bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uptake of Protoporphyrin and Violet Light Photodestruction of Propionibacterium acnes
Authors: Melø Thor B. 
Published: August 2018

Abstract
The uptake of protoporphyrin IX by Propionibacterium acnes in suspension has been studied by fluorescence spectroscopy. Protoporphyrin, after it was injected into a cell suspension, was firstly bound to receptors on the cell surface and in this state protoporphyrin was non-fluorescent. Subsequently, probably as a result of lateral diffusion in the cell wall, these protoporphyrinreceptor complexes formed dimers. The final step in the overall uptake process of protoporphyrin by the cells from the surroundings consisted in a jum p of such dimers from waterlike to lipidlike com partm ents in the cell mem brane where protoporphyrin became fluorescent. The lipidlike com partm ents in the cells had a limited binding capacity of protoporphyrin.
The fraction of surviving cells versus light dose has also been studied for varying amounts of protoporphyrin added to the cell suspensions. The survival curves were exponentially decaying with the irradiation time and there was a direct proportionality between the inverse slope of the survival curves and the intensity of protoporphyrin fluorescence from the lipidlike compartm ents. The relevance of these results to the therapy of Acne vulgaris is also discussed.
Intermolecular H-Abstraction of Thiyl Radicals from Thiols and the Intramolecular Complexing of the Thiyl Radical with the Thiol Group in 1,4-Dithiothreitol. A Pulse Radiolysis Study
Authors: Shahid Akhlaq M. , von Sonntag Clemens 
Published: August 2018

Abstract
Hydroxyl radicals were generated by pulse radiolysis of N2O-saturated aqueous solutions. The OH radicals react with thiols such as 1,4-dithiothreitol by abstracting S-bound H-atoms (k = 1.5 × 1010 dm3 mol-1 s-1). The 1,4-dithiothreitol radical HSCH2(CHOH)2CH2S (2) closes the ring (k - 1.5 × 106 s-1) thereby forming the three-electron-bonded species

(3) in equilibrium (2, 3: ε(380 nm) = 450 dm3 mol-1 cm-1) which has a reported pKa value of 5.2. At pH 7.2 3 deprotonates (k = 105 s-1) yielding the ring-closed radical anion 4 which is characterized by a strong absorption at 390 nm (ε = 5900 dm3 mol-1 cm-1). The deprotonation of 3 is catalyzed by HPO2
4 (k - 6 .8 × 107 dm3 mol-1 s-1). The ring-closed radical anion 4 has also been generated by reacting trans-4,5-dihydroxy- 1,2-dithian with the solvated electron and the H atom in Ar-saturated solution. Its protonation by protons yielding 3 occurs with k - 1.8 × 1010 dm3 mol-1 s-1, with H2PO-
4 with k = 3.8 × 107 dm3 mol-1 s-1.
In its reaction towards tetranitrom ethane 3 differs from its non-complexed analogue HOCH2-CH2S‘ (1) in that 3 is rapidly oxidized (k = 2 × 108 dm3 mol s-1) while 1 is not. Isoenergetic H transfer from 1,4-dithiothreitol to 1 occurs with a rate constant of k = 1.7 × 107 dm3 mol-1 s-1.
1,4-Dithiothreitol has pKa values at 9.12 and 10.15. At pH 9.1 thiolate ions com pete with ringclosure by complexing with 2 thereby forming an open-chain disulphide radical anion 6 which has very similar spectral properties as its ring-closed analogue 4.
Species and Sex Specificity in the Odour Composition of Two Panurgine Bees (Hymenoptera, Andrenidae)
Authors: Francke W. , Schröder W. , Borg-Karlsson A. K. , Bergström G. , Tengö J. 
Published: August 2018

Abstract
From the volatile constituents of the solitary bee species Panurgus banksianus Kirby and P. calcaratus Scopuli 31 compounds could be identified. The cephalic secretion of P. banksianus is a sex specific m ulticomponent mixture of terpenes and aliphatic carboxylic acid esters while P. calcaratus contains monoterpenes only. The major component in the Dufour’s gland secretion of P. banksianus is a macrocyclic lactone, eicosanolide, which is absent in P. calcaratus. In contrast, the new terpenoid ester, geranyl citronellate, is present in large amounts in the Dufour’s gland secretion of P. calcaratus.
Protein Sequence and Structure of N-terminal Amino Acids of Subunit Delta of Spinach Photosynthetic ATP-Synthase CF1
Authors: Berzborn Richard J. , Finke Werner , Otto Joachim , Meyer Helmut E . 
Published: August 2018

Chloroplast ATP-synthase (CF1) subunit delta (δ) has been isolated from spinach thylakoids in the presence of SDS. By automated Edman degradation and online analysis of PTH derivatives the 35 N-terminal amino acid residues were sequenced. The mature protein starts with: NH2-Val-Asp-Ser-Thr-Ala-Ser-Arg-Tyr-Ala-. This protein sequence allows alignment of spinach δ with the sequences of Z. mays 25 kDa polypeptide, the δ subunit of Rps. blastica, Rsp. rubrum and E. coli F1, and of bovine OSCP, but not with mitochondrial δ.
Secondary structure calculations and helical wheel plots reveal a conserved secondary structure. The analyzed N-terminal sequences probably build a short amphipathic alpha helix with two adjacent turns. The such aligned polar residues around Tyr8 of subunit δ are suitable to channel protons.
Thin Layer Chromatographic and Infra Red Spectral Evidence for the Presence of Phosphonolipids in Cicada oni
Authors: Moschidis Michael C. 
Published: August 2018

Abstract
The phosphonolipids from whole Cicada oni have been isolated by preparative thin-layer chromatography (TLC) in methanol-water (2:1, v/v) and have been identified by TLC, infra-red spectroscopy, phosphono phosphorus determinations and elemental microanalyses. The presence has been confirmed of the phosphono analogues of phosphatidyl choline, phosphatidyl ethanolamine, sphingomyelin and of ceramide aminoethyl phosphonate.
Adnexal Glands Chemistry of Messor ebeninus Forel (Formicidae: Myrmicinae)
Authors: Coll M. , Hefetz A . , Lloyd H. A . 
Published: August 2018

Abstract
Anabasine is the major volatile product in the poison gland exudate of Messor ebeninus, acting as a defensive compound. Exudates of the poison gland also contain minor, yet unidentified, components that are possibly responsible for the alarm behavior that is also elicited by the venom.
Dufour’s gland secretion is characterized by aliphatic hydrocarbons of which 1-pentadecene predominates. Upon exposure to Dufour’s gland secretion the ants recruited to the emitting source, but did not exhibit any aggressive behavior. The possible concordant effects of both adnexal glands secretions is discussed.
Esters of Caffeic Acid with Aliphatic Alcohols in Bud Exudate of Populus nigra
Authors: Greenaway W. , Wollenweber E. , Scaysbrook T. , Whatley F. R. 
Published: August 2018

Abstract
A fraction of poplar bud exudate was analyzed by GC/MS and the novel aliphatic hydrocarbon esters 2-methylpropyl-, 2-methyl-2-propenyl-, 2-methylbutyl-, 3-methylbutyl-, 2-methyl-2- butenyl-, 4-methylpentyl-, (5)-methylhexyl- and 3,7-dimethyl-2,6-octadienyl(geranyl)- caffeate were identified.
Characterization of Hexokinase and Fructokinase from Suspension-Cultured Catharanthus roseus Cells
Authors: Yamashita Yüko , Ashihara Hiroshi 
Published: August 2018

Abstract
Two different hexose-phosphorylating enzymes, hexokinase and fructokinase, were partially purified from suspension-cultured Catharanthus roseus cells. One of the enzymes, hexokinase, catalyzed the phosphorylation of both glucose and fructose. The Km values for glucose and fructose were 0.06 mM and 0.23 mM, respectively. The Vmax of the enzyme with fructose was approximately three times higher than with glucose. This enzyme was specific in its requirement for ATP and its Km value for ATP was 52 μM. The optimum pH was 8.0 and Mg2+ or Mn2+ was required for the activity. The activity was inhibited by considerably higher concentrations of ADP (i.e., 4 mM ADP was required for 50% inhibition). The second enzyme, fructokinase, was specific for fructose, and no activity was detected with glucose as substrate. This enzyme used UTP or CTP as phosphate donor. The Km values of this enzyme for fructose and UTP were 0.13 mM and 0.15 mM, respectively. The pH optimum was 7.2, and Mg2+ or Mn2+ was required for the activity. These divalent cations could be partially replaced by Ca2+. The activity was inhibited noncompetitively by ADP and AMP. 90% inhibition of the activity by 0.5 mM ADP was observed in the presence of 2 mM UTP and 5 mM MgCl2. Fructose-2,6-bisphosphate, glucose-1,6-bisphosphate, glucose-6-phosphate, and fructose-6-phosphate had little or no effect on the activity of both the hexokinase and the fructokinase. Based on these results, a discussion is presented of the role of hexokinase and fructokinase and their involvement in the regulation of the metabolism of sugars in Catharanthus cells.
Hämaktivierte Oxidationen mit dem Chlorit-Sauerstoff-Komplex „TCDO" (OXOFERIN®) - eine Übersicht / Heme-Activated Oxidations by the Chlorite-Oxygen Complex "TCDO" (OXOFERIN®)
Authors: Elstner Erich F. 
Published: August 2018

Abstract
Several chlorooxygen compounds, hydrogen peroxide and reducing molecules in the presence of chelated iron (Fenton systems) are oxidants of biological relevance. These compounds are either produced in living tissues or are in use as desinfectants or drugs. Tetrachlorodecaoxide as the active principle in the drug OXOFËRIN® can be differentiated from the above mentioned oxidants by means of simple biochemical test systems where different activators and detector molecules are used.
Trichoplax adhaerens F. E. Schulze (Placozoa): The Formation of Swarmers
Authors: Thiemann Martin , Ruthmann August 
Published: August 2018

Abstract
Flageilated swarmers representing an alternative mode of asexual reproduction are budded off as hollow spheres at the dorsal surface. They are covered by cells of the dorsal epithelium and the interior cavity is lined by ventral epithelium. Fiber cells are in the interspace. Early primordia in the interspace between both epithelia of the mother animal are cavities filled with granular material and surrounded by non-flagellated epithelium cells. No mitoses are seen during growth of the bud whose interior becomes densely flagellated as is characteristic for the ventral epithelium. Fiber cells are passively included. The bud at first forms a bulge at the dorsal surface which is then pinched off. The flattened shape of Trichoplax is attained via cup-shaped and C-shaped intermediate stages after opening of the hollow sphere.
The Occurrence of Phenols as Degradation Products of Natural Sporopollenin – a Comparison with "Synthetic Sporopollenin"
Authors: Herminghaus Susanne , Gubatz Sabine , Arendt Sibylle , Wiermann Rolf 
Published: August 2018

1. A highly purified sporopollenin fraction from Corylus avellana pollen was obtained using a gentle method employing hydrolyzing enzymes (pronase, lipase, cellulase, amylase, cellulysin) and an exhaustive extraction using different solvents.
2. The sporopollenin fractions were degraded by potash-fusion and nitrobenzene oxidation and the low molecular decomposition products were analyzed by TLC and HPLC. The investigation centered solely on the proof of phenolic compounds.
3. The degradation by potash-fusion yielded p-hydroxybenzoic acid as a main component, while the degradation by nitrobenzene oxidation (NBO) resulted in the formation of p-hydroxybenzaldehyde as the main component. In addition phenolic components such as p-coumaric acid, ferulic acid, vanillin and vanillic acid were formed to different degrees by using NBO as degradation procedure.
4. A comparison of the products formed following degradation of Corylus sporopollenin and “synthetic sporopollenin” shows, that phenolic compounds, if they indeed occurred as degradation products of “synthetic sporopollenin”, are generated only in extremely small quantities. It appears that, in contrast to several reports in the literature, phenols are integral constituents of natural sporopollenin. This view is supported by unpublished tracer experiments.
Elicitation of Pterocarpan Phytoalexins in Cell Suspension Cultures of Different Chickpea (Cicer arietinum L.) Cultivars by an Elicitor from the Fungus Ascochyta rabiéi
Authors: Keßmann Helmut , Daniel Susanne , Barz Wolfgang 
Published: August 2018

Cell suspension cultures of two chickpea (Cicer arietinum L.) cultivars, resistant and susceptible towards the chickpea pathogen Ascochyta rabiei, were compared with regard to elicitor-induced changes in phytoalexin and isoflavone accumulation. The elicitor was isolated from fermentergrown mycelium of A. rabiei and it mainly consisted of glucose, mannose and N-acetylgalactosamin.
Time course and dose response studies on elicitor action demonstrated that the cell culture of the resistant cultivar ILC 3279 accumulated large amounts of the pterocarpan phytoalexins medicarpin and maackiain within 8 h. The cell culture of the susceptible cultivar ILC 1929 accumulated only small amounts of the phytoalexins some 12 h after elicitor treatment. Growth of the cell cultures and the accumulation of isoflavones and isoflavone conjugates were not altered by elicitor treatment except for a higher accumulation of formononetin 7-O-glucoside-6″-O-malonate in cell culture ILC 3279 subsequent to the maximum of phytoalexin accumulation.
Kinetic Properties of Potassium Stimulated ATPase Purified from Gastric Mucosa
Authors: Tükel Seyhan , İsbir Turgay 
Published: August 2018

In this study, partially purified K+-H+ ATPase from frog gastric mucosa were obtained by using differential and density gradient centrifugation.
Optimum activity of K+-H+ ATPase (Vmax), Michealis-Menten constant (Km) and Hill coefficient (h) were found as 83.3 μmol Pi·mg prot-1 h-1, 95.2 μᴍ and 0.91, respectively. Enzyme preparations were more stable in glycerol solutions stored at -40 °C. Minimum activity lost was determined for samples stored in 40% (v/v) glycerol solution at -40 °C for two months.
Synthesis of Flavonoid Sulfates. III. Synthesis of 3′,4′-ortho Disulfates Using Sulfur Trioxide-trimethylamine Complex, and of 3′-SuIfates Using Aryl Sulfatase
Authors: Barron Denis , Ibrahim Ragai K. 
Published: August 2018

Abstract
A number of flavonoid 3′,4′-disulfates were synthesized from the corresponding 4′-sulfate esters, using sulfur trioxide-trimethylamine complex. Desulfation of the sulfate esters using aryl sulfatase demonstrated that the rate of hydrolysis of the 3′-sulfate group was slower than either the 7- or 4′ groups, thus allowing the specific synthesis of flavonol 3,3′-disulfates. The effects of ortho-disulfation on the 13C NMR spectra of flavonoids, and the regative FAB-MS spectra of diand trisulfated flavonoids are discussed.
Wyerol and Wyerone Accumulation in Tissue Cultures of Vicia faba
Authors: Wolff Andreas B. , Thynn Maung , Gorge Elisabeth , Werner Dietrich 
Published: August 2018

Abstract
Callus cultures of various cultivars of Vicia faba were studied for regeneration. During callus growth on agar or in liquid medium a black tissue was often observed correlated with an autolysis of some cells. With those tissues callus growth and regeneration of plants was inhibited. In black callus the phytoalexin synthesis is induced without infection by microorganism. The main phytoalexins in the callus tissue are wyerol and wyerone, with some wyeronic acid and dihydrowyerone. Wyerol was found especially in the cultivar Troy at a high concentration. In four cultivars the pooled phytoalexin concentration varied between 10 and 150 μg · g-1 fresh weight.
Cell Movement and Symmetry of the Cellular Environment
Authors: Gruler Hans 
Published: August 2018

Abstract
The movement of micro-organisms was investigated in different cellular environments. The type of movement was described in terms of the symmetry of the cellular environment: (i) Random movement - isotropic symmetry of the environment, (ii) contact guidance - apolar symmetry of the environment and (iii) directed movement as Chemotaxis and galvanotaxis - polar symmetry of the environment. To quantitate cell movement it was necessary to parameterize the environment as well as the cell movement by observables. The random movement was quantitated by the diffusion coefficient. The contact guidance of the nematic type and the contact guidance on a bent surface were quantified by an apolar order parameter. The contact guidance constant for fibroblast on a glass cylinder was 87.5 pm. The directed movement was quantified by a polar order parameter. Dose-response curves were derived and compared for different types of cells: Chemotaxis of granulocytes KCT
-1 = 2.2 mm for 10 μᴍ f-Met-Met-Met, galvanotaxis of granulocytes KG
-1 = 0.2 V/mm, galvanotaxis of fibroblast KG
-1 = 0.28 V/mm, galvanotaxis of spermatozoids of bracken fern KG
-1 =0.024 V/mm.
9 β-Hydroxymarasmic Acid and Other Sesquiterpenoids from Submerged Cultures of a Basidiomycete [1]
Authors: Anke Heidrun , Hillen-Maske Elisabeth , Steglich Wolfgang 
Published: August 2018

Abstract
9 β-Hydroxymarasmic acid, a new sesquiterpenoid, marasmic acid and isovelleral were isolated from cultures of a basidiomycete. Comparison of the antimicrobial activity of the three natural compounds together with two n-butyl ether derivatives of marasmic acid revealed MICs against bacteria in the range of 0 .2 -20 ng/ml. The antifungal, cytotoxic and phytotoxic activities of isovelleral were similar to those exhibited by marasmic acid, whereas the marasmic acid deriva­ tives were considerably less active than the parent compound. Isovelleral was the only compound to show hemolytic activity.
Effects of Glufosinate on Anion Uptake in Lemna gibba G 1
Authors: Trogisch Gudrun D. , Köcher Helmut , Ullrich Wolfram R. 
Published: August 2018

Abstract
The duckweed Lemna gibba G 1 was used as a model to study inhibitory sites with the herbicide and glutamate analogue glufosinate (PPT). Growth and chlorophyll formation were partly inhibited by 25 n-M, completely suppressed by 250 (im PPT. Photosynthesis showed partial inhibition within few hours, dark respiration ( 0 2 consumption) increased already within one hour. In the presence of 1 mM PPT in the light, the ammonium pool of Lemna increased to 600% within few hours, later to 1000%. The overall amino acid pool exhibited a slower increase to 300%, the nitrate pool only a slight increase, while total phosphate remained almost unchanged. In the dark all these effects were less pronounced than in the light. Nitrate, nitrite and phosphate uptake were partially inhibited by PPT, especially after 19 h PPT pretreatment. Nitrate reductase activity in vitro, after PPT treatment in vivo, showed an inhibition similar to that of nitrate uptake. Ammonium was not taken up but released under the same conditions.
The data are explained by a combined effect of PPT, by inhibition of glutamine synthetase leading to accumulation of ammonium from photorespiration and proteolysis, by membrane depolarization and inhibition of anion/proton cotransport, by secondary uncoupling of phosphorylation, and by secondary inhibition of nitrate reductase activity.
Influence of Inhibitors of Polyamine Biosynthesis on Polyamine Levels and Growth of Plants
Authors: Felix Hansruedi , Harr Jost 
Published: August 2018

Abstract
Inhibitors of enzymes involved in polyamine biosynthesis which stop the growth of bacteria, fungi and animal cell systems were analyzed for their potential to interfere with plant cell systems. Several compounds were found to be potent inhibitors of plant enzymes, namely the decarboxylases of ornithine, arginine and S-adenosylmethionine as well as the aminopropyltransferase. Application of enzyme inhibitors (α-difluoromethylornithine. l-aminooxy-3-aminopropane, a-difluoromethylarginine, methylglyoxal bis(guanyl-hydrazone), cyclohexylamine) or combinations of these on whole plant systems resulted neither in a large decrease in polyamine content nor in a significant growth reduction. The lack of response cannot be explained by hindered inhibitor uptake into plants. Inhibition of single enzymes may induce alternative biosynthetic pathways.
Effect of Non-Solubilizing SDS Concentrations on High Affinity Ca2+ Binding and Steady State Phosphorylation by Inorganic Phosphate of the Sarcoplasmic Reticulum ATPase
Authors: Fassold Elisabeth , Hasselbach Wilhelm , Küchler Bernd 
Published: August 2018

Abstract
In this investigation low, non-solubilizing concentrations of the strong anionic detergent SDS were used to perturbate the interaction of Ca2+ and Pi with their respective binding domains on the sarcoplasmic reticulum Ca-transport ATPase. Rising SDS concentrations produce a two-step decline of Ca2+-dependent ATP hydrolysis. At pH 6.15, SDS differently affects high affinity Ca2+ binding and phosphorylation by inorganic phosphate and releases the “mutual exclusion” of these two ligand binding steps. The degree of uncoupling is considerably more pronounced in the presence of 20% Me2SO.
The reduction of Ca2+ binding by SDS is demonstrated to be a result of decreased affinity of one of the two specific high affinity binding sites and of perturbation of their cooperative interaction. Higher SDS partially restores the original high Ca2+ affinity but not the cooperativity of binding. Phosphorylation exhibits a higher SDS sensitivity than Ca2+ binding: Increasing SDS competitively inhibits and then completely abolishes phosphoenzyme formation. Thus. SDS binds to the phosphorylation domain, evidently involving the Lys352 residue of the ATPase molecule; this is accompanied by a more unspecific concentration-dependent SDS effect, probably mediated by hydrophobic force, which, finally, suppresses phosphorylation.
Me2SO does neither qualitatively affect the SDS-dependent chemical properties of the vesicular material nor the SDS-dependent perturbation of the investigated reaction steps.
Molecular Genetic Approaches to the Study of Phytopathogenic Fungi
Authors: Peterson Todd C. 
Published: August 2018

Abstract
The broad application of chemical crop protectants and intensive plant breeding for the development of agriculture and the management of plant disease have created conditions of environ­ mental concern. Molecular genetic m ethods are being applied to the analysis of phytopathogenic fungi and their corresponding diseases. Rapid development of this research field will permit the isolation and characterization of genes involved in pathogenic processes. A detailed understanding of the molecular events of disease onset and progression will facilitate the design of improved procedures for disease prevention and control. Invited Trends Article
Diphosphatase Related to Lipid Metabolism and Gluconeogenesis in Cucumber Cotyledons: Localization in Plasma Membrane and Etioplasts but not in Glyoxysomes
Authors: Kirsch Thomas , Rojahn Barbara , Kindi Helmut 
Published: August 2018

Abstract
Diphosphatase (inorganic pyrophosphatase) activity was localized within compartments of cotyledons of germinating cucumber seeds during the stage of maximal conversion of fat into carbohydrates. At this stage, almost 2 mol pyrophosphate are produced during the formation of one mole sucrose from 0.28 mol triglyceride. When organelles of the 2000 x g pellet or 10,000 x g pellet were separated by density gradient centrifugation and gradient flotation, the diphosphatase activity paralleled the profiles of markers of the plastid stroma but was virtually absent from the glyoxysomes. Within the fraction of small vesicles and membranes, diphosphatase was attributed to the plasma membrane.
The main portion of diphosphatase, contained in the plastids, was partially purified by chromatography on anion exchange resin and molecular sieving, leading to a 75-fold enrichment compared to the stroma fraction. Trace amounts of diphosphatase observed in the glyoxysomal fraction were analyzed in the same way. Comparison of the isoelectric points and the activity profile at different pH values and the inhibitory effect of the various cations indicated that the trace amounts of diphosphatase activity in the glyoxysome fraction represented contaminations originating from the plastids.
The plasma membrane form of diphosphatase is an integral membrane protein which was solubilized with octylglucoside. It was shown to differ from the plastid form in pH optimum and sensitivity towards bivalent cations. All forms of diphosphatase were clearly distinguished from other phosphohydrolytic activities.