bluuebunny/crossref_metadata_2025 huggingface dataset:
Antifungal Compounds Induced in the Dual Culture with Phytolacca americana Callus and Botrytis fabae
Authors: Kobayashi Akio , Hagihara Kohtatsu , Kajiyama Shin-ichiro , Kanzaki Hiroshi , Kawazu Kazuyoshi
Published: August 2018

In order to investigate new metabolites which are only induced in a plant callus infected by a pathogenic fungus, dual cultures with combinations of 10 species of fungi and 6 plant cell lines from different species were established. Among the combinations tested, the methanolic extract of a dual culture consisting of a plant cell line, Phytolacca americana and a fungus, Botrytis fabae showed a marked antifungal activity to Cladosporium herbarum. The main active constituent of this extract was identified to be phytolaccoside B (Pls B) by the spectroscopic analyses.
5-Hydroxy-3-vinyl-2(5H)-furanone -a New Inhibitor of Human Synovial Phospholipase A2 and Platelet Aggregation from Fermentations of a Calyptella Species (Basidiomycetes)
Authors: Lorenzen Kirsten , Anke Timm , Konetschny-Rapp Silvia , Scheuer Werner
Published: August 2018

5-Hydroxy-3-vinyl-2(5H)-furanone, a potent and selective inhibitor of human synovial phospholipase A2 was isolated from fermentations of a Calyptella species. Its structure as identified by spectroscopic methods is identical to PA 147, an antibiotic previously isolated from a streptomycete. 5-hydroxy-3-vinyl-2(5H)-furanone inhibits the aggregation of human and bovine platelets stimulated by different inducers and exhibits weak antimicrobial activities.
Secretion of Neutral and Acid DNases in Cultivated Human Lymphocytes after Incubation with DNA; Possible Consequences for Inhalation Anesthesia
Authors: Reitz Manfred , Löber Günter , Kleemann Peter , Dick Wolfgang
Published: August 2018

After incubation with DNA human lymphocytes release neutral and acid DNase activities into the culture medium; the release depends on DNA concentration and time of cultivation. The electrophoretic mobility of the released neutral DNase activity is in accordance with DNase I and the electrophoretic mobility of the released acid DNase activity with DNase II. The released DNase activities do not originate from dead cells and are not influenced by blast cell formation. The anesthetic halothane can inhibit the released neutral and acid DNase activities. Inhalation anesthesia can possibly disturb the correlation between DNA and DNases in human blood.
Periodic Current Injection (PCI) -A New Method to Image Steady-State Membrane Potential of Single Neurons in situ Using Extracellular Voltage-Sensitive Dyes
Authors: Borst Alexander
Published: August 2018

A new method is described which allows to image the steady-state distribution of m em ­ brane potential of single neurons in situ. The method consists of staining the tissue with an extracellular voltage-sensitive dye (Di-4-ANEPPS) and impaling a single neuron with a microelectrode. After focusing the imaging system onto the cell a large series of images are taken with a CCD camera at the appropriate excitation wavelength of the voltage-sensitive dye while the neuron’s membrane potential is shifted by a periodic current injection (PCI). Afterwards two groups of images are averaged separately: those images while the cell was at rest and those images while the cell was hyperpolarized. After subtraction of these averaged images, the resulting difference image shows only the membrane potential of the cell which was altered periodically. The success of the method is demonstrated on leech cells in intact ganglia. If applied to cells with a basically two-dimensional arborization pattern, the decrease of activity in the difference image in areas further away from the injection site should relate to a decrease in membrane potential according to the passive electrotonic properties of the cell under study.
Notes: On the Chemical Nature of Epicuticular Waxes in Some Succulent Kalanchoe and Senecio Species
Authors: Siems Karsten , Jas Gerhard , Arriaga-Giner F. Javier , Wollenweber Eckhard , Dörr Marion
Published: August 2018

Leaves and other aerial parts of several succulent species each of Kalanchoe and Senecio exhibit more or less obvious wax coatings. The major components of these waxes were identified to be pentacyclic triterpenes. Some of these are rare natural products, while others are rather widespread.
Notes: Osmundalin (Lactone Glucoside) Stimulates Receptor Cells, Associated with Deterrency, of Bombyx mori
Authors: Shimizu T. , Asaoka K. , Numata A.
Published: August 2018

Osmundalin, a glucoside of osmundalactone, isolated from the royal fern, Osmunda japonica, stimulated the deterrent cell (“R receptor” cells, associated with deterrency) in the medial sensilla styloconica of Bombyx mori. From the dose-response curve, the lower limit of detection was 3.6 x l0-5 - 3.6 x l0-4 ᴍ. This is the first report that glucoside lactone elicits the impulses from the deterrent cell of Bombyx mori.
Studies on Sporopollenin Structure during Pollen Development
Authors: Meuter-Gerhards Andrea , Schwerdtfeger Claus , Steuernagel Stefan , Wilmesmeier Sabine , Wiermann Rolf
Published: August 2018

To clarify whether the structure of sporopollenin varies during pollen development FTIR and 13C NMR spectroscopic analyses of Tulipa and Cucurbita sporopollenin from three different developmental stages were carried out.

The spectra of sporopollenin obtained from an early, a middle postmeiotic and the mature stage have been compared. The assumption that sporopollenin mainly consists of long chain aliphatics with varying amounts of aromatics is corroberated by our results.

Only slight changes in sporopollenin structure could be recognized during pollen wall development of Cucurbita maxima. In contrast to this the spectra of Tulipa sporopollenin of the three developmental stages exhibited significant differences concerning the aliphatic and aromatic components.
A Study on Tea Aroma Formation Mechanism: Alcoholic Aroma Precursor Amounts and Glycosidase Activity in Parts of the Tea Plant
Authors: Ogawa Kenji , Moon Jae-Hak
Published: August 2018

We have shown in molecular basis that alcoholic tea aroma is mainly formed by endogenous enzymatic hydrolysis of glycosidic aroma precursors during manufacturing. Amounts of alcoholic aroma precursor and glycosidase activity in each part of the tea shoot ( Camellia sinensis var. sinensis cv Yabukita and a hybrid of var. assamica & var. sinensis cv Izumi) were indirectly measured by means of a crude enzyme assay. The aroma precursors were abundant in young leaves and decreased as the leaf aged. Glycosidase activity also decreased as leaves aged, but was high in stems.
Structural Modifications of the Photosynthetic Apparatus in the Region of Photosystem I in Nicotiana tabacum as a Consequence of an Increased CO2-Content of the Atmosphere
Authors: Makewicz A. , Radunz A. , Schmid G. H.
Published: August 2018

Nicotiana tabacum was grown with a CO2-content in the atmosphereof 350 ppm and 700 ppm. After three weeksof growth in the respective atmospherewe were able to show that chloroplasts from plants grown under 700 ppm CO2 exhibited an 18% higher photosystem I-mediatedelectron transport activity. Furthermore, we were able to show that in plants grown under the higher CO2-concentration the peptide composition of photosystem I had been quantitatively changed. It appeared that the CPI-peptides were increased, whereasthe LHCPI peptides were decreased. Corresponding to this change in the peptide composition the ratio chlorophyll/carotenoids/protein changes from 1:0.16:3.6 in the control plants to 1:0.23:5 in the “CO2-plants”. The chlorophyll a/b ratio changes from 1.9 in the control plants to 2.3 in the “CO2 plants”. Furthermore, the carotenoid composition appears to be changed, β-carotene increases by 60% as expected from the increased CPI-content. The xanthophylls lutein, violaxanthin, neoxanthin and zeaxanthin increase also but to a lesser extent. Using specific antisera to lipids, we were able to show that photosystem I contains only the membrane lipids monogalactosyldiglyceride and phosphatidylglycerol. Both lipids are specifically bound in a restricted number onto peptides of the photosystem I complex. Both lipids differ with respect to their binding strength on the peptides of photosystem I. The changes in the peptide and lipid composition were established by chemical analyses and by immunological techniques (Western blot) using monospecific antisera to the photosystem I peptides, to the chloroplast lipids as well as to the chloroplast carotenoids. From the quantitative and qualitative analyses of the peptides, carotenoids and lipids, the molecular distribution of the carotenoids and lipids in the CPI and LHCPI complex of photosystem I was established.
Effect of Foliar Treatment with Simulated Acid Mists on Biomass Formation and Nutrient Composition of Plants
Authors: Mandre Malle , Klyshejko Jaan
Published: August 2018

Plants of Phaseolus vulgaris L. were exposed to mists consisting of distilled water at pH 5.6 (control) or H2SO4+ HNO3 (molar ratio 1.5:1) in distilled water at pH 4.5, 3.0 and 2.3. At the end of 21-days treatment the growth of the plants in height was not reduced: however, significant changes were detected in the mineral nutrient content and partitioning in plant organs. Treatments at pH 2.3 led to greatly decreased Ca and K content and increased S. N and P content in the leaves. In the roots the most significant increases occurred in the levels of P, S, N, K. Ca, and Mg, in the stems in the levels of N, S and P.
Effects of Juvenile Hormone Analogues (JHA) on the Development of Trypanosoma cruzi
Authors: Fichera L. , Esteva M. , Wimmer Z. , Rodriguez J. B. , Gros E. G.
Published: August 2018

Juvenile hormone analogues were tested for their lytic activity on Trypanosoma cruzi Chagas, 1909 blood tripomastigotes cultivated in vitro. The results indicated that the carbamate 4 and the phenoxyphenol derivative 1 are considered good candidates for blood sterilization. The compounds were also assayed for inhibition of development of parasites in infected mice showing a moderated degree of activity.
The Subcellular Distribution of Calcium in the Visual Cells of Crayfish, Observed with the Combined Oxalate-Pyroantimonate Technique, Depends on Extracellular Calcium
Authors: Jarminowski Hans
Published: August 2018

1. With the combined oxalate-pyroantimonate method we determined the subcellular distribution of calcium in the photoreceptor cells of the crayfish Orconectes limosus.

2. The calcium antimonate deposits were identified with the electron microscope. Energydispersion X -ray analysis verified that the electron dense deposits contained calcium and antimony.

3. Calcium antimonate deposits were found in the submicrovillar cisternae, mitochondria, multivesicular bodies, and pigment granules, as well as in the cytoplasm .

4. The calcium deposits in the cytoplasm of the retinula cell and in the pigment granules were reduced after incubation of the retinae in a solution with a lowered calcium concentration and even more after we permeabilized the plasma membrane with the saponin β-escin.

5. We suppose that the calcium -storing pigment granules participate in the regulation of the cytosolic calcium concentration of the crayfish photoreceptor cells.
Notes: External Flavonoids of Three Species of Viguiera, Section Hypargyrea (Asteraceae)
Authors: Wollenweber Eckhard , Dörr Marion , Roitman James N. , Schilling Edward
Published: August 2018

The flavonoid aglycones excreted by aerial parts of three Viguiera species have been analyzed. One of them is a rare natural product. So far unpublished NMR data are reported for three flavones. Each species of V. sec­tion Hypargyrea exhibits a distinctive flavonoid profile based on different patterns of methoxylation, but the taxonomic section as a whole is not characaterized by any distinctive characters of its flavonoid chemistry.
Xanthine Oxidase and Xanthine Dehydrogenase from an Estivating Land Snail
Authors: Hermes-Lima Marcelo , Storey Kenneth B.
Published: August 2018

During arousal from estivation in land snails. Otala lactea, active metabolic functions are restored within minutes and oxygen consumption increases dramatically. During the transition from the hypoxic conditions of estivation to normoxia it is possible that xanthine oxidase (XO ) in hepatopancreas contributes to the observed lipid peroxidation. Using a fluorometric assay that is based on the oxidation of pterin, the activities and some properties of XO and XO+XDH (sum of XO and xanthine dehydrogenase activities) were measured in hepatopancreas extracts. Km values for pterin for XO and X O +XDH were 9 and 6 μm, respectively, and the Km of XDH for methylene blue was 5 μm . Both XO +XDH and XO activities were inhibited by allopurinol (I50 = 2 μm ) , pre-incubation at 40 °C, and by 5 min H2O2 pre-exposure. Inclusion of azide in the reaction promoted a rise of approximately 70-fold in the inactivation power of H2O2 due to inhibition of high endogenous catalase activity. The /so for H2O2 of XO +XDH and XO activities in the presence of azide was 0.04 and 0.11 mM , respectively. Unlike the situation for mammalian XO. a previous reduction of O. lactea XO (by pterin) was not necessary to make the enzyme susceptible to H2O2 effects. Interestingly, methylene blue partially prevented both heat- and H20 2-induced inactivation of XO +XDH activity. These data indicate that the formation of an enzyme-methylene blue complex induces protection against heat and oxidative damage at the FAD-active site. Both XO and XO +XDH activities were significantly higher in snails after 35 days of estivation compared with active snails 24 h after arousal from dormancy. The ratio of XO /(XO +XDH) activities was also slightly increased in estivating O. lactea (from 0.07 to 0.09; P < 0.025). XO activity was 0.03 nmol · min-1 · mg protein-1 in estivating snails. Compared with hepatopancreas catalase, XO activity is probably too low to contribute significantly to the net generation of oxyradicals, and hence to peroxidative damage. Rather, the low potential of XO to induce oxidative stress may constitute an adaptive advantage for O. lactea during arousal periods
Action of Hypochlorous Acid on Polymeric Components of Cartilage. Use of 13C NMR Spectroscopy
Authors: Schiller Jürgen , Arnhold Jürgen , Arnold Klaus
Published: August 2018

Hypochlorous Acid, Cartilage, Chondroitinsulphate, Carbon NM R Spectroscopy It is a well known fact that neutrophil-derived hypochlorous acid plays an important role in cartilage destruction during rheumatoid arthritis. It has been shown by 1H NMR spectro­scopy in a previous paper (Schiller et al. (1994), Biol. Chem. Hoppe-Seyler 375, 167-172) that sodium hypochlorite affects primarily the N-acetyl side chains of polymeric carbohydrates of cartilage like chondroitinsulphate and hyaluronic acid. An instable intermediate, likely to be a chloramine, is involved in these processes. The present paper deals with the application of carbon NMR spectroscopy for the study of these degradation processes, because carbon NMR gives the opportunity to detect changes on the single sugar ring carbons. Although it was not possible to prove the involvement of an intermediate, because of its fast hydrolysis, we were able to show that the reaction between sodium hypochlorite and N-acetylglucos-amine affects mainly the side chain, accompanied by of a large excess of sodium hypochlorite leads to under the formation of formiate.
Isolation and Characterization of an Angular- Type Dihydropyranocoumaringlycoside from the Fruits of Ammi visnaga (L.) LAM. (Apiaceae)
Authors: Sonnenberg H. , Kaloga M. , Eisenbach N. , Frömming K.-K.
Published: August 2018

An angular-type dihydropyranocoumaringlucoside, namely, cis-Khellactone-3′-β-D-glucopyranoside (1) was isolated from the fruits of Ammi visnaga (L.) LAM. (Apiaceae). The structure was established on the basis of acid hydrolysis and spectral data
Specifities of Rabbit Antisera to Multiple Antigen (MAP) Peptides
Authors: Chersi Alberto , Modugno Francesca di , Falasca Giuliana
Published: August 2018

Two multiple antigen peptides consisting of 6 and 7 amino acid residues, respectively, plus a 12-residue fragment, used as a control, all linked to a polylysine core, were used as immunogens in rabbits in order to obtain an immune response. Rabbit antisera against such polymers were then tested in ELISA against a panel of antigens in order to analyze the specificites of the resulting antibodies. The responses were different for all three immunogens, being partially or totally directed, for two of the three compounds, including the 12-residue control MAP peptide, against the polylysyl core, which is considered as non immunogenic. The third MAP polymer was practically unable to elicit an immune response
Self-Organized Criticality and Dynamic Instability of Microtubule Growth
Authors: Babinec Peter , Babincová Melánia
Published: August 2018

We have shown that the distribution of lengths of site nucleated microtubules obey an algebraic power law relationship D(s) = As-τ, where D(s) is relative number of microtubules with length 5, A and τ are constants. This relationship indicates the possibility of a self-organized criticality in the dynamic instability of microtubule growth
C-Methyl Flavones from the Leaf Wax of Leptospermum laevigatum (Myrtaceae)
Authors: Wollenweber Eckhard , Roitman James N.
Published: August 2018

Flavonoid aglycones were detected as minor constituents of the leaf wax of the Myrtaceae Leptosperm um laevigatum. They belong to the rarely encountered C-methyl flavonoids. One of them is a new natural product, 5-hydroxy-3,7,3′,4′-tetramethoxy-6-C-methyl flavone.
A Minimum Essential Structure of LN-3 Elicitor Activity in Bean Cotyledons
Authors: Tai Akihiro , Ohsaw Eri , Kawazu Kazuyoshi , Kobayashi Akio
Published: August 2018

A great deal of an elicitor-active oligosaccharide (1.47 g) was obtained from 40 g of poly­ saccharide laminaran with the guidance of elicitor activity in the bean cotyledon assay. Physicochemical means suggested that the oligosaccharide was a β-1,3-and β-1,6-linked triglucoside. This was a partial structure of LN-3, having elicitor activity to alfalfa and bean. The triglucoside exhibited a specific elicitor activity to bean, not to alfalfa and pea. The highly digested hydrolysate containing monom er and dimers as major components did not show elicitor activity in the bean cotyledon assay. The structural feature was essential for elicitation of phytoalexin accumulation in bean cotyledons. These results suggested that this triglucoside had a specific elicitor activity and a minimum elicitor-active entity to bean cotyledons.
Involvement of the Xanthophyll Cycle in Regulation of Cyclic Electron Flow around Photosystem II
Authors: Gruszecki W. I. , Strzałk K. , Bader K.P. , Radunz A. , Schmid G.H.
Published: August 2018

In our previous study (Gruszecki et al., 1995) we have postulated that the mechanism of cyclic electron transport around photosystem II, active under overexcitation of the photosynthetic apparatus by light is under control of the xanthophyll cycle. The combination of dif­ferent light quality and thylakoids having various levels of xanthophyll cycle pigments were applied to support this hypothesis. In the present work photosynthetic oxygen evolution from isolated tobacco chloroplasts was measured by means of mass spectrometry under conditions of high or low levels of violaxanthin, being transformed to zeaxanthin during dark incubation in an ascorbate containing buffer at pH 5.7. Analysis of oxygen evolution and of light-induced oxygen uptake indicate that the de-epoxidation of violaxanthin to zeaxanthin results in an increased cyclic electron transport around PS II, thus dimishing the vectorial electron flow from water. An effect similar to de-epoxidation was observed after incubation of thylakoid membranes with specific antibodies against violaxanthin.
The Light-Stimulated Cytosolic Calcium Transient in Limulus Ventral Nerve Photoreceptors: Two Components in the Rising Phase
Authors: Stommel Georg , Dorlöchter Marlies , Rüsing G abriele , Stieve Hennig
Published: August 2018

1. Light-evoked electrical responses were measured in Limulus ventral nerve photoreceptors simultaneously with changes in the cytosolic free calcium concentration, by means of arsenazo III.

2. It has been shown here for the first time that the rise of the arsenazo signal consists of two phases. Only the slow phase in the rise of the signal depends on the membrane voltage. The reversal potential of the amplitude of this slow rising phase was about +196 mV. After removal of external calcium the reversal potential was about +20 mV.

3. When Na+ in the superfusate was replaced by Li+, the amplitude of the fast rising phase was reduced on the average to 50%, while the slow rising phase was not affected.

4. We conclude that the fast rising phase is caused by release of calcium from internal stores while the slow increase in [Ca2+]i is due to influx across the plasma membrane, possibly through light-activated ion channels.
Bi-and Triflavonoids of Representative Moss Species from Six Different Families
Authors: Zinsmeister Hans Dietmar , Weyand Judith , Voigt Ariane , Seeger Tassilo , Geiger Hans
Published: August 2018

The identity of the bi- and triflavonoids of six moss species from six different families has been proved by NMR. The individual flavonoids are: 3′, 3‴-binaringenin, 5′, 3‴-dihydroxy-amentoflavone, 5′, 3‴-dihydroxyrobustaflavone, campylopusaurone, aulacomniumtriluteolin, philonotisflavone, dicranolomin, and 2, 3-dihydrodicranolomin.
Temperature Dependence of the O2-Oscillation Pattern in the Filamentous Cyanobacterium Oscillatoria chalybea and in Chlorella kessleri
Authors: Burda K , He P , Bader K. P , Schmid G. H
Published: August 2018

Five characteristic discontinuities of the pattern of oxygen evolution have been detected for the filamentous cyanobacterium Oscillatoria chalybea in the temperature range of 0°C to 30°C. The temperatures at which these discontinuities occur are: ≈ 5°C, ≈ 11°C, ≈ 15°C, ≈ 21°C and ≈ 25°C. The calculated initial 5-S state distribution, the miss parameter and the fraction of the fast transition S3 → S0+ O2 are affected. The discontinuities are observed at the same transition temperature also for Chlorella kessleri hence are not specific for the cyanobacterium. Based on these studies it is concluded that the not vanishing oxygen signal under the first flash of a flash train in Oscillatoria cannot have its origin in interactions between oxygen-evolving complexes. A decrease of temperature should slow down the expected charge exchanges, improve the oscillations, thus reduce or lower the first two oxygen amplitudes of the oscillatoria pattern. Lowering of the temperautres improves the oscillations but does not lower the first O2 signal of the pattern.
Human Neutrophil Chemotaxis in Response to Diepoxides of Linolenic Acid
Authors: Scheick C , Spiteller G , Fröhlich W
Published: August 2018

Diepoxides of linolenic acid were found to be chemoattractants. The concentration that produces 50% of maximal chemotaxis was 4.5 10-7 mol/l for human neutrophils when investigated in a chemotaxis test based on the method of spectrophotometric determination of myeloperoxidase activity with buffers containing bovine serum albumin. Leukotriene B4 was used as positive control. The concentration of leukotriene B4 that produces 50% of maximal chemotaxis was 1.8 nmol/l. No chemotactic activity was observed when monoepoxides of linoleic or linolenic acid, diepoxides of linoleic acid or triepoxides of linolenic acid were used. Mono-, di-and triepoxides of polyunsaturated fatty acids were synthesized with meta-chloroperbenzoic acid, separated by TLC and HPLC and identified by GC/MS.
Crystallization of Intact and Subunit L-Deficient Monomers from Synechocystis PCC 6803 Photosystem I
Authors: Jekow Petra , Schubert Wolf-Dieter , Fromme Petra , Kruip Jochen , Chitnis Parag R. , Rögner Matthias , Saenger Wolfram
Published: August 2018

Photosystem I monomers from wildtype cells of Synechocystis PCC 6803 and from a mu­ tant deficient in the psaL gene were crystallized. PsaL encodes for the hydrophobic subunit L, which has been proposed to constitute the trimerization domain in the PS I trimer. The absence of subunit L facilitated crystallization of the PS I monomer. The unit cell dimensions and the space group for the crystals from this preparation could be determined to be a = b = 132 Å , c -525 Å, α = β = 90°, y = 120°, the space group is P61 or P65. The results show the potential of using specifically designed deletion mutants of an integral membrane protein for the systematic improvement of crystal structure data.
Photosynthesis and Transpiration in Damaged and Undamaged Spruce Trees
Authors: Wild Aloysius , Sabel Peter , Wild-Peters Lucia , Schmieden Ursula
Published: August 2018

The investigations presented here focus on the CO2/H2O gas exchange in damaged and undamaged spruce trees while using open-air measurements as well as measurements under defined conditions in the laboratory. The studies were performed at two different sites in the Hunsrück and the Westerwald mountains. In the laboratory the CO2/H2O gas exchange was measured on detached branches under controlled conditions in the course of two years. CO2 saturation curves were also generated. In addition CO2 compensation points were deter­ mined employing a closed system. In the natural habitat diurnal course measurements of photosynthesis and transpiration as well as light-saturation curves for photosynthesis were performed. In parallel with the photosynthesis and transpiration measurements, measurements of the water potential were taken at both locations. The photosynthetic capacity and transpiration rate show a typical annual course with pronounced maxima in spring and late summer and minima in summer and winter. The needles of the damaged trees exhibit higher transpiration rates and a distinct reduction in photosyn­ thesis than the needles of the undamaged trees during two seasons. The diurnal course measurements of net photosynthesis and transpiration show a maximum in photosynthesis and transpiration in the afternoon in May and September, but a characteristic midday depression in July. Photosynthesis was markedly lower and transpiration higher in the needles of the damaged trees. The damaged trees show a lower increase in the light and CO2 saturation curves and higher CO2 compensation points as compared to the undamaged trees. The water potential reaches much lower values during the course of the day in needles of the dam­ aged trees. The reduction of the photosynthetic rate on one hand and the increase in transpiration on the other hand result in an extreme lowering of the water use efficiency in photosynthesis. The damage to the thylakoid membranes and to the guard cells obviously results in a pro­ found disturbance of the physiological homeostasis of the needles and could thus lead to premature needle loss.
Interaction of Penicillin G with the Human Erythrocyte Membrane and Models
Authors: Suwalsky M. , Villena F. , Aguilar F. , Sotomayor C. P.
Published: August 2018

Penicillin G (PEN) is a widely used antibiotic whose mechanism of action is related to the interference with the synthesis of bacteria cell wall. In order to evaluate its perturbing effect upon human cell membranes PEN was made to interact with human erythrocytes, isolated resealed human erythrocyte membranes and molecular models. The latter were multibilayers of the phospholipids dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidyl-ethanolamine (DMPE) as well as DMPC large unilamellar vesicles. These studies were per­ formed by scanning electron microscopy, fluorescence spectroscopy and X-ray diffraction methods. The observed results coincide in that PEN did not exert any significant effect upon the structures of the red cell membrane neither on its molecular models. This is in agreement with its reported lack of major toxicity and hem atological reactions.
Optimization of Fast-Fluorescence in situ Hybridization with Repetitive α-Satellite Probes
Authors: Durm Markus , Haar Frank-Martin , Hausmann Michael , Ludwig Horst , Cremer Christoph
Published: August 2018

A rapid FISH (fluorescence in situ hybridization) technique (Fast-FISH) for quantitative microscopy has been recently introduced. For highly repetitive D N A probes the hybridization (renaturation) time and the number of necessary washing steps were reduced considerably by omitting formamide or equivalent denaturing chemical agents. Due to low stringency conditions major and minor binding sites of the probes used showed visible FISH signals well suited for quantitative image-microscopy. The discrimination of minor and major binding sites was possible by automated image-processing. Here, a further, quantitative optimization of the Fast-FISH technique is described that allows to clearly discriminate major and minor binding sites of a-satellite probes by an easy image classification parameter. With respect to the optimization it was necessary to verify two sensitive parameters (hybridization time and temperature) of the given rapid FISH protocol. A s examples the systematic optimization for the two probes D 12 Z 2 (major binding site on the centromere of chromosome 12) and D 8 Z 2 (major binding site on the centromere of chromosom e 8) are shown. The optimal hybridiza­tion conditions concerning rapidness and quality of chromosome morphology were obtained using a hybridization temperature of 70 °C and a hybridization time of 60 min. For these conditions major and minor binding sites were clearly discriminated by the intensity maxi­ mum Smax of the corresponding FISH-spots.
Catecholate Siderophores from Chryseomonas luteola
Authors: Adolphs M. , Taraz K. , Budzikiewicz H.
Published: August 2018

Two catecholate siderophores (chrysobactin and chryseomonin) were isolated from an iron-deficient culture medium of Chryseomonas luteola. Their structures were elucidated by chemical degradation studies and spectroscopic methods, especially 2D-NMR techniques, and confirmed by synthesis. Chryseomonin constitutes a novel type of catecholate siderophore.
Does the B820 Subcomplex of the B880 Complex Retain Carotenoids?
Authors: Moskalenko Andrey , Toropygina Olga , Kuznetsova Nina
Published: August 2018

A study is reported on the modification of the B880-RC assembly of Chromatium minutissimum during octyl-β-D -glucopyranoside/dodecyl-β-D -maltoside/Deriphat polyacrylamide gel electrophoresis followed by electroelution with dodecyl-β-D-maltoside and high performance liquid chromatography with octyl-β-D-glucopyranoside according to the method developed by Kerfeld et al. (Biochim. Biophys. Acta 1185, 193-202 [1994a]) for isolation of the B820 subcomplexes of Chromatium purpuratum. The B880-RC assembly of Chromatium minutissimum isolated by electrophoresis was contaminated by the B 800-850 complex. It was further separated into four components, three of which were in agreement with the cited work: (i) colorless contaminations, (ii) the B880-RC assembly, (iii) the B 800-850 complex. In contrast with Kerfeld et al. (1994a), the fourth band was a band of free pigments (Bchl or Bchl-t-carotenoids) which had the same molecular mass as the B820 subcomplex of Chromatium purpuratum.

For comparison, the B880-RC enriched fraction of Rhodospirillum rubrum modified by lyophilization in the presence of octyl-β-D-glucopyranoside with or w ithout carotenoids was separated by high performance liquid chromatography with octyl-β-D-glucopyranoside. The apparent molecular mass of the B820 subcomplex was 30 kD a for the sample without carotenoids and 245 kD a for that with carotenoids.

The common principles of organization of the B880 complex, the interaction of the B 800- 850 complex with the B880-RC assembly, the participation of carotenoids in the stabilization of the B880 complex structure and the ability of different isolation steps to modify the structure of the B880 complex are discussed. It was concluded that there are other explanations for the presence of carotenoids in the B820 subcomplex. Hence, the question of whether the B820 subcomplex retains carotenoids remains open.
On the Determination of the 5-State Distribution in the Kok Model
Authors: Burda K. , Schmid G. H.
Published: August 2018

We use the Markow chain theory to analyze the oscillation pattern of oxygen evolution during water oxidation in photosystem II under short saturating light flashes. We propose a method based on the standard least square deviation (test X2) to determine the number of 5-states in the Kok model. As pointed out by Burda et al. (1995) this information is amongst others important for the interpretation of the role of calcium for oxygen evolution. A specific mathematical representation for a situation when the S4 state is longer living than generally assumed is introduced which requires an explicit extension of the Kok model to five states. The higher stability is modelled by introducing additional decay channels, e.g. a nonvanishing probability for the transition of S3 to the S0 state and a further transition probability for the transition from S3 to S4. Our analysis is extended to the case of damped oscillations of oxygen evolution caused, for example, by the lack of electron acceptor or the short life time of photosystem II particles.
The Exocrinology of the Queen Bumble Bee Bombus terrestris (Hymenoptera: Apidae, Bombini)
Authors: Hefetz Abraham , Taghizadehr Timo , Francke Wittko
Published: August 2018

Chemical analyses are presented of prominent exocrine glands of queen Bombus terrestris including mandibular, labial and hypopharyngeal glands in the head, Dufour’s gland and tarsal glands. A plethora of about 500 substances were identified belonging to various ali­phatic compounds including hydrocarbons, various classes of esters, alcohols, methyl ketones and fatty acids. A group of chiral hydroxy acids and their butanoic acid esters are reported for the first time in bees.
The Subcomplex Organization of the Major Chlorophyll a/b-Protein Light- Harvesting Complex of Photosystem II (LHCII) in Barley Thylakoid Membrane
Authors: Jackowski Grzegorz
Published: August 2018

The major chlorophyll a/b-protein light-harvesting complex of photosystem II (LHCII) isolated form barley photosynthetic membrane was shown to contain five major polypeptides only two of which (26.7 and 25.6 kDa) were found to be its true constituents as judged by the ability to migrate as oligomers in various analytical systems. When analyzed by a vertical-bed non-denaturing isoelectric focusing the LHCII was resolved into five trimeric subcom­plexes (designated 1 -5 in order of decreasing p I) containing either only 26.7 kDa polypeptide (subcomplexes 1 and 2) or 26.7 and 25.6 kDa ones associated at 2:1 ratio (subcomplexes 3 -5) . The polypeptide of 26.7 kDa could be split by denaturing isoelectric focusing into fifteen molecular forms while nine molecular species were found to be constituents of 25.6 kDa polypeptide. The subcomplexes 1 -5 contained molecular forms of one or both polypep­ tides associated in sets of 7 -9 .

Our findings favour the view that the apoproteins of LHCII are much more heterogenous than thought before.
Senescence-Related Changes in the Subcomplex Arrangement of the Major Light-Harvesting Chlorophyll a/b-Protein Complex of Photosystem II (LHCII) as Influenced by Cytokinin
Authors: Jackowski Grzegorz
Published: August 2018

The major light-harvesting chlorophyll a /b -protein complex of photosystem II (LHCII) from fresh barley leaves could be resolved by non-denaturing IEF into five trimeric subcomplexes designated 1 -5 in order of decrasing pi value. IEF-based analysis of PSII particles isolated from leaves in which the processes of senescence were induced by detachement and dark-incubation in the presence of water for 0 -8 days let us reveal that substantial rearrangements of LHCII organization took place throughout the course of senescence comprising a step-wise decline in relative abundance of subcomplexes 1 -3 (down to 0-58% of the initial abundance during 8 days of aging) and an increase in the relative abundance of the subcomplexes 4 and 5. Using SDS-PAGE and immunoblot analysis it was shown that the rearrangements were linked to the changes in the relative levels of LHCII apoproteins i.e. 26.7 and 25.6 kDa ones. The changes comprised the preferential disappearance of the 26.7 kDa polypeptide and an enrichment of 25.6 kD a one and most probably reflect the hetero­ geneity among LHCII apoproteins concerning their stability under the conditions of chi loss. Kinetin was able to repress the senescence-related rearrangements in LHCII subcomplex organization at late stages of aging (5 -8 days) by preventing over this time period the disappearance of 26.7 kD a polypeptide and the enrichement of 25.6 kDa one.
Lachnellins A, B, C, D, and Naphthalene-l,3,8-triol, Biologically Active Compounds from a Lachnellula Species (Ascomycetes)
Authors: Semar Martin , Anke Heidrun , Arendholz Wolf-Rüdiger , Veiten Robert , Steglich Wolfgang
Published: August 2018

In the course of our search for new biologically active metabolites, lachnellin A (1), a metabolite with high cytotoxic and antimicrobial activities, the structurally related lachnellins B, C and D (3, 4, 7), and naphthalene-1,3,8-triol (8), an inhibitor of malate synthase (EC 4.1.3.2), were isolated from submerged cultures of the ascomycete Lachnellula sp. A 32 -8 9 . The antimicrobial, cytotoxic and phytotoxic activities of lachnellin A depended on its reactivity and could be abolished by the addition of cysteine. The enzyme inhibiting activity of (8) was due to reactive intermediates during melanization and was no longer observed in the presence of serum albumin. In addition, rac-scytalone (9), (+)-trans-3,4-dihydro-3,4,8-trihy-droxy-1(2H)-naphthalenone (10). 2,5-dihydroxytoluene (11), and (R)-(-)-5-methylmellein (12) were obtained from the same source and biologically characterized.
Solid Phase Micro Extraction Technique Used for Collecting Semiochemicals. Identification of Volatiles Released by Individual Signalling Phyllonorycter sylvella Moths
Authors: Borg-Karlsona Anna-Karin , Mozuraitis Raimondas
Published: August 2018

The SPME (solid phase micro extraction) technique was used in the collection of volatiles released by calling females of the 4 -6 mm long tentiform leafminer moth Phyllonorycter sylvella (Lepidoptera, Gracillariidae). The volatiles released by the calling P. sylvella females were identified by GC-M S as a mixture of Z10-tetradecenyl acetate (92 %), E10-tetrad ecen yl acetate (2 %) and Z8 -tetradecenyl acetate (6 %). The amount of volatiles released by one calling female during three hours and collected on a polydimethylsiloxane fibre, was as large as the amount extracted from the glands of 20 females. The SPME technique gives the opportunity of continuously following the release of behaviour mediated signals from weak scented living organisms.
Stress Factors Enhancing Production of Algal Exudates: a Potential Self-Protective Mechanism?
Authors: Maršálek Blahoslav , Rojíčková Renata
Published: August 2018

Algae are known to produce extracellular organic substances under optimum conditions and increase their production under stress. The changes in amount and composition of extracellular carbohydrates and proteins of three green algae Scenedesmus quadricauda, Chlorella kessleri and Raphidocelis subcapitata (known as Selenastrum capricornutum) were studied after a 5-days’ cultivation under the influence of different types of stress factors (osmotic, organic, and heavy metal stressors). NaCl enhanced the quantity of carbohydrates more than proteins. A higher increase of proteins than carbohydrates was observed after addition of 3,5-dichlorophenol, glyphosate and cadmium chloride to algal cultures. The production of dissolved organic matter differs from species to species, with the age of a culture and the type of stressor
Extracts from Viscum and Crataegus are Cytotoxic against Larynx Cancer Cells
Authors: Sáenz M. T. , Ahumada M. C. , García M. D.
Published: August 2018

The effects of hexanoic extracts of Viscum cruciatum Sieber parasitic on Crataegus mono­gyna Jacq. (I), Crataegus monogyna Jacq. parasitized with Viscum cruciatum Sieber (II), and Crataegus monogyna Jacq. non-parasitized (III), and of a triterpenes enriched fractions isolated from I, II and III (CFI, CFII, CFIII respectively), on the growth of HEp-2 cells have been evaluated. All the samples demonstrated significant cytotoxic activity against cultured HEp-2 cells, and all of them showed a stronger in vitro activity than 6-mercaptopurine solution used as a positive control. With the hexanoic extracts I, II and III almost similar activity was obtained, but the hexanoic extract I showed comparably better results. Almost complete inhibition was observed with triterpenes-enriched fractions CFI, CFII and CFIII, at the dose 6 μg/ml, after 72 h of treatment. The most intense response was obtained with the triterpenesenriched fraction CFIII (from Crataegus monogyna non-parasitized), where the inhibition was 93%, but the fraction CFI and CFII showed similar inhibition (92% and 83%).
Effect of Platinum(II) Complexes of 4-Methoxy-and 4-Chlorobenzoic Acid Hydrazides on Saccharomyces cerevisiae
Authors: Tabakova Svoboda , Dodoff Nicolay
Published: August 2018

This study reports the anti-yeast effect of the 4-methoxybenzoic acid hydrazide (pmbah), 4-chlorobenzoic acid hydrazide (pcbah) and their Pt(II) complexes: cis- [PtL2X2] and cis- [PtL(NH3)Cl2] where L is either pcbah or pmbah and X is Cl, Br or I. MICs of the 4- substituted analogues (20 000-625 μм) are much lower than those of the previously reported benzoic acid hydrazide and 3-methoxybenzoic acid hydrazide. Complex formation results in significant increase of potency which may be due to a change in the mechanism of action, but the MIC (>400-50 μм) and the IC50 (>400-1 μм) values show that higher activity of the ligands in the free state does not result in enhanced complex activity. Differences in the potency of iodo-, chloro- and bromo complexes suggest MIC and IC50 values may be in correlation with the stability of the complex, rather than with the activity of the free ligands. Osmotically unstable mutants were more susceptible to the compounds than their parent strains, but differences among the parent strains were greater.
Thiodiacetic Acid -a Metabolite of Ethylene Oxide
Authors: Scheick C. , Spiteller G. , Dasenbrock C.
Published: August 2018

Urine samples of premature babies contain high amounts of thiodiacetic acid (TDA). Since these pre-term infants are exposed to an increased oxygen atmosphere in the incubator, we supposed that these high levels of thiodiacetic acid might be produced from ethylene, generated in the course of lipid peroxidation processes. Considering that conversion of ethylene to ethylene oxide (EO) is well known in biology we investigated whether ethylene oxide is metabolised to thiodiacetic acid or not. Therefore Sprague-Dawley rats and NMRI mice were exposed to ethylene oxide for six hours. Urine specimens were collected after exposure and the amount of thiodiacetic acid was determined by gas chromatography/mass spectrometry. The quantity of excreted TDA increased enormously compared to control samples. So thiodiacetic acid seems to be a metabolite of ethylene oxide in vivo.
Identification of Lactobacillus Species Associated with Selected African Fermented Foods
Authors: Olasupo N. A. , Olukoya D. K. , Odunfa S. A.
Published: August 2018

Two hundred isolates of Lactobacillus were obtained from seven indigenous fermented foods namely: 'fufu' (fermented cassava), 'iru' (fermented African locust bean), 'kenkey' and 'ogi' (fermented maize), 'kunu-zarki' (fermented millet), 'ugba' (fermented African oil bean) and 'wara' (fermented skimmed cow milk). Lactobacillus species identified were Lacto­ bacillus casei (17.0%), L. lactis (4.5%), L. plantarum (41.5%), L. brevis (11.5%), L. jensenii (5.5%), L. acidophilus (3.5%) L. cellobiosus (5.0%), L. delbrueckii (2.5%), L. salivarius (3.5%), L. leichmannii (3.5%) and L. fermentum (2.0%). The commonest species isolated was L. plantarum. This paper highlight the importance of Lactobacillus in the processing of African fermented foods.
Effects of Compatible Solutes on Mammalian Cytochrome P450 Stability
Authors: Kühn-Velten W. Nikolaus
Published: August 2018

The sensitivity of pig cytochrome P450cl7 (CYP17), an endoplasmic reticulum membrane-bound enzyme, towards heat denaturation (48 °C) was measured by the P450-to-P420 spectral transition indicating conforma­tional labilization of the protein. Both sucrose and glucose have comparable and increasingly protective effects at concentrations ranging from 100 to 800 mм, while ectoine, a novel zwitterionic compatible solute which regulates bacterial osmoadaptation and stabilizes cytoplasmic enzymes, has a strong labilizing effect on CYP17 and favours its proteolytic inactivation possibly by electrostatic derangements. Sucrose or glucose, but not ectoine, can therefore eventually be proposed as compatible stabilizers of cytochrome P450 structures.
Identical Pyoverdines from Pseudomonas fluorescens 9AW and from Pseudomonas putida 9BW
Authors: Budzikiewicz H. , Kilz S. , Taraz K. , Meyer J.-M.
Published: August 2018

Pseudomonas fluorescens, Pseudomonas putida, Pyoverdine, Siderophore, Bacterial Classification From Pseudom onas fluorescens 9AW and from Pseudomonas putida 9BW identical pyo-verdine-type siderophores were isolated and their structures were elucidated by spectroscopic methods and degradation studies. These novel compounds are of interest as they contain L-threo-β-hydroxy histidine in their peptide chains, an amino acid sofar encountered in nature only rarely. The co-occurence of the same pyoverdine in different Pseudom onas species and its significance for the classification is discussed.
1-O-trans-Cinnamoyl-β-ᴅ -glucopyranose: Alcohol Cinnamoyltransferase Activity in Fruits of Cape Gooseberry (Physalis peruviana L.)
Authors: Latza Stefan , Berger Ralf G.
Published: August 2018

Methyl and ethyl cinnamate are aroma volatiles frequently occurring in fruits. Evidence was obtained that the enzymatic transfer of cinnamic acid to endogenous alcohols present in fruits (methanol, ethanol, 1-propanol) depended on energy-rich 1-O-glycosyl esters of cinnamic acid which served as acyl donor molecules. A putative 1-O-trans-cinnamoyl-β-ᴅ-gluco-pyranose; alcohol cinnamoyltransferase from cape gooseberry (Physalis peruviana L.) was active towards 1-O-trans-cinnamoyl-β-ᴅ-glucopyranose and 1-O-trans-cinnamoyl-β-ᴅ-gentiobiose. The enzyme was purified 290-fold by a protocol including ammonium sulphate precipi­tation, solubilization by Triton X-100, gel permeation and affinity chromatography on concanavalin A. The acidic glycoprotein (pI = 4.8) most probably is membrane bound. The distribution of alcohol cinnamoyltransferase activity in gel chromatography fractions suggests a native Mr of 75,000. For 1-O-trans-cinnamoyl-β-ᴅ-glucopyranose, an apparent Km of 69 μm was determined. At pH > 6.0, non-enzymatic transesterification superposes the enzymatic transformation.