bluuebunny/crossref_metadata_2025 huggingface dataset:
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

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

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.
Chemical Composition and Morphology of Epicuticular Waxes from Leaves of Solanum tuberosum
Authors: Sen A.
Published: August 2018

The chemical com position and morphology of leaf surface waxes of Solanum tuberosum were analysed using FT - IR . GLC and MS studies. There is a predominance of saturated and long chained components resulting in a crystalline wax layer in the form of ribbons, n-alkanes are a major constituent with C31 being p rominent. Wax esters and 5-alcohols form the other major components. Wax composition of five other solanaceous plants, viz., Solanum eleagnifolium, Lycopersicon esculentum, Nicotiana tabacum, Datura stromonium and Solanum nigrum were compared with those of potato using TLC techniques and do not show any qualitative differences.
Enzymatic Synthesis of 4′-and 3′, 4′ -Hydroxylated Flavanones and Flavones with Flower Extracts of Sinningia cardinalis
Authors: Stich K. , Forkmann G.
Published: August 2018

Flowers of Sinningia (syn. Rechsteineria) cardinalis contain glycosides of the flavones apigenin (4′-OH) and luteolin (3′,4′-OH) respectively, and of the related 3-deoxyanthocyanidins apigeninidin and luteolinidin. Studies on substrate specificity of the key enzyme of flavonoid biosynthesis, chalcone synthase, revealed that the 3′,4′-hydroxylated flavonoids are formed by hydroxylation of flavonoid compounds rather than by incorporation of caffeoyl-CoA into the flavonoid skeleton during the condensation reaction. In fact, flavonoid 3′-hydroxylase activity could be demonstrat­ed in the microsomal fraction of the flower extracts. The enzyme catalyses hydroxylation of naringenin and apigenin in the 3′-position to eriodictyol and luteolin, respectively, with NADPH as cofactor. Besides flavanone 3′-hydroxylase a further NADPH-dependent enzyme activity (flavone synthase II) was observed in the microsomal fraction catalysing the oxidation of naringenin to apigenin and of eriodictyol to luteolin. The Cytochrome P-450 inhibitor ancymidol was found to abolish completely flavone synthase II activity, whereas flavonoid 3′-hydroxylase activity was not impaired.
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.
CARS Investigation of Changes in Chromophore Geometry of C-Phycocyanin from Mastigocladus laminosus Induced by Titration with p-Chloromercuribenzenesulfonate
Authors: Schneider S. , Baumann F. , Klüter U.
Published: August 2018

Titration of trimers of C-phycocyanin with p-chloromercuribenzenesulfonate (PCMS) changes spectroscopic and kinetic properties of chromophore B84. The resonance-enhanced CARS spec­tra of room temperature solutions indicate that these changes are due to a modification in B84 chromophore geometry (movement of ring D) as judged by the disappearance of the 1245 cm-1 vibration.
Inhibition by Sethoxydim of Pigment Accumulation and Fatty Acid Biosynthesis in Chloroplasts of Avena Seedlings
Authors: Lichtenthaler Hartmut K. , Kobek Klaus
Published: August 2018

The cyclohcxanedionc derivatives sethoxydim and alloxydim block leaf growth and inhibit the accumulation of photosynthetic pigments (chlorophylls, carotenoids) in expanding leaves of oat seedlings, but do not affect the rate of photosynthesis in the primary or secondary leaves. In isolated intact oat chloroplasts the incorporation of [2-14C)acetate into the total fatty acid fraction is strongly inhibited by the two herbicides sethoxydim and alloxydim. The I50 -values for the inhibition of [14C]acetate incorporation into fatty acids are 5 × 10-7 ᴍ for sethoxydim and 2 × 10-6 ᴍ for alloxydim. The desethoxyimino derivative of sethoxydim. M1-S, a degradation product of sethoxydim, does not interfere with the fatty acid biosynthesis of isolated oat chloro­plasts. In isolated chloroplasts of the dicotyledonous plants pea and spinach, which as whole plants are tolerant towards sethoxydim, no significant inhibition of the fatty acid biosynthesis by sethoxydim could be found. It is assumed that the primary mode of action of sethoxydim and alloxydim is in blocking the fatty acid biosynthesis in the sensitive gramineous plants.
Notes: Formation of Large Thioredoxin f Accompanies Chloroplast Development in Scenedesmus obliquus
Authors: Langlotz Petra , Follmann Hartmut
Published: August 2018

Chloroplast-free mutant cells C-2A′ of the green algae Scenedesmus obliquus lack thioredoxin f, which functions in the light activation of chloroplast enzymes, but do con­tain the regular thioredoxins I and II. When dark-grown algae are transferred to light, thioredoxin f activity appears rapidly and increases in parallel with photosynthetic ac­tivities: however it precedes chlorophyll biosynthesis. The formation of thioredoxin f is inhibited by cydoheximide indicating that it occurs on the cytoplasmic ribosomes, in accord with the lack of thioredoxin genes on the chloroplast genomes.
Thin Layer Chromatographic and Infra Red Spectral Evidence for the Presence of Phosphonolipids in Cicada oni
Authors: Moschidis Michael C.
Published: August 2018

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

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.
Metabolism of the Prenylated Pterocarpan Edunol by Aspergillus flavus
Authors: Tahara Satoshi , Ingham John L.
Published: August 2018

When incubated in liquid culture with Aspergillus flavus, the prenylated pterocarpan (-)-edunol [2-(3,3-dimethylallyl)-3-hydroxy-8,9-methylenedioxypterocarpan (1)] was converted into a dihydrofurano-pterocarpan (2), a dihydropyrano-pterocarpan (3). and a 2,3-dihydro- dihydroxyprenyl-substituted pterocarpan (4).
Novel Flavonoids from the Fern Notholaena sulphurea
Authors: Arriaga-Giner F. J. , Mizuno M. , Iinuma M. , Tanaka T. , Scheele C. , Wollenweber E.
Published: August 2018

The major constituent of the yellow frond exudate of the fern Notholaena sulphured was identified by spectroscopic methods as 3,5,2′-trihydroxy-7-methoxy-8-acetoxy flavone and its structure was confirmed by synthesis. This novel natural flavonoid was also detected in the frond exudate of five other Notholaena species. In the yellow form of N. sulphurea, the rare 5,2′- dihydroxy-7,8-dimethoxy flavone was also found, along with some trivial flavonoids. The white form of N. sulphurea produces three dihydrochalcones that are accompanied by some kaempferol methyl ethers and apigenin-7-methyl ether. The 3-acetoxy as well as the 3-butyroxy and the 4′- butyroxy derivatives of 7-methyl aromadendrin were also identified in this material. One of them was shown to belong to the extremely rare group of 3-cis-dihydroflavonols.
Dependence of a Sleeping Parameter from the N-S or E-W Sleeping Direction
Authors: Ruhenstroth-Bauer G. , Rüther E. , Reinertshofer Th.
Published: August 2018

In an earlier study it was shown that an isotonic salt solution within a measuring chamber of a cytopherometer is rotating caused by Lorentz forces, if the magnetic earth field crosses the electric field in the chamber. This may be a model of the ability of certain higher organisms to recognize the direction of the magnetic earth field. The topic of this study was the possible effect of the magnetic earth field in humans. It is shown that the duration of REM latency is influenced by the position of sleepers in N-S or E-W direction: it is shortened in E-W direction (p = 0.02).
Biflavones from some mosses
Authors: Geiger Hans
Published: August 2018

From Antitrichia curtipendula and Racomitrium lanuginosum 5′,3‴-dihydroxyrobustaflavone and 5′, 8″-biluteolin were isolated. In Plagiomnium elatum the new biflavone 5′-hydroxyamentoflavone was detected
Production and accumulation of phenylpropanoids in tissue and organ cultures of pimpinella anisum
Authors: Reichling Jürgen , Martin Rainer , Thron Ulla
Published: August 2018

A leaf-differentiating callus culture and a root organ culture of Pimpinella anisum have been established in liquid nutrition medium. Their behaviour in accumulation of phenylpropanoids was shown to be different from that of the entire plant. This makes them, together with their special growth behaviour, suitable for labelling experiments with the biosynthesis of pseudoisoeugenols
Isolation and characterization of the androgen receptor of murine preputial gland
Authors: Wiegand Manfred , Eisele Karl
Published: August 2018

The androgen receptor of murine preputial gland showed in binding experiments a biphasic saturation curve and a biphasic Scatchard plot. The receptor converted from an 8.5-9 S form to a 4.5-5 S form in high ionic strength buffer. The apparent dissociation constant was KD 0.5 ± 0.2 nᴍ for the 8.5-9 S receptor form. A 6.5-7 S receptor form could be detected in some experiments. The ligand specificity was evaluated by competition experiments: testosterone > androstenedione > dihydrotestosterone > androstanediol > estradiol > progesterone > dexamethasone. The receptor of murine preputial gland was less stable than the androgen receptor of skeletal muscle of the same mice
Sedimentation von nukleoiden aus thymus- und milzzellen der ratte nach ganzkörper-röntgenbestrahlung / Sedimentation of nucleoids from thymic and splenic cells of the rat following total-body x-irradiation
Authors: Tempel Karlheinz , Heinzelmann Rüdiger
Published: August 2018

The sedimentation of nucleoids from thymic and splenic cells of rats was tested following totalbody X-irradiation (TBI) with doses ranging from 24 to 1520 cGy. The principal results may be summarized as follows: 1) The nucleoid sedimentation of the cells was reduced immediately after TBI with doses of ≥ 760 cGy. In the following postirradiation period, an enhancement of sedimentation rate has been observed which could be neutralized by addition of proteinase K to the nucleoid preparation. 2) When nucleoids were prepared 6 h after TBI with doses ≥ 190 cGy, beside the main nucleoid band a smaller nucleoid fraction appeared in the ethidium bromide containing saccharose gradient. This fraction was of less sedimentability than the main nucleoid peak and could not be distinguished from pure, high molecular DNA. - From the present results it is suggested that the reduction of the nucleoid sedimentation immediately following high doses of TBI is the result of primary (non-repaired) DNA lesions whereas the changes detectable some hours later are due to the secondary enzymatic changes connected with the interphase death of the cells. With respect to the detection of in vivo effects of X-irradiation, the nucleoid sedimentation has to be regarded much less sensitive than some biochemical and/or cytomorphological methods
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

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

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

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

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.
Pressure Induced Structural Fluctuations in Hemoglobin, Studied by EPR-Spectroscopy
Authors: Paul J. , Goldammer E. v. , Wenzel H. R.
Published: August 2018

A quartz based cavity for pressure dependent EPR measurements on liquid samples allowing pressures up to 0.6GPa was constructed. First investigations with this setup were done on spin labeled horse hemoglobin derivatives both in ferric and ferrous state of oxidation. The second derivative EPR spectra show changes of the label’s mobility, which are not correlated with spin state changes of the Fe-porphyrin complex, but which point out structural fluctuations inside the globin protein matrices.
New Constituents of Essential Oil from Elsholtzia pilosa
Authors: Bestmann H. J. , Kobold U. , Claßen B. , Vostrowsky O. , Sah G. C. , Pant A. K. , Melkani A. B. , Mathela C. S.
Published: August 2018

By means of GC and GCMS 31 constituents of the essential oil of Elsholtzia pilosa have been identified, 1.8-cineol representing the main component (50%). The oil composition with respect to its major constituents has been compared with other Elsholtzia species.
Evidence for Cyclic GMP in the Yeast Saccharomyces cerevisiae, and Studies on Its Possible Role in Growth
Authors: Eckstein Hans
Published: August 2018

The yeast Saccharomyces cerevisiae is shown to be equipped with cyclic GMP, the level of which ranges from 6 pmol/109 cells with pressed baker’s yeast to 21 pmol/109 cells with exponentially growing cells. In extracts from synchronized growing yeast, cyclic GMP increases stepwise, being doubled at the time of each mitosis. Theophylline and 3-isobutyl-1-methylxanthine induce a rapid increase of cyclic GMP, followed by a premature formation of the septal cell wall between mother cell and bud. The effects of 3-isobutyl-1-methylxanthine are reversible. Dibutyryl-cyclic GMP, and, after a pronounced lag, also dibutyryl-cyclic AMP, induce a premature cell division, too. Cholera toxin induces premature cell divisions without a preceding increase in cyclic GMP. Neither theophylline nor 3-isobutyl-1-methylxanthine, cholera toxin or one of the dibutyryl-cyclic nucleotides modify the growth rate of the culture. None of the agents has significant effects on the level of cyclic AMP. The results suggest that cyclic GMP possibly controls an early step of mitosis, whereas ADP-ribosylation might govern a subsequent event.
Primary Cilia in Locust Spermatocytes: Formation, Fate, and Possible Function
Authors: Daub Agnes-M. , Hauser Manfred
Published: August 2018

During locust spermatocyte development, rudimentary cilia originate from all centrioles of the doubled prophasic centrosome, located in the centrosphere and specifically linked to the nuclear envelope. Membranous vesicles at the bases of the centrioles fuse to form an intracellular ampulla that contributes the ciliary membranes. Later in prophase the ampulla’s membrane is integrated into the plasma membrane so that all primary cilia project into the extracellular medium and lose contact with the nucleus. As the centrioles remain ciliated on their way to their polar positions, w e propose a mechanism for this migration which is based on this intimate association between centrosomes and plasma membrane, on membrane fluidity and on a contractile cell cortex. We noted a translocation of the ciliated centrioles below the cell surface at the metaphase/-anaphase transition which may be regarded as “deciliation” by light microscopy. Some possible explanations for the primary cilium’s role in cell cycle regulation are suggested.
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.
Two New Enzymes of Rosmarinic Acid Biosynthesis from Cell Cultures of Coleus blumei: Hydroxyphenylpyruvate Reductase and Rosmarinic Acid Synthase
Authors: Petersen Maike , Alfermann A. W.
Published: August 2018

Rosmarinic acid biosynthesis can be stimulated in cell cultures of Coleus blumei by culturing the cells in medium with 4% sucrose. In enzyme extracts of these cells two new enzymes of rosmarinic acid biosynthesis were discovered. Hydroxyphenylpyruvate reductase reduces 4-hydroxyphenylpyruvate and 3,4-dihydroxyphenylpyruvate to 4-hydroxyphenyllactate and 3,4-dihydroxyphenyllactate, respectively, using NADH. Rosmarinic acid synthase transfers the caffeoyl moiety of caffeoyl-CoA to the non-phenolic OH-group of 3,4-dihydroxyphenyllactic acid, in course of which rosmarinic acid is formed.
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.
A Simple, Reliable and Inexpensive Silver Stain for Nerve Fibers in Bleached Skin
Authors: Fritzsch Bernd , Zakon Harold H.
Published: August 2018

A procedure for silver staining is described which leads to the selective and reliable impregnation of nerve fibers in bleached skin of vertebrates and invertebrates. In combination with osmium, the protocol enhances the staining of secondary sensory cells of mechanosensory and electrosensory organs so that the innervation pattern of each organ and the number of sensory cells per organ can easily be evaluated. The technique can be also used for staining nerve fibers in whole embryos.
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

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

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

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

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

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

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

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

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

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.
Effect of Neurotransmitters on Movement of Screening Pigment in Insect Superposition Eyes
Authors: Hamdorf Kurt , Höglund Gunnar , Juse Achim , Stusek Peter
Published: August 2018

Com pound Eye, Pigment Migration, Adrenaline, Octopamine, Noradrenaline The light-induced expansion of the screening pigment in the com pound eyes of the sphingid moth Deilephila and the owlfly Ascalaphus is counteracted by local application of noradrenaline or octopamine. Ata critical concentration, similar for both drugs, the expanding effect caused by a light stimulus is completely neutralized, and at higher drug concentrations light stimulation induces a contraction of the screening pigment. The contracting effect of noradrenaline and octopamine is counteracted by adrenaline. None of the other putative neuroactive substances tested (acetylcholine, GABA , histamine, melatonin, serotonin and taurine) has a com parable effect on light-induced pigment movement. It is hypothesized that pigment migration is controlled by a system of antagonistically acting catecholamines, similar to the noradrenaline/adrenaline system present in vertebrates.
Antitumoral Property of Ethanolic Extract of Propolis in Mice-Bearing Ehrlich Carcinoma, as Compared to Bleomycin
Authors: Scheller S. , Krol W. , Owczarek S. , Swiacik J. , Gabrys J. , Shani J.
Published: August 2018

Antitum oral effect of ethanolic extract of propolis (EEP) was demonstrated in mature mice-bearing Ehrlich carcinoma. Survival rate after EEP treatment was compared to that of bleomycin, given alone or in combination every two days for 36 days and follow ed up for 14 additional days. The survival rate at 50 days was 55% after EEP and 40% after bleomycin, while all the mice-treated with EEP + bleomycin combination demonstrated shorter survival than the controls. It is concluded that while the in vivo activity of bleomycin is reduced in the presence of cytochrome-C-reductase inhibitors (like some of the EEP components are), the antitumoral property of EEP in the tumored animal model studied is significant and lasting.
The Essential Root Oil of Peucedanum lancifolium Lange and Chemotaxonomic Implications
Authors: Kubeczka K.-H. , Schmaus G. , Schultze W. , Ullmann I.
Published: August 2018

The composition of the essential root oil of Peucedanum lancifolium Lange (A piaceae), growing in the Atlantic coast regions of France, North-West Spain und Portugal was investigated by chromatographic and spectroscopic methods. Forty five terpenoids, many of them of already known structure, and several aliphatic esters have been identified. Besides the main constituent, the irregular sesquiterpene alcohol trans-sesquilavandulol, representing 53.37% of the total oil, some hitherto unknown sesquiterpenoids with an irregular carbon skeleton were found. The possible chemotaxonomic value of the essential oil com position with regard to the close botanical relationship of Peucedanum lancifolium Lange and Peucedanum palustre (L .) M oench is briefly discussed. With the exception of these two species, trans-sesquilavandulol was not found in any other member of the genus Peucedanum.
Theoretical Investigations on the Role of Steroid-Skeleton C4 = C5 Unsaturation in Competitive Aromatase Inhibition
Authors: Bohl Martin , Simon Zeno , Lochmann Jens Reiner
Published: August 2018

A quantitative structure-activity relationship (QSAR ) approach by use of the minimal topological difference (MTD) method including 46 derivatives of 4-androstene-3,17-dione and 5a-androstane- 3,17-dione is applied to give indications about the role of the C 4 = C5 double bond in competitive inhibition of human placental aromatase and about sterical requirements in steroidaromatase interactions. The inhibitory activity is found to correlate with the sterical MTD variable, hydrophobicity, and π-system conjugation in the A,B-ring region.

A comparison of the MTD results reveals a good agreement with interpretations based on freeenergy data derived from inhibition constants.

By means of MM2 molecular mechanics and PCILO quantum-chemical calculations, the 4-ene structure is shown to significantly influence conformational features of C19 substituents which are important in enzym atic transformations. While 19-hydroxy-5a-androstane-3,17-dione favour a conformation having the hydroxyl group in the enzyme-directed out-of-ring position, the C 4 = C5 double bond energetically enables the steroid to adopt a conformation which can be hydroxylated without internal rotations.

According to present theoretical findings, the 4-ene unsaturation thus exerts an indirect conformational influence by hydroxyl positioning appropriate to aromatase interactions and a direct electronic influence by π conjugation.
Photochemical and Non-Photochemical Quenching of Chlorophyll Fluorescence Induced by Hydrogen Peroxide
Authors: Neubauer Christian , Schreiber Ulrich
Published: August 2018

Chlorophyll Fluorescence. Fluorescence Quenching, Hydrogen Peroxide. Active Oxygen. Ascorbate Peroxidase Chlorophyll fluorescence quenching induced by H 20 2 in intact spinach chloroplasts was investi­gated with a modulation fluorometer which allows to distinguish between photochemical and non­ photochemical quenching components by the so-called saturation pulse method. Residual catalase activity was removed by washing and percoll gradient centrifugation. H2O2 was found to induce pronounced photochem ical and non-photochemical quenching, characteristic for the action of a Hill reagent, with a half-maximal rate already observed at 5 × 10-6 m . The saturation characteris­tics and maximal rate of H2O2-reduction were very similar to those of methylviologen reduction. H2O2-dependent quenching was stimulated by ascorbate and inhibited by cyanide and azide in agreement with previous findings by other researchers that H2O2-reduction involves the ascorbate peroxidase scavenging system and that the actual “Hill acceptor” is an oxidation product of ascorbate, i.e. monodehydroascorbate or dehydroascorbate. With well-coupled intact chloro­plasts reducing CO2 at 150 (μmol (mg Chl)-1h-1, iodoacetamide stopped CO2-dependent O2-evolution and consequent addition of 10″3 m H2O2 produced an O2-Solution rate of 240 (μmol (mg Chl)-1h-1 .It is concluded that light-dependent H 20 2 reduction is a very efficient reaction in intact chloroplasts. As H2O2 formation and consequent reduction also occur in vivo, the corre­sponding quenching should be considered when assimilatory electron flow is estimated from quenching coefficients. It is suggested that proton flux associated with H2O2-formation and reduc­tion may be important for the adjustment of appropriate ATP /NADPH ratios required for CO2-fixation in vivo. Furthermore, H2O2-reduction may serve as a valve reaction whenever Calvin cycle activity is limited by factors different from NADPH supply, thus protecting against photo-inhibitory damage.
In vitro Binding of Nitracrine to DNA in Chromatin
Authors: Wilmańska Dorota , Szmigiero Leszek , Gniazdowski Marek
Published: August 2018

In the presence of sulfhydryl compounds nitracrine, an anticancer drug, binds covalently to DNA . The accessibility of DNA in chromatin both to nitracrine and to 8-methoxypsoralen. which was used as a reference compound in this study, when assayed in NaCl concentrations from 0 to 2 m show similar characteristics. The initial decrease reaches a minimum at 0.15 m NaCl above which dissociation of non-histone proteins and histones at higher ionic strengths is demonstrated by an increase in accessible sites. The relative accessibility of DNA in chromatin to nitracrine is, however, lower than that found for 8-methoxypsoralen. Partial dissociation of chromatin with 0.7 m NaCl increases the accessibility of DNA in chromatin when assayed in the absence of NaCl but has no apparent influence when estimated at ionic strength close to physiological conditions.
Flavonoid Aglycones in the Leaf Exudate of the Genus Leucocyclus (Compositae)
Authors: Valant-Vetschera Karin M. , Wollenweber Eckhard
Published: August 2018

The monotypic genus Leucocyclus, consisting of only two subspecies, was investigated for its exudate flavonoids. Major flavonoid aglycones were polymethoxyderivatives of 6-hydroxyflavones and, to a lesser extent, of 6-hydroxyflavonols. The two subspecies differed in their accumula­tion trends, but populational variation reduced the significance of taxonomic implications. Cultivated material corre­sponded largely to the original material collected from nature. The accumulation trends of Leucocyclus coincide with those of the closely related genus Achillea.
Elicitation of Canthin-6-one Alkaloid Accumulation in Cell Suspension Cultures of Ailanthus altissima (Mill.) Swingle
Authors: Krauss Gudrun , Krauss Gerd-Joachim , Baumbach Renate , Gröger Detlef
Published: August 2018

Cell suspension cultures of Ailanthus altissima (Simaroubaceae) were cultivated under illumination and in the dark. Under influence of a yeast elicitor and cell wall preparations of various Phytophthora species, respectively, alkaloid formation was stimulated. Canthin-6-one and 1- methoxycanthin-6-one accumulation could be increased up to a 125-fold and 2.5-fold, respectively within 96 h by elicitors in dark grown cultures. In response to elicitors canthin-6-one is accumulated in the cells and the growth medium.
Organ-Specific Composition of Epicuticular Waxes of Beech (Fagus sylvatica L.) Leaves and Seeds
Authors: Gülz Paul-Gerhard , Müller Edith , Prasad R. B. N.
Published: August 2018

The leaf, seed shell and seed coat epicuticular waxes of beech (Fagus sylvatica L.) contained the following common wax lipids: alkanes, wax esters, aldehydes, primary alcohols and fatty acids, all occurring in a homologous series of very long chained and saturated components with variations in the maxima in each homologous series. In addition, small amounts of benzylacyl esters in leaves, and ketones in seed shells and coats were also found in homologous series. β-Sitosterol was present only in seed shells and coats. Free primary alcohols (34.8%) were found to be the major class in the leaves whereas free fatty acids were predom inant in seed shells (39.5%) and coats (42.1% ). The beech organs studied showed always a specific wax composition.