bluuebunny/crossref_metadata_2025 huggingface dataset:
Histochemical Demonstration of an ATP-Dependent Ca2+-Pump in Bullfrog Myocardial Cells
Authors: Meyer R. , Stockem W. , Schmitz M. , Haas H. G.
Published: August 2018

In the present investigation different finestructural and histochemical procedures were employed to demonstrate normal morphology and Ca2+-transport mechanism in bullfrog atrial myocardium. For normal morphology specimens were fixed in 1% OsO4, 2.5% glutaraldehyde or liquid propane at - 185 °C before they were prepared for conventional embedding and freeze-etching, respectively. Special interest was focussed on the caveolae system, which is composed of single, spherical membrane invaginations (diameter, 85 nm), randomly distributed at the entire cell periphery. The caveolae enlarge the cell surface by 24.5% and occupy 8.5% of the cellular volume. The caveolae membrane contains a few intramembraneous particles with a diameter of 8.4 nm comparable to the size of ATPases as found in other cells.

For histochemistry the specimens were first stabilized by treatment with 50% glycerol, 0.025% glutaraldehyde or 0.15% formaldehyde and then incubated in a medium containing 4 mᴍ CaCl2, 4 mᴍ EGTA, 5 mᴍ MgCl2, 5 mᴍ K2C2O4, 5 mᴍ ATP and 20 mᴍ histidine at pH 7.0. This incubation always succeeded in the formation of electron-dense deposits with elliptical shape, measuring 100 -200 nm in length and 10 -30 nm in diameter. According to X-ray spectra they deliver a characteristic calcium-peak and can be found within two different cellular compartments: in small invaginations of the sarcolemma, i. e. the caveolae-system, and in the intrafibrillar sarcoplasmic reticulum.

The elliptical deposits can be clearly distinguished from round electron-dense granules measuring 16 nm in diameter, which are located within randomly distributed small vesicles and composed of potassium and phosphate. Contrary to the elliptical deposits the round granules are also present in controls and seem to be identical with the so-called atrial granules.

In comparison to observations obtained with the same method in other muscular systems and derived from various control experiments the results of this study favour the existence of an ATP-dependent Ca2+-pumping mechanism in frog atrial muscle bound to both, the sarcoplasmic reticulum and the caveolae system.
Notizen: Effect of Penicillins on the Level of Inorganic Pyrophosphatase in Escherichia coli K 12
Authors: Kukko E. I. , Heinonen J. K.
Published: August 2018

The relative rate of DNA synthesis increases over control level and the synthesis of inorganic pyrophospha­tase is stimulated when cells of E. coli are cultured in the presence of penicillins which inhibit cell division and cause filamentation of the cells. In contrast to that in temperature sensitive cell division mutants filamentation at 42 °C does not change the DNA/cell mass ratio and the synthesis of inorganic pyrophosphatase is not stimulated. This suggests that the change in the synthesis of the enzyme is not correlated with the filamentation but is a consequence of the supernormal DNA/cell mass ratio that appears in the presence of penicillins.
Herbicides which Inhibit Electron Transport or Produce Chlorosis and Their Effect on Chloroplast Development in Radish Seedlings. III. Plastid Pigment and Quinone Composition
Authors: Grumbach K. H.
Published: August 2018

The effect of DCMU, bentazon, amitrole and SAN 6706 on the formation of chloroplast pigments and quinones was investigated using plants that were grown in total darkness or continuous white, red or far-red light.

All herbicides assayed affected the formation of chlorophylls, carotenoids and quinones but DCMU had only minor effects. Like for chlorophylls and carotenoids the formation of quinones was most suppressed in plants grown in the presence of the herbicide in continuous white or red light, but the effect on the formation of quinones was much lower as compared to the pigments. The observation that the biosynthesis of quinones is still maintained in SAN 6706 treated bleached plastids which are lacking chlorophylls and carotenoids indicates that quinones are synthesized at the plastitd envelope and stored in the osmiophilic plastoglobuli.

Amitrole and SAN 6706 induced a strong chlorosis. It was of particular interest that chlorosis was also induced by the photosystem II inhibitor bentazon. DCMU was not effective. The inhibitor concentration for 50% inhibition in the chlorophyll and carotenoid content was 5 × 10-6 ᴍ for SAN 6706,3 × 10-4 ᴍ for amitrole and 10-3 ᴍ for bentazon.

As already reported by others SAN 6706 treated plants accumulated phytoene in large amounts. The highest phytoene content was observed in plants that were grown in the dark. Amitrole treated plants accumulated lycopene. But in addition other carotenoid precursors like phytoene and phytofluene were also accumulated. In contrast to phytoene lycopene was only accumulated in plants that were grown in the light.

Particularly for SAN 6706 and amitrole the expression of the bleaching effect was depending on the light intensity and light quality that was used during plant growth. The herbicide effect ewas predominantly expressed at higher light intensities and after irradiation with red light. The observation that the induction of chlorosis is very sensitive to red light as compared to white or blue light is suggesting that phytochrome is involved in the development of the herbicide toxicity. It also supports that in SAN treated plants chlorophylls are photodecomposed directly by light because of the lack of photoprotecting carotenoids but mainly β-carotene in these plastids. Further support for this was given by the demonstration that SAN treated plants which were grown at very low light intensities turned green and were photosynthetically active.
The Anatomy of the Sarcoplasmic Reticulum in Vertebrate Skeletal Muscle: Its Implications for Excitation Contraction Coupling
Authors: Sommer Joachim R.
Published: August 2018

The sarcoplasmic reticulum in situ is an intricate tubular network that surrounds the contractile material in striated muscle cells. Its topographical relationship to other intracellular components, especially the myofibrils, is rather rigidly mainiained by a cytoskeleton which enmeshes Z line material and sarcoplasmic reticulum and, ultimately, is anchored at the plasmalemma. As a result, the two main components of the sarcoplasmic reticulum, the junctional SR and the free SR, retain their typical location in the A band region and in the I band region, respectively. The junc­tional SR, which is thought to be the site for calcium storage and release for contraction, is, thus, always well within one micron of the regulatory proteins associated with the actin filaments. The junctional SR, a synonym for terminal cisterna applying to both skeletal and cardiac muscle, is generally held to be involved in the translation of the action potential into calcium release, mainly because of the close topographic apposition between the junctional SR and the plasmalemma, especially in skeletal muscle. This attractive structure-function correlation is challenged by the observation that in bird cardiac muscle 80% of the junctional SR is spacially far removed from plas­malemma, the site of electrical activity. This anomalous topography is not in conflict with the notion that translation of the action potential into calcium release may be accomplished by a dif­fusible transmitter substance, e.g. calcium. Any hypothesis dealing with this problem must ac­ count for the anatomy of the bird heart.
Electromechanical Coupling II. The Effect of Perchlorate Upon Excitation-Contraction Coupling in Frog Skeletal Muscle Fibres
Authors: Gomolla Michael , Gottschalk Gernot , Lüttgau Hans-Christoph
Published: August 2018

In single skeletal muscle Fibres perchlorate causes a large shift of the potential dependence of contraction activation to more negative potentials without a corresponding alteration in the kinetics of the inactivation process.
Isolation and Identification of Lathycarpin, a New Pterocarpan Phytoalexin from Lathyrus sativus
Authors: Ingham John L. , Markham Kenneth R.
Published: August 2018

After treatment with the fungus Helminthosporium carbonum or aqueous copper sulphate, excised Lathyrus sativus leaflets produce pisatin and a second isoflavonoid phytoalexin (lathycarpin) identified as (+)-6aR; 11aR-2,3-dimethoxy-6a-hydroxy-8,9-methylenedioxypterocarpan.
A New Red Dipyrromethene Pigment from Candida boidinii
Authors: Lang Siegmund , Beyer Hanna , Sistig Peter , Wagner Fritz , Trowitzsch Wolfram , Wray Victor
Published: August 2018

The yeast Candida boidinii ATCC 32195 produces a cell-bound red pigment during growth on 1% ethanol in the presence of 0.05% monofluoracetate. Its isolation and purification are described. The structure was elucidated by chemical degradation and physical methods, mainly mass and nuclear magnetic resonance spectroscopy.
Wirkung von Silatranen auf Wachstum, Sauerstoffentwicklung und Dunkelatmung von Cyclotella cryptica (Diatomeae) / The Effect of Silatranes on Growth, Photosynthetic Oxygen Evolution and Dark Respiration of Cyclotella cryptica (Diatomeae)
Authors: Roth Richard , Viktor Viktor P. , Stom Devard I. , Werner Dietrich , Voronkov Michail G.
Published: August 2018

The effect of 5 silatranes RSi(OCH2CH2)3N, where R = C2HsO; C6H5; ClCH2 and RSi[OCH(CH3)CH2]3N, where R = C6H5, ClCH2 and tetraethoxysilane were studied on the growth, photosynthetic oxygen evolution and dark respiration of the marine centric diatom Cyclotella cryptica. Both silica-free and Si(OH)4 supplemented media were used. Only 1-ethoxy- silatrane was hydrolyzed by the diatom, giving sufficient quantities of Si(OH)4 to maintain growth without exogenous Si(OH)4. In this case the diatoms multiplied by a factor of 18 within 48 h. With silica in the medium, 1-phenylsilatrane, 1-phenyl-3,7,10-trimethylsilatrane, 1-chlormethylsilatrane and 1-chlorm ethyl-3,7,10-trimethylsilatrane exhibited only slightly inhibitory activity. In contrast, however, tetraethoxysilane (5 · 10-4 mol/1) inhibited growth almost completely. Respiration was unaffected by all the silatranes tested, but net photosynthetic oxygen evolution was reduced by approx. 50% by 1-chlormethylsilatrane and 1-chlormethyl- 3,7,10-trimethylsilatrane and almost completely by 1-phenylsilatrane and 1-phenyl-3,7,10-tri- methylsilatrane. In the absence of silica as nutrient in the medium, the silatranes hardly affected dark respiration within 24 h. Conversely, the same samples showed no photosynthetic oxygen evolution after 24 h, and 24 h later again a negative O2 balance was produced in the light. Different silatranes produced significant differences in the final oxygen balance.
On the Origin of the Non-Haemic Iron Transferrin ESR Signal: ESR Investigations on Histidine-Iron-Ascorbic Acid Systems
Authors: Lohmann W. , Holz D. , Kiefer B. , Schmidt D.
Published: August 2018

The nature of the ferric high spin iron complex located at g = 4.3 has been investigated by means of electron spin resonance spectroscopy. It could be shown that the iron is bound to two histidines, three ascorbic acids, and one bicarbonate. This agrees well with previous findings according to which the ligand field of iron is composed mainly of oxygen and nitrogen atoms. Another low-field signal located at g = 9.5 appears always concomitantly with the g = 4.3 signal. It should be due, therefore, to a transition between the two sublevels of the low-lying Kramers doublet in one principal direction.
The Flavones of the European Species of Silene Section Elisanthe
Authors: Mastenbroek O. , Knorr J. J. , Kamps-Heinsbroek R. , Maas J. W. , Steyns J. M. , Brederode J. van
Published: August 2018

The flavones present in three European species of Silene section Elisanthe (Silene diclinis, S. heuffelii and S. marizii) have been identified. The flavones of these species were compared with the flavones present in the three remaining species of section Elisanthe in Europe (5. dioica, 5. noctiflora and 5. pratensis). It was found that isovitexine-7-O-glucoside is present in all these species. The other flavones. notably the 2′-O-glycosylated ones, show a distribution over the species. The presence of flavone glycosylating genes in 5. diclinis, S. heuffelii and S. marizii was tested by biochemical means. The results of this experiment show that the gene g-G. controlling the formation of isovitexin-7-O-glucoside, is the basic flavone glycosylating gene in European species of section Elisanthe. The other flavone glycosylation genes, g-X, gl, gl-A, gl-R, fg and Fg are not present in all specie
Structure of Ascorbic Acid and Its Biological Function:
Authors: Lohmann W. , Winzenburg J.
Published: August 2018

It could be shown by the reduction of the spin label (1,14) located within DPPC vesicles, that Na-ascorbate and K-isoascorbate can permeate membranes. At physiologic pH value, these two compounds exist as electroneutral radicals with a cyclic side chain structure. Ascorbic acid and isoascorbic acid, on the contrary, can hardly permeate such an artificial membrane. Since the radical will cause lipid peroxidation, it must be modified prior to permeation. This can be done by GSH which changes the radical state but maintains the electroneutral bicyclic configuration
Purification and Characterization of a Dissimilatory Nitrite Reductase from the Phototrophic Bacterium Rhodopseudomonas palustris
Authors: Preuß Michaela , Klemme Jobst-Heinrich
Published: August 2018

A dissimilatory nitrite reductase from the facultatively phototrophic bacterium , Rhodopseudomonas palustris strain 1a1 was studied. A basic level of the enzyme (10 -50 mU/mg protein) was measured in dark, aerated and anaerobic, photosynthetic cultures. A marked derepression of enzyme synthesis occurred under conditions of oxygen limitation (200-300 mU/mg protein). The addition of nitrite (or nitrate) to the culture medium had only a slight effect on the maximal nitrite reductase titer of cells. The enzyme was purified from photosynthetically grown cells by precipitation with ammonium sulfate, gel filtration through Sepharose 6B and repeated chromatography on DE 52-cellulose. As estimated by gel filtration, the nitrite reductase had a molecular weight of about 120 000 ± 12 000 and yielded only one band (mol. wt. of about 68 000 ± 7000) in SDS-gel electrophoresis. The isoelectric point of the enzyme was at pH 5.1. Nitric oxide (NO) was identified as the reaction product of nitrite reduction. The enzyme also exhibited cytochrome c-oxidase activity and was active with chemically reduced viologen dyes, FMN and cytochrome c as electron donors. Highly purified nitrite reductase preparations contained 10 mol% of a c-type cytochrome. Trace metal analyses indicated the presence of Cu in the enzyme. Consistent with the detection of Cu was the finding that the Cu-chelator, diethyldithiocarbamate, strongly inhibited the nitrite reductase
Incorporation of 15N-Ammonia into Serotonin in Cotyledons of Maturing Walnuts
Authors: Große Wolfgang , Artigas Francesc
Published: August 2018

Cotyledons isolated from maturing seeds of Juglans regia incorporate supplied [15N]-ammonia into serotonin (5-HT). A 15N incorporation of about 9% into the indolic nitrogen of 5-HT is detectable by gas chromatographymass spectrometry following isolation of 5-HT by preparative HPLC. This 15N incorporation supports the hypothesis that biosynthesis and accum ulation of 5-HT play a role in ammonia detoxification in maturing walnut seeds
Growth Characteristics of Anaerobically Treated Early and Late S-Period of Ehrlich Ascites Tumor Cells after Reaeration
Authors: Merz Rainer , Schneider Friedhelm
Published: August 2018

Utilizing centrifugal elutriation, early and late S-phase cells were separated from 4, 8 and 12 h anaerobically cultured Ehrlich Ascites tumor cells strain Karzel. The cytokinetic properties of these fractions after reaeration were studied by flow cytometry and the BrdU-H 33258-technique of flow cytometry. After a 4 h period of anaerobiosis, growth of early S-phase cells is not changed, 8 h deprivation of oxygen causes a delay of cell cycle progression, while the main fraction of 12 h anaerobically treated early S-populations did not divide after reaeration within 24 h. In comparison to early S-phase cells the cell cycle progression of the main fraction of late S-period is accelerated after a 4 h exclusion of oxygen. A fraction of 8 h anaerobically pretreated late S-cells continues to cycle, but a considerable number reinitiates DNA synthesis without preceeding division. Cells with DNA content up to 8 c are detected by flow cytometry. 12 h anaerobically cultured late S-cells do not divide after reaeration, a large number of these cells starts again to synthesize DNA. A considerable part of tetraploid cells retain viability, divide and enter a new cell cycle, another part of the cells disintegrates
Meta-Methylation of Flavonol Rings A (8-) and B (3'-) Is Catalysed by Two Distinct O-Methyltransferases in Lotus corniculatus
Authors: Jay Maurice , De Luca Vincenzo , Ibrahim Ragai
Published: August 2018

Two O-methyltransferases specific for flavonol rings A and B were isolated from young flower buds of Lotus corniculatus. They were partially purified by ammonium sulphate precipitation and successive chromatography on Sephadex G-100 and Polybuffer ion exchanger. One enzyme focused at pI 5.5 and catalysed the O-methylation of position 8 of flavonols with a pH optimum of 8.1. The other enzyme had a pi of 5.1 and preferentially attacked position 3' at an optimum pH of 7.7. The methylated products of both enzymes seem to contribute to the flower colour of Lotus and may be used as biochemical markers in genetic studies of this genus.
A Cysteine Desulfhydrase Specific for ᴅ-Cysteine from the Green Alga Chlorella fusca
Authors: Schmidt Ahlert , Erdle Ingrid
Published: August 2018

A cysteine desulfhydrase was purified 110-fold from the green alga Chlorella using conven­tional techniques. The isolated cysteine desulfhydrase was specific for ᴅ-cysteine having no activity towards ʟ-cysteine. ᴅ- and ʟ-cysteine desulfhydrase activities can be separated using DEAE-cellulose chromatography techniques. The isoelectric point of this enzyme was deter­mined to be around a pH of 4.5 using a chromatofocussing column. The pH-optimum for the ᴅ-cysteine desulfhydrase was found to be in the range of 8.5 to 9 and the apparent Kᴍ for ᴅ-cysteine was determined to 0.16 mᴍ. The enzyme was active without addition of metal ions and EDTA or citric acid did not inhibit this activity.
Studies on the Distribution of Phytosterols in Dioscorea Species Tubers
Authors: Kadkade P. G. , Lujan C. , Rolz C.
Published: August 2018

A survey was made of the distribution of sterols in five Dioscorea species tubers. All contained /7-sitosterol, stigmasterol, cholesterol and campesterol, whereas cycloartenol was detected only in two Dioscorea species.
3,7,11,15-Cembratetraen-6-ol, a New Cembranoid from Tobacco, III
Authors: Heemann Volker , Bylov Anne-Marie , Brümmer Ursula , Hass Werner , Seehofer Friedlieb
Published: August 2018

3,7,11,15-Cembratetraene-6-ol (1) was isolated from tobacco and identified as a new natural product by spectral data and chemical degradation. 1-H-NMR, 13-C-NMR and MS data are given.
Synthesis of Mono-, Di-and Trigalloyl-β-ᴅ-glucose by β-Glucogallin-Dependent Galloyltransferases from Oak Leaves
Authors: Gross Georg G.
Published: August 2018

Cell-free extracts from oak (Quercus robur) leaves were found to contain at least two β-glucogallin-dependent galloyltransferases. One enzyme catalyzed a rapid exchange of the galloylmoiety of β-glucogallin with free glucose. A second enzyme fraction was shown to form digalloylglucose, utilizing β-glucogallin both as acyl-donor and acceptor molecule; in addition, evidence for the synthesis of trigalloylglucose was obtained. Both enzyme-systems had their pH-optimum at pH 6.0-6.5. It is assumed that these newly described galloyltransferases are involved in the biosynthesis of gallotannins.
New Papaveraceae Alkaloids Including an 7,8-Oxygenated Isoquinoline, the Postulated Precursor of the Cularine Alkaloids
Authors: Blaschke G. , Scriba G.
Published: August 2018

The first 7,8,3',4'-oxygenated benzylisoquinoline, the probable precursor of the cularine alkaloids, has been isolated together with 2 new cularines and 10 other alkaloids from Corydalis claviculata.
Epicuticular Waxes from Leaves and Stems of Jojoba (Simmondsia chinensis [Link] Schneider)
Authors: Gülz Paul-Gerhard , Eich Claudia
Published: August 2018

Epicuticular waxes were extracted with chloroform from air dried Jojoba leaves and stems. These cuticular waxes consisted of homologues of n-alkanes, branched alkanes, alkenes, wax esters, aldehydes, acetates, esters, free long chain fatty acids and alcohols. Both leaves and stems showed the same qualitative and quantitative composition with similar distribution patterns. Very long chain and in most cases saturated compounds are dominating. The composition of epicuticular waxes from Jojoba leaves and stems is quite different from that of Jojoba pericarp and seed coats and demonstrates an organ specific wax composition of different aerial parts of this plant.
3′-Hydroxylation of 4′-Methoxyisoflavones by Fusarium oxysporum f. lycopersici
Authors: Mackenbrock K. , Barz W.
Published: August 2018

3′-Hydroxylation of isoflavones by Fusarium oxysporum f. lycopersici mainly proceeds with 4′-methoxy-7-hydroxyderivatives; this reaction is used for quantitative conversion of 14C-labelled isoflavones.
Chemistry of Bacteriochlorophyll b: Identification of Some (Photo)Oxidation Products
Authors: Steiner R. , Cmiel E. , Scheer H.
Published: August 2018

Photoreactions of bacteriochlorophyll b have been studied. They all arise from reactions at the Δ8,81 double-bond. The Δ7,8-isomerisation product 3 is formed under anaerobic conditions. Irradiation in the presence of oxygen leads to three products arising from an autoxidation reaction involving singlet oxygen. The structures of two of them (4, 5) have been established from their methylpheophorbides 10 and 11 containing an 8-acetyl and 8-(meth)oxyethyl-substituent, respectively, in addition to the isomerized Δ7,8-double bond.
Electroimmunodiffusion — a Powerful Tool for Quantitative Determinations of Both Soluble and Membrane Bound Chloroplast ATPase, CF1
Authors: Roos Peter , Berzborn Richard J.
Published: August 2018

1. Electroimmunodiffusion can be used for routine specific quantitative microdeterminations of photosynthetic ATP-synthase. The method has been worked out for samples of both the dissociated (CF1) and the membrane bound enzyme (CF0CF1).

2. Only a monospecific antiserum against CF1 , is required for relative determinations of CF1 in any fraction. If beyond this an absolute determination is intended of either the separated or the membrane bound ATPase, in addition a pure CF1 , is needed for calibration.

3. A varying CF1/chlorophyll ratio between 1/700 and 1/1200 has been found for thylakoids of spinach plants grown under various light intensities.

4. Since the amount of CF1 , was the limiting factor of photophosphorylation capacity in the electron transport system used (PMS), from simultaneous measurement of CF1 , content and photophosphorylation capacity a turn over time of the ATPsynthase of 4 ms /ATP /CF0CF1 could be recalculated.
DCMU-Induced Fluorescence Changes and Photodestruction of Pigments Associated with an Inhibition of Photosystem I Cyclic Electron Flow
Authors: Ridley Stuart M. , Horton Peter
Published: August 2018

Diuron (DCMU) induces the photodestruction of pigments, which is the initial herbicidal symptom. As a working hypothesis, it is proposed that this symptom can only be produced when the herbicide dose is sufficiently high to inhibit not only photosystem II electron transport almost completely, but also inhibit (through over oxidation) the natural cyclic electron flow associated with photosystem I as well. Using freshly prepared chloroplasts, studies of DCMU-induced fluorescence changes, and dose responses for inhibition of electron transport, have been compared with a dose response for the photodestruction of pigments in chloroplasts during 24 h illumination. Photodestruction of pigments coincides with the inhibition of cyclic flow.
Increased Binding of [14C]Ioxynil in Unicellular Green Algae under Anaerobiosis and by Addition of Other Phenolic Herbicides or Uncouplers
Authors: Neumann Wiltrud , Laasch Henrik , Urbach Wolfgang
Published: August 2018

Binding of the phenol-type herbicide ioxynil in intact algal cells is strongly increased under anaerobic conditions. This increase is most pronounced at low concentrations of bound ioxynil (< 3 nmol/mg chlorophyll). The affinity of binding sites is improved, rather than new sites are created.

Other phenol-type herbicijdes, as well as uncouplers like carbonylcyanidechlorophenylhydra- zone. also significantly increase ioxynil binding in algae. Binding of DCMU-type herbicides, however, was not affected.

These results demonstrate high variability of ioxynil binding in algal cells and are discussed in respect of low affinity binding.
The Diphenyl-Ether Herbicide Oxyfluorfen: A Potent Inducer of Lipid Peroxidation in Higher Plants
Authors: Kunert Karl-Josef
Published: August 2018

Measurements of ethane and ethylene as indices of in vivo lipid peroxidation and of chemically- induced stress, respectively, were done on mustard seedlings (Sinapis alba), treated with oxyfluorfen[2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene]. When seedlings were exposed to low light intensity of 14W/m2, only stress-ethylene production but not per- oxidative ethane evolution was significantly higher over 10 days in herbicide-treated seedlings than in the untreated control. Exposure to high light intensity of 390 W/m2 did not increase stress-ethylene production in oxyfluorfen-treated plants after 24 h. Lipid peroxidation, however, measured as ethane evolution, was substantially higher after 24 h in herbicide-treated plants, exposed to high light intensity, than in the control, and peroxidation was directly related to strong oxidation of antioxidants and to severe membrane damage.
Hydroxycinnamoyl Esters of Malic Acid in Small Radish (Raphanus sativus L. var. sativus)
Authors: Brandi Wilfried , Herrmann Karl , Grotjahn Lutz
Published: August 2018

The esters of p-coumaric, ferulic and caffeic acid with malic acid were isolated from leaves, the ester of sinapic acid with malic acid from cotyledons of Raphanus sativus plants via preparative HPLC. The esters were identified by hydrolyses and following capillary GC , by H-NMR and FAB-MS. Their concentrations in leaves and tubers were determined by gradient HPLC on reversed phase material.
Epicuticular Waxes of Seed Coats from Species of the Genus Cistus L. (Cistaceae)
Authors: Krollmann Patrick , Eich Claudia , Gülz Paul-Gerhard
Published: August 2018

Epicuticular waxes were extracted with hexane from seed coats of 16 species from the genus Cistus (Cistaceae) in amounts corresponding to an average of 0.07% per dry weight. All cuticular waxes obtained from the various Cistus species consisted of hydrocarbons, wax esters, triterpenol esters, aldehydes, primary alcohols and free fatty acids. These compounds were present as homologues in changing patterns. In addition two unidentified acids and two unknown alcohols were found. Epicuticular waxes from seed coats differed qualitatively and quantitatively from those of Cistus leaves and petals and confirmed the existence of organ specific compositions of epicuticular waxes. The wax components secreted in this composition result in a cover which in scanning electron microscopic pictures resembles a smooth layer of solidified fluid lacking any crystalline structure.
Characterization of Volatile Constituents from Photomixotrophic Cell Suspension Cultures of Ruta graveolens
Authors: Drawert Friednch , Berger Ralf G. , Godelmann Rolf , Collin Susanne , Barz Wolfgang
Published: August 2018

Photomixotrophic cell suspension cultures of Ruta graveolens were qualitatively and quantita­tively analyzed by gaschromatography and mass spectroscopy for volatile compounds. The terpenoid hydrocarbons geijerene and pregeijerene, the C9-C13 methylketones and a series of aliphatic esters, respectively, were found as main constituents. The esters consisted of acetic acid, 2-methylbutyric acid and 3-methylbutyric acid which were esterified with straight chain or branched C8-C11 alcohols. The data are discussed in comparison to previous studies on callus cultures.
Untersuchung der Struktur-Wirkungsbeziehung antihepatotoxischer Naturstoffe (Silybin-Antamanid) durch Röntgenstrukturanalyse / Examination of the Structure Activity Relationship of Antihepatotoxic Natural Products (Silybin-Antamanide) by X-Ray Analysis
Authors: Lotter Hermann L.
Published: August 2018

Both, the flavonolignane silybin and the decapeptide antamanide, protect animals against the mushroom poison phalloidin from Amanita species. The X-ray structures of silybin and anta­manide have been solved in previous studies. Here an attempt has been made to explain the antagonistic antihepatotoxic protection by similar chemical structure elements in the two compounds. It can be shown that two aromatic rings in a definite arrangement are essential for the attachment to the target structure of the liver cell membrane. Comparable pharmacological tests are discussed.
Chemical Defense of Leguminosae. Are Quinolizidine Alkaloids Part of the Antimicrobial Defense System of Lupins?
Authors: Wink M.
Published: August 2018

Growth of 6 bacteria (Serratia marcescens, Bacillus megaterium, Bacillus subtilis, Streptococcus viridis, Micrococcus luteus, and Mycobacterium phlei) was inhibited by 50% if the growth medium contained sparteine at concentrations between 0.5-10mᴍ. Total growth inhibition, which was bacteriostatic in nature, was achieved at 20 mᴍ. The growth of 6 phytopathogenic fungi was also affected: at a sparteine concentration of 15 mᴍ the growth of Alternaria porri was reduced by 40% as compared to the untreated control. Respective values were 18% inhibition for Piricularia oryzae, 33% for Helminthosporium carbonum, 15% for Rhizoctonia solani, 5% for Fusarium oxysporum, and 42% for Asperquillus oryzae. Since the concentrations of quinolizidine alkaloids range from 1-200 mᴍ (roots, leaves, or stems) or 10-200 mmol/kg (seeds) in Leguminosae, it is discussed whether quinolizidine alkaloids are involved in the antimicrobial defense of lupins, in addition to their potential role as allelopathic or herbivore repellent defense compounds.
A Granulopoiesis Inhibitor Partially Purified from Large-Scale Serum-Free Cultures of Porcine Leukocytes
Authors: Kästner Michael , Maurer H. Rainer , Gerlach Ute , Renner Hellmut , Wissler Josef H.
Published: August 2018

A method is described for the partial purification of a granulomonopoiesis inhibitor derived from 2001-batches equivalent to 1 kg or 2 · 1012 leukocytes of porcine blood. Serum-free condi­tioned media were concentrated and separated via ammonium sulfate precipitation, acetone partitioning, ultrafiltration and gel chromatography. The active substance revealed a molecular mass of 500-700 Da and was not thiol-dependent, thus contrasting it with previously-reported granulopoiesis inhibitors. Inhibition of colony formation in an in vitro myeloid stem cell assay using various colony-stimulating factors showed that mature granulocytes and monocytes were equally affected. Apparent lack of cytotoxicity was suggested using a new reversibility test.
Rabbit Antipeptide Antibodies against Restricted Domains of the Histocompatibility Complex
Authors: Chersi Alberto , Houghten Richard A.
Published: August 2018

The work reported here concerns the specificty of four antibodies elicited by synthetic peptides corresponding to three domains of the HLA-B7 glycoprotein, and one of the β2 microglobulin. One of the four peptides had been previously investigated, but the data obtained by its elicited antibodies were uncomplete.

Of the three HLA-B7 peptides assayed, one was unable to raise an immune response. The other two produced antibodies in good titer that reacted with the antigen peptide, but were unable to recognize antigenic determinants when tested on membrane glycoproteins solubilized from human lymphoblastoid cells. In contract, the antibody elicited by the only fragment from the β2microglobulin recognized the native β2microglobulin molecule as well as HLA/β2m com­plexes, and reacted with intact human cells, as determined by ELISA and by FACS analysis. This peptide, which contains one of the most hydrophylic fragment of the whole molecule, is likely an important antigenic site, since it is also recognized by traditional antisera raised against native β2 microglobulin.
Abscisic Acid in Phytopathogenic Fungi of the Genera Botrytis, Ceratocystis, Fusarium, and Rhizoctonia
Authors: Dörffling Karl , Petersen Wolfgang , Sprecher Ewald , Urbasch Irene , Hanssen Hans-Peter
Published: August 2018

Strains of the phytopathogenic species Botrytis cinerea, Ceratocystis coerulescens, C.fimbriata, Fusarium oxysporum, and Rhizoctonia solani were cultivated on a de­fined synthetic culture medium. The plant hormone abscisic acid (ABA) was identified by gas chromato- graphy/mass spectrometry and gas chromatography data, and the contents determined in mycelia (15.9-31.9 ng/g mycel) and culture media (1.0-4.6 ng/ml) by scintillation counting.
Pistillarin, ein charakteristischer Inhaltsstoff der Herkuleskeule (Clavariadelphus pistillaris) und einiger Ramaria-Arten (Basidiomycetes) / Pistillarin, a Characteristic Metabolite of Clavariadelphus pistillaris and Several Ramaria Species (Basidiomycetes)
Authors: Steglich Wolfgang , Steffan Bert , Stroech Klaus , Wolf Maria
Published: August 2018

From Clavariadelphus pistillaris and several Ramaria species a bitter substance, pistillarin, has been isolated which is responsible for the green colour reaction of the fruit-bodies with FeCl3. Its structure has been determined as N1,N8-bis(3,4-dihydroxybenzoyl)spermidine (1).
Conformation about the Glycosidic Bond and Susceptibility to 5 '-Nucleotidase of 8-Substituted Analogues of 5'-GMP
Authors: Lassota Piotr , Stolarski Ryszard , Shugar David
Published: August 2018

Susceptibilities to snake venom 5′;-nucleotidase (EC 3.1.3.5) have been evaluated for several 8-substituted analogues of 5′-GM P with varying populations of syn /anti conformations about the glycosidic bond. Improved syntheses of some of these are described, including direct chlorination of 5′-GMP to give 8-chloro-5′-GMP, a procedure which should be applicable to other purine nucleotides. The conformations of the various analogues were determined by means of 1HNMR spectroscopy, with particular emphasis on the glycosidic bond conformations. All the 8-substituted derivatives of 5′-GM P were relatively poor substrates of 5 ′-nucleotidase. This was shown to result largely from steric effects and the nature of the 8-substituent, and consistent with a requirement for the anti conformation. Although ribose-5-phosphate was not a substrate, it was a weak inhibitor, and its inhibitory properties account in part for the weak inhibitory properties of the 8-substituted 5′-GMP, and other, analogues. Attention is drawn to the hitherto largely neglected differences in properties of 5′-nucleotidases from different sources and their relevance to the present findings.
Nickel-Dependent Uptake-Hydrogenase Activity in the Blue-Green Alga Anabaena variabilis
Authors: Almon Helmar , Böger Peter
Published: August 2018

Abtract

Uptake-hydrogenase activity in the blue-green alga (cyanobacterium) Anabaena variabilis is dependent on the presence of nickel. Nickel depletion leads to an enhancement of net lightinduced hydrogen evolution, which is catalyzed by nitrogenase. Addition of nickel chloride to the culture reverses this effect by stimulating hydrogenase activity. Methylviologen/dithionitedriven hydrogen formation of permeabilized cells is decreased by nickel depletion.
Cell Cycle Kinetics and Metabolism of Ehrlich Ascites Tumor Cells in the Presence of Chloramphenicol as Inhibitor of Mitochondrial Protein Synthesis
Authors: Kroll Werner , Schneider Fr.
Published: August 2018

In the presence of 150(μ/ml of chloramphenicol, viability (dye exclusion test) of Ehrlich ascites tumor cells is not severely affected within 48 h; however the number of dead cells increases above this concentration; more than 10 mg/ml render all of the cells dye-positive within a culture period of 24 h. With the highest concentration tested (25 mg/ml) cells begin to lose viability 8 h after beginning of treatment.

In the first passage in the presence of the antibiotic, proliferation of the cells is reduced by about 50%; in the second passage cell growth was about 65% that of controls. As is shown by flow cytometric analysis and BrdU-H33258 technique of flow cytometry, the reduction of proliferation in the second passage is caused by retardation of cell cycle progression of about 8 h; in the third passage the cell cycle is delayed by further 8 h as compared to controls. On recultivation in the third passage in the absence of the inhibitor an increase of cell number of about 75% of controls was observed.

Lactate production and glucose uptake of the cells were stimulated by the inhibitor by about 20%; oxygen consumption was 60% that of controls after 24 h; however the ATP/ADP ratio of chloramphenicol treated cells was in the range of controls.

Over a time period of 24 h the incorporation of [2-14C]thymidine is reduced to 34 ± 3%, incorporation of [2-14C]uridine was 88 ± 4% that of controls, incorporation of [U-14C]lysine was not significantly affected by 150 μg/ml of chloramphenicol; the same was found for the uptake of [2-14C]-α-aminoisobutyric acid.

Electron micrographs of chloramphenicol treated cells reveal a high amplitude of swelling of all mitochondria with a translucent appearance of the inner compartment. The mitochondrial membranes remain largely intact but the number of cristae is drastically reduced.
Electron Microscopic Evidence for the Transmembrane Displa cement of Calcium ATPase
Authors: Scales Donald J. , Highsmith Stefan R.
Published: August 2018

Incubation of the Ca2+-ATPase in vanadate solutions leads to the formation of two-dimensional arrays in the sarcoplasmic reticulum membrane. Electron micrographic freeze fracture replicas show depressions on the inner leaflet for the first time. This indicates that the ATPase has moved perpendicular to the plane of the membrane. Our results also suggest that aggregation of the Ca2+-ATPase into the two-dimensional arrays occurs before they move into the membrane. These phenomena were observed as soon as 15 minutes after vanadate was added. The effects of vanadate appear to be completely reversible. When SR was incubated in the vanadate solutions and was then diluted into a buffer containing Ca2+ and ATP, the ATPase activity was normal for up to several hours of incubation and only somewhat reduced after 3 days.
Dose Rate Dependence of Radiation Induced IgG Membrane Receptor Alteration [1]
Authors: Ojeda F. , Moraga D. , G uarda M. I. , Folch H.
Published: August 2018

Mouse lymph node lymphocytes are irradiated at different dose rates and the B-cell receptors to anti IgG are tested. The expression of receptors is inhibited by irradiation. It is shown that the effectivity of irradiation increases with decreasing dose rate suggesting that membrane damage may be important for situations of chronic irradiation or implant radiotherapy.
Pressure Induced Shifts in Spectral Properties of Pigment-Protein Complexes and Photosynthetic Organisms
Authors: Brody Seymour Steven , Heremans Karel
Published: August 2018

Application of elevated pressure (up to 1200 bars) results in a bathochromic shift of the absorption bands of photosynthetic pigments. The photosynthetic systems studied include: photosystem I particles, chloroplasts, acetone extracts of chloroplasts, AUT particles and light harvesting particles of Rh. sphaeroides, light harvesting particles of R26. Similar spectral changes are observed in all systems. The spectral shifts appear to be associated with pressure-induced changes in the local electric fields of the pigments, rather than changes in the index of refraction of the solvent.
Oxygen Supply of Roots by Gas Transport in Alder-Trees
Authors: Große Wolfgang , Schröder Peter
Published: August 2018

It is generally accepted that oxygen diffuses according to the gradient of its partial pressure from the surface of the plants into the heterotrophic tissues through the inter­cellular spaces. The present experiments show evidence of an additional manifold higher oxygen supply due to a gas transport in leaved as well as leafless trees of Alnus glutinosa (L.) Gaertner. This gas transport is directed from the stems to the roots. It is driven by a thermo-osmotic pressurisation within the air space system of the stems, resulting from temperature gradients up to 3.6 K between the stem and the ambient air following the absorption of light energy by the brownish pigments of the bark. This gas phase phenomena appears to enable the alder-trees to survive and grow in wet soil resulting from a high water table or in waterlogged soil.
Identification and Field Evaluation of a Sex Pheromone of the European Pine Moth
Authors: Priesner E. , Bogenschütz H. , Albert R. , Reed D. W. , Chisholm M. D.
Published: August 2018

The principal component of the female sex pheromone of the European pine moth Dendrolimus pini L. (Lasiocampidae) was identified as (Z ,E)-5 ,7-dodecadienal by capillary gas chromatography, mass spectrometry, single receptor analyses, and field trapping tests. Traps initially baited with 1000 μg of (Z,E)-5,7-dodecadienal (>99%ZE) effectively monitored low D. pini populations over 6 weeks without rebaiting. Captures disappeared upon addition of ≧1% of either (E,Z)-5,7-dodecadienal or (Z,E)-5,7-dodecadienyl acetate, the key stimulants for additional receptor cell types located in male antennal hair sensilla.
Regulation of Acetyl-Coenzyme A Carboxylase and Acetyl-Coenzyme A Synthetase in Spinach Chloroplasts
Authors: Sauer Andreas , Heise Klaus-Peter
Published: August 2018

In analogy to chloroplast fatty acid synthesis from acetate the key enzymes of acetate fixation, acetyl-CoA synthetase and acetyl-CoA carboxylase, in rapidly Triton X-100 lysed spinach chloroplasts show an activation by light and deactivation in the dark. The stim ulation of acetyl-CoA carboxylase by dithiothreitol in darkened chloroplasts points to an involvement of reducing equivalents in the light activation of this enzyme. But more than by alterations of the activation state per se, these enzymes appear to be effected by changes in their catalytic activity due to differences in the proton-, Mg2+- and adenine nucleotide levels of the chloroplast stroma. Thus the pH dependence of both enzymes, as immediately extracted from Triton X-100 lysed chloroplasts, resembles that recently found for lipid incorporation of acetate into intact spinach chloroplasts in the light with an identical pH optim um of about pH 8.5 for the acetyl-CoA carboxylase. Moreover, in the same extracts both enzyme activities show the already postulated requirement for MgATP and free Mg and are com petitively inhibited by free ATP and ADP with respect to MgATP. But on account of the fact, that the extractable acetyl-CoA synthetase as opposed to the carboxylase activities exceed by far the lipid incorporation rates of acetate by illuminated chloroplasts before disruption, acetyl-CoA synthetase will be excluded as rate limiting step in fatty acid synthesis from acetate. From key enzymes of acetate fixation only the carboxylase appears to be involved therefore in the light regulation of acetate incorporation into long-chain fatty acids
Photoinactivation of Propionibacterium acnes by Near-Ultraviolet Light
Authors: Kjeldstad B.
Published: August 2018

Photodestruction of Propionibacterium acnes was investigated by broad-band near-ultraviolet light. The inactivation of the bacteria was found to be oxygen dependent, and without O2, practically no photoinactivation occurred. D2O caused an increased inactivation (D10 = 5 kJ/m2 - in D2O as compared to D10 = 11 kJ/m2 in normal water). Decreased temperature during illumination increased the ability to form colonies. The results are compared with corresponding results for other types of cells and the destruction mechanism is discussed
γ-butyrolactone from the black stink bug: aethus indicus westwood (hemiptera: pentatomidae)
Authors: Olagbemiro T. O. , Khan M. N. , Mohammed A.
Published: August 2018

The volatile constituents of the black stink bug, Aethus indicus Westwood (Hemiptera: Pentatomidae) from Nigeria has been examined by combined gas chromatography- mass spectrometry. γ-Butyrolactone along with with several straight carbon-chain aliphatic materials have been identified in the scent gland complex
Identification of a major pathway of strand break formation in poly u induced by oh radicals in presence of oxygen
Authors: Schulte-Frohlinde D. , Bothe E.
Published: August 2018

A reaction mechanism is presented for strand break formation in poly U induced by OH radicals in N2O/O2- saturated aqueous solution based on experimental results obtained with different methods
Conversion of Dihydroflavonols to Flavonols with Enzyme Extracts from Flower Buds of Matthiola incana R. Br.
Authors: Spribille R. , Forkmann G.
Published: August 2018

Soluble enzyme preparations from flower buds of Matthiola incana catalysed the conversion of dihydrokaempferol to kaempferol and of dihydroquercetin to quercetin. The reaction required 2-oxoglutarate, ascorbate and Fe2+ as cofactors and had a pH-optimum at about 7.0. Highest enzyme activity was already present in the youngest buds followed by a rapid decline during bud and flower development. Furthermore, a substantial correlation was observed between the enzyme activity for flavonol formation and the flavonol content of the buds and flowers.
Studies on the Possible Mechanism of Inactivation of Phenylalanine Hydroxylase by Destructive Oxygen Species
Authors: Fink Rita M. , Elstner Erich F.
Published: August 2018

The enzymic hydroxylation of phenylalanine by phenylalanine hydroxylase (E.C. 1.14.16.1.) in vitro is dependent on the presence of hydrogen peroxide removing processes.

The loss of phenylalanine hydroxylase activity can be prevented to the same extent by catalase as well as the presence of optimized amounts of both peroxidase and superoxide dismutase.

Peroxidase alone exhibited only two third of the maximal protective effect of catalase whereas superoxide dismutase alone was not able to exert any protective influence on phenylalanine hydroxylase. These findings suggest that the termination of phenylalanine hydroxylation in the absence of hydrogen peroxide removing reactions is probably due to destructive oxygen species generated at the active site iron of phenylalanine hydroxylase in the presence of H2O2 and the tetrahydropterin cofactor.
Distribution of the H1 Histone Subfractions in Syrian Hamster Chromatin Fractions
Authors: Modrzejewska Hanna , Gałązka Grażyna , Szemraj Janusz , Panusz Henryk
Published: August 2018

Chromatin from two Syrian hamster tissues: the Kirkman-Robbins hepatoma and the liver, has been separated into soluble (S) and insoluble (P) fractions. Both fractions contain the complete set of five main histones but differ in respect of H1 subfractions. The hepatoma chromatin is known to contain an unusual H1 subfraction, H1 slow [12, 13], probably identical with a similar subfration present in hamster testes. The content of H1 slow in total H1 histone has been estimated for total, S and P chromatin from hamster hepatoma. The values 20.9 ± 7.2, 13.8 ± 1.8 and 26.8 ± 4.2%, respectively, were obtained.