white needles from the deep-blue fruit skins of Lasianthus japonica, and in the same tissue eriodictyol and scopoletin were also found to occur in a small amount by means of paper chromatography.
Unprogrammierte DNA-Synthese (DNA-Reparatur) in Milz-und Thymuszellen der Ratte nach Einwirkung von UV-Licht, Röntgenstrahlen oder Methylmethansulfonat in vitro / Unscheduled DNA Synthesis (DNA-Repair) within Splenic and Thymic Cells of the Rat under the Influence of UV-Light, X-Irradiation and/or Methyl-methanesulfonate
Authors: Tempel K. 
Published: August 2018

Abstract
DNA -Repair, Splenocytes, Thymocytes, Irradiation, Methyl-M ethanesulfonate Unscheduled DNA synthesis (UDS) of splenic and thymic cells of the rat has been stimulated in vitro by UV-light (8-128 J × m-2), X-rays (120-3480 rd), methyl-methanesulfonate (MMS), and/or a combination of UV-light and X -irradiation. The height of U DS-induced stim ulation of incorporation of [3H] thymidine into splenic and thymic cell DNA at saturation doses of UV-light (splenic cells: 8, thymic cells: 96 J × m-2) or X -irradiation (splenic cells: 960, thymic cells:~3480 rd) suggest that the greater sensitivity of T-cells (represented by thymic cells) towards UV-light and the greater sensitivity of B-cells (represented by splenic cells) towards X-rays can be explained - at least partly - in terms of less efficient excision repair systems.
Arabinose Conformations of 9-β -ᴅ-Arabinofuranosyladenine (ARA-A) Analogues Modified at the 2',3' or 5' Positions
Authors: Klimke G. , Cuno I. , Lüdemann H.-D. , Mengel R. , Robins M. J. 
Published: August 2018

The solution conformations of 9-β-ᴅ-arabinofuranosyladenine analogues modified at the 2′,3′ or 5′ positions are derived from the HRNMR spectra and the longitudinal relaxation rates of the protons. The compounds studied are: 9-β-ᴅ-arabinofuranosyladenine and its 2′-amino-2′-deoxy, 2′-chloro-2′-deoxy, 2′-azido-2/-deoxy, 3′-amino-3′-deoxy, 3′-bromo-3′-deoxy, 3′-chloro-3′- deoxy, 3′-fluoro-3′-deoxy, 3r-azido-3′-deoxy, 2,,3,-diamino-2′,3′-dideoxy, 2′,5′-diamino-2′,5′-di- deoxy and 2′,5′-diazido-2′,5′-dideoxy analogues. It is derived from the data that the conforma­tional equilibria of the furanoside rings can be described by the two state N ⇔ 5 model of Altona and Sundaralingam.
The emphasis in this work is to study systematically the influence of the different chemical modifications upon the conformational equilibria of the nucleosides. For the arabinosides it is found that substitution of the hydroxyl groups at C2′ or C3′ by other atoms or groups always stabilizes the N conformation oi the araoinose ring. The only exception is fluorine, where S is stabilized. The preference for the N state is correlated with an increasing population of the g+ rotamer of the exocyclic 5′-CH2OD group. From the relaxation study of 2′-chloro-2′-deoxy- arabinofuranosyladenine the position of the syn ⇔ anti equilibrium of the base was estimated to be predominantly anti. Thus a preference for the anti-N-g+ conformation was derived for the arabinosides excluding an intramolecular hydrogen bond between the 2′ and 5′ hydroxyl groups that was found in the solid state. The stabilization of the N conformer in the modified compounds can be qualitatively explained by steric effects.
Xylose Conformations of 9-β-ᴅ-Xylofuranosyladenine Analogues Modified at the 2'3' or 5'-Positions and Lyxose Conformations of 9-β-ᴅ-Lyxofuranosyladenine
Authors: Klimke G. , Cuno I. , Lüdemann H.-D. , Mengel R. , Robins M. J. 
Published: August 2018

Proton magnetic resonance studies of 9-β-ᴅ-xylofuranosyladenine (xyloA), its 2′-amino-2′- deoxy, 2′-azido-2′-deoxy, 2′-bromo-2′-deoxy, 3′-thio-3′-deoxy, 3′-amino-3′-deoxy, 3′-azido-3′- deoxy, 3′-chloro-3′-deoxy, 3′-fluoro-3′-deoxy, 3′-O-methyl, 3′,5′-diazido-3′,5′-dideoxy analogues and 9-β-ᴅ-lyxofuranosyladenine (lyxoA) have been carried out to study the effect of chemical modifications at the sugar moiety on the solution conformational equilibria in these classes of nucleosides. Analogously to previous studies the xylose pucker can be described in the two-state N ⇔
S model of Altona and Sundaralingam. For the xylosides, however, a somewhat different N state (C3′-endo-C4′-exo) has to be used than for the ribosides and arabinosides (C2′-exo-C3′- endo).
The results of the conformational analysis are that xyloA exists almost exclusively as an N conformed The effect of the substitutions in the modified compounds is to destabilize the N state. This decrease in the mole fraction of N is accompanied by an increase in the population of the g+ rotamer of the exocylic 5′-CH2OD group. Thus for the xylosides a correlation N-t/g- or S- g+, respectively, can be derived. Proton relaxation rate measurements on 2′-azido-2′-deoxyxylo- furanosyladenine indicate that in the xylosides the standard syn or anti ranges do not represent stable positions for the adenine base, but that a glycosyl torsion angle (Χ∼160°, Υ∼80°) be­ tween syn and anti is preferred. LyxoA behaves similar to the xylosides and also favours the N state of the sugar pucker.
In a summarizing discussion the conformational equilibria of the different modified pentosides - ribose, arabinose, xylose and lyxose - are compared. It is shown that generally intramolecular hydrogen bonding does not yield an important contribution to the stabilization of conformational equilibria in solution. It is also not possible to derive a quantitative relationship between such parameters as Van-der-Waals’ radii or electronegativity of the substituents and the mole fractions of the different conformers. It can, however, be seen that in all cases, where the hydroxyl groups at C2′ or C3′ are substituted by a more voluminous atom or group, steric effects become dominant and allow a qualitative explanation of the changes of the conformational equilibria. Only for the smallest and most electronegative substituents, like fluorine, other interactions (e.g. electrostatic) may become important. It is thus suggested that the purine(β)nucleoside conforma­tion is essentially determined by steric interactions between the different parts of the molecule.
Distribution of Terpenes and Phenol Ethers of Asarum Species Growing in Islands in Pacific Ocean
Authors: Hayashi Nanao , Maeshim Kazuyuki , Noguchi Isamu , Komae Hisashi , Sakao Takashi 
Published: August 2018

Abstract
A survey of chemical compositions of ten species of Asarum subgenus Heterotropa growing in some islands in Pacific Ocean showed that two groups could be distinguished on the basis of terpene and phenyl propane compositions.
Kollagen-Einschlußverbindungen / Inclusion Compounds of Collagen
Authors: Newesely H. , Hosemann R. , Uther B. 
Published: August 2018

Abstract
Small angle X-ray diagrams of native collagen of rat tail treated with phospho tungstic acid or mercury chloride or cobalt- and uranyl-nitrate, osmiumoxide or hydroxy apatite show the same characteristic new reflections and reflection lines. The only remarkable difference exists between fibers treated under stress or relaxed. These experiments give new evidence for the paracrystallinity of collagen. More than 100 parallel aligned ca. 40 Å thick octafibrils consist of 670 Å long micro­ paracrystals with 5 ca. 25 Å thick soft segment layers. In these soft segments the holes of the octafibrils build up a lattice of vacancies with lattice cells of 38,5×35×135 Å3 length. The above mentioned molecules penetrate from the lateral sides through the soft segments into these vacancies building up complexes with peptide groups of collagen. Under stress only a small amount of vacancies is occupied, statistically distributed over the vacancy-lattice, because the soft segments of the octa­ fibrils are constricted. Without stress about 10 to 25% of the octafibrils within one paracrystal are filled up with sediments in the soft regions. With increasing precipitation finally 500 Å long nee­dles are formed of the inclusive material as detected by Höhling with the electron microscope in collagen of turkey tendon. The importance of the paracrystalline collagen model is emphasized to understand the biological process like the mineralisation of collagen and β-keratin in organism or the activity of bone apatite in exchanging calcium ions.
Influence of Magnesium Ions on the Action of Photosystems I and II at Different Wavelengths. Experiments with Barley Chloroplasts of Different Chlorophyll b Content
Authors: Loos Eckhard , Kellner Ernst 
Published: August 2018

Abstract
Barley leaves grown under a natural light/dark regime have a chlorophyll content of 1300 µg/g fresh weight and a chlorophyll a/b ratio of 2.5 -3. When the plants are grown under cycles of 2 min light/118 min dark, the respective values are 50 and 5 - 9. With chloroplasts with low chlorophyll b content variable fluorescence is depressed by about 30% by MgCl2; with those of high chlorophyll b content a threefold increase is seen instead. Action spectra for variable fluorescence of chloroplasts of high chlorophylll b content show enhancement by Mg2+ around 475 and 650 nm; for the system I-mediated methyl viologen reduction, a depression is seen at these wavelengths. These effects are practically absent in chloroplasts with low chlorophyll b content. The data corroborate the hypothesis that a chlorophyll b-containing pigment protein complex is required for re­gulation of energy transfer to system I and II by magnesium ions.
Formation of Cyclic Adenosine-3'-5'-monophosphate (cAMP) from Adenosine-5'-phosphosulfate (APS) in Chlamydomonas reinhardtii CW 15?
Authors: Kühlhorn Friedrich , Schmidt Ahlert 
Published: August 2018

Abstract
Levels of cyclic adenosine monophosphate (cAMP) have been determined in the green alga Chlamydomonas reinhardtii strain CW 15. In the early exponential growth no cAMP was detected, however, in the middle of the exponential growth phase 2.4 pmol cAMP/mg protein were found and the cAMP level increased to 18.8 pmol/mg protein in the stationary phase.
An enzyme fraction has been isolated from Chlamydomonas, which produced cAMP in vitro using adenosine-5'-phosphosulfate (APS) as a substrate. This protein fraction was isolated by am-moniumsulfate precipitation, DEAE-cellulose chromatography and Sephadex-G-100 gel filtration. A solvent system was developed for thin layer chromatography to separate cAMP from APS, adenosine-5'-phosphoramidat (APN), 5'-AMP and adenosine. The product was identified as cAMP by cochromatography, coelectrophoresis, treatment with phosphodiesterase, chromato­ graphy on Biorad-columns and by the protein-binding assay. The so far purified protein fraction produced 151 pmol cAMP/mg protein and hour in vitro, using APS as a substrate.
The Role o f Eye Accommodation in the Depth Perception of Common Toads
Authors: Jordan M. , Luthardt G. , Meyer-Naujoks Chr. , Roth G. 
Published: August 2018

Abstract
Distance estimation in prey catching was as exact in monocular toads (Bufo bufo (L.)) as in binocular ones. Application of Atropine or Miotic® had no significant effect on binocular animals, whereas in monocular toads it made accurate distance estimation impossible. The accom­ modative state of the eye is decisive for depth estimation of monocular, but not of binocular toads.
Spatio-Temporal Visual Receptive Fields as Revealed by Spatio-Temporal Random Noise
Authors: Hida Eiki , Naka Ken-ichi 
Published: August 2018

Abstract
A means was devised to visualize the retinal receptive fields in time and space using the noise on unused television channels as spatio-temporal inputs and performing correla­ tion between the input and output photographically. The method was applied to characterize the receptive fields of catfish retinal ganglion cells. The results were 1) there were two major types of receptive fields, circular and elliptical, 2) shapes and sizes of the field components changed with time (latency), and 3) a field's surround was often localized as hot spots.
Inhibitors of Calmodulin-Dependent Phosphorylation Simultaneously Inhibit Calcium Uptake and Calcium-Dependent ATPase Activity in Skeletal Muscle Sarcoplasmic Reticulum and Transiently Induce Calcium Release
Authors: Hasselbach Wilhelm 
Published: August 2018

Keywords
Under adequate experimental conditions calmodulin antagonists like compound 48/80 do not dissociate calcium uptake from the calcium -dependent ATP hydrolysis of skeletal muscle sarcoplasmic reticulum membranes but simultaneously inhibit both processes. Apart from the agent’s pump inhibiting effect, they interact with the caffeine sensitive calcium channel in the sarcoplasmic reticulum causing a rapid transient calcium release.
Notizen: Exkret-Flavonoide bei Hieracium intybaceum (Asteraceae) / Exudate Flavanoids in Hieraceum intybaceum, an Alpine Hawkweed (Asteraceae)
Authors: Wollenweber E. 
Published: August 2018

Abstract
The hawkweed Hieracium intybaceum is covered with glandular trichomes that produce a sticky resinous exudate. This material, assumedly of terpenoid nature, contains trace amounts of flavonoid aglycones. They could be identified to be known flavones and flavanones. This is the first time that an alpine Asteraceae was found to exude flavonoid aglycones.
The Presence of a Specialized-β-GIucosidase: Linamarase, in the Leaves of Trifolium repens is Controlled by the Gene Li
Authors: Kakes P. , Eeltink H. 
Published: August 2018

Abstract
Cyanogenesis, β-Glucosidase, Linamarase, Trifolium repens Linamarase was purified by a three-step procedure from leaves of a clone of Trifolium repens. The partially purified enzyme was used to produce antilinamarin. The antiserum contained anti-linamarase as well as antibodies against one or more other β-glucosidases. By incubation with an extract of a plant without linamarase activity pure antilinamarase could be obtained. Comparison of the titration curves of crude and purified antilinamarase shows that linamarase is an enzyme antigenically different from other β-glucosidases, and that this enzyme is absent from plants recessive for the gene Li.
Effect of Salinity on Photosynthetic 14CO2 Fixation and Amino Acid Pools of Bellerochea yucatanensis (v. Stosch) and Thalassiosira rotula (Meunier)
Authors: Döhler Günter , Zink Joachim 
Published: August 2018

Abstract
The marine diatoms Bellerochea yucatanensis and Thalassiosira rotula were grown at different salinities (20/25, 35, and 40/45‰ salinity (S), respectively) under normal air (0.035 vol.% CO2). No significant variations in the percentage of gross photosynthetic products (e.g. total amino acids, sugar phosphates) were found as a function of salinity during growth. The bulk of the soluble 14C-radioactivity was detected in amino acids. 14C-labelling of glutamine increased markedly with salinity. Low salt - grown algae are characterized by enhanced amino acid pools, mainly of aspartic acid, asparagine and glutamine. It was found that the tested amino acids are not involved in osmoregulation.
Composition and Distribution of Lipids in Tissues of Bogue (Boops boops)
Authors: Kapoulas Vassihos M. , Miniadis-Meimaroglou Sofia 
Published: August 2018

Abstract
Total lipids from liver, head, skin and muscle of Bogue were separately isolated and their composition was investigated by a combination of analytical determinations, and column and thin layer chromatography.
The major components of the neutral lipid fractions from all tissues studied were triglycerides, followed by cholesterol. The triglyceride fraction of skin and head contains significant amounts of glyceryl ether analogs. Low contents of free fatty alcohols were also identified, decreasing in the order: head, muscle, skin and liver.
The major components of all phospholipid fractions was phosphatidylcholine (viz. 36-59% of total phospholipids) followed by phosphatidylethanolamine (viz. 23-34% of total phos­ pholipids). Low amounts of sphingomyelin and phosphatidylserine were also identified in all cases. All the tissues studied were found to contain plasmalogens, as well as glyceryl ether analogs in both, the depot fats and the phospholipid fractions.
Volatile Constituents of the Red Wood Ant Formica rufa L. (Hymenoptera: Formicidae)
Authors: Francke W. , Borchert J. , Klimetzek D. 
Published: August 2018

Abstract
From workers of the red wood ant Formica rufa L. 68 compounds could be identified by combined gas chromatography-mass spectrometry. Abdomina contain a row of bishomologue saturated and unsaturated uneven numbered hydrocarbons with undecane as the major product. In addition, 13 formic acid esters could be identified among which hexadecyl formate is present in particularly large amounts. Main components of the head extracts are methyl 3-ethyl-4-methyl-pentanoate, 3-ethyl-4-methylpentanol and tricosane.
Notizen: The Influence of Spin Label on the Transport of Ascorbate across Artificial Membranes
Authors: Lohmann W. , Tian P. z. , Holz D. 
Published: August 2018

Spin label 1,14 studies on DPPC membranes revealed an increased rigidity of the membrane with increasing spin label concentrations. This causes a retardation in permeation rate of Na-ascorbate. At temperatures > 40 °C, that is above the phase transition temperature, the ESR spectrum of a spin labelled DPPC membrane is very similar to a free spin label spectrum and yet the permeation rate of NaASC is reduced considerably. From this it can be concluded that the spin label has caused certain reinforcements between the lipids, an effect which cannot be reversed by temperatures of about 60 °C.
Structural and functional investigations of membranes using spin labels have to consider always the effect described.
On the Role of Magnesium in the Reaction of the Pyruvate Kinase from Salmonella typhimurium
Authors: Garcia-Olalla Concepcion , Garrido-Pertierra Amando 
Published: August 2018

Abstract
The kinetics of the two purified forms of pyruvate kinase from Salmonella typhimurium LT-2 were studied in assays at pH 6.8 where the relationships between the initial velocities of the catalysed reactions and Mg2+ are non-hyperbolic. The analysis show that Mg2+ display positive homotropic interactions in their binding behaviour with Hill coefficient values of 2.5 and 1.2 for the form I and II, respectively.
The binding sites of the cation to the pyruvate kinases seem to be independent to those for phosphoenolpyruvate and adenosine 5′-diphosphate; changes in the magnesium concentration might be of physiological significance in relation to a rapid regeneration of adenosine 5′-triphosphate by means of the pyruvate kinase reaction.
Sensitivity of a Phototrophic Bacterium to the Herbicide Sulfometuron Methyl, an Inhibitor of Branched Chain Amino Acid Biosynthesis
Authors: Schneider Irmgard , Klemme Jobst-Heinrich 
Published: August 2018

Abstract
Sulfonyl urea-herbicides (sulfometuron methyl, chlorsulfuron) strongly inhibit phototrophic growth of the bacterium Rhodospirillum rubrum in the absence of ʟ-valine as a feedback inhibitor of the enzyme acetohydroxy acid synthase. The latter enzyme was shown to be highly sensitive to the sulfonyl urea and, to a much lesser extent, to an imidazolinone herbicide (Arsenal®).
Aspects of Mycobacterial Response to Beryllate Ions in vitro
Authors: H. J. MacCordick 
Published: August 2018

Abstract
Comparative growth measurements of the mycobacterial species Mycobacterium phlei and Mycobacterium tuber­culosis were carried out with liquid cultures supplemented with oxalatoberyllate ions in the concentration range 0-120 μᴍ Be. For both species, the effect of beryllium on specific growth parameters can be represented by a Be con­centration-dependent, exponential expression. Evidence for beryllium binding to cellular phospholipids (~ 15% of Be uptake) is provided by 31P NMR spectroscopy, thin-layer chromatography and atomic absorption spectrometry.
Nucleic Acid-Binding Activities of the Intermediate Filament Subunit Proteins Desmin and Glial Fibrillary Acidic Protein
Authors: Vorgias Constantin E. , Traub Peter 
Published: August 2018

Abstract
In analogy to experimental results previously obtained with vimentin and neurofilament triplet proteins, the intermediate filament (IF) proteins desmin and glial fibrillary acidic protein (GFAP) were also found to have high capacities to associate with nucleic acids. Employing a collection of native and heat-denatured pro-and eukaryotic DNAs, a series of naturally occurring single­ stranded (ss)RNAs and a variety of synthetic polynucleotides of the RNA and DNA type, both proteins could be shown to bind preferentially to single-stranded polynucleotides. In the case of ssDNA and synthetic polyribonucleotides, a clear dependency of the binding activity on the G-content of the nucleic acids was demonstrated. The interaction of desmin with ssDNA and tRNA was characterized by strong cooperativity. When a mixture of desmin and vimentin was offered to excess ssDNA, the cooperativity effect brought about segregation of both protein species into two distinct populations of deoxyribonucleoprotein particles with substantially differ­ent sedimentation rates; this segregation is in sharp contrast to the ability of desmin and vimentin to form heteropolymers in filament assembly. In general, desmin and GFAP were found to be similar to vimentin and neurofilament proteins in their nucleic acid-binding properties. However, there were also striking differences between individual non-epithelial IF proteins at this level.