Published by De Gruyter

Volume 38 Issue 9-10

Issue of Zeitschrift für Naturforschung C

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Journal Overview

Open Access June 2, 2014

Epicuticular Waxes from Leaves and Stems of Jojoba (Simmondsia chinensis [Link] Schneider)

Paul-Gerhard Gülz, Claudia Eich

Page range: 679-682

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Abstract

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.

Open Access June 2, 2014

Chemistry and Morphology of Epicuticular Waxes from Various Organs of Jojoba (Simmondsia chinensis [Link] Schneider)

Paul-Gerhard Gülz, Kurt Hängst

Page range: 683-688

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Abstract

The surface of leaves and seed coats of Jojoba is covered with similar amounts of epicuticular waxes per surface area. The composition of these waxes was analysed by chemical methods, whereas their microscopic structures in situ were revealed by scanning electron microscopy. Differences in the chemical structure and com position of the complex mixtures cause differences in the morphological appearance of wax on the surface of both organs. The predominance of saturated and long chain components in leaf wax results in a crystalline wax layer on this organ. In contrast, the seed coat carries a cover of non-crystalline fluid consistency. The lower melting point of this wax mixture is caused by shorter chain and unsaturated compounds predominating on this organ.

Open Access June 2, 2014

Isolation and Structural Determination of a New Methylated Triterpenoid from Rhizomes of Iris versicolor L.

Wolfgang Krick, Franz-Josef Marner, Lothar Jaenicke

Page range: 689-692

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Abstract

A monocyclic C 31 -triterpenoid was isolated from rhizomes of Iris versicolor L. Its structure was elucidated as 12 by spectroscopy combined with oxidative degradation. The identity of the degradation-products was proven by comparison with synthetic references.

Open Access June 2, 2014

Antifungal Phytoalexins in Phaseolus aureus Roxb

Melanie J. O’Neill, Saburi A. Adesanya, Margaret F. Roberts

Page range: 693-697

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Abstract

Eight phytoalexins have been isolated from Phaseolus aureus (mung bean) seedlings after treatment with aqueous CuCl 2 . These compounds include three isoflavones: genistein, 2′-hydroxygenistein and a compound tentatively identified as 2,3-dehydrokievitone, four isoflavanones: dalbergioidin, kievitone, cyclokievitone and 5-deoxykievitone, and the pterocarpan phaseollidin. The antifungal activities against Cladosporium cucumerinum were determined.

Open Access June 2, 2014

Aureol and Phaseol, Two New Coumestans from Phaseolus aureus Roxb

Melanie J. O'Neill

Page range: 698-700

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Abstract

Two new coumestans, aureol and phaseol, isolated from Phaseolus aureus have been characterized as 1,3.9-trihydroxycoumestan and 3,9-dihydroxy-4-(γ,γ-dim ethylallyl)-coumestan, respectively.

Open Access June 2, 2014

Synthesis and Biological Evaluation of 7α,7α,7α,8α,8α,8α- Hexafluororiboflavin and 7α,7α,7α,8α,8α,8α-Hexafluoro-FMN

Peter Nielsen, Adelbert Bacher, Diana Darling, Mark Cushman

Page range: 701-707

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Abstract

7α,7α,7α,8α,8α,8α-Hexafluororiboflavin (4) has been prepared and its oxidation-reduction potential determined polarographically to be + 0.02 V with respect to the standard hydrogen electrode. Compound 4 does not by itself promote the growth of Lactobacillus casei. However, in the presence of low riboflavin (1) concentrations, the hexafluoro analog 4 has some growth enhancing activity. The FMN analog 7α,7α,7α,8α,8α,8α-hexafluororiboflavin 5′-phosphate (10) was also synthesized and found to bind tightly to apoflavodoxin from Megasphaera elsdenii. The dissociation constant (3.2 × 10 -9 m) is about one order of magnitude larger than that of FMN (1.1 × 10 -10 м). However, apoflavodoxin reconstituted with hexafluororiboflavin 5′-phosphate (10) has no coenzyme activity. Hexafluoro-FMN (10) was also unable to act as a coenzyme for luciferase from Photobacterium fisheri. Hexafluororiboflavin 4 did not inhibit the light riboflavin synthase from Bacillus subtilis to a significant extent {K i > 10 -4 м).

Open Access June 2, 2014

3′-Hydroxylation of 4′-Methoxyisoflavones by Fusarium oxysporum f. lycopersici

K. Mackenbrock, W. Barz

Page range: 708-710

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Abstract

3′-Hydroxylation of isoflavones by Fusarium oxysporum f. lycopersici mainly proceeds with 4′-methoxy-7-hydroxyderivatives; this reaction is used for quantitative conversion of 14 C-labelled isoflavones.

Open Access June 2, 2014

Kinetin-Mediated Stimulation of Accumulation of Buckwheat Flavonoids in the Dark

U. Margna, T. Vainjärv

Page range: 711-718

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Abstract

A short treatment of excised buckwheat cotyledons with a solution of kinetin lead to an up to 9-fold stimulation of anthocyanin biosynthesis, to an about 50 percent increase in the accumulation of rutin, and to an about 30 percent increase, on the average, in the accumulation of C-glycosylflavones in the treated material during its posttreatment incubation in the dark. When the treated cotyledons were incubated in a solution of ʟ--phenylalanine anthocyanin accumulation in the dark practically attained the same high level as it was observed in the illuminated cotyledons fed with exogenous ʟ--phenylalanine. In experiments with l4 C-labelled L-phenylalanine kinetin induced a sharp rise in the labelling (resp. in the utilization of exogenous substrate for biosynthesis) of anthocyanins and rutin in the dark and a slight increase in the radioactivity of C-glycosylflavones. Similar labelling changes occurred in the illuminated cotyledons. However, both kinetin and light still more effectively promoted biosynthetic use of the endogenous substrate. As a result the relative portion of flavonoids formed from exogenous L-phenylalanine under these conditions showed a decrease as compared with the ratio of precursor use in the untreated cotyledons. The results show that low accumulation rates of anthocyanins and other flavonoids in the dark are conditioned by the limited access of substrate (ʟ--phenylalanine) molecules to the flavonoid enzymes lending further support to the idea that flavonoid biosynthesis is normally controlled at the substrate rather than at the enzymic level.

Open Access June 2, 2014

Uptake and Release of Abscisic Acid by Runner Bean Root Tip Segments

Wolfram Hartung, Barbara Dierich

Page range: 719-723

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Abstract

Uptake of abscisic acid by 5 mm long decapped root tips is a linear function of the external ABA concentration in the range of 2.9 × 10 -8 m to 10 -4 м and decreases dramatically with increasing pH. At pH 8.0 uptake rate is extremely low, even at high ABA concentrations. This indicated that nearly all of the ABA is taken up as the undissociated molecule ABAH. Uptake of ABA is influenced by agents modifying the pH gradients between the medium and the tissue such as salts of weak acids incubated at low external pH (inhibition of uptake and stimulation of ABA release by abolishing the pH gradients), protonophores such as CCCP (inhibition of uptake) and fusicoccin (stimulation of uptake by increasing the pH between medium and cytoplasm). It is concluded that ABA distributes between the compartments of the root cells according to the pH gradients with the undissociated molecule as the only penetrating species. Uptake and release occur without participation of a saturable component by diffusion. In contrast IAA permeates the plasmalemma as both IAAH and IAA - .

Open Access June 2, 2014

Distribution and Variation of the Catalytic Activity of the Enzyme Responsible for Carthamin Synthesis in Safflower Seedlings

Koshi Saito, Yoshiyuki Takahashi, Mizu Wada

Page range: 724-729

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Abstract

Catalytic activityof the enzyme which mediates the synthesis of carthamin was examined in the etiolated hypocotyl tissues of Carthamus tinctorius L. The enzyme was optimally active at pH 5.2 in citrate buffer. The activity of the enzyme was highest in the extract from 2-day-old seedlings after sowing and it declined sharply with tissue ageing. The enzyme activity was localized in the apical region of the seedlings and moreover it was preferentially associated with the cytosol fraction.

Open Access June 2, 2014

Further Studies on Induction of Enzymes of Phytoalexin Synthesis in Soybean and Cultured Soybean Cells

Joachim Leube, Hans Grisebach

Page range: 730-735

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Abstract

The glucan elicitor from cell walls o f the fungal pathogen, Phytophthora megasperma f. sp. glycinea, caused a decrease in activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase in wounded soybean cotyledons, whereas wounding alone led to an increase in the activity of this enzyme. A decrease o f HMG -CoA reductase activity after elicitor treatment was also found in soybean hypocotyls and soybean cell cultures. In contrast to the activity o f HMG -CoA reductase, the activity of dimethylallylpyrophosphate: 3,6a,9-trihydroxypterocarpan dimethylallyltransferase increases after elicitor challenge of soybean cell cultures and after inoculation of soybean hypocotyls (cv Amsoy 71) with mycelium of either race 1 (incompatible) or race 3 (compatible) of P. megasperma.

Open Access June 2, 2014

Effects of Pyridazinone Herbicides during Chloroplast Development in Detached Barley Leaves I. Effects on Pigment Accumulation and Fluorescence Properties

G. Laskay, E. Lehoczki, I. Maróti

Page range: 736-740

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Abstract

The effects of three differently substituted pyridazinone herbicides on the accumulation of photosynthetic pigments and on the fluorescence properties of greening barley leaves were studied. The two trifluoro-methyl derivatives, SAN 6706 and 9789 caused inhibition in the accumulation of carotenes only after the first 24 h of greening. By the 48th hour of greening no detectable amounts of carotenes were present in the treated leaves. Considerable amounts of xanthophylls however remained present, and no bleaching of the leaves was observed. It is suggested that SAN 6706 and 9789 prevent the formation of the enzyme(s) catalyzing the desaturation of phytoene and phytofluene. Fluorescence spectra indicate that the organization of pigment forms altered seriously in the treated leaves. This experimental system may be useful to study the action of pyridazinone herbicides without causing complete photobleaching of the photosynthetic apparatus. SAN 9785 had only minor effects on pigment accumulation and also on the organization of pigment forms. The possible explanations of the effects observed are discussed.

Open Access June 2, 2014

Effects of Pyridazinone Herbicides during Chloroplast Development in Detached Barley Leaves II. Effects on Lipid Content, Fatty Acid Composition and Ultrastructure of Chloroplasts

G. Laskay, E. Lehoczki, K. Gulya

Page range: 741-747

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Abstract

The effects of three differently substituted pyridazinone herbicides were studied on the lipid content, fatty acid composition of glycerolipids, fatty acid synthesizing capacity and ultrastructure of chloroplasts after 72 h of greening of etiolated barley leaves. SAN 9789 caused a nearly threefold increase in the total fatty acid content of chloroplasts. and this increase was accompanied by an increase in the DGDG- and phospholipid-content as well. SAN 6706 and 9785 caused reduction in the linolenic to linoleic acid ratio in nearly all lipid classes, only PC was unaffected. Both herbicides reduced the saturated to unsaturated ratio in the PG, SAN 9789 had no effect on the fatty acid composition of the PG. Fatty acid synthesis was inhibited in the SAN 6706- and 9789-treated leaves as monitored by incorporation of labelled acetate, but all of the three pyridazinones stimulated the incorporation of labelled galactose into chloroplast galactolipids. SAN 6706 and 9789 also caused abnormal organization of chloroplast lamellar system.

Open Access June 2, 2014

Chemistry of Bacteriochlorophyll b: Identification of Some (Photo)Oxidation Products

R. Steiner, E. Cmiel, H. Scheer

Page range: 748-752

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Abstract

Photoreactions of bacteriochlorophyll b have been studied. They all arise from reactions at the Δ8,8 1 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.

Open Access June 2, 2014

Urobiliverdin, a New Bile Pigment Deriving from Uroporphyrin

Eva Benedikt, Hans-Peter Köst

Page range: 753-757

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Abstract

5-Aminolevulinic acid is incubated with a crude enzyme extract from Rhodopseudomonas spheroides, mutant R 26. The formed porphyrins (main product: uroporphyrin III) are isolated. Incorporation of iron, ring-splitting by coupled oxydation and subsequent iron removal leads to a mixture of pigments, from which urobiliverdin, a new bile pigment with eight carboxylic acid side chains, is isolated. It is characterized by its chromatographic behaviour, chromic acid degradation and UV-vis spectroscopy.

Open Access June 2, 2014

Conformational Study of Catecholamines in Solution

P. Šolmajer

Page range: 758-762

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Abstract

Conformations of noradrenaline, dopamine and ephedrine have been studied in aqueous solutions using high resolution PMR spectroscopy. We found that for dopamine the mole fraction of trans rotamer is increased if pH is changed from acidic to basic while for noradrenaline and ephedrine the opposite trend is observed: gauche rotamer forms of the side chain become more populated. These changes are discussed in relation to the role of the benzylic hydroxyl group for conformation and/or binding to a receptor site in the biophase.

Open Access June 2, 2014

The Effects of Tumor Sera on Cell Shape and Photosynthesis of Euglena gracilis

H. G. Ruppel, B. Benninghoff

Page range: 763-769

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Abstract

Cells of Euglena gracilis treated with human sera show a marked change in cell shape: Fully elongated cells have nearly totally been transformed to disk-shaped cells. This serum-mediated contraction is followed by irreversible cytolysis. Disintegration of chloroplast membranes leads to decreased photosynthetic O 2 evolution. Sera from humans suffering from tumors reveal higher lytic activities than sera from individuals not suffering from tumors. Heating sera at 56 °C for 10 min or addition of EDTA destroyed or inhibited, respectively, the lytic activities completely. Polysaccharides transformed in polyanions by sulphatisation like dextransulphates or heparin seem to protect Euglena against serum activities. The effects described for human sera are believed to display the role of the complement pathway in the cytolysis of Euglena gracilis.

Open Access June 2, 2014

Lipids and Enzymatic Activities in Vacuolar Membranes Isolated via Protoplasts from Oat Primary Leaves

Britta Verhoek, Renate Haas, Käthe Wrage, Michael Linscheid, Ernst Heinz

Page range: 770-777

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Abstract

Vacuoles were released from oat (Avena sativa) mesophyll protoplasts and purified by sedimentation and flotation. Disruption of isolated vacuoles followed by density gradient centrifugation gave two membrane bands which after combination were further purified on sucrose gradients. A significant contamination by microbodies, thylakoids, mitochondria, endoplasmic reticulum and Golgi membranes can be excluded, whereas markers for plasma membrane and chloroplast envelope were present in the final membrane preparation. In the purified membrane fraction the following enzymatic activities were detected: NADH- cytochrome C reductase E.C. 1.6.2.2, ATPase E.C. 3.6.1.3. UDPG: sterol glucosyltransferase, UDP-Gal: diacylglycerol galactosyltransferase E.C. 2.4.1.46, glucan synthetase II, CDP-choline: diacylglycerol phosphocholinetransferase E.C. 2.7.8.2, formation of acylgalactosyl diacylglycerol and acyl-CoA thioesterase E.C. 3.1.2.2. None of these can be considered to be specific for the tonoplast. Acid phosphatase E.C. 3.1.3.2 was present in the cell sap. The vacuolar membranes contain phospholipids and glycolipids of the most complex composition found so far in a membrane system isolated from mesophyll protoplasts. About half of the glycolipids were accounted for by glycosyl diacylglycerols usually considered to be confined to plastids. Steryl glycosides and acyl steryl glycosides were other prominent glycolipids. A cerebroside was the predominating lipid component of this membrane preparation.

Open Access June 2, 2014

A Study on Oxygen Evolution and on the S-State Distribution in Thylakoid Preparations of the Filamentous Blue-Green Alga Oscillatoria chalybea

Klaus P. Bader, Pierre Thibault, Georg H. Schmid

Page range: 778-792

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Abstract

When thylakoid preparations of the filamentous blue-green alga Oscillatoria chalybea are exposed to short (2 or 8 μs) saturating light flashes, the oxygen evolution pattern can be distinguished in several respects from the one usually observed in Chlorella. Thus, it appears that a substantial electrochemical signal is already seen under the first flash with maximal flash yield always occurring under the fourth flash. This refers to dark adapted preparations (up to 60 min). Fitting of such an experimental sequence in the 4-state Kok model yields an S-state population consisting of 36-41% S 0 , 40-49% S 1 , 1-10% S 2 and up to 13% S 3 . No abnormality under the first flash is seen in such preparations. Characteristic for sequences with Oscillatoria preparations is a high level of misses which are in the region of 25 per cent, whereas double hits do not seem to play a substantial role in the damping of such sequences. The existence of metastable S 3 , anyway inconsistent with the coherent Kok model, is not confirmed by mass spectrometry. No 18 O 2 seems to be evolved under the first flash from Oscillatoria thylakoids suspended in 50% H 2 18 O. although, when judged from the absolute amperometric signal amplitude, mass spectrometric detection of O 2 should have been possible. With the same method we are fully able to detect 18 O 2 under the second flash in Chlorella vulgaris. In Chlorella this is true for experimental conditions in which the amperometric signal amplitude under the second flash is even smaller than those under the first or second flash in Oscillatoria. The attempt to correlate the amperometrie signal observed under the first flash with a photoinhibition of respiration in our prokaryotic organism was not successful. However, the attempt to incorporate the phenomenon in the coherent Kok model shows that the Oscillatoria sequence fully resembles those with Chlorella, if the first flash signal and 40-50% of the signal observed under the second flash is simply removed from the sequence. The remaining sequence exhibits the usual properties known from Chlorella or higher plant chloroplasts. If one assumes contribution of the reduced state S -1 to the dark population of S-states, a fit in the five rank Kok model yields correct adjustments with a S-state distribution of 6-20% S -1 , 31-40% S 0 , 49-54% S 1 , 0% S 2 and 0% S 3 which would be fully consistent with the Kok model and corresponds to the distribution observed with Chlorella or higher plant chloroplasts. The question what the first electrochemical signal is due to remains unanswered.

Open Access June 2, 2014

The Use of O₂-Evolving Subchloroplast Particles to Study Acceptor and Inhibitor Sites on the Reducing Side of Photosystem II

W. S. Cohen, J. R. Barton

Page range: 793-798

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Abstract

Photosystem II particles that retain the ability to evolve O 2 have been used to examine acceptor and inhibitor sites in the photosynthetic electron transfer chain between Q and plastoquinone. Employing the water to dichlorobenzoquinone reaction to assay photosystem II activity, we have demonstrated that electron transport in thylakoids and particles is equally sensitive to inhibition by DCMU. dinoseb, metribuzin, HQNO and DBMIB. Based on differential sensitivity to inhibition by DCMU vs. HQNO or DBMIB, we suggest that when synthetic quinones, e.g. 2,6-dichlorobenzoquinone operate as Hill reagents in particles they are reduced primarily by the plastoquinone pool. When synthetic quinones, e.g. 5,6-methylenedioxy-2,3-dimethyl benzoquinone act as autoxidizable acceptors they accept electron from the Q/B complex at a point that is located between the DCMU and HQNO (DBMIB) inhibition sites.

Open Access June 2, 2014

Electroimmunodiffusion — a Powerful Tool for Quantitative Determinations of Both Soluble and Membrane Bound Chloroplast ATPase, CF₁

Peter Roos, Richard J. Berzborn

Page range: 799-805

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Abstract

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 (CF 1 ) and the membrane bound enzyme (CF 0 CF 1 ). 2. Only a monospecific antiserum against CF 1 , is required for relative determinations of CF 1 in any fraction. If beyond this an absolute determination is intended of either the separated or the membrane bound ATPase, in addition a pure CF 1 , is needed for calibration. 3. A varying CF 1 /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 CF 1 , was the limiting factor of photophosphorylation capacity in the electron transport system used (PMS), from simultaneous measurement of CF 1 , content and photophosphorylation capacity a turn over time of the ATPsynthase of 4 ms /ATP /CF 0 CF 1 could be recalculated.

Open Access June 2, 2014

Analoga des Hippurans: [¹⁰³Ru]Ruthenocenoyl-glycin-Derivate. Synthese, Organ-Verteilung und Clearance /Analogue of Hippuran: Labelled Ruthenocenoyl-glycin. Synthesis, Organ Distribution and Clearance

Martin Wenzel, Gert Schachschneider

Page range: 806-811

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Abstract

The analogue of hippuric acid, ruthenocenoyl-glycine was synthesized and labelled with the γ-emitter 103 Ru. As a by-product of the synthesis the labelled diamide from ruthenocene- dicarbonic acid and glycine was gained. With these ruthenocene derivatives the organ distributions in mice and rats were measured. All ruthenocene-glycine derivatives showed primary a high kidney accumulation followed by very rapid renal excretion. After application of the cytostatic PtCl 2 (NH 3 ) 2 , causing toxic effects in the kidney of mice, the excretion of ruthenocenoyl-glycine is decreased. Biochemical data suggest the use of labelled ruthenocenoyl-glycine as a substitute for Iodo-labelled hippuran.

Open Access June 2, 2014

Immobilization of E. coli Cell as an Antigen by Radiation Polymerization Method

lsao Kaetsu, Minoru Kumakura, Shintaro Kikuchi, Shoichi Adachi, Mieko Suzuki

Page range: 812-814

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Abstract

E. coli NIJ cells were immobilized by radiation polymerization of 2-hydroxyethyl methacrylate at low temperatures. The immobilized E. coli cells as an antigen were reacted with peroxidase labeled anti-E. coli in competition with the free E. coli cells. It was found that E. coli cells can be assayed quantitatively with the immobilized E. coli cells in disc form. Microorganisms such as gram negative bacteria had no specific affinity to anti-E. coli. Cross reactivity of the immobilized E. coli cells with the E. coli cells from various strains was examined.

Open Access June 2, 2014

Hydratwasseraustausch und Alkanol-induzierte Molekulare Umordnungen an Kollagen/Exchange of the Structural Water of Collagen and Alcanol-Induced Molecular Rearrangement

Th. Nemetschek, E. Knörzer, W. Folkhard, W. Geerken, K. Jelinek, C. Kuhlemann, E. Mosler, H. Nemetschek-Gansler

Page range: 815-828

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Abstract

The exchange of the structural water of collagen for alcanols was investigated using X -ray diffraction combined with mechanical measurements. The stepwise dehydration with methanol, ethanol or 1-propanol is reflected by the reversible loss of the characteristic equatorial reflexions of native rat tail tendons. The exchange for 1-alcanols in ascending homologous order is characterized by: 1. an increase in the distance between the axes of the triple helices depending on the number of carbon atoms of the alkyl chain, 2. a shortening of the long-spacing of 67 nm characteristic of native collagen and 3. the herewith correlated increase in tension on isometrically measured fibres. The stepwise dehydration with 2-propanol leads first to a loss of the equatorial reflexions that are characteristic of native collagen, then to their reappearance at smaller diffraction angles. The exchange for 2-alcanols in ascending homologous order is characterized by: 1. a splitted equatorial reflexion at 4.1 ± 0 .1 nm, that stays constant up to 2-nonanol, and moves to 4 .8 - 5 .0 ± 0 .1 nm with more than 9 carbon atoms in the alkyl chain, 2. a shortening of the long spacing of 67 nm characteristic of native collagen and 3. the herewith correlated increase in tension on isometrically measured fibres. Stereochemical requirements are discussed as well as consequences for the structural model of collagen.

Open Access June 2, 2014

Preparation and Characterization of Actin from Liver

B. Jaberg

Page range: 829-833

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Abstract

G-actin was prepared from pork liver by gelfiltration on AcA 44 Ultrogel. The purity of the actin was 95-98% and the yield was 45-150 mg from 500 g liver, corresponding to a maximum efficiency of recovery of about 30%. High viscosities of actin-enriched solutions were reduced by a specific pH-step. In SDS-gel electrophoresis a single band of about ~ 45000 daltons was seen. The G-actin was polymerizable as shown by high shear viscosity measurements. The isoelectric points of the β- and γ-isoactins were 5.6 and 5.7.

Open Access June 2, 2014

Transient Activation of the Ca²⁺-ATPase from Sarcoplasmic Reticulum during Thiol Modification by 5 ,5′-Dithiobis(2-nitrobenzoate)

Gertrude Swoboda, Wilhelm Hasselbach

Page range: 834-844

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Abstract

In the reaction of sarcoplasmic reticulum m em branes with excess 5,5′-dithiobis(2-nitrobenzoate) (DTNB) some new features were observed: 1) The Ca 2+ -dependent ATPase activities of increasingly modified preparations were considerably enhanced during the initial stage of thiol blockage. A maximum (130 -160% of the control activity) was reached when about 1.5 - 2 mol thiol groups per 10 5 g vesicular protein had reacted, in the absence of ATP and detergent. At higher extents of modification inactivation occurred. Purified ATPase behaved principally similar to native sarcoplasmic vesicles. 2) In the presence of Mg 2+ and ATP the activity maxim um (up to 180% of control) was broadened and shifted towards a higher degree of thiol blockage. Concomitantly the modification and inactivation rates were considerably reduced. 3) Glycerol (10 -30 % , v/v) slightly enhanced the ATPase activity maximum and reduced the rate of inactivation essentially only by decreasing the DTNB modification rate. 4) In the presence of sufficient myristoylglycerophosphocholine for solubilization no activation was observed. 5) The steady state level of phosphoprotein from ATP was raised to about 150% of the control level 10 s after addition of DTNB (about 1/2 thiol blocked), followed by a linear decrease with the number of thiols labeled, while the Ca 2+ -dependent ATPase activity of preparations modified under equivalent conditions (10 -4 м Ca 2+ and 2 x 10 -3 м Mg 2+ present) showed a broader maximum corresponding to 1.5 thiols blocked.

Open Access June 2, 2014

Phosphorylation of Ca-ATPase of Sarcoplasmic Reticulum with Different Substrates

Hector Barrabin, Leopoldo de Meis

Page range: 845-847

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Abstract

ATP and GTP as substrate for phosphorylation of sarcoplasmic reticulum ATPase are compared. Maximal levels of phosphoenzyme are between 4.5 and 4.8 nmol per mg of protein when either substrate is used provided that phosphoenzyme hydrolysis are strongly inhibited by high calcium concentration (20 mм) and low temperatures ( 0 ° C ) . The maximal values obtained with GTP are lower than those previously reported. It is shown that this difference is due to underestimation of the specific activity of labeled nucleotides used in previous studies, as revealed by UV absorption and HPLC analysis. The dependence of the phosphoenzyme levels on calcium concentration, pH and temperature confirm previous findings indicating that ATP, but no GTP, accelerates the rate limiting step of the catalytic cycle.

Open Access June 2, 2014

Composition of the Heterogeneous Sex Attracting Secretion of the Dung Beetle, Kheper lamarcki

B. V. Burger, Zenda Munro, Marina Röth, H. S. C. Spies, Verona Truter, G. D. Tribe, R. M. Crewe

Page range: 848-855

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Abstract

The white flocculent sex attracting secretion produced by the male dung beetle, Kheper lamarcki MacLeay, was found to consist of tubular polypeptide fibres containing hexadecanoic acid, 2,6-dimethyl-5-heptenoic acid and (E)-nerolidol as major components, while a trace of skatole is responsible for the unpleasant odour of the secretion.

Open Access June 2, 2014

Stimulation of Juvenile Hormone Biosynthesis in vitro by Locust Allatotropin

Hans-Joerg Ferenz, Ingrid Diehl

Page range: 856-858

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Abstract

In Locusta migratoria the gonotrophic cycles are regulated by juvenile hormone. The cyclical changes of juvenile hormone synthesis in locust corpora allata seem to be regulated by a neuro-hormonal factor. Such an allatotropin could be extracted from corpora cardiaca and brains of Locusta migratoria. It is a small pronase-sensitive and heat-stable peptide. Extract of one corpus cardiacum stimulates corpus allatum biosynthetic activity in vitro 5 to 20-fold.

Open Access June 2, 2014

Notizen: Interaction of Ascorbic Acid with Disulfides

James E. Fleming, Klaus G. Bensch, Jörg Schreiber, Wolfgang Lohmann

Page range: 859-861

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Abstract

Electron spin resonance (EPR) spectra demonstrate the formation of a complex between the ascorbate ion and disulfides such as oxidized glutathione, cystine, gamma globulin, bovine serum albumin, 4-4′ dithiopyridine, and dithiobutyric acid. However, except in the case of 4-4′ dithiopyridine. ascorbic acid (AH 2 ) is not capable of reducing the disulfide bond in these compounds. These results can be explained in terms of the redox potential of ascorbic acid and its radical semidehydroascorbic acid (SDA). These compounds can reduce the S-S bond of 4-4′ dithiopyridine, the redox potential of which is E′ = -0. 1 V and, thus, more positive than the ones determined for the ascorbic acid system.

Open Access June 2, 2014

Notizen: ESR Investigations on the M odification o f the Ascorbic Acid-Erythrocyte Interaction by Ferrous Ions

W. Lohmann, B. Kiefer, D. Holz, D. Schmidt, J. Schreiber

Page range: 862-863

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Abstract

An ascorbic acid-erythrocyte interaction results in the formation of the semidehydroascorbate (SDA) radical and an increase in spin concentration. Addition of a more than ten-fold concentration of Fe 2+ (as FeSO 4 ) to such a system compensates the effect produced by ascorbic acid, that is the electron spin resonance spectrum obtained resembles very closely that of erythrocytes only. With the disappearance of the SDA radical a high spin ferric ion signal appears concomitantly at g = 4.3.

Open Access June 2, 2014

Notizen: The Effect of Alcohol Oxidase on the Ascorbic Acid-Erythrocyte Interaction: ESR Investigations

W. Lohmann, J. Schreiber, D. Holz

Page range: 864-865

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Abstract

Addition of alcohol oxidase to erythrocytes treated with ascorbic acid reverses the vitamin C effect, as expressed by the appearance of the semidehydroascorbate signal, and the increase in spin concentration. The original erythrocyte electron spin resonance (ESR) signal is, how ever, never restored completely, as it is in the case if ascorbate oxidase is used. Additional interaction between the enzyme alcohol oxidase and haemoglobin iron must occur, since both o f the iron ESR signals at g = 4.3 and g = 6 disappear and the erythrocyte ESR spectrum at g ≈ 2 is changed characteristically. The spin concentration of the latter spectrum increases again above a certain concentration of alcohol oxidase.

Open Access June 2, 2014

Notizen: Photosensitized Effects of Furocoumarins: the Possible Role of Singlet Oxygen

Daniela Vedaldi, Francesco Dall'Acqua, Armando Gennaro, Giovanni Rodighiero

Page range: 866-869

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Abstract

The capacity of various furocoumarins to generate singlet oxygen in aqueous solution has been determined. The antiproliferative and the skin-photosensitizing activities of the same furocoumarins did not show any correlation with the capacity to generate the singlet oxygen, while these photobiological properties could be correlated with the capacity of furocoumarins to induce photolesions to the DNA.

Open Access June 2, 2014

Notizen: Supplementary Data on the Sex Attractant System of Panolis flammea

Ernst Priesner, Martin Schroth

Page range: 870-873

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Abstract

Pheromonal synergism and inhibition in P. flammea was further studied through electrophysiological and field trapping tests. Z11-tetradecenyl acetate and Z11-hexa - decenyl acetate, each acting upon a separate type of male sensory cell, were equally effective in synergizing attraction responses to the major pheromone component, Z9-tetradecenyl acetate. Addition of Z7-dodecenyl acetate to these lures reduced captures. Male attraction specificity markedly varied with local moth density.

Open Access June 2, 2014

Notizen: Receptors for Di-Unsaturated Pheromone Analogues in the Male Summerfruit Tortrix Moth

Ernst Priesner

Page range: 874-877

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Abstract

The antennal Sensilla trichodea in male Adoxophyes orana (F. v. R.) contain specialist receptor cells for 3 reported pheromone components (Z9- and Z11-tetradecenyl acetates and Z9-tetradecen -1-ol) and, additionally, the analogues Z9 ,E11- and Z9,E12-tetradecadienyl acetate. Possible behavioural functions of these dienes are briefly considered.

Open Access June 2, 2014

Notizen: Effect of Ecdysterone on Food Intake of Locusta migratoria Hoppers

P. J. Rao, H. Rembold

Page range: 878-880

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Abstract

Ecdysterone administration at physiological concentrations (35 μg /hopper) on alternate days decreased the live weight gain and faecal production in both sexes of 5th instar nymphs of Locusta migratoria. All treated hoppers at this dose failed to moult. No such effects were observed when the hoppers were administered with half of the dose.

Open Access June 2, 2014

Aminoacyl-tRNA Synthetases in Liver, Spleen and Small Intestine of Aged Leukemic and Aged Normal Mice

Hans-Joachim Gabius, Sigrun Gabius, Gerhart Graupner, Friedrich Cramer, Sabine Rehm

Page range: 881-882

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Abstract

The specific activities of 17 aminoacyl-tRNA synthetases in liver, lung, heart, spleen, kidney and small intestine of old female normal and leukemic (reticulum -cell sarcoma, type A) mice have been monitored. No difference appears for lung, heart and kidney; small increases with varying particular changes for liver and marked increases in spleen and small intestine of the tumor bearing mice have been found, following a similar pattern. This finding suggests a coordinated adaptation to modulation of the requirements of protein synthesis imposed by histiocytic sarcoma.

Open Access June 2, 2014

A Non-Thermal Effect of Millimeter Wave Radiation on the Puffing of Giant Chromosomes

C. Koschnitzke, F. Kremer, L. Santo, P. Quick, A. Poglitsch

Page range: 883-886

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Abstract

A non-thermal influence of millimeter wave radiation (swept in frequency from 64.1 GHz to 69.1 GHz, sweeptime 6 s, and with stabilized frequencies of 67.200 ± 0.001 GHz and 68.200 ± 0.001 GHz, power density S≦ 6 mW/cm 2 ) on the puffing of giant chromosomes of the midge Acricotopus lucidus (Diptera, Chironomidae) was found. The effect is manifested as a reduction in size of a specific puff that expresses genes for a secretory protein. The non-thermal nature of the effect was proved by experiments in which the sham-exposed sample was warmed up by 2.5 °C which is more than the eight-fold microwave induced temperature increase of ≦0.3°C. Concerning the very low photon energy of mm-waves compared to the thermal energy kT, it seems likely that the coherence of the radiation is essential for the observed effect.

Open Access June 2, 2014

Determination of Measles Virus Protein Molecular Weights on High Percentage, Highly Cross-Linked SDS Polyacrylamide Gels

M. J. Carter, K. Baczko

Page range: 887-890

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Abstract

A recent examination of measles virus mRNA molecules has shown that the nucleocapsid and haemagglutin messengers are of the size expected from a consideration of their protein products. How ever, the mRNA for membrane protein is approximately 50% larger than the size required. The molecular weight of matrix protein has been determined by SDS-polyacrylamide gel electrophoresis, and this procedure can lead to an underestimation of the true size of hydrophobic molecules which show increased SDS binding. It is therefore appropriate to examine the molecular weight determination of this protein to exclude such an artefactual discrepancy in mRNA and protein sizes. We report here that measles virus membrane protein does not shown such anomalous behaviour and confirm that the size discrepancy is a true phenomenon.

About this journal

Objective

A Journal of Biosciences: Zeitschrift für Naturforschung C (ZNC) is an international scientific journal and a community resource for the emerging field of natural and natural-like products.

The journal publishes original research on the isolation (including structure elucidation), bio-chemical synthesis and bioactivities of natural products, their biochemistry, pharmacology, biotechnology, and their biological activity and innovative developed computational methods for predicting the structure and/or function of natural products.

A Journal of Biosciences: Zeitschrift für Naturforschung C (ZNC) welcomes research papers in fields on the chemistry-biology boundary which address scientific ideas and approaches to generate and understand natural compounds on a molecular level and/or use them to stimulate and manipulate biological processes.

Topics

Bio-chemical synthesis and bioactivities of natural products
Isolation (including structure elucidation)
Biochemistry
Biotechnology
Pharmacology
Chemistry
Biology

Article formats

Original research articles, research notes, letters and review articles

Please have a look at the call for papers for two upcoming Special Issues:

Special Issue on CAZymes

Special Issue on Chitin Structures and Pathways as Targets for Biopesticides and Drugs

Volume 38 Issue 9-10

Issue of Zeitschrift für Naturforschung C

Epicuticular Waxes from Leaves and Stems of Jojoba (Simmondsia chinensis [Link] Schneider)

Abstract

Chemistry and Morphology of Epicuticular Waxes from Various Organs of Jojoba (Simmondsia chinensis [Link] Schneider)

Abstract

Isolation and Structural Determination of a New Methylated Triterpenoid from Rhizomes of Iris versicolor L.

Abstract

Antifungal Phytoalexins in Phaseolus aureus Roxb

Abstract

Aureol and Phaseol, Two New Coumestans from Phaseolus aureus Roxb

Abstract

Synthesis and Biological Evaluation of 7α,7α,7α,8α,8α,8α- Hexafluororiboflavin and 7α,7α,7α,8α,8α,8α-Hexafluoro-FMN

Abstract

3′-Hydroxylation of 4′-Methoxyisoflavones by Fusarium oxysporum f. lycopersici

Abstract

Kinetin-Mediated Stimulation of Accumulation of Buckwheat Flavonoids in the Dark

Abstract

Uptake and Release of Abscisic Acid by Runner Bean Root Tip Segments

Abstract

Distribution and Variation of the Catalytic Activity of the Enzyme Responsible for Carthamin Synthesis in Safflower Seedlings

Abstract

Further Studies on Induction of Enzymes of Phytoalexin Synthesis in Soybean and Cultured Soybean Cells

Abstract

Effects of Pyridazinone Herbicides during Chloroplast Development in Detached Barley Leaves I. Effects on Pigment Accumulation and Fluorescence Properties

Abstract

Effects of Pyridazinone Herbicides during Chloroplast Development in Detached Barley Leaves II. Effects on Lipid Content, Fatty Acid Composition and Ultrastructure of Chloroplasts

Abstract

Chemistry of Bacteriochlorophyll b: Identification of Some (Photo)Oxidation Products

Abstract

Urobiliverdin, a New Bile Pigment Deriving from Uroporphyrin

Abstract

Conformational Study of Catecholamines in Solution

Abstract

The Effects of Tumor Sera on Cell Shape and Photosynthesis of Euglena gracilis

Abstract

Lipids and Enzymatic Activities in Vacuolar Membranes Isolated via Protoplasts from Oat Primary Leaves

Abstract

A Study on Oxygen Evolution and on the S-State Distribution in Thylakoid Preparations of the Filamentous Blue-Green Alga Oscillatoria chalybea

Abstract

The Use of O2-Evolving Subchloroplast Particles to Study Acceptor and Inhibitor Sites on the Reducing Side of Photosystem II

Abstract

Electroimmunodiffusion — a Powerful Tool for Quantitative Determinations of Both Soluble and Membrane Bound Chloroplast ATPase, CF1

Abstract

Analoga des Hippurans: [103Ru]Ruthenocenoyl-glycin-Derivate. Synthese, Organ-Verteilung und Clearance /Analogue of Hippuran: Labelled Ruthenocenoyl-glycin. Synthesis, Organ Distribution and Clearance

Abstract

Immobilization of E. coli Cell as an Antigen by Radiation Polymerization Method

Abstract

Hydratwasseraustausch und Alkanol-induzierte Molekulare Umordnungen an Kollagen/Exchange of the Structural Water of Collagen and Alcanol-Induced Molecular Rearrangement

Abstract

Preparation and Characterization of Actin from Liver

Abstract

Transient Activation of the Ca2+-ATPase from Sarcoplasmic Reticulum during Thiol Modification by 5 ,5′-Dithiobis(2-nitrobenzoate)

Abstract

Phosphorylation of Ca-ATPase of Sarcoplasmic Reticulum with Different Substrates

Abstract

Composition of the Heterogeneous Sex Attracting Secretion of the Dung Beetle, Kheper lamarcki

Abstract

Stimulation of Juvenile Hormone Biosynthesis in vitro by Locust Allatotropin

Abstract

Notizen: Interaction of Ascorbic Acid with Disulfides

Abstract

Notizen: ESR Investigations on the M odification o f the Ascorbic Acid-Erythrocyte Interaction by Ferrous Ions

Abstract

Notizen: The Effect of Alcohol Oxidase on the Ascorbic Acid-Erythrocyte Interaction: ESR Investigations

Abstract

Notizen: Photosensitized Effects of Furocoumarins: the Possible Role of Singlet Oxygen

Abstract

Notizen: Supplementary Data on the Sex Attractant System of Panolis flammea

Abstract

Notizen: Receptors for Di-Unsaturated Pheromone Analogues in the Male Summerfruit Tortrix Moth

Abstract

Notizen: Effect of Ecdysterone on Food Intake of Locusta migratoria Hoppers

Abstract

Aminoacyl-tRNA Synthetases in Liver, Spleen and Small Intestine of Aged Leukemic and Aged Normal Mice

Abstract

A Non-Thermal Effect of Millimeter Wave Radiation on the Puffing of Giant Chromosomes

Abstract

Determination of Measles Virus Protein Molecular Weights on High Percentage, Highly Cross-Linked SDS Polyacrylamide Gels

Abstract

The Use of O₂-Evolving Subchloroplast Particles to Study Acceptor and Inhibitor Sites on the Reducing Side of Photosystem II

Electroimmunodiffusion — a Powerful Tool for Quantitative Determinations of Both Soluble and Membrane Bound Chloroplast ATPase, CF₁

Analoga des Hippurans: [¹⁰³Ru]Ruthenocenoyl-glycin-Derivate. Synthese, Organ-Verteilung und Clearance /Analogue of Hippuran: Labelled Ruthenocenoyl-glycin. Synthesis, Organ Distribution and Clearance

Transient Activation of the Ca²⁺-ATPase from Sarcoplasmic Reticulum during Thiol Modification by 5 ,5′-Dithiobis(2-nitrobenzoate)