bluuebunny/crossref_metadata_2025 huggingface dataset:
Flavonoids and Terpenoids from the Exudates of Some Baccharis Species
Authors: Wollenweber Eckhard , Schober Ingrid , Dostal Pia , Hradetzky Dagmar , Arriaga-Giner Francisco J. , Yatskievych George
Published: August 2018

Seven species of the genus Baccharis have been analyzed for flavonoid aglycones. Many known methylated flavones, flavonols and flavanones were identified. From B. sarothroides, two novel flavonols were isolated and elucidated as 5,7,4′-trihydroxy-3,6,8-trimethoxyflavone and its methyl ether, 5,4′-dihydroxy-3,6,7,8-tetramethoxyflavone. Previous literature reports on flavonoids in Baccharis are summarized and their distribution and external occurrence is discussed. One novel diterpene and one rare triterpene were found in the terpenoid fractions that constitute most of the exudate material in these and other Compositae.
Transformation-Related Cellular Protein p53: Increased Level in Untransformed Rat Cells Following Treatment with the Tumorpromoter, Tetradecanoylphorbol-Acetate
Authors: Hebei Michael , Brandner Gerhard , Hochkeppel Heinz K. , Braun Dietmar G.
Published: August 2018

12-O-Tetradecanoylphorbol-13-acetate (TPA, 100 ng ml-1), a tumor promoting phorbol ester, is able to induce enhanced levels of the transformation-associated cellular antigen p53 in normal rat2 cells which had not been previously initiated by a carcinogen. p53 was estimated in ethanolfixed treated cells on microtiter plates with ELISA using the monoclonal antibody Pab 1620 [EMBO J. 7, 1485, (1984)]. Induction of p53 was confirmed by immunoblotting. This effect of TPA is an additional phenotypic characteristic of tumor cells which can be induced by TPA in untransformed rodent cells.
Glykosphingolipid-Analyse von menschlichen myeloischen Leukämien / Glycosphingolipid Analysis of Human Myeloid Leukemias
Authors: Kniep Bernhard , Mühlradt Peter F.
Published: August 2018

Neutral glycosphingolipids of human myeloid leukemia cells in different differentiation stages from nine patients were analyzed by high performance liquid chromatography. All cells contained ceramide monohexoside, lactosylceramide and neutral glycosphingolipids of the lacto-series. However, some of the leukemic cells contained neutral glycosphingolipids of the globo-series. Especially myelomonocytic cells (French-American-British or FAB classification M4) and poorly differentiated cells (FAB MO and M1) were found to contain globo glycosphingolipids. On myeloblast cells, (FAB M2), globo glycosphingolipids were missing or present only in very low amounts. It seemed, therefore, that on myeloid leukemic cells the glycosphingolipid composition may be dependent on their differentiation stage.
Metabolism of the Plant Growth Regulator (E)-[3H]2-Ethylhex-2-enoic Acid in Hordeum vulgare
Authors: Schneider Bernd , Schütte Horst-Robert , Preiss Alfred
Published: August 2018

The metabolism of (E)-[3H]2-ethylhex-2-enoic acid (EHA) was studied in excised seedlings of barley (Hordeum vulgare). It was rapidly taken up from the nutrient medium. The metabolites, isolated by extraction with methanol, separated and purified by TLC and HPLC, were identified by enzymatic, chemical, and spectrometric methods, especially 1H-NMR spectroscopy.

The time course of metabolism during 6 , 12, 24, 48, and 72 h is presented, indicating interconversation reactions. A rapid conjugation with glucose was observed, decreasing in concentration again after longer time periods in favour of disaccharide esters, higher conjugates, and a hydroxylation product which was present in free and conjugated form.
Chemical Investigations of Tropical Medicinal Plants, XXI [1] Long Chain Alkyl Esters of Ferulic and p-Coumaric Acid from Bauhinia manca
Authors: Achenbach Hans , Stöcker Markus , Constenla Manuel A.
Published: August 2018

17 Esters of ferulic acid and p-coum ric acid were isolated from the stem extract of Bauhinia manca ; the alcohol components range from C22H45 to C28H57.
Genetic and Biochemical Studies on the Conversion of Dihydroflavonols to Flavonols in Flowers of Petunia hybrida
Authors: Forkmann G. , Vlaming P. de , Spribille R. , Wiering H. , Schram A. W.
Published: August 2018

Soluble enzyme preparations from flower buds of Petunia hybrida catalyzed the conversion of dihydroflavonols to flavonols. Dihydrokaempferol and dihydroquercetin were readily converted to the respective flavonols, whereas dihydromyricetin was a poor substrate. The reaction required 2-oxoglutarate, ascorbate and Fe2+ as cofactors and had a pH optimum at about 6.5. In the presence of the dominant allele Fl, high enzyme activity for flavonol formation was found, whereas in enzyme preparations from flower buds of recessive genotypes (fl/fl) only low enzyme activity could be observed. A substantial correlation was found between enzyme activity for flavonol formation and the flavonol content of buds and flowers during development.
Volatiles from Liquid Cultures of Lentinellus cochleatus (Basidiomycotina)
Authors: Hanssen Hans-Peter , Abraham Wolf-Rainer
Published: August 2018

The basidiomycete Lentinellus cochleatus CBS 201.47 was cultivated on a defined synthetic liquid culture medium containing glucose (2%), asparagine (0.15%), malt extract (0.2%), and mineral salts. 12 weeks old cultures produced a “sweet” odour with an anise-or cinnamon-like note. 3 major volatiles could be identified from the steam distillates by their GC/MS-and 1H NMR data. Predominant constituents were the acyclic sesquiterpene alcohols trans-nerolidol (41.4%) and fokienol (14.8%). 2,2-Dimethyl-6-formylchromene (6.1%) is described for the first time as a natural product. Besides these, 15 minor constituents could be identified or chemically charac­terized, respectively, the majority of them being sesquiterpene hydrocarbons and alcohols.
A Simple and Rapid Method for Isolation of 124 kDa Oat Phytochrome
Authors: Grimm Rudolf , Rüdiger Wolfhart
Published: August 2018

Native (124 kDa) phytochrome has been isolated from etiolated oat seedlings in 25% yield. The procedure includes only one chromatographic step namely a hydroxylapatite column, besides several centrifugation steps. Large scale preparations with 3 kg of fresh tissue are completed within 16 h. The purity of isolated phytochrome is as good as or even better than that of previous preparations as deduced from SDS gelelectrophoresis and from the absorbance ratio A667 / A280 = 0.99
Investigation of the Peptide Chain of 124 kDa Phytochrome: Localization of Proteolytic Fragments and Epitopes for Monoclonal Antibodies
Authors: Grimm Rudolf , Lottspeich Friedrich , Schneider Hansjörg A. W. , Rüdiger Wolfhart
Published: August 2018

Isolated oat phytochrome (124 kDa) was digested with endogenous proteases from oat and with trypsin. Fragments were isolated by SDS polyacrylamide gel electrophoresis (PAGE) blotted onto an activated glass fiber sheet and applied to microsequencing. Comparison of the amino terminal sequences of the fragments with the complete amino acid sequence derived from DNA sequence studies (Hershey et al., Nucleic Acid Res. 13, 8543 - 8560, [1985]) allowed the exact localization of each fragment. The reaction of the various fragments with monoclonal antibodies raised against 114/116 or 124 kDa oat or maize phytochrome were tested by means of Western blotting. Differential reactivity of the localized fragments allowed the localization of epitopes for several antibodies.
Effect of External Calcium Concentration on the Intensity Dependence of Light-Induced Membrane Current and Voltage Signals in Two Defined States of Adaptation in the Photo-Receptor of Limulus
Authors: Stieve H. , Gaube H. , Klomfaß J.
Published: August 2018

The intensity dependence of the response of the Limulus ventral nerve photoreceptor to light flashes was determined in alternating measurements for the membrane current signal (receptor current) under voltage clamp conditions and the membrane voltage signal (receptor potential). Responses were obtained at two reproducible states of adaptation, while the photoreceptor was superfused by physiological saline (10 mmol/l Ca2+), or by salines with either lowered (250 μmol/l) or raised (40 mmol/l) calcium concentration.

For the dark-adapted state of the photoreceptor the double logarithmic plot of the response current-time integral F (or the current amplitude) vs. flash intensity rises in a steep, supralinear section (slope 2-4) to a curve knee towards a less steep, sublinear section (slope 0.2-0.6), but does not reach saturation in the intensity range tested. Light adaptation shifts the response size vs. intensity curve towards higher light intensities. This sensitivity shift is enlarged in raised, and almost abolished in low external [Ca2+].

The changes of response latency and time-to-peak with stimulus intensity or adaptation are almost identical for receptor current and receptor potential. The decrease-time of the receptor current response, however, depends much less on the stimulus intensity or the state of adaptation than that of the receptor potential. The relative changes in the time course of the receptor current caused by light adaptation are not much influenced by variation of the [Ca2+]ex.

Interpretation: The macroscopic receptor current signal consists of a volley of overlapping bumps; the size of these bumps is scaled by a calcium-dependent attenuation function which increases with delay time. This gradual growing attenuation a(t) acts as automatic gain control and may be responsible for the sublinear slope of the intensity dependence of the size of the receptor current. The supralinear slope of this dependence at lower stimulus intensities is probably caused by cooperative effects. Changes in the time course of the macroscopic receptor current due to light adaptation or varied calcium concentration are based on changes in the latency distribution of the underlying bump volley, and the size of the attenuation function.
Rearrangement of Glaucolide A into Vernojalcanolide 8-O-Methacrylate
Authors: V. Mariano Martínez , F. Antonio Sánchez , B. Guadalupe López , Joseph-Nathan Pedro
Published: August 2018

The isolation of vernojalcanolide 8-O-methacrylate, a cadinanolide sesquiterpene from Vernonia morelana D .C . is described. The rearrangement of glaucolide A into ver­nojalcanolide 8-O-methacrylate is also reported. Biogene­tic aspects are briefly discussed.
Microfilament-Supported Macrovilli in the Hindgut of the Polychaete Dinophilusgyrociliatus
Authors: Oster Ulrich
Published: August 2018

Large macrovilli of 7.7 μm maximal length and a diameter of 0.4 μm with several hundred cytochalasin B-sensitive 6 nm microfilaments are found as bordering lateral struc­tures in the ciliary groove of the hindgut of Dinophilus gyrociliatus. The microfilament bundle, accompanied by microtubules, extends with its tapering rootlets to the base of the cells. Another cell type in the middle of the groove bears the cilia and equally broad, but shorter macrovilli with a cytochalasin-sensitive microfilament core.
Siderophore vom Pyoverdin-Typ aus Pseudomonas aeruginosa [1] / Pyoverdine Type Siderophores from Pseudomonas aeruginosa
Authors: Briskot G. , Taraz K. , Budzikiewicz H.
Published: August 2018

From Pseudomonas aeruginosa three siderophores belonging to the pyoverdine group have been isolated which differ only in the acid side chains bound to the quinoline chromophore.
4-O-β-ᴅ-Glucosides of Hydroxybenzoic and Hydroxycinnamic Acids — Their Synthesis and Determination in Berry Fruit and Vegetable
Authors: Schuster Bernhard , Winter Michael , Herrmann Karl
Published: August 2018

Protocatechuic acid-4-, gallic acid-4-, caffeic acid-4-, ferulic acid- and p-coumaric acid-O-β-ᴅ-glucoside were synthesized. These substances were characterized by UV, 1H NMR, 13C NMR and FAB-MS. Their proportions in berry fruit and vegetable were determined by means of HPLC and capillary GC.
1-acetyl-S-indolylmethylglucosinolate in Seedlings of Tovaria pendula Ruiz et Pav.
Authors: Schraudolf Helmut , Bäuerle Rolf
Published: August 2018

The existence of 1N-acetyl-3-indolylm ethylglucosinolate in young seedlings of Tovaria pendula Ruiz et Pav. has been proven by HPLC and mass-spectrometric methods. This compound is accompanied by 4-hydroxy-glucobrassicin, glucobrassicin, 4-methoxy-glucobrassicin and neoglucobrassicin (1N-methoxy-glucobrassicin).
Increased Lipoxygenase Activity is Involved in the Hypersensitive Response of Wheat Leaf Cells Infected with A virulent Rust Fungi or Treated with Fungal Elicitor
Authors: Ocampo Carlos A. , Moerschbacher Bruno , Grambow Hans J.
Published: August 2018

The hypersensitive reaction in incompatible wheat-rust interactions is characterized by an increase in lipoxygenase activity detectable as early as 28 h after penetration of the pathogen. In contrast, lipoxygenase activity in the compatible interaction did not increase until the onset of sporulation.

Lipoxygenase activity also increased following treatment of wheat leaves with an elicitor fraction from germ tubes of Puccinia graminis tritici.
Structure Investigations of Agonists of the Natural Neurotransmitter Acetylcholine, IV [1]. X-Ray Structure Analyses of Trimethylpentylammonium-chloride and (4-Acetoxybutyl) trimethylammonium-iodide
Authors: Gieren Alfred , Kokkinidis Michail
Published: August 2018

The crystal structures of the title compounds which display cholinergic activity at the ganglionic receptor have been determined by X-ray structure analysis. [(CH3)3N+C5H11]Cl- (1) crystallizes in the orthorhombic space group Pbnm with half a formula unit per asymmetric unit, a = 11.381(14). b = 12.871(17), c = 7.316(4) Å. The intensities of 1106 independent reflections were collected with an automatic diffractometer. The structure refinement converged at R = 0.133 for the 355 observed reflections. The cation of 1 is disordered. [(CH3)3N + (CH2)4-O-C(O)-CH3]I- (2) crystallizes in the orthorhombic space group P212121 with four formula units per unit cell, a = 16.783(8), b = 10.276(6), c = 7.427(10) Å. The intensities of 1469 independent reflections were collected. The structure refinement converged at R = 0.071 for 1383 observed reflections. In both compounds the trimethylammonio methyl groups are coordinated nearly tetrahedrally by four anions in the first coordination sphere. Anions which occupy a special face type (B) of the tetrahedron of the (CH3)3N+ -CH2-group may be treated as a “model binding site” of the receptor. In the crystal structure of 2 the anions occupying B-type faces form together with the ammonium nitrogen and the carbonyl oxygen so called “Activity triangles”. The almost equal geometries of these activity triangles are correlated with the mode of pharmacological action.
Selective Abolition of Sarcoplasmic Reticulum Vesicles’ Calcium Releasing Mechanisms
Authors: Hasselbach Wilhelm , Ungeheuer Martina , Migala Andrea , Ritter Karl
Published: August 2018

The ability of calcium lo ad ed heavy sarcoplasmic reticulum vesicles to specifically respond to the addition of various agents such as caffeine, calcium ions and calmodulin antagonists to rapidly released calcium can largely be diminished by passing the vesicular suspension in 0.3 м sucrose, 0.6 m KCl, 4 mм C Cl2, pH 7.0 through a Sepharose 6 B column or by centrifuging it through a sucrose gradient prepared with the same salt medium. Inactivation of calcium release does neither interfere with calcium uptake nor with the unspecific releasing effect caused by the application of high concentrations of calmodulin antagonists.
Esters of Benzyl Alcohol and 2-Phenyl-ethanol-1 in Epicuticular Waxes from Jojoba Leaves
Authors: Gülz Paul-Gerhard , Marner Franz-Josef
Published: August 2018

Esters of very long chain fatty acids with benzyl alcohol and the homologue 2-phenyl-ethanol-1 were found in the epicuticular waxes from Jojoba (Simmondsia chinensis) leaves. The isolation of these esters by chromatographic methods, the structural elucidation by GC-MS and their chemical reactions and synthesis are described.
UDP-Glucose: Anthocyanidin/FIavonol 3-O-Glucosyltransferase in Enzyme Preparation from Flower Extracts of Genetically Defined Lines of Matthiola incana R. Br.
Authors: Teusch M. , Forkmann G. , Seyffert W.
Published: August 2018

In flower extracts of Matthiola incana an enzyme catalyzing the transfer of glucose from UDP- glucose to the hydroxyl group at 3-position of anthocyanidins and flavonols was demonstrated. The pH-optimum of this reaction is at pH 8.5 for pelargonidin and pH 9.5 for quercetin as substrate. The reaction is inhibited by both substrates above 10 nmol per assay. The enzyme is highly active, within 30 sec 3 nmol of 3-glucosides were formed. At 30 °C the enzyme is stable for hours and at -20 °C months. Besides UDP-glucose, TDP-glucose is a suitable glucosyl-donor, but with a reduced (70%) reaction rate. Enzyme activity is clearly inhibited by Fe2+ and Cu2+ ions, and by diethylpyrocarbonate. Acyanic or pale coloured mutants of several genes interfering with anthocyanin synthesis after dihydroflavonol formation show a more or less drastically reduced enzyme activity (5-40%). But none of these genes can be regarded as the structural gene for the 3-glucosyltransferase. The influence of these genes on enzyme activity and flower colour is dis­cussed.
Cyanidin 3-Oxalylglucoside in Orchids
Authors: Strack Dieter , Busch Ekkehard , Wray Victor , Grotjahn Lutz , Klein Erich
Published: August 2018

A new acylated anthocyanin has been isolated from flowers of Nigritella and Orchis and identified as cyanidin 3-O-β-(6”-O-oxalyl)-glucoside on the basis of TLC , HPLC , FABMS, 1H and 13C NMR . This pigment was found to be present in various members of the Orchidaceae.
Nitrogen and Sulfur Starvation of the Cyanobacterium Synechococcus 6301 An Ultrastructural, Morphometrical, and Biochemical Comparison
Authors: Wanner G. , Henkelmann G. , Schmidt A. , Köst H.-P.
Published: August 2018

The effects of nitrogen and sulfur limitation on various cellular parameters of the cyanobacterium Synechococcus 6301 were studied by electron microscopy, morphometry and biochemical methods. Nitrate and sulfate starvation for 70 h results in a massive glycogen accumulation in parallel to a loss of soluble protein and chlorophyll. Phycobilisomes disappear prior to the degradation of photosynthetic membranes. For sulfate-starved cells, a formation of “storage granules” (poly-β-hydroxy-butyric acid) is typical which amount up to 10% of the cell volume. The composition of polar lipids is simple: equal parts of C 16:0 and C 16:1 are present under all nutritional conditions; their amount is directly correlated with the total cellular membrane area as deter­mined by morphometry.

Nitrate starved cells regenerate almost completely in structure and composition within 9 h after nitrate supplementation. Regeneration of sulfate starved cells is retarded; in spite of significant synthesis of phycocyanin within 9 h the cells still exhibit marked signs of starvation.
Conjugated Enamino Compounds, a New Molecular Probe for the Mechanism of Photosynthetic Electron Transport
Authors: Asami Tadao , Takahashi Nobutaka , Yoshida Shigeo
Published: August 2018

A series of 2-(1-alkylamino)vinylidene-1,3-cyclohexanedione was synthesized and assayed as inhibitors of the Hill reaction in isolated chloroplasts. The pI50 value of this series was dramatically changed by modification of the peripheral of its hydrophilic moiety and the maximum pI50 value of this series was almost equal to that of DCMU . The results suggest that this series may be a good probe for searching the environment of inhibitors binding site because of its chemical and biological characteristics and its ease of synthesis.
Azadirachtin, a Chemical Probe for the Study of Moulting Processes in Rhodnius prolixus
Authors: Garcia Eloi S. , Uhl Marianne , Rembold Heinz
Published: August 2018

The effects of azadirachtin A after injection into timed 4th-instar nymphs of Rhodnius prolixus were studied. A dose-response relationship of Aza A was established using moulting inhibition and mortality as effective parameters. Aza A , if injected 1 to 3 days after blood feeding, inhibited the moulting process. However, if injected during and after the onset of epidermal mitosis, ecdysis was not affected. A single dose of Aza A was able to block the onset of mitosis in the epiderm is, which is associated with the moulting cycle and is triggered by moulting horm one. Ecdysteroid titres, determined by radioimmunoassay, were too low for an induction of ecdysis in the Aza A treated nymphs. During the peak maximum, the predom inant ecdysteroid was 20-hydroxyecdysone. The conjugated ecdysteroids were based on 20-hydroxyecdysone and ecdysone in the same ratio. The significance of these findings in relation to the possibility of Aza A to act either directly on the prothoracic glands or indirectly through releasing sites in the brain or through Corpus allatum is discussed.
Protein Phosphorylation — Dephosphorylation in the Cytosol of Pea Mesophyll Cells
Authors: Hracky Ruth , Soll Jürgen
Published: August 2018

Soluble protein kinase and protein phosphatase activities were localized in the cytosol of pea mesophyll cells using protoplasts fractionation techniques. The molecular weights of the phosphorylated cytosolic proteins, as determined by polyacrylamide gel electrophoresis, were 68, 55, 46, 38, 36, 30, 22 and 12 kDa. Histone and, to a much lesser extent, casein but not phosvitin were accepted as exogenous substrates. In every case serine served as acceptor amino acid for the phosphate residue. The protein phosphorylation activity had an alkaline pH optimum, and showed no response to varying Mg-2, Ca2+, Pi cyclo-AMP or calmodulin concentrations. The kinase activity was competitively inhibited by ADP and pyrophosphate with apparent Ki values of 0.5 and 0.17 mᴍ , respectively. High ATP concentrations (1-4 mᴍ) resulted in a strong decrease of radioactivity in the 32P labeled proteins. It is proposed that the ratio of protein phosphorylation to protein dephosphorylation is regulated by the ATP to ADP ratio in the cytosol.
Biosynthesis and Turnover of Cell Wall Glycoproteins during the Vegetative Cell Cycle of Chlamydomonas reinhardii
Authors: Voigt Jürgen
Published: August 2018

Biosynthesis and turnover of the different cell wall components have been studied during the vegetative cell cycle of Chlamydomonas reinhardii by pulse-labelling with [3H]proline and [35S]methionine and by pulse-chase experiments. Two phases of biosynthesis of insoluble cell wall material could be distinguished:

1. de novo synthesis of the daughter cell walls during cytokinesis and

2. cell wall enlargement during cell growth.

During the cell enlargement period, a turnover of the insoluble wall component was observed.

The released fragments were found to be accumulated in the culture medium.

The LiCl-soluble cell wall glycoproteins were found to be precursors of the insoluble cell wall layer. Biosynthesis of the LiCl-soluble cell wall glycoproteins was observed mainly during the time period between cytokinesis and the end of the following cell enlargement period. Labelling of all the cell wall components was found to be strongly reduced during the time period between the end of the growth phase and cytokinesis.

During cytokinesis, labelling of the insoluble cell wall material preceded the incorporation of radioactive precursors into the LiCl-soluble wall fraction.
The C-Glycosylflavone Pattern of Passiflora incamata L.
Authors: Geiger Hans , Markham Kenneth R.
Published: August 2018

From the herbage of Passiflora incarnata have been isolated eight flavone-C-glycosides based on apigenin and luteolin, six of them had not been found before in that plant. The constitution of all compounds is prooven.
Glutamic Acid-1-semialdehyde, a Hypothetical Intermediate in the Biosynthesis of 5-Aminolevulinic Acid
Authors: Kah A. , Dörnemann D.
Published: August 2018

Whether glutamate-1-semialdehyde (G-1-SA) or 4,5 dioxovalerate (DOVA) is the intermedi­ate between glutamate and ALA in the C-5 tetrapyrrol pathway is still a matter of controversy. Since no data characterizing G-1-SA are available it is not possible either to identify G-1-SA as intermediate or a precursor of ALA. Therefore, attempts were made to establish a chemical synthesis of this compound. Two strategies were developed: starting from protected glutamate via an open chain mechanism or from the cyclic compound pyroglutamic acid or derivatives. None of the attempts were successful. Both approaches yielded undefined polymeric products when it was tried to liberate G-1-SA from the last intermediate of the synthesis sequence.
Magnetotactic Bacteria from Freshwater
Authors: Oberhack Matthias , Süssmuth Roland , Frank Hermann
Published: August 2018

Four species of magnetotactic bacteria have been detected in alkaline waters with pH 7.4-8.7. They were of coccoid to rod-like shape. Each of the species showed different patterns of movement. Two various types of magnetosomes, a chain-like arrangement and a scattered distributional pattern and a lateral polytrich flagellated type could be demonstrated with the coccoid species.
Re-Investigation of the Protein Structure of Coenzyme B12-Dependent Diol Dehydrase
Authors: Tanizawa Katsuyuki , Nakajima Nobuyoshi , Toraya Tetsuo , Tanaka Hidehiko , Soda Kenji
Published: August 2018

We have purified diol dehydrase, an adenosylcobalamin-dependent enzyme, from Klebsiella pneumoniae by two different procedures to re-investigate its protein structure; one including its extraction with detergent from the membrane fraction, and the other consisting of only chromato­graphic separations of the soluble fraction. The enzyme preparations obtained by these two methods were different in the subunit structure, but both are identical in molecular weight, and in enzymological and immunochemical properties. In addition, the enzyme preparation obtained from the membrane fraction dissociated reversibly into two dissimilar protein components (F and S) in the absence of substrate, as did the preparation from the soluble fraction. Although the subunit multiplicity of component S might be partly due to proteolytic cleavage during the enzyme purification as revealed by limited digestion with trypsin, component F is not a product of proteolytic cleavage of component S, but a primordial and essential constituent of the enzyme.
Characterization of Some Claviceps Strains Derived from Regenerated Protoplasts
Authors: Schumann Brigitte , Maier Walter , Gröger Detlef
Published: August 2018

Three ergoline alkaloids producing Claviceps strains easily formed protoplasts when treated with snail digestive extract ex Helix pomatia. Colonies obtained after regeneration of protoplasts were monitored for alkaloid production. Among the regenerated progeny strains could be isolated which differ considerably in the quantity of ergolines and the composition of the alkaloid mixture compared with parental strains. Protoplast-derived strains were stable in morphology and alkaloid production for more than four years if the propagation was performed with hyphal fragments. Activities of some alkaloid-specific enzymes e.g. oxygenases and ergotamine syntheta­se were studied in various related strains.
Semicontinuous and Continuous Production of Citric Acid with Immobilized Cells of Aspergillus niger
Authors: Eikmeier H. , Rehm H. J.
Published: August 2018

The citric acid excretion of Ca-alginate-immobilized cells of Aspergillus niger in batch culture decreased with a half-time of approximately 19 days. Reactivation of the biocatalysts by regeneration in growth medium was possible, but it was followed by a submerged sporulation of the fungus, and medium was highly contaminated with free cells. Citric acid production could better be prolonged by semicontinuous cultivation with medium exchange every 7 or 14 days, respectively. After 32 days the remaining activity in semicontinuous culture was 1.4-fold higher than in comparable batch experiments. Similar improvements were obtained with a continuous process at a dilution rate of 0.125 v/v · d, whereby medium efflux completely free of detaching mycelia.
6-Methylpurine, 6-Methyl-9-β-ᴅ -ribofuranosylpurine, and 6-Hydroxymethyl-9-β-D-ribofuranosylpurine as Antiviral Metabolites of Collybia maculata (Basidiomycetes)
Authors: Leonhardt Klaus , Anke Timm , Hillen-Maske Elisabeth
Published: August 2018

6-Methylpurine (1), 6-methyl-9-β-ᴅ -ribofuranosylpurine (2) and 6-hydroxymethyl-9-β-ᴅ -ribo- furanosylpurine (3) were isolated from mycelial cultures of Collybia maculata and their antifungal, cytotoxic and antiviral activities investigated. This is the first report on the natural occurrence of these compounds.
Functional Group Recognition of Pheromone Molecules by Sensory Cells of Antheraea polyphemus and Antheraea pernyi (Lepidoptera: Saturniidae)
Authors: Bestmann H. J. , Cai-Hong Wu , Döhla B. , Li-Kedong  , Kaissling K. E.
Published: August 2018

The pheromone components of A. polyphemus, (6 E, 11 Z)-6 ,11-hexadecadienyl acetate and (6 E, 11 Z)-6 ,11-hexadecadienal, both effective also in A. pernyi, were synthetically varied in their chemical structures and these compounds electrophysiologically tested in single cell recordings. It appeared that for the interaction between the signal molecule and the receptor region at the dendritic membrane of the receptor cell the electronic character of the functional end group (acetate or aldehyde) of the stimulus molecule is important. The excitation of the sensory cell also depends on the chain length.
Metabolism of the Herbicide 2-(2,4-Dichlorophenoxy)-propionic Acid (Dichlorprop) in Barley (Hordeum vulgare)
Authors: Bärenwald Gabryele , Schneider Bernd , Schütte Horst-Robert
Published: August 2018

The metabolism of the herbicide [14C]2-(2,4-dichlorophenoxy)-propionic acid (dichlorprop) was studied in excised seedlings of barley (Hordeum vulgare). It was rapidly taken up and metabolized by the plants yielding 5 metabolites. The metabolites, isolated by extraction with aqueous acetone, separated and purified by TLC, were identified by enzymatic, chemical, and spectrometric methods. Hydroxylation takes place at the 4-position of the aromatic ring, involving the NIH-shift of the chlorine to the 5-position and, to a minor extent, to the 3-position. The parent compound and also the 4-hydroxy derivatives undergo conjugation with mono- and diglucoses at the carboxyl and at the hydroxyl group, respectively. The time course of metabolism during 24, 48, and 72 h is presented, indicating interconversion reactions.
Synthesis, Analysis and Characterization of the Coenzyme A Esters of o-SuccinyIbenzoic Acid, an Intermediate in Vitamin K2 (Menaquinone) Biosynthesis
Authors: Kolkmann Rainer , Leistner Eckhard
Published: August 2018

One of the carboxyl groups of o-succinylbenzoic acid (OSB, 1) is activated during the biosyn­ thesis of vitamin K2 and anthraquinones. In an attempt to determine the exact structure of the naturally occurring OSB coenzyme A thioester, the three possible esters were prepared via the imidazolides of OSB. HPLC systems were developed for the successful separation of the esters and their structural analogues. The structures of the coenzyme A esters were investigated and their products of hydrolysis determined quantitatively. Two of the esters were highly labile at pH 7 and 30 °C. UV spectroscopy is a suitable method to distinguish between different positions of activation. Fast atom bombardment mass spectrometry was successfully employed to charac­ terize two of the esters.

The data strongly indicate that the “aliphatic” coenzyme A ester is the intermediate in vitamin K2 and anthraquinone biosynthesis.
Energy-Dependent Chlorophyll Fluorescence Quenching in Chloroplasts Correlated with Quantum Yield of Photosynthesis
Authors: Krause G. Heinrich , Laasch Henrik
Published: August 2018

Chlorophyll a fluorescence quenching was studied in intact, CO2 fixing chloroplasts isolated from spinach. Energy-dependent quenching (qᴇ), which is correlated with the light-induced pro­ ton gradient across the thylakoid membrane presumably reflects an increase in the rate-constant of thermal dissipation of excitation energy in the photosynthetic pigment system . The extent of qᴇ was found to be linearly related to the decrease of quantum yield of photosynthesis. We suggest that this relationship indicates a dynamic property of the membrane to adjust thermal dissipation of absorbed light energy to the energy requirement of photosynthesis.
Reactivation of Streptolysin S by Oligonucleotide
Authors: Taketo Akira , Taketo Yoriko
Published: August 2018

Oligonucleotide-streptolysin S complex inactivated by alkali treatment remains nonhemolytic, even after acidification and mixing with intact carrier oligonucleotide rich in guanyl residue. Upon dehydration, how ever, the inactive streptolysin S-oligonucleotide mixture turned to be hemolytic, and this reactivation of the hem olysin was promoted by treatment with guanidine hydrochloride. After alkaline hydrolysis, streptolysin S was freed from nucleotide moiety, by gel filtration through a Sephadex G -50 column. From this nonhemolytic apotoxin as well, active streptolysin S complex was reconstructed upon dehydration with the carrier.
Stereospecific Inhibitor Probes of the PS II Herbicide Binding Site
Authors: Huppatz John L. , Phillips John N.
Published: August 2018

The influence of steric factors on the activity of 2-cyanoacrylic esters as inhibitors of the Hill reaction was examined. The spatial arrangement of the different groups in the inhibitor molecule was found to be an important factor in determining potency. The positioning of the phenyl ring in aralkylamino derivatives and the steric properties of the β-substituent are particularly significant in the interaction of molecules with the) hydrophobic domain of the receptor site. The difference in activity observed with optically active α-methylbenzylamino derivatives confirmed the importance of the orientation of the phenyl ring and indicated an interaction with a specific hydrophobic region.
Cyanoacrylate Inhibitors of the Hill Reaction IV. Binding Characteristics of the Hydrophobic Domain
Authors: Huppatz John L. , Phillips John N.
Published: August 2018

Aryl- and aralkyl-amino derivatives of 2-cyanoacrylic esters were synthesized and assayed as inhibitors of the Hill reaction in isolated pea chloroplast fragments.

Aryl- and aralkyl-amino 2-cyanoacrylates unsubstituted in the β-position were weak inhibitors but activity could be greatly enhanced by inclusion of a β-alkyl group with the increase in potency being dependent on the carbon chain length of the β-substituent. The magnitude of this effect appeared independent of the nature of the aryl- or aralkyl-amino function.

Inclusion of a carbon chain between the phenyl and amino functions of phenylamino-2-cyano- acrylates produced a stepwise increase in activity with increasing chain length, indicating a prefer- red orientation for the phenyl ring within the hydrophobic binding domain.
Herbicide and Quinone Binding to Chromatophores and Reaction Centers from Rhodobacter sphaeroides
Authors: Oettmeier Walter , Preuße Silvana
Published: August 2018

Besides s-triazine and triazinone herbicides the chromone stigmatellin and tetrahalogen-substituted 1.4-benzoquinones are inhibitors of photosynthetic electron flow from reduced cytochrome c to ubiquinone-6 in isolated bacterial reaction centers. With isolated bacterial chromatophores binding experiments with radiolabeled herbicides can be performed in a similar way as with thylakoids from higher plants. Tetrahalogen-substituted 1.4-benzoquinones in a Michael type reaction can add onto nucleophilic groups in proteins. In bacterial reaction centers, a [14C]tetra- bromo-1.4-benzoquinone (bromanil) exclusively binds to the H-subunit.
Can Quantitative Structure Activity Analyses and Molecular Graphics Assist in Designing New Inhibitors of Photosystem II?
Authors: Draber Wilfried
Published: August 2018

A calculation, based on various plausible assumptions, shows that under optimal conditions a rate of less than 10 g/ha of a potent photosynthesis inhibitor would be sufficient for good herbidical action. The possibility to achieve this by computer assisted drug design (CADD) is discussed. In order to provide some background, several methods of “classical” OSAR and the most frequently used parameters are discussed. Moreover, some aspects of molecular graphics are described. This powerful new CADD-method gives results that are qualitatively different from QSAR. It is not only intellectually demanding but also expensive with regard to hard- and software. In conclusion, one successful QSAR-based prediction of a herbicide is reviewed.
Structural and Physiological Comparisons of Triazine-Susceptible, -Resistant, and "Mixed" Biotypes of Poa
Authors: Vaughn Kevin C. , Gasquez Jacques
Published: August 2018

Triazine-resistant (R) biotypes of several dicot weed biotypes have been shown to differ from triazine-susceptible (S) biotypes both structurally and biochemically. To this point, no R monocot has been examined, however. In this report, we examine the ultrastructure and physiology of three biotvpes of Poa annua L.: a S biotype, a R biotype, and a “mixed” (M) biotype that displays a level of resistance just slightly less than the R biotype, as well as a unique fluorescence in the so- called M region of the fluorescence induction curve. Like the dicots investigated previously, the R and M biotypes have larger grana stacks, and more light-harvesting chlorophyll alb protein than the S biotype. These are similar to the differences described between “shade-type” and “sun- type” chloroplasts although anatomical parameters, that normally vary between sun and shade type plants, do not appear to be different in the three biotypes. These data indicate that the structural and biochemical modifications of the chloroplast reported previously in R biotypes of dicots are also found in R biotypes of monocots and further indicate that these are natural consequences of the slower electron transport found in R biotypes.
Interconversion of Prenyl Pyrophosphates and Subsequent Reactions in the Presence of FMC 57020
Authors: Sandmann Gerhard , Böger Peter
Published: August 2018

In vitro studies of the influence of FMC 57020 on terpenoid biosynthesis have shown that this herbicide acts at an early stage. It affects the conversion of isopentenyl pyrophosphate to geranylgeranyl pyrophosphate catalyzed by isopentenyl pyrophosphate isomerase and prenyl transferase. An inhibition of the carotenogenic enzymes phytoene desaturase, ζ-carotene desaturase, and lycopene cyclase could be excluded.

Comparison of I50 values for in vivo chlorophyll, carotenoid, ergosterol and gibberellin biosyn- thesis as well as in vitro formation of phytoene. phytol and kaurene in various autotrophic and heterotrophic organisms have shown that terpenoid biosynthesis in the chloroplast is much stronger affected than extraplastidic terpenoid formation.
Use of Pyruvate-Phosphate Dikinase as a Target for Herbicide Design: Analysis of Inhibitor Specificity
Authors: Lawyer Arthur L. , Kelley Sarita R. , Allen Judith I.
Published: August 2018

Pyruvate-phosphate dikinase (PPDK) was targeted for inhibitor design because of its central role in C4-type photosynthetic carbon metabolism and its relative absence in C3-type plants and organisms of the animal kingdom. Compounds were tested for their activities as reversible and irreversible inhibitors of PPDK isolated from maize. The relative activity of the test compounds against phosphoenolpvruvate carboxylase (PEPCase), isolated from wheat, was used as a measure of the specificity of the inhibitors for the targeted enzyme. PPDK. An ideal compound for successful herbicide design should be an inhibitor which is specific toward the targeted enzyme and either effectively inhibits enzyme activity at very low concentrations or inactivates the enzyme through an irreversible mechanism. Using results obtained with commercially purchased compounds. the discussion will emphasize the difficulty of obtaining specific inhibitors toward PPDK. Another report from this laboratory (A. L. Lawyer. S. R. Kelley, and J. I. Allen, in: Proc. Seventh Internat. Congr. Photosynth. (.I. Biggins, ed.). in press) emphasizes other results obtained from the targeting of PPDK for herbicide activity.
Chemical Control of Photorespiration: Steady-State Kinetic and Conformational Changes of Ribulose-1,5-bisphosphate Carboxylase/Oxygenase Obtained with O-p-Nitrophenylhydroxylamine
Authors: Van Assche C. J. , Reinier N. , Courtiade B. , Chancel A. , Huber S.
Published: August 2018

Spinach RuBP carboxylase-oxygenase (Rubisco) purified from the commercially available enzyme, underwent kinetic changes when micromolar concentrations of O-p-nitrophenylhy- droxvlamine (NPHA) were applied on fully activated enzyme. Under steady-state conditions, a decrease of Km CO2 was observed without changes in Vmax. Double reciprocal plots showed a competitive stimulation of carboxylase function. The substrate specificity factor k = Vc Ko/Vo Kc was increased from approximatively 15-20% upon treatment with NPHA, using both parallel and simultaneous determinations of RuBP-carboxylase and oxygenase activities.

Such a limited change in partition between Rubisco functions actually resulted into an increase in CO2 fixation of intact soybeans leaves treated with NPHA. arising from a substantial alleviation of O2-inhibition of photosynthesis.

From spectrophotometric and sulfhydryl group titration data, evidence was accumulated for a conformational change of the native enzyme, induced by NPHA. bringing about an increased ratio of carboxylase to oxygenase activities. Direct interaction of NPHA with a cysteine residue of Rubisco near the catalytic site, appears as a candidate for such chemically-induced conformational modification.
Structure of Azadirachtin B
Authors: Rembold Heinz , Forster Hans , Sonnenbichler Johann
Published: August 2018

The structures of azadirachtin B and of detigloylazadirachtin have been determined on the basis of detailed 1H and 13C NMR spectroscopic analysis. Comparison of the data from both com pounds unequivocally proves esterification by tiglic acid at position 3. Our data thus confirm the structure as proposed by Klenk et al., J. Chem. Soc., Chem. Commun. 1986, 523-524.
Pflanzenabwehrstoffe XXXI [1] Molluskizide Eigenschaften von Chinonen
Authors: Schildknecht Hermann , Lubosch Johannes
Published: August 2018

The quinone 2-methoxy-6-n-pentyl-2,5-cyclohexadien-1,4-dion (Primin) was found to possess molluscicidal activity against the snail Planorbis corneus. The synthesis of homologous and isomers and the results in the biotests are reported.
Interaction in vitro of Non-Epithelial Intermediate Filament Proteins with Histones
Authors: Traub Peter , Perides Georg , Kühn Siegfried , Scherbarth Annemarie
Published: August 2018

Non-epithelial intermediate filament (IF) subunit proteins show a high and specific affinity for core histones at physiological ionic strength. When IF proteins are titrated with a mixture of core histones and linker histone H1, in general the latter is totally excluded from com plexation and in the adducts formed the moderately-arginine-rich histones H2A and H2B are progressively replaced by the very-arginine-rich histones H3 and H4. At histone saturation, 2 molecules of nonneuronal IF protein bind 1 histone HI molecule or 8 core histone m olecules, whereas due to its glutamic acid rich, C terminal extensions one dimer of thp 68 kD npnrofilament nrotein associates with 3 molecules of histone H1 or 24 molecules of core histones. The salt stability of the insoluble association products is dependent on the amount and arginine content of the constituent histone species. Rem oval of the non-α-helical N- and C-terminal polypeptides from IF proteins by partial chymotryptic digestion does not affect their histone-binding characteristics. Since core histones are only partially inactivated by limited tryptic digestion, they also appear to react through their a-helix-rich central domains; the limit peptide derived from histone H1 is com pletely inactive at physiological ionic strength. Affinity chromatography of rod domains of IF proteins on core histone-Sepharose 4B and of histones and their limit peptides on vim entin-Sepharose 4B has shown that the interactions involving fractions of histones H3 and H4 are extrem ely resistant to salt and can be dissociated only with arginine or salt under denaturing conditions. In general, the experim ental results revealed close parallels between the association of histones with IF proteins and their interaction with DNA.
Lipid Influence on the Structure of the Light Harvesting B 800—850 Proteins
Authors: Peschke Joachim , Möhwald Helmuth
Published: August 2018

Interaction of the antenna protein B 800-850 with the lipid environment and with the reaction center of the photosynthetic bacterium Rhodopseudomonas sphaeroides is studied by fluorescence spectroscopy, transient absorption techniques, light scattering and electron microscopy. Using vesicles of synthetic phospholipids it is shown that solidification of the m em brane causes a structural protein change evident from a reduction in fluorescence quantum yield. The change occurs at a tem perature up to 5 °C below that corresponding to the gel/fluid transition tem perature and indicates local melting. The structural change is not specific for the lipid head group nor chain length (investigated for lengths of 12 to 16 CH2 groups) and can be understood applying a simple elastic model. It can also be included isothermally by changing the ionic milied and thus varying the lipid phase state.

Energy transfer LHCP→RC is proven to be highly efficient in model m em branes and is not affected by the existence of a phase transition. This indicates two LHCP fractions one tightly - and one non-bound to the RC.
Daffodil Chromoplast DNA: Comparison with Chloroplast DNA, Physical Map, and Gene Localization
Authors: Hansmann Paul
Published: August 2018

In daffodil, development of chloroplasts or chromoplasts is not accompanied by plastid DNA modification. This has been shown by comparing the fragment pattern of different restriction endonucleases, and by the lack of methylation of CCGG sequences. A physical map has been constructed for the plastome using the restriction endonucleases Sal I, Pst I, and Bgl I. The fragments containing the genes for the large subunit of ribulose bisphosphate carboxylase/oxygenase (rbcL), the alpha, beta, and epsilon subunits of the ATP synthase complex (atpA , atpB, atpE ), cytochrome f(petA ), and for the 51 kDa chlorophyll apoprotein of photosystem II (psbB) have been identified. The respective gene locations correspond to those on spinach chloroplast DNA.
The Contents of the Dufour Gland of the Ant Harpagoxenus sublaevis Nyl. (Hymenoptera: Formicidae)
Authors: Ollett D. G. , Morgan E. D. , Attygalle A. B. , Billen J. P. J.
Published: August 2018

The volatile components of the Dufour gland secretion of workers cf the ant Harpagoxenus sublaevis have been analysed by gas chrom atography and mass spectrometry. Over 20 com ponents have been identified, consisting of linear and terpenoid hydrocarbons. Each gland contains approximately 6 ng of hydrocarbons with n-heptadecene (40% ) and /n-heptadecadiene (30% ) as the major components. Two terpenoid hydrocarbons, (E)-β-farnesene and a homofarnesene isomer were also identified.
Inhibition of cAMP-Phosphodiesterase by Molybdate
Authors: Ofenloch-Hähnle Beatus , Eisele Karl
Published: August 2018

Inhibition of 3′:5′-cyclic-AMP-5′-nucleotidohydrolase (EC 3.1.4.17) type II (cAMP-phosphodiesterase) by sodium molybdate was studied: While determination of inorganic phosphate and 5′-ribonucleotide phosphohydrolase (5′-nucleotidase) (EC 3.1.3.5) activity was not disturbed by sodium molybdate in concentrations up to 10 mM , cAMP-phosphodiesterase was inhibited by millimolar concentrations of molybdate. The half maximal effect was observed at about 2 mM sodium molybdate (0.75 mM cAMP in the assay).