bluuebunny/crossref_metadata_2025 huggingface dataset:
A Micromethod for Rapid Quantitative Determination of Phosphonate Phosphorus
Authors: Kapoulas Vassilios M. , Mastronicolis Sofia K. , Nakhel Ibrahim C. , Stavrakakis Helen J.
Published: August 2018

A rapid method for initial quantitative estimation of the phosphate present in compound containing a carbon-phosphorus bond is described.

Two phosphorus assays are employed. One assay is for total phosphorus, which can be determined by digesting with perchloric acid and the other assay is for total non phosphonate phosphorus which can be determined by digesting with sulfuric acid simultaneously. The difference between total phosphorus and the non phosphonate phosphorus determined represents the amount of phosphorus present in a carbon-phosphorus linkage in a crude phospholipids sample
Mechanisms of Adriamycin-Dependent Oxygen Activation Catalyzed by NADPH-Cytochrome c-(Ferredoxin)-Oxidoreductase
Authors: Paur Eva , Youngman Richard J. , Lengfelder Edmund , Elstner Erich F.
Published: August 2018

Under aerobic conditions, O2 uptake and production of O2
- and H2O2 by isolated NADPH - cytochrome c-(ferredoxin)-oxidoreductase from Euglena gracilis was strongly stimulated by adriamycin. Further stimulation was not observed with 0.1 mᴍ Fe3+-EDTA. Methionine fragmentation (measured as ethylene release), as a reliable indicator for the formation of OH- radical-like oxidants under aerobic conditions (100 μmol O2 in a 10 ml reaction vessel) was strongly stimulated by 0.1 mᴍ Fe3+-EDTA or, in the absence of iron, by partial anaerobiosis (1 μmol O2 per vessel). The highest rate of methionine fragmentation was observed under anaerobic conditions in the presence of both reduced adriamycin and added H2O2.

Aerobic methionine fragmentation in the presence of adriamycin and Fe3+-EDTA was inhibited by superoxide dismutase and catalase by more than 90%, while methionine fragmentation under semianaerobiosis in the absence of Fe3+-EDTA was inhibited by superoxide dismutase to only about 50%, while catalase again inhibited by more than 90%. These results indicate that the adriamycin-catalyzed production of a strong oxidant appears to be governed by different mechanisms depending on oxygen availability; namely the production of a Fenton-type oxidant driven by adriamycin-catalyzed superoxide formation and also, the formation of the “crypto-OH- radical” by direct electron donation from the adriamycin semiquinone radical to H2O2 under oxygen limiting conditions
Flavonoid Aglycones in the Leaf Resin of Some Cistus Species
Authors: Wollenweber Eckhard , Mann Karin
Published: August 2018

Members of the genus Cistus excrete a leaf resin that consists mainly of terpenoids. This resin also contains methylated flavonoids as aglycones. Rare methyl derivatives of myricetin have been isolated from C. monspeliensis, along with uncommon methyl derivatives of quercetin. Further flavonoids encountered in the leaf resin of this and six further species are methyl derivatives of kaempferol and quercetin, some of apigenin and in one species also of luteolin. The results indicate that there might exist species-specific flavonoid patterns
Structure determination of 6-c-ß-d-glucopyranosyl- 8-c-α-l-arabinopyranosyltricetin from radula complanata
Authors: Markham Kenneth R. , Mues Rüdiger
Published: August 2018

The flavone di-C -glycoside earlier isolated from Radula complanata and tentatively identified as tricetin 6-C-β-dglucopyranosyl- 8-C-α-ʟ-arabinopyranoside is now positively identified by 13C- and 1H-NMR spectroscopy. Although this com pound is thought to have been isolated before, this is the first substantial support for its structure, previously assigned on the basis of MS evidence
Eine geeignete Methode zur Synthese der p-Hydroxy-β-[carboxymethyl]-zim tsäure (Sphagnumsäure) / A Convenient Synthesis of p-Hydroxy-β-[carboxymethyl]-cinnamic Acid (Sphagnum Acid)
Authors: Wächter Doris , Rudolph Hansjörg
Published: August 2018

Sphagnum acid is a cinnamic acid which up to now has only been traced in the cell walls of Sphagna. This plants contain this substance up to the quantity of 100 (μg per 100 mg dry weight. p-Hydroxy-β-[carboxymethyl]-cinnamic acid can be produced synthetically by condensation of phenol and acetonedicarboxylic acid
The Crystal Structure of Anhydrous Xanthosine Displays Intramolecular O(2′)H ... O(3′) Hydrogen Bond
Authors: Lesyng Bogdan , Marck Christian , Saenger Wolfram
Published: August 2018

From an equimolar dipeptide/xanthosine mixture in water/methanol, only the nucleoside crystallized in anhydrous form, space group P212121 with a = 17.406 (5) Å, b = 12.378 (4), c = 5.350 (2) Å, Z = 4, C10H12O6N4, FW = 284.26, Dx = 1.639 g · cm-3. The structure was determined by direct methods on the basis of 984 X-ray data and refined to an agreement index of R = 3.9%. Xanthosine occurs in the syn conformation with χ = -132.7° which is stabilized by an intramolecular hydrogen bond N (3) - H ... O(5′). The pseudorotation parameters for sugar puckering are P = 156° and τm = 38.7° corresponding to C(2′)-endo form. The crystal packing of xanthosine in anhydrous and dihydrate modifications are very different, yet the molecular conformations are similar. In the anhydrous form, an unusual intramolecular hydrogen bond O (2′) - H ... O(3′) is observed.
Effects of Vitamin A in the Presence of Vitamins D3, E, K, on Red Cell Membrane Structure
Authors: Cicero R. , Callari D. , Guidoni L. , Viti V. , Scalia M. , Maida I. , Billitteri A. , Sichel G.
Published: August 2018

The incubation of erythrocyte ghosts with mixtures of vitamins A + D 3, A + E, A + K1 , produces decrease or increase of fluorescence anisotropy r of the DPH probe, depending on the vitamin/vitamin ratio. We found a correlation between the order parameter S and cell fusion phenomena observed by phase contrast microscopy.
Notizen: In vivo Metabolism of [4-13C]Phenacetin in an Isolated Perfused Rat Liver Measured by Continuous Flow 13C NMR Spectroscopy
Authors: Albert Klaus , Kruppa Gerd , Zeller Klaus-Peter , Bayer Ernst , Hartmann Franz
Published: August 2018

Metabolism, [4-13C]Phenacetin, Continuous Flow 13C NMR Continuous flow 13C NMR spectroscopy has been used for the first time to monitor the metabolism of a 13C labeled drug in an isolated liver. Continuous and almost immediate information on the metabolite formation could be obtained using 13C labeled phenacetin without alteration of the biological system. The data are consistent with those observed by conventional techniques (HPLC, aliquot 13C NMR measurements). From the biological point of view the sensitivity of continuous flow 13C NMR spectroscopy is still low (10-3 ᴍ). The results presented demonstrate however that non-invasive and non-radio-active real time monitoring of drug metabolism in intact organs is possible.
Induced and Constitutive Isoflavonoids in Phaseolus mungo L. Leguminosae
Authors: Adesanya Saburi A. , O’N eill Melanie J. , Roberts Margaret F.
Published: August 2018

Sixteen isoflavonoids have been isolated from the black gram. Phaseolus mungo L. (syn. Vigna mungo) following treatment with aqueous CuCl2. These include 12 known isoflavonoids: genistein. 2′-hydroxygenistein. 2′-hydroxydaidzein, kievitone, dalbergioidin, cyclokievitone. 5-deoxykievitone, 2′-hydroxydihydrodaidzein, isoferreirin, aureol, glycinol and demethylvestitol. In addition, kievitone hydrate, which was previously known only as a fungal metabolite of kievitone, was isolated together with 3 novel natural isoflavanones which were characterized as 4′-O-methylkievitone, cyclokievitone hydrate and 5-deoxykievitone hydrate.
Phospholipids and Glycerides Composition during Spheroplasts Formation of Mycobacterium smegmatis ATCC 14468
Authors: Murty M. V. V. S. , Venkitasubramanian T. A.
Published: August 2018

The phospholipids and glycerides composition of spheroplasts of Mycobacterium smegmatis ATCC 14468 was examined. The percent total phospholipids in total lipids as well as cardio-lipin were found to be higher in spheroplasts as compared to their parent forms. Increase in cardiolipin and free fatty acids content and decrease in triglycerides levels were observed during spheroplasts formation. The results suggest that increase in cardiolipin content in sphero­ plasts is an adaptational change concomittant with the loss of cell walls.
Cell Fusion by Simulated Atmospheric Discharges: Further Support for the Hypothesis of Involvement of Electrofusion in Evolution
Authors: Küppers Gottfried , Diederich Karl-Josef , Zimmermann Ulrich
Published: August 2018

Electrofusion of mesophyll cell protoplasts of Avena sativa was induced by simulated atmospheric discharges. It is shown both experimentally and theoretically that the potential differences which occur at quite long distances from the point of lightning stroke are large enough to induce fusion. Besides electromagnetic waves which are emitted during lightning (G. Küppers and U. Zimmermann, FEBS Lett. 164, 323 (1983)) cell fusion may have also occurred directly by means of the voltage built-up on the earth during evolution in response to a lightning stroke.
The Cellular Substrate: A Very Important Requirement for Baculovirus in vitro Replication
Authors: Miltenburger Herbert G. , Naser Werner L. , Harvey Jeanne P. , Huber Jürg , Huger Alois M.
Published: August 2018

We established more than 200 primary cell lines of Cydia pomonella (codling moth). 81 of them were selected and screened for replication of two baculoviruses (from two different subgroups): the Choristoneura murinana NPV and the Cydia pomonella GV. Although all these cell lines had been derived from the same insect species, they varied largely in their response to challenge with the NPV. Most of them showed CPE or produced different amounts of poly-hedra. Interestingly, we also found a few cell lines that were permissive for GV replication. To our knowledge this is the first time that GV replication in cell lines has been obtained. Our results show that cell line properties are most important for baculovirus in vitro replication.
Determination of 4-Pregnene-3-ones in Thymus Tissue Sam ples by High Performance Liquid Chromatography*
Authors: Reisch Johannes , Norrenbrock Josef
Published: August 2018

A high performance liquid chrom atography method for determining the levels of 4-pregnene-3-ones in tissue containing fat, e.g. in thymus is reported. Following the extraction with chloroform/methanol the fat has been separated from the steroidal-fraction by using disposable extraction-columns. The steroidal-fraction has been analysed in two separation systems, on a RP18-column with a methanol/water gradient and on an amino column with a isopropanol/hexane gradient. The applicability of the described method is demon­ strated with calf thymus samples.
Degradation of Glutathione in Plant Cells: Evidence against the Participation of a γ-Glutamyltranspeptidase
Authors: Steinkamp Reinhard , Rennenberg Heinz
Published: August 2018

When γ-glutamyltranspeptidase activity in tobacco cells was measured using the artificial substrate γ-glutamyl-p-nitroanilide, liberation of p-nitroaniline was not reduced, but stimulated by addition of glutathione. Therefore, glutathione was not acting as a donator, but as an acceptor of γ-glutamyl moieties in the assay mixture, suggesting that γ-glutamvltranspeptidase is not participating in degradation of glutathione. Feeding experiments with [35S-cys]glutathione sup­ported this conclusion. When tobacco cells were supplied with this peptide as sole sulfur source, glutathione and γ-glutamylcysteine were the only labelled compounds found inside the cells. The low rate of uptake of glutathione apparently prevented the accumulation of measurable amounts of radioactivity in the cysteine pool. A γ-glutamylcyclotransferase, responsible for the conversion of γ-glutamylcysteine to 5-oxo-proline and cysteine was found in ammonium sulfate precipitates of tobacco cell homogenates. The enzyme showed high activities with γ-glutamylmethionine and γ-glutamylcysteine, but not with other γ-glutamyldipeptides or glutathione. From these and previously published experiments [(Rennenberg et a!., Z. Naturforsch. 35c, 708-711 (1980)], it is concluded that glutathione is degraded in tobacco cells via the following pathway: γ-glu-cys-gly → γ-glu-cys → 5-oxo-proline → glu.
Phospholipid Transfer from ER to the Peribacteroid Membrane in Soybean Nodules
Authors: Mellor R. B. , Christensen T. M. I. E. , Bassarab S. , Werner D.
Published: August 2018

Organelle membranes subfractionated from nodules of Glycine max differed in lipid compo­sition. Of the enzymes assembling phospholipids, choline kinase (EC 2.7.1.32) was recovered in the cytoplasmic fraction whereas CDP choline 1,2-diacylglyceride choline phosphotransferase (EC2.7.8.2) was located in the ER. When methyl [14C]CDP choline was supplied to nodules in vivo radioactivity was found in the ER. On longer labelling periods [14C]phosphatidylcholine spread into denser regions of the gradient, including the peribacteroid membrane (which surrounds the Rhizobium japonicum symbiont). [14C]Phosphatidylcholine was a notable component of such membranes.

Adenosine triphosphatase (EC 3.6.1.3) activity in the peribacteroid membrane fraction was compared to that of other major organelle fractions. The peribacteroid membrane ATPase was equally active on pH 6.0 and 8.0, was stimulated by K+ and inhibited by DES, DCCD and MoO4. In these respects it was more similar to the ATPase activity in the ER and mitochondria than in tonoplast or cytoplasm.

The results are discussed in relation to modes of peribacteroid membrane biogenesis, in­cluding enzyme modification.
Higher Cardol Homologues (5-Alkenylresorcinols) from Rye Affect the Red Cell Membrane-Water Transport
Authors: Kozubek Arkadiusz
Published: August 2018

The influence of 5-heptadecenylresorcinol and total rye 5-alkenylresorcinols isolated from rye grains on the red blood cell water permeability was studied using osmotic shrinkage experiments performed in 300 mᴍ sucrose. The studied compounds induced significant increase of erythro­cyte water permeability. The threshold concentration needed for the increase of water per­meability was in an order of 10-6mol/l. The temperature dependence of the observed process showed the discontinuity which was related to the 5-alkenylresorcinol transition temperatures. It was shown also that alkenylresorcinols did not exert the biphasic action on hypotonic lysis of erythrocytes usually observed for water soluble surfactants. The specific lysine activity is postulated for the studied compounds.
Effects of Carbohydrates on the Ion Conductance of the Hemocyanin Channel
Authors: Menestrina Gianfranco , Pasquali Flavia
Published: August 2018

The effects of glucose and sucrose on the ionic conductance properties of the channel formed by Megathura crenulata hemocyanin in planar lipid bilayers have been studied using membranes of different compositions. It was found that glucose at high concentrations strongly affects the time constants of the current relaxations observed in membranes containing many channels after a step in the voltage clamp from ground to a positive value. At much lower concentrations both sucrose and glucose strengthened the binding of Ba2+ to the protein, what in turn has the effect to shift the conductance voltage curve of the pore towards negative potentials. The possible mechanism underlying these effects and the analogies with other studies on the interaction of sugars and alcohols with proteins have been discussed.
Photodestruction of Propionibacterium acnes Porphyrins
Authors: Melø T. B. , Reisaeter G. , Johnsson A. , Johnsson M.
Published: August 2018

The fluorescence spectra of colonies of Propionibacterium acnes were studied under various experimental conditions.

The spectra contained peaks at 580 nm and 620 nm. These bands were due to two different components; the 580 nm component was likely to be a metalloporphyrin, and there are indications that the 620 nm component could be a coproporphyrin.

The 580 nm fluorescence was destroyed by the combined action of light and oxygen (no destruction under strict anaerobic conditions). A dark period interrupting the bleaching light stopped the destruction of this component for the time of the dark period.

The initial production of the 620 nm component was due to the oxygen exposure. Upon light irradiation this component was later destroyed by the combined action of oxygen and light.
Identification of Cyclic Enolethers from Insects: Alkyldihydropyranes from Bees and AIkyldihydro-4H-pyran-4-ones from a Male Moth*
Authors: Francke W. , Mackenroth W. , Schroder W. , Schulz S. , Tengö J. , Engels E. , Engels W. , Kittmann R. , Schneider D.
Published: August 2018

Mass spectrometric fragmentation patterns of alkyl-3,4-dihydro-2H-pyranes and alkyl-2,3-dihydro-4H-pyran-4-ones are described. Through GC/MS analyses, respective compounds showing unbranched carbon skeletons are identified for the first time as volatile signals of social and solitary bees and of the male moth Hepialus hecta L.
Further Evidence for a Functional Relationship between L-Amino Acid Oxidase Activity and Photosynthetic Oxygen Evolution in Anacystis nidulans. Effect of Chloride on the Two Reactions
Authors: Pistorius Elfriede K.
Published: August 2018

The ʟ-amino acid oxidase from Anacystis nidulans is inhibited by cations as well as anions. The inhibition by cations has been previously described (E. K. Pistorius, Eur. J. Biochem. 135, 217-222 [1983]). We have shown that the order of effectiveness was M3+ > M2+ > M+, when e.g. La3+, Ca2+ and K+ were compared. However, in the concentration range where the monovalent cations inhibited, the inhibition was not entirely due to the cation, but an influence of the anion could also be observed. When monovalent anions were compared as the corresponding sodium salts, the order of effectiveness was SCN- > NO3
- > CL-, Br- > I- > F- > HCOO- > CH3COO- . The inhibition of the ʟ-amino acid oxidase activity by the various salts was strongly influenced by the pH of the reaction mixture. It could be shown that the inhibition by cations increased in the alkaline pH region, while the inhibition by anions increased in the acidic pH region.

Our previous results have also shown that a functional relationship might exist between ʟ-amino acid oxidase activity and photosynthetic O2 evolution (E. K. Pistorius and H. Voss, Eur. J. Biochem. 126, 203-209 [1982]). Since the water-splitting complex of photosystem II is affected by a number of anions, although only Cl- and Br- lead to activation of O2 evolution, we investigated whether a correlation could be obtained between the anion effect on the ʟ-amino acid oxidase and on photosynthetic O2 evolution. The results show that those anions which have a higher affinity for the enzyme than CL- or Br-, are especially effective in causing inactivation of the O2 evolution. Moreover, we show that ʟ-arginine which is a substrate of the ʟ-amino acid oxidase, and Cl- have antagonistic effects on the ʟ-amino acid oxidase reaction and on photosynthetic O2 evolution. We suggest that this flavoprotein with ʟ-amino acid oxidase activity is modified by Ca2+ and CL- in such a way that it can now interact with Mn2+ and catalyze the water-splitting reaction of photosystem II.
Preparation of an Enzyme Associated with Carthamin Formation in Carthamus tinctorius L
Authors: Saito Koshi , Takahashi Yoshiyuki , Wada Mizu
Published: August 2018

An enzyme associated with carthamin formation in Carthamus tinctorius L. (carthamin-synthe-sizing enzyme) was isolated from the soluble protein extract of the hypocotyl tips of the etiolated seedlings and purified up to 157-fold by the procedures applying (NH4)2SO4 fractionation, Ca(CH3CO2)2 precipitation, protamine sulfate treatment, Celite adsorption chromatography, and Sephadex G-100 gel filtration. Results from atomic absorption spectral analysis of the enzyme protein showed to contain K as a major component, and Ca and Mg as minor ones. Fe, Cu, and Mn could not be detected in the preparation. At pH 4.8 in 50.0 mᴍ acetate buffer, the partially purified enzyme reacted positively with a flame-coloured precarthamin to produce a reddish product in open cuvettes with incubation medium. The reaction product was identified as carthamin by examining its colour, chromatographic mobilities in different developing solvents and spectroscopic properties inclusive shifts, often by comparing with those of an authentic specimen. Anaerobic incubation reduced the enzyme activity, while exogenously applied O2 slightly enhanced the catalytic rate of carthamin formation. The enzyme was sensitive to phosphorus sub­ stances. Among those compounds tested at 1.2 mᴍ level, orthophosphate showed the most striking inhibitory action on the enzyme. Metal ions affected on the enzyme activity by different extents. Mn2+ stimulated the enzyme reaction, while Cu2+ and Mo6+ exhibited reverse effects. Fe2+, Fe3+, Zn2+, Mg2+, and Co2+ were also unfavourable to the enzyme catalyzed carthamin formation. The preparation of the carthamin-synthesizing enzyme showed no activity of polyphenol oxidase or peroxidase under the conditions specifically designed for detecting both enzyme activities.
Formation and Decay of the Vanadate Complex of the Sarcoplasmic Reticulum Calcium Transport Protein
Authors: Medda Pankaj , Hasselbach Wilhelm
Published: August 2018

The calcium free sarcoplasmic reticulum calcium transport ATPase incorporates in the presence of magnesium ions approx. 8 nmol monovanadate per mg protein, indicating the formation of a complex containing one vanadate residue per enzyme molecule. On ligand-removal or dilution, the saturated enzyme complex displays biphasic decay kinetics, while the unsaturated complex slowly dissociates monophasically. - Ligand competition by raising the concentrations of unlabeled vanadate results in a progressive decrease of the dissociation rate of the unsaturated enzyme. The complicated dissociation kinetics indicate a sequential mode of interaction between two ligand binding sites. The one to one stoichiometry of the complex suggests that the two sites are located at adjacent ATPase molecules. - It appears unlikely that the decay of the enzyme, vanadate complex is retarded by the formation of a stable quaternary complex between the enzyme, magnesium, mono-and polyvanadate.
DNA in the Nucleomorph of Cryptomonas Demonstrated by DAPI Fluorescence
Authors: Hansmann Paul , Falk Heinz , Sitte Peter
Published: August 2018

DNA has definitely been demonstrated in the nucleomorph of a marine Cryptomonas species by combining thin sectioning of Lowicryl K4M-embedded material and DAPI-induced DNA fluorescence.
Physicochemical Characterization of Tetraether Lipids from Thermoplasma acidophilum. II. Film Balance Studies on the Monomolecular Organization of the Main Glycophospholipid in Monofilms
Authors: Strobl Christoph , Six Lambert , Heckmann Klaus , Henkel Birgit , Ring Klaus
Published: August 2018

The bipolar main tetraether lipid (MPL) of Thermoplasma acidophilum has been shown to form typical liquid expanded films at the air-water interface. The limiting molecular area at the collaps pressure is approximately Ac=73 Å2 per molecule. Monopolar aiphytanyl diether lipids were found to occupy the same area at high surface pressure as MPL. Thus, it was concluded that in the monofilm only one of the two polar headgroups of the MPL molecules is hydrated, i.e. that the single MPL molecules arc oriented upright. The packing properties of MPT. in the monofilm are determined by the properties of the branched alkyl chains only; the polar head groups do not contribute to the space requirement in the film. The collaps pressure of the MPL film is approximately 39 mN m-1 at 8°C. At a surface pressure of π = 30 mN m-1 and 20 °C the film is stable for many hours.
Sex Pheromone Components in the New Zealand Brownheaded Leafroller. Ctenopseustis obliquana (Lepidoptera: Tortricidae)
Authors: Young H. , Galbreath R. A. , Benn M. H. , Holt V. A. , Struble D. L.
Published: August 2018

The sex pheromone of Ctenopseustis obliquana was found to contain (Z)-8-tetradecenyl acetate and (Z)-5-tetradecenyl acetate in approximately 4:1 ratio. No A 11-tetradecenyl compound was detected in C. obliquana, in contrast with the pheromones thus far reported from species of the tribe Archipini elsewhere in the world.
Site of H Atom Attack on Uracil and Its Derivatives in Aqueous Solution
Authors: Das Suresh , Deeble David J. , Sonntag Clemens von
Published: August 2018

Hydrogen atoms from the radiolysis of water at pH 1.6 add to the 5,6-double bond of pyrimidines. The preferen­tial site of attack is the C(5) position (values in brackets) in the case of 6-methyluracil (87%), 1,3-dimethyluracil (71%), uracil (69%) and poly(U) (60%). This reaction yields a radical of reducing properties which can be monitored by its reaction with tetranitromethane in a pulse radiolysis experiment. In thymine (37%), thymidine (32%) and 1,3-dimethylthymine (25%) H-addition no longer pre­ferentially occurs at C(5), but addition is now mainly at C(6). Hydrogen abstraction from the methyl groups or the sugar moiety is negligible (≦ 5.5%). A comparison is made with literature values for the equivalent reactions of OH radicals.
Localization of Chromenes and Benzofurans in the Genus Encelia (Asteraceae)
Authors: Proksch Peter , Proksch Margareta , Weck Waltraud , Rodriguez Eloy
Published: August 2018

Phytochemical and microscopial analysis of leaves and stems of various species of Encelia showed a strict correlation between the presence of resin ducts and the accumulation of benzopy­rans and benzofurans. Fluorescence microscopy of Encelia farinosa proved unambigously that these compounds are stored exclusivly in the resin ducts and the surrounding cells.
The Widespread Occurrence in Nature of Anthocyanins as Zwitterions
Authors: Harborne Jeffrey B. , Boardley Marian
Published: August 2018

An electrophoretic survey of anthocyanins in flowers of 81 species belonging to 27 plant families indicated that malonated or similarly substituted zwitterionic anthocyanins occur in half the sample. In particular, almost all species surveyed in the Compositae and the Labiatae were positive. The same results were also indicated by HPLC separations. Detailed examination of the anthocyanins of Dahlia variabilis and Plectranthus argentatus confirmed the presence of malonylation through glucose. It appears that anthocyanins substituted by aliphatic dicarboxylic acids may be widespread in the angiosperms.
Biflavonoids, Quinones and Xanthones as Rare Chemical Markers in the Family Iridaceae
Authors: Williams Christine A. , Harborne Jeffrey B.
Published: August 2018

Amentoflavone has been characterised from leaves of Patersonia glabrata. This is the first report of a biflavone in the Monocotyledoneae. The quinone plumbagin, a characteristic con­stituent of three dicotyledonous families, is now found to be a useful marker for the genus Aristea; it also occurs in two Sisyrinchium species and in Sparaxis tricolor. Mangiferin, a C-glucosylxan-thone known previously in the Iridaceae only from Crocus, Iris and Gynandriris has now been found in Eleutherine, Rigidella, Gelasine and Tigridia. results is discussed.
Action of Methylthiopyrimidine Experimental Herbicides as Diuron-Like Inhibitors of Photosynthesis
Authors: Ducruet Jean-M arc , Scalla René
Published: August 2018

Derivatives of 6-chloro-5-methylthiopyrimidines provide potent inhibitors of the photosynthe­tic electron flow, which act like Diuron on fluorescence induction kinetics and competitively displace it from its binding site. Structure-activity relationships show that, unlike triazines, ac­tivities of 2-or 4-alkylamino derivatives are restricted by steric hindrances. Decreases in inhibit­ory activities of these compounds observed in triazine-resistant chloroplasts are lower than de­creases reported for triazines themselves.
Inhibition of Photosynthetic Electron Transport by Halogenated 4-Hydroxy-pyridines
Authors: Trebst A. , Depka B. , Ridley S. M. , Hawkins A. F.
Published: August 2018

Herbicidal halogen substituted 4-hydroxypyridines are inhibitors of photosynthetic electron flow in isolated thylakoid membranes by interfering with the acceptor side of photosystem II. Tetrabromo-4-hydroxypyridine, the most active compound found, has a pI50-value of 7.6 in the inhibition of oxygen evolution in both the reduction of an acceptor of photosystem I and an acceptor of photosystem II. The new inhibitors displace both metribuzin and ioxynil from the membrane. The 4-hydroxypyridines, like ioxynil, have unimpaired inhibitor potency in Tristreated chloroplasts, whereas the DCMU-type family of herbicides does not. It is suggested that 4-hydroxypyridines are complementary to phenol-type inhibitors, and a common essential element is proposed.

The 4-hydroxypyridines do not inhibit photosystem I or non-cyclic electron flow through the cytochrome b/f complex. But they do have a second inhibition site in photosynthetic electron transport since they inhibit ferredoxin-catalyzed cyclic electron flow, indicating an antimycin-like property.

A comparison of the in vitro potency of the compounds with the in vivo potency shows no correlation. A major herbicidal mode of action of the group is related to the inhibition of carotenoid synthesis, and access to the chloroplast lamellae in vivo for inhibition of electron transport may be restricted.
γ-Radiolysis of 2′-Deoxyguanosine The Structure of the Malondialdehyde-Like Product
Authors: Langfinger Dieter , Sonntag Clemens von
Published: August 2018

In the -γradiolysis of N2O/O2-saturated solutions of 2′-deoxyguanosine, 2′-deoxyguanosine-5′-aldehyde has been identified as the major product (G = 0.27) which gives rise to a positive 2-thiobarbituric acid test usually associated with malondialdehyde or structurally closely related compounds. From experiments with tetranitromethane as oxidant instead of oxygen it is concluded that the major primary precursor is not the radical at C(5′) of the sugar moiety but a base radical. The relevance of these observations with respect to radiation-induced changes in DNA is discussed.
Inhibition of Bluelight-Induced, Flavin-Mediated Membraneous Redoxtransfer by Xenon
Authors: Schmidt Werner
Published: August 2018

Xenon as a potential triplet quencher is capable of in­hibiting bluelight-induced, flavin-mediated transport of redox-equivalents across lipid membranes. The experiments described are based on a model system developed recently. Ferricytochrome c as a potential electron acceptor is trap­ped in the lumen of unilamellar lipid vesicles, EDTA* as a potential electron donor added to the bulk volume and amphiphilic flavin as a mediator bound to the vesicle mem­brane. However, Under isotropic aqueous conditions the bluelight-driven electron transport chain comprising EDTA, flavin and Cyt c is not significantly affected by xenon. These data call for the reinterpretation of results obtained with xenon as potential inhibitor of phototropic curvature of grass coleoptiles. which were taken to suggest the flavin singlet as active species.
Photoaffinity Labeling of Spinach Thylakoids and Cytochrome b6/f-Complex by the Hydrophobic Reagent 3-(Trifluoromethyl)-3-(m-[125I]iodophenyl)-diazirine
Authors: Oettmeier Walter , Soli Hans-Joachim , Olschewski Ellen
Published: August 2018

In isolated spinach thylakoids the hydrophobic photo­reactive probe 3-(trifluoromethyl)-3-(m-[125I]iodophenyl-diazirine almost exclusively labels the photosystem I reac­tion center and the light-harvesting chlorophyll a/b protein. In isolated cytochrome b6/f-complex, all four components of the complex get labeled, but to a different extent. The amount of labeling in the protein components is correlated to the number of polypeptide segments embedded in the membrane system.
Vergleichende Untersuchungen zur Bildung und Akkumulation von ätherischem Öl in der intakten Pflanze und in Zellkulturen von Pimpinella anisum L. / Comparative Studies on the Production and Accumulation of Essential Oil in the W hole Plant and in the Cell Culture of Pimpinella anisum L
Authors: Reichling J. , Becker H. , Martin R. , Burkhardt G.
Published: August 2018

Comparative studies on the essential oil of the whole plant and callus-and suspension cultures of Pimpinella anisum L. were carried out. Both the whole organism and the cell cultures were shown for the first time to be similar in their constituents e.g. anethole, pseudoisoeugenol-(2-methyl-butyrate), epoxy-pseudoisoeugenol-(2-methyl-butyrate) and β-bisabolene. In difference to the plant, the callus-culture contained myristicine.
2-Hydroxy-Swietenin, ein neues Limonoid aus Swietenia mahagoni DC. / 2-Hydroxy-Swietenin, a New Limonoid from Swietenia mahagoni D C .
Authors: Daily Amir , Seligmann O. , Lotter H. , Wagner H.
Published: August 2018

From the seeds of Swietenia mahagoni two limonoids have been isolated and identified as swietenine and the hitherto not described methyl-2,3,6-trihydroxy-melia-C-8(30)-enate-3-tiglate (2-hydroxy-swietenine) by spectroscopic methods.
The Action of Saraca asoca Roxb. de Wilde Bark on the PGH2 Synthetase Enzyme Complex of the Sheep Vesicular Gland
Authors: Middelkoop T. B. , Labadie R. P.
Published: August 2018

Extracts of S. asoca bark and pure compounds isolated from the bark were tested for properties that might inhibit the conversion of arachidonic acid by the PGH2 synthetase. They were assayed spectrophotometrically with adjrenaline as cofactor. Methanol- and ethyl acetate extracts inhibited the conversion. The observed inhibition was confirmed in an oxygraphic assay. Two procyanidin dimers from the ethyl acetate extract showed enzyme catalyzed oxidation in our assay. The ether extract of the bark was also found to contain yet unknown substances which were capable of being oxidised by the PGH2 synthetase. The combined action of the components of the bark may explain the mode of action of the drug Asoka Aristha, the main ingredient of which is the bark of S. asoca. The drug is traditionally used in Sri Lanka to treat menorrhagia.
Vergleich verschiedener Immun-Dekorationsmethoden für die Rasterelektronenmikroskopie am Beispiel eines Protein-Antigens auf der Oberfläche der Hefe Candida albicans/ A Comparison of Decoration Techniques for the Demonstration of Immunocomplexes by Scanning Electron Microscopy: Labeling of a Protein Antigen on the Surface of the Yeast Candida albicans
Authors: Borg Margarete
Published: August 2018

The labeling of immunocomplexes for scanning electron microscopy (SEM) is a fairly new technique, and the various procedures, that have been proposed, have not yet been compared. Such comparative evaluation was performed with Candida protease as a target antigen. This secretory enzyme of the opportunistic yeast Candida albicans can be localized on the surface of fungal blastopores and mycelia, both after growth in proteinaceous medium and upon infection of murine peritoneal macrophages. The presence of the protease antigen was confirmed by immunofluorescence and by immunoperoxidase-light microscopy.

The decoration of protease - anti protease complexes for SEM was attempted with colloids derived from the immunoperoxidase reaction, by the immunogold technique, and by antibodies linked to beads of synthetic polymers (polystyrene, polymethacrylate, polyacrolein). In addition, inactivated Staphylococcus aureus was used, which binds to antibodies through its protein-A.

The high resolution by SEM of surface structures was matched only by the colloid based decoration techniques. All conjugates with beads suffered from inconsistent binding, which did not correspond with the distribution of the surface antigen. The comparatively best result with beads was obtained with polystyrene (Latex). Colloid based techniques in addition allow for critical point drying, which cannot be applied to synthetic beads in the usual manner.
Isotopic Effect on the Kinetic of Thermal Denaturation of Ceruloplasmin
Authors: Sportelli L. , Desideri A. , Campaniello A.
Published: August 2018

The kinetics of thermal denaturation of ceruloplasmin in water and in water with different percentage of D20 in the temperature range 25 - 85 °C, following the optical density change of the 610 nm charge transfer band of the protein has been investigated.

A temperature Tt ≃ 65 °C above which an irreversible denaturation process of the protein active site takes place has been found.

The kinetics of the denaturation process of the protein are fitted by two first order reactions, which have been assigned to a different thermal denaturation behaviour of the two Cu2+ type I sites existing in the protein. Addition of D2O to the protein solution affects the two kinetics in a different way, i.e. the rate of one of them is increased whilst that of the other is decreased.

The different effect of D2O on the kinetics of disruption of the two copper sites is discussed in terms of different location and degree of hydrophobicity of the two Cu2+ type I sites.
Acetohydroxyacid Synthase Inhibitors: N-Phthalyl-ʟ-valine Anilide and Related Compounds
Authors: Huppatz John L. , Casida John E.
Published: August 2018

The potency of ʟ-valine as an inhibitor of Zea mays acetohydroxyacid synthase (AHAS) is increased more than 80110-fold on conversion to its N-phthalyl anilide derivative which is active at 2 µᴍ. The ᴅ-valine, α-aminobutyric acid, isoleucine and phenylalanine analogs are 11- to 43-fold less potent, and similar N-phthalyl anilide derivatives of other branched-chain amino acids are essentially inactive. Full potency is retained on replacing the phthalimide moiety of the valine anilide with cyclohexane-1,2-dicarboximide or 1-cyclohexene-1.2-dicarboximide groups and partial activity with 4-cyclohexene-1,2-dicarboximide and methyl- or dimethylmaleimide groups. Inhibition of the enzyme and of root growth by the valine derivatives may result from binding at or near the site involved in feedback control of AHAS by ʟ-valine.
The Kinetics of the Reaction of Thiocyanate and Nitrite Ions with Orconectes limosus Oxyhemocyanin
Authors: Gondko Roman , Serafin Eligiusz , Mazur Janusz , Jeżowska-Trzebiatowska Bogusława , Jezierski Adam
Published: August 2018

The time course of the reaction of oxyhemocyanin from the arthropod Orconectes limosus with SCN− and NO2
− was investigated. After addition of one of these anions to oxyhemocyanin solu­tion an exponential decay of A340 was found, indicating a removal of oxygen from the active site. The order of reaction with respect to ligand was about 3 for thiocyanate and about 1 for nitrite. On this basis, a possible arrangement of ligands in the active site has been proposed. The final product of reaction with SCN− yielded a mononuclear copper EPR spectrum while the reaction product with NO2
− gave a characteristic spectrum of two coupled Cu2+ ions. It was possible to remove the ligands from the active site by dialysis. The reaction patterns showed distinct changes in a narrow pH range, 5.3-6.5. A possible effect of structural alterations of the protein moiety on the course of the reaction of oxyhemocyanin with ligands is suggested.
Chlorophyll Photobleaching in Pigment-Protein Complexes
Authors: Carpentier Robert , Leblanc Roger M. , Bellemare Guy
Published: August 2018

Pigment photobleaching was performed in thylakoid membranes of Hordeum vulgare (wild type, mutant Chlorina f2, Norfluranzon treated seedlings) and in pigment-protein complexes (CP-I and LHCP) isolated from H. vulgare and Chlamydomonas reinhardtii. Multiphasic kinetics were obtained in all of the above cases. Energy transfer towards pigments absorbing at longer wavelength is postulated as a general protection mechanism against photobleaching. This mechanism explains a substantial bleaching of carotenoids and a faster bleaching of chlorophyll aggregates, absorbing at long wavelength. These conclusions were valid for isolated complexes as well as for thylakoid membranes, although membranes were less sensitive to light.
Notizen: Volatiles from the Defensive Secretions of Two Rove Beetle Species (Coleoptera: Staphylinidae)
Authors: Dettner Konrad , Schwinger Gerhard
Published: August 2018

From the defensive secretion of the rove beetles (Coleoptera: Staphylinidae) Ontholestes murinus (L.) and Xantholinus glaber (Norden) nine volatiles have been identified by GC-MS data. From O. murinus a spiroketal was recorded for the first time from an arthropod defensive secretion. X . glaber has been found to represent the first staphylinid sequestering the monoterpenes limonen and isopulegol.
Storage of Quinolizidine Alkaloids in Epidermal Tissues
Authors: Wink Michael
Published: August 2018

Epidermal cells of lupine leaves, petioles and stems are the main storage site for quinolizidine alkaloids with an alkaloid content of 5-6 mg/g fw (= 15 - 25 mmol/kg). Epidermal tissue also store malate and hydrogen ions and show a vacuolar pH of < 5. It is argued that the specific storage of alkaloids in the vacuoles of epidermal cells might be due to active transport via carrier proteins and cannot be explained by a simple diffusion and ion trap mechanism.
Characterization and Properties of Different Glucosyltransferases Isolated from Suspension-Cultured Cells of Daucus carota
Authors: Ingold Edgar , Seitz Hanns Ulrich
Published: August 2018

Particulate enzymes (14,000 g pellet) from suspension-cultured carrot cells (Daucus carota L.) incorporated glucose from UDP-glucose and GDP-glucose into ethanol-insoluble products which were characterized as glucans or glucoprotein. Based on the test system to assay glucansynthe- tases I and II four different enzymatic activities could be distinguished on the basis of their substrate and divalent cation requirements, the influence of active substances such as nucleotides, nucleotide sugars, cellobiose, and in vivo inhibitors of cell wall glucan synthesis, their distribution in linear sucrose gradient and the nature of their products. The enzymatic activities which incor­porated glucose from UDP-glucose or GDP-glucose at low substrate concentrations (10 -6 ᴍ) were both localized in membranes of a density of 1.129 g em-3 (Golgi membranes) and synthesized a β-1,4-glucan chain. Both showed similar properties in most of the characterization experiments. The glucosyltransferase that catalysed the formation of a β-1,3-glucan from UDP-glucose (0.48 mᴍ) was found in membranes which accumulated at a density of 1.170 g · cm-3 (plasma membrane) and differed in its properties from the Golgi-localized glucosyltransferase activities in many aspects. A soluble glucosyltransferase (175,000 × g supernatant) which was also active at low concentrations of UDP-glucose (10-6 ᴍ) but showed enhanced activity under conditions where the other glucosyltransferases were inactive incorporated glucose into a proteinase-sensi­tive product. In linear sucrose gradients this enzyme migrated to different gradient densities depending on conditions.
Characterization of a Defective Mutant of the Dahlemense Strain of Tobacco Mosaic Virus
Authors: Wertz J. M. , Smitamana P. , Sarkar S.
Published: August 2018

A mutant of tobacco mosaic virus has been isolated after treating the dahlemense strain with nitrous acid and called D 16y. Like dahlemense it produces necrotic lesions on java-type tobacco but induces a strong chlorosis on samsun tobacco, in which it spreads systemically. Yield of virus from infected plants is significantly lower than that of dahlemense and the virus particles are unstable in vitro, and probably also in vivo. It is serologically closely related to dahlemense, its coat protein is somewhat less electronegative in weakly alkaline medium and it is inactivated at elevated temperatures more easily than dahlemense. Its coat protein contains a histidine residue, that is not present in dahlemense. The poor biological activity and the instability of D 16y toward storage and high temperatures are properties that are common with many defective mutants. D 16y is possibly the first induced mutant of dahlemense and with its several altered characters is expected to be very useful for comparative studies on the structure and action of TMV.
Electronmicroscopical Contrast by Palladium Chloride
Authors: Ferrer J. M. , Tato A. , Stockert J. C.
Published: August 2018

Thin sections of glutaraldehyde-fixed, epoxy resin-embedded bone marrow from rats were treated with 2% palladium chloride in 2% concentrated HCl. This procedure was found to induce high electron density in chromatin from all cell types and in cytoplasmic granules of neutrophils and eosinophils. In the latter, the crystalline body showed more contrast than the matrix.
Partial Purification and Some Properties of 1-Sinapoylglucose: Choline Sinapoyltransferase ("Sinapine Synthase") from Seeds of Raphanus sativus L. and Sinapis alba L.
Authors: Gräwe Walter , Strack Dieter
Published: August 2018

Hydroxycinnamoyltransferases which catalyze the formation of O-sinapoylcholine (sinapine) using 1-0-sinapoyl-β-ᴅ-glucose as acyl donor have been isolated from seeds of radish (Raphanus sativus L. var. sativus) and mustard (Sinapis alba L.) and purified 420-and 293-fold, respectively. The enzymes (“sinapine synthase”) had apparent molecular weights of about 60,000 daltons and showed highest activities at pH 7.2 and 7.6, respectively, at 45 °C with apparent energies of activation at 53 kJ mol-1. There were no requirements for divalent cations or sulfhydryl reagents. The apparent Km’s of the radish and mustard enzymes were 0.48 and 0.71 mᴍ for 1-sinapoylglucose and 5.3 and 6.5 mᴍ for choline, respectively. The ratios of the Vmax/Km values for 1-sinapoyl-1-feruloyl- and 1-p-coumaroylflucose were found to be 100:19:19 (radish) and 100:20:29 (mustard). 6-0-Sinapoylglucose, 3-0-sinapoylfructose, 1-0-benzoyl- and 1-0-galloylglucose were not accepted as donors.
Inhibition of Phenylalanine Ammonia-Lyase in vitro and in vivo by (1-Amino-2-phenylethyl)phosphonic Acid, the Phosphonic Analogue of Phenylalanine
Authors: Laber Bernd , Kiltz Hans-Herrmann , Amrhein Nikolaus
Published: August 2018

The phosphonic analogue of ʟ-phenylalanine, (R)-(1-amino-2-phenylethyl)phosphonic acid (APEP), inhibits buckwheat phenylalanine ammonia-lyase (PAL) competitively with a Ki value of 1.5 μM. The Ki value for the (S)-enantiomer is 11.6 μM. The corresponding values for the enantiomers of the phosphonous analogue are 35 and 205 μm , respectively. APEP inhibits the light-induced synthesis of anthocyanin in hypocotyls of etiolated buckwheat seedlings and causes a specific increase in the endogenous phenylalanine concentration in buckwheat hypocotyls as well as other plant tissues. Kohlrabi seedlings develop normally in the presence of APEP, while their anthocyanin content is greatly reduced. These results indicate that APEP inhibits PAL in vivo.
Tyrosine Biosynthesis in Sorghum bicolor: Characteristics of Prephenate Aminotransferase
Authors: Siehl Daniel L. , Connelly James A. , Conn Eric E.
Published: August 2018

A stable activity which transfers the amino group from glutamate to prephenate was extracted from 4-day old etiolated shoots of sorghum. The activity was retained on DEAE cellulose and eluted as a single peak. Prephenate aminotransferase co-eluted with a very abundant α-ketoglutarate: aspartate aminotransferase, but heating at 70 °C resulted in loss of α-ketoglutarate: aspar­tate activity with nearly full retention of prephenate: glutamate aminotransferase activity. The heated enzyme displayed high affinity and specificity for prephenate. Among 7 donors tested, only glutamate, and aspartate at less than 20% the rate with glutamate, supported prephenate aminotransferase activity. In the reverse direction, a reaction rate comparable to that in the forward direction was unchanged as the concentration of α-ketoglutarate was reduced from 1.0 to 0.09 mᴍ. The apparent Km for arogenate was 0.8 mᴍ. The forward reaction was unaffected by the inclusion of tyrosine, phenylalanine or tryptophan. Together with the discovery of arogenate dehydrogenase in sorghum [3], these data indicate that, in the sorghum plant, tyrosine derives from prephenate by transamination and aromatization. rather than the reverse sequence.