bluuebunny/crossref_metadata_2025 huggingface dataset:
Eriodictyol-7-glucoside and Other Phenolics in the Blue Fruits of Lasiauthus japonica
Authors: Ishikura Nariyuki , Sugahara Keishin , Kurosawa Kazu
Published: August 2018

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

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

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

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

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

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.
Mechanism Proposal for a Fluorescent Amanitin Derivative Formation
Authors: Plancke Y. , Hénichart J. P.
Published: August 2018

A quantitative fluorimetric detection of a-amanitin treated by H3PO" is proposed. Spectra for both amanitin and tryptophan suggest an extended aromatic structure clearly confirmed by JH NMR spectrography.
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

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

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.
Unterschiede zwischen Milz-und Thymuszellen der Ratte in der Wirkung von Ethidiumbromid auf die unprogrammierte DNA-Synthese (DNA-Reparatursynthese) und die Nucleoidsedimentation / Differences between Rat Splenic and Thymic Cells with Respect to the Effects of Ethidium Bromide on the Unsheduled DNA Synthesis (DNA Repair Synthesis) and the Nucleoid Sedimentation
Authors: Tempel K. , Goette A. , Schmerold I.
Published: August 2018

To get further insight into the causes of differences between rat splenic and thymic cells with regard to DNA repair synthesis, scheduled (SDS) and unscheduled (UDS) DNA synthesis as well as nucleoid sedimentation of the cells were investigated under the influence of ethidium bromide (EB, 1 -1000 μg/ml). - At concentrations of ≳ 25 μg/ml, EB inhibited SDS of both cell species and UDS of thymic cells; much higher additions of the drug (>200 μg/ml) were needed to diminish UDS of splenic cells, lower EB-concentrations (25- 175 μg/ml) stimulating the UDS of the splenic cell preparation. - The sedimentation rate of splenic and thymic cell nucleoids within neutral sucrose gradients had a biphasic dependence on the EB-concentrations. As compared to thymic cells however, preincubation of splenic cells with 50-250 μg EB/ml resulted in a significant greater (15-30 percent) sedimentation distance. - The results suggest that a relation­ship exists between the stimulation of UDS and the ability of cells to establish a greater DNA compactness in the presence of EB.
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

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

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

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

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

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.
Effect of the CO2-Concentration during Growth on the Oxygen Evolution Pattern under Flash Light in Chlorella
Authors: Shiraiwa Yoshihiro , Schmid Georg H.
Published: August 2018

Photosynthetic O2-evolution patterns were determined in cells of Chlorella vulgaris 211 - 11 h, grown under air enriched with 2% CO2 (High CO2- cells) and under ordinary air (Low CO2-cells). Oxygen evolution in these algae was measured as consequence of short saturating light flashes with the three electrode system according to Schmid and Thibault, Z. Naturforsch. 34c, 414 (1979). It was shown that Low CO2-cells had the usual Joliot-Kok pattern of O2 evolution whereas High CO2-cells exhibited a more reduced pattern characterized by the fact that maximal flash yield was observed under the 4th flash and that damping due to misses was more important than in Low CO2-cells. Moreover, the amplitudes of the amperometric signals in High CO2-cells were consistently lower. The observations clearly speak in favor of a more reduced condition of the S-state system, when the cells are grown under high CO2. This was confirmed by the fact that higher concentrations of hydroxylamine had to be added to bring Low CO2-cells into the maximally reduced condition namely S-2, than was the case with High CO2-cells. Our observations suggest that the redox condition of the S-state system of photosystem II in Chlorella vulgaris is affected either by changes of CO2 concentrations during algal growth or that the S-state system is only maintained in the 4 state Kok condition when the enzyme carbonic anhydrase is present.
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.
Cyanidin 3-Gentiobioside from Primary Leaves of Rye (Secale cereale L.)
Authors: Busch E. , Strack D. , Weissenböck G.
Published: August 2018

An anthocyanin has been isolated from primary leaves of Secale cereale L. and identified as cyanidin 3-O-gentiobioside on the basis of UV spectroscopy, hydrolysis and cochromatography.
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

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

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®).
Structure Investigations of Agonists of the Natural Neurotransmitter Acetylcholine VI [1]. X-Ray Structure Analysis of Trimethyl[2-(propionyloxy)ethyl]- ammonium-iodide (O-Propionylcholine-iodide)
Authors: Gieren Alfred , Kokkinidis Michail
Published: August 2018

The title compound (1) crystallizes in the orthorhombic, noncentrosymmetric space group Pna21 with a = 10.241(11), b = 12.903(12), c = 9.312(9) Å and with one formula unit per asymmetric unit. The stereochemically comparable torsion angles of the cation of 1 and of acetylcholine chloride are analogous. In the crystal structure the trimethylammonio methyl group is surrounded by three anions in the first coordination sphere. The geometry of a triangle formed by one of these counterions which occupies a special face of the N+C4 tetrahedron of the (CH3)3N+-CH2-R moiety, the nitrogen atom of the ammonium group and the oxygen atom of the carbonyl group is typical for nicotinic agonists.
Aspects of Mycobacterial Response to Beryllate Ions in vitro
Authors: H. J. MacCordick
Published: August 2018

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

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.
Latitude Dependent Circadian Rhythms of Carabid Beetles
Authors: Leyk Gisela , Martin Wolfgang
Published: August 2018

Comparative studies of circadian activity rhythms were performed with three stocks of the species Pterostichus rhaeticus Heer (from Southern Europe, Central Europe, and the Subarctic) and with one Central European stock of the sibling species Pterostichus nigrita Paykull. The hehaviour was investigated in various LD conditions, constant conditions including LL with changes of the illumination intensity and constant darkness with light pulses. The data were analysed with the program system “Timesdia” containing various techniques like power spectrum estimation, periodogram analysis and complex demodulation. This allowed to reveal the time course of rhythms and to determine the number of phase jumps as a measure for precision. With the help of these methods, the activity patterns are classified in different types of behaviour: synchronization, temporarily synchronization, aperiodic behaviour, free run, temporarily free run, relative entrainment, and relative coordination. Besides graduated differences between the populations in south-to-north direction (e.g. in the tendency to rhythmic behaviour) the analysis revealed splitting of rhythms into two or even three components of different frequencies and transitions from rhythmic to aperiodic behaviour or vice versa after arbitrarily chosen light pulses in constant darkness. This behaviour cannot be explained by a system which is composed of one single limit cycle oscillator, but the results rather support a multi-oscillator model.
The Effect of Guanidinium Chloride on the Self-Association of Bovine Liver Glutamate Dehydrogenase: A Gel Filtration Study
Authors: Mazzini Alberto , Favilla Roberto
Published: August 2018

The associative behaviour of bovine liver glutamate dehydrogenase has been studied by gel chromatography at neutral pH in 1 ᴍ guanidinium chloride and 1 ᴍ sodium chloride. In guanidinium chloride both the elution volume and the elution profile of the enzyme are independ­ent of protein concentration, whereas in sodium chloride they are strongly dependent on it. In NaCl the enzyme behaves as expected according to the well established random association model, whereas in guanidinium chloride it appears to have completely lost the self-associative property. Furthermore, since the elution volume of the enzyme in guanidinium chloride corre­sponds to that of an hexamer, trimer formation reported to occur in these conditions is not confirmed by this technique.
A Simple Analysis of Purine and Pyrimidine Nucleotides in Plant Cells by High-Performance Liquid Chromatography
Authors: Ashihara Hiroshi , Mitsui Kaori , Ukaji Toshiko
Published: August 2018

Purine and pyrimidine nucleotides, extracted from cultured plant cells with 6 % perchloric acid, were separated directly with HPLC using anion-exchange Shimpack WAX -1 column. More than fifteen nucleoside mono-, di-, and triphosphates and nucleotide sugars were clearly separated and quantified without any interference from plant phenolic compounds.
A Vitamin D3 Steroid Hormone in the Calcinogenic Grass Trisetum flavescens
Authors: Rambeck W. A. , Weiser H. , Zucker H.
Published: August 2018

The grass Trisetum flavescens (golden oat grass, Goldhafer) causes soft tissue calcification in cattle and in sheep. The calcinogenic principle of the plant is the active vitamin D steroid hormone 1,25-Dihydroxyvitamin D3, the major physiological regulator of calcium homeostasis in higher animals. From comparison with synthetic vitamin D metabolites in different bioassays, it is concluded that T. flavescens contains the 25-glucoside of 1,25(OH)2D3. This compound, or rather the 1,25(OH)2D3 liberated by ruminal fluid, is the calcinogenic factor of the grass.
In vivo Screening of Glutathione Related Detoxification Products in the Early State of Drug Development
Authors: Prox A. , Schmid J. , Nickl J. , Engelhardt G.
Published: August 2018

Glutathione (GSH) adducts and consecutive degradation products thereof are indications of reactive intermediates during drug metabolism. As demonstrated with the analgesic SX-PP 16 (4-amino-3,5-dibromacetanilide), however, interactions of a drug with GSH can be detected by labelling the GSH-stores with labelled cysteine, and consecutive administration of the unlabelled drug even at therapeutic doses. The GSH-adducts are sensitively and specifically traced by HPLC, applying column-switching and a combination of diode array-and radioactivity detection. This approach seems to be much more sensitive than a classical GSH-depletion study. The structure of the main metabolite of SX-PP 16 (46% of urinary excretion) was elucidated as 3-bromo-4-amino-5-mercapturyl-acetanilid.
Genetic Engineering of Herbicide Resistance: Saturation Mutagenesis of Isoleucine 229 of the Reaction Center L Subunit
Authors: Bylina Edward J. , Youvan Douglas C.
Published: August 2018

Oligonucleotide-mediated mutagenesis has been used to change isoleucine 229 of the reaction center L subunit of Rhodopseudomonas capsulata to seventeen other amino acids. A system of deletion strains and complementing plasmids has been used to assay the effects of changing this residue, which forms part of the secondary quinone Oв binding site. The reaction center is assembled in all seventeen mutants. Ten of the seventeen mutations (Gly, His, Tyr, Trp, Asn, Asp. Gin, Glu, Arg, and Lys) result in the loss of photosynthetic growth. The remaining seven mutations yield varying levels of photosynthetic growth (Ile, Val, Ala, Leu, Met>Thr, Cys, Ser). Six of these mutations lead to varying atrazine resistance (Met, Leu > Ser, Ala, Thr, Cys>Val, He). None of the mutations lead to atrazine sensitivity. These results suggest that hydrophobic residues of moderate size function best at this position. This set of mutations at isoleucine L229 include the first examples of mutants with null quinone function and the first examples of crystal- lography-based genetic engineering in the design of herbicide resistant reaction centers.
Photosystem II Heterogeneity in Triazine-Resistant and Susceptible Biotypes of Chenopodium album
Authors: van Rensen Jack J. S. , M. Spätjens Leon E. E
Published: August 2018

The heterogeneity of photosystem II with respect to α and β centers was investigated in triazine-resistant and susceptible biotypes of Chenopodium album . In both biotypes the light harvesting antenna sizes of photosystem II α centers was larger than those of β centers. In the resistant biotype the antenna size of the α centers was smaller than those in the susceptible one. There was not much difference in the antenna sizes of the β centers. The proportion of β centers was larger in the resistant biotype compared with the sensitive one.
Binding and Peroxidative Action of Oxyfluorfen in Sensitive and Tolerant Algal Species
Authors: Lambert R. , Sandmann G. , Böger P.
Published: August 2018

Peroxidative activity of oxyfluorfen and binding of this nitrodiphenyl ether to cell fractions was investigated with the susceptible alga Scenedesrnus aeutus and the resistant alga Bumilleriopsis filiformis. Although a 10-fold higher concentration of oxyfluorfen was applied to Bumilleriopsis, the lag phase for initiation of peroxidative evolution of short-chain hydrocarbons from fatty acids was much longer than found with Seenedesmus. Oxyfluorfen was predominantly recovered after homogenization from the pellet which was separated into a lipid and a chloroform/methanol insoluble fraction. Parts of the oxyfluorfen which is present in the insoluble pellet fraction during the lag phase before the onset of peroxidation can be found in the lipid fraction when measurable peroxidative activities have started. This was observed with Seenedesmus as well as with Bumilleriopsis. During peroxidation initiated by oxyfluorfen acyl lipids are degradated as monitored by the disappearance of the plastidic sulfolipid. Analysis of bound fatty acids showed that they are targets for peroxidative reactions in acyl lipids. Destruction of polyunsaturated fatty acids was higher than for saturated ones.
The 14β-Hydroxylation in the Biosynthesis of Cardenolides in Digitalis purpurea. The Role of 3β-Hydroxy-5β-pregn-8(14)-en-20-one
Authors: Deluca Mónica E. , Seldes Alicia M. , Gros Eduardo G.
Published: August 2018

Labelled 3β-hydroxy-5β-pregnan-20-one was incorporated by Digitalis purpurea plants into digitoxin while 3β-hydroxy-5β-pregn-8(14)-en-20-one was not. This result excluded the intermediary role of the latter compound as precursor of cardenolides in the mentioned plant.
Bioenergetics Studies of the Cyanobacterium Anabaena variabilis
Authors: Scherer Siegfried , Sadowski Heike , Böger Peter
Published: August 2018

A cell-free system exhibiting both photophosphorylation (P/2e= 1) and oxidative phosphoryltion (P/O up to 0.8) is described for the cyanobacterium Anabaena variabilis. NADH ant NADPH were found to be equally effective as electron donors for oxidative phosphorylation. Low concentrations of UHDBT, an inhibitor of the cytochrome b/c complex of mitochondria ant loroplasts, were found to inhibit photosystem-II electron transport reactions, but did not affet the cytochrome b6/f-complex of Anabaena. The inhibition by myxothiazol, antimycin and heptyihydroxyquinoline corroborates the hypothesis that both respiration and photosynthesis share the cytochrome b6/f-complex.
Efficacy of Sustained-Release Radioprotective Drugs in vivo
Authors: Shani Jashovam , Benita Shimon , Abdulrazik Muhamed , Yerushalmi Aharon
Published: August 2018

In previous publications from this laboratory we suggested the use of radioprotective drugs in a sustained-release form as a practical way to cope with their high toxicity and quick metabolism and excretion. Cysteine and cysteamine, well-established radioprotectants, were used as model drugs and compressed at various concentrations (0-65%) into an insoluble tablet matrix, composed of ethylcellulose and stearic acid at various ratios and compression pressures. We demonstrated in vitro that when the release rate of the radioprotectants was measured under nitrogen, the kinetic data conformed with the Higuchi square root of time equation, indicating that the release of both drugs correlates with Higuchi’s diffusional mechanism. In the present in vivo study, tablets containing cysteine or cysteamine in a slow-release matrix were implanted, into the stomachs of female rats. The rats were irradiated at various time intervals up to 12 h after implantation and their survival recorded daily. Utilizing a 1:3 ratio of ethylcellulose: stearic acid as a matrix, the protective effect of the drugs was remarkable eight hours after tablet implantation. The results reported indicate that slow-release tablet formulation is a possible method for delivering of radioprotective drugs over an extended period of time.
Automatic Turgor Pressure Recording in Plant Cells
Authors: Buchner K.-H. , Wehner G. , Virsik W. , Zimmermann U.
Published: August 2018

An automatically-regulated pressure probe is described, which facilitates the direct and continuous measurement of turgor pressure and water relation parameters in plant cells. An optoelectronic sensor drives a feed back system so that the position of the oil/cell sap interface in the measur­ing capillary remains constant. The sensor is easily applied to most measurement set-ups by mounting it on a focusing screen connected to the microscope used for observation. The position of the oil/cell sap boundary is sensed by its movement along the image of the capillary on the screen and can be set to any appropriate position. The optical coupling of the regulation signal is advantageous because it leaves the experimenter free to measure the electrical or other parameters of the cell. Experiments on cells of Eremosphaera viridis have shown that the device allows much faster and more exact measurements of water rela­tion parameters, and over longer periods, than the earlier method.
A New Highly Effective Synthetic Pheromone Mimic for Lobesia botrana (Lepidoptera: Tortricidae)
Authors: Brückner Christiane , Buschmann Ernst , Becker Rainer , Seufert Walter , Kramer Jacobus Jan de , Krieg Wolfgang
Published: August 2018

(Z)-9-Dodecen-7-yn-1-yl acetate (y7Z9-12Ac) (3) is suggested as a pheromone mimic for Lobesia botrana. It was synthesized in two different ways and its activity was demonstrated electrophysiologically and in behavioural laboratory and field experiments.
Chirality Evaluation of 2-Heptanol and Z-4-Hepten-2-ol from Banana Fruit Using Multidimensional Gas Chromatography
Authors: Fröhlich Otmar , Huffer Manfred , Schreier Peter
Published: August 2018

A polar fraction obtained from banana fruit pulp by high-vacuum distillation / solvent extraction (pentane-dichlorom ethane, 2 + 1) and subsequent liquid chromatography on silica gel was derivatized with isopropylisocyanate. Separation of enantiom ers of heptan-2-ol and Z-4-hepten-2-ol was performed via their carbamates by means of multidimensional gas chromatography using an achiral (D B -5, column 1) and a chiral (X E -60, column 2) capillary column. The enantiomeric ratios of heptan-2-ol and Z-4-hepten-2-ol were determ ined to be (/?)( - ) 39% and (S)( + ) 61% as well as (/? )(+ ) 26% and (S )(-) 74% , respectively. The absolute configuration of optically enriched ( 5 ) (-)-Z-4-hepten-2-ol was determined from its (R)-2-phenylpropionic acid ester by 1H NM R spectroscopy.
A New Method of Solvation Analysis: Applications to Quinones
Authors: Keske Jonathan M. , Bruce J. Malcolm , Dutton P. Leslie
Published: August 2018

A new method of analysis of the factor contributing to solvation of small molecules is described. Approximations of the energetic contributions to the entry of a molecule into water have been derived from partition coefficient data of solutes and selected derivatives from a multiplicity of solvents. These include taking separate account energy of the cost of introduction of a molecular cavity in water, the strength of solute-water dipolar interactions, and the strengths of hydrogen bond formation with water of the lone pairs and hydroxylic hydrogens associated with the molecule. In this report the solvation-free energies of benzoquinone and hydroquinone in water are described. We also consider the solvation of the sem iquinone anion and show it to be fundamentally different from that of either the quinone or hydroquinone; this is discussed as a potentiality for selective binding (“solvation”) of quinone, sem iquinone and hydroquinone in sites of redox catalysis such as those found in the photosynthetic reaction center.
Re-Activation of the Expression of Glyoxysomal Genes in Green Plant Tissue
Authors: Birkhan Ralf , Kindl Helmut
Published: August 2018

Biochemie, Fachbereich Chemie, Universität Marburg, Hans-Meerwein-Straße, D-3550 Marburg, Bundesrepublik Deutschland Z. Naturforsch. 45c, Isocitrate Lyase c DNA, Malate Synthase c DNA, Glyoxysome, Leaf Peroxisome, Transition of Organelles Glyoxysomes are being replaced by leaf-type peroxisom es during the greening of dark-grown cucumber cotyledons. Light functions in this process as negative modulator of the gene expression of glyoxylate cycle enzymes but as positive regulator for the activation of glycollate oxidase formation. The differential gene expression was investigated at the level of m RNA amounts using c DNA probes hybridizing with malate synthase m RNA, isocitrate lyase m RNA, and glycollate oxidase m RNA. Hybrid ization probes were obtained from a c DNA library complementary to the germinationspecific m RNA s of cucumber cotyledons. The process of replacem ent of glyoxysomal proteins by leaf peroxisom al proteins was reversed to a certain extend when greened cotyledons were brought back in the dark. Hybridization on Northern b lots provided evidences that in greened cotyledons the amount of malate synthase m RNA and isocitratelyase m RNA starts to increase up on dark treatment.
Flavonoid Diversity In The Liverwort Genus Monoclea Hooker*
Authors: Kraut Ludwig , Klein Rainer , Mues Rüdiger
Published: August 2018

Many samples of Monoclea gottschei from Central and South America and the Caribbean Islands have been compared for their flavonoids. The species exhibits the most diverse flavonoid pattern ever observed for a liverwort. From different chemotypes 28 flavones were isolated: 8 aglycones, 3 monoglycosides, 9 diglycosides, 6 triglycosides and 2 oligo- or polyglycosides. The chromatographic and spectroscopic data of previously unidentified compounds are presented. Samples of M . forsteri from New Zealand have been analyzed for flavonoids too, but their flavone patterns are much less diverse: 1 aglycone, 1 polyglycoside and 2 further mono-or-diglycosides were isolated. The differences in flavonoid production of both species are an additional feature for the distinction of the two Monoclea species
Alkaloid Composition of Lupinus albescens (Fabaceae) from South America
Authors: Planchuelo-Ravelo A. M , Wink M.
Published: August 2018

Alkaloid extracts of leaves and seeds of the South American taxon Lupinus albescens Hooker & Arnott were analyzed by capillary gas-chromatography (G LC ) and G LC-mass spectrometry. Multiflorine and albine figured as major, and ammodendrine, lupanine, 11,12-seco-12,13-didehydromultiflorine 13a-hydroxyultiflorine and 13-tigloyloxymultiflorine as minor alkaloids. Three new alkaloids were tentatively identified as a dehydromultiflorine, N -formylalbine and 13-methoxymultiflorine.
Hysteresis and Reversible Cold-Inactivation of ADP-Glucose Pyrophosphorylase From Barley Seeds
Authors: Kleczkowski Leszek A. , Villand Per , Olsen Odd-Arne
Published: August 2018

ADP-glucose pyrophosphorylase (AGP) from barley (Hordeum vulgare L.) seed endosperm showed a lag in activity when assayed after storage at -20 °C. The cold-stored enzyme could regain most, or all, of its activity during 40-60 min following exposure to ambient tempera­tures. The lags were not observed when 2 mM MgCl2 was added to the storage buffer before freezing. Storage at -20 °C, in the absence of MgCl2, led to the appearance of a low activity A GP form which was activated up to 3-fold by 3-phosphoglycerate (PGA) and had high Km values with ATP of 0.3 and 1.2 mM (with and without PGA, respectively). In contrast, storage at -20 °C in the presence of MgCl2 or incubation at +20 °C resulted in an active enzyme which was only weakly activated by PGA (up to 30%) and had the respective Km values with ATP of 0.1 and 0.3 mM . It is suggested that low temperature may induce a change in the conformation and/or oligomerization state of the AGP protein, resulting in a low activity enzyme form which has distinct regulatory and kinetic properties.
Interaction and Compartmentalization of the Components of Bacterial Enzyme Systems Involved in Cell Energetics
Authors: Gerberding Holger , Mayer Frank
Published: August 2018

Bacterial enzyme systems, especially those which are involved in cell energetics, often show a common characteristic feature: their constituents (either interacting enzymes or subunits of a given enzyme complex) are physically separated. They are located in different functional enti­ties, such as cytoplasm or periplasmic space. This kind of cellular and macromolecular organi­zation enables the cell to establish spatially separated but neighbouring zones in which distinct conditions are created or maintained. This intrinsic imbalance is one of the keys for the process of life. As the mediator between the two compartments, the cytoplasm and the periplasmic space, the cytoplasmic membrane -itself a functional entity -not only acts as a barrier, but carries a set of functional enzyme components, thus contributing to the interaction between compartments. Examples to illustrate this concept are enzyme systems involved in anaerobic glycine metabolism, aerobic utilization of carbon monoxide, proton or sodium translocation across the membrane, and intracellular hydrogen cycling used by the cell for the generation of a proton gradient.
UDP-D-Glucose: Flavonol 3 -0 -and 7-O-Glucosyl Transferases from Young Leaves of Paederia scandens var. mairei
Authors: Ishikura Nariyuki , Yang Zhi-qing , Teramoto Susumu
Published: August 2018

Two different O-glucosyl transferases (F3GT and F7GT ) catalyzing the transfer of ᴅ-glucose from UDP-ᴅ-glucose to the 3 and 7 positions of flavonol, respectively, were isolated from the young leaves of Paederia scandens var. mairei. F3GT and F7GT, which were recovered in about a 1:1 ratio in the activity, were purified by about 140- and 136-fold, respectively, by precipitation with ammonium sulfate followed by ion exchange chromatography and chromatofocusing. F3GT and F7GT both had a pH optimum of 7.5 in Tris-HCl buffer, and an Mr of 43 kDa. Neither F3GT nor F7GT had a Mg2+ requirement. Both were inhibited by each 1 mᴍ of Zn2+, Cu2+, N-ethylmaleimide and p-chloromercuribenzoate, and both were stimulated by 14 mᴍ 2-M E . F3GT and F7GT were different from each other in having an isoelectric point (pI) at pH 5.12 and 4.50, respectively. F3GT mediated the transfer of D-glucose exclusively to the 3-hydroxyl group of kaempferol and some flavonols, but neither the 7-O-glucosides nor the 3-O-glucosides of their flavonols were able to accept D-glucose. On the other hand, F7GT mediated the transfer of D-glucose exclusively to the 7-hydroxyl group of kaempferol and some flavonols, and in addition, the 3-O -glucosides of kaempferol and quercetin were able to accept D-glucose thoughn less efficiently. Consequently, the possibility of sequential steps of 3-O- and then 7-O-glucosylations of flavonols to give the 3,7-di-O-glucoside was discussed.
Preferential Deactivation of the S3 State of the Water-Oxidizing Complex, Favoured by Plastoquinone Reduction in Barley Chloroplasts
Authors: Franck Fabrice , Schmid Georg H.
Published: August 2018

Departement de Botanique, Service de Photobiologie, Universite de Liege, Sart-Tilman, Belgium and Georg H. Schmid