bluuebunny/crossref_metadata_2025 huggingface dataset:
High Performance Liquid Chromatographic Identification of Anthocyanins
Authors: Strack Dieter , Akavia Naaman , Reznik Hans
Published: August 2018

A high performance liquid chromatographic procedure for a rapid identification of antho- cyanins is described. Besides their characteristic retention times, anthocyanins can easily be identified by an HPLC examination of the kinetics of appearance and disappearance of their partial hydrolysis products. This method is also applicable to 3-deoxyanthocyanins which is demonstrated with an extract from the fern Blechnum brasiliense.

The described method allows optimal resolution of complex anthocyanin mixtures in the fol­lowing sequence of elution: 3-sophoroside-5-glucoside; 3-rutinoside-5-glucoside; 3,5-diglucoside; 3-sophoroside; 3-galactoside; 3-glucoside; 3-rutinoside; 5-glucoside; aglycone, and finally the forms acylated with p-coumaric acid. Substitution in the B-ring of the aglycone structure is the key factor for the range of the retention time. Thus cyanidin 3,5-diglucoside elutes earlier (-38 sec) than pelargonidin 3-sophoroside-5-glucoside.
Influence of Medium Composition on the Formation of Secondary Compounds in Cell Suspension Cultures of Catharanthus roseus (L.) G. Don
Authors: Knobloch K.-H. , Berlin J.
Published: August 2018

Cell suspension cultures of Catharanthus roseus have been subjected to various media condi­tions in order to stimulate the formation of indole alkaloids. High ajmalicine contents (up to 0.5 mg/g cell fresh weight) were achieved by transferring 2-week-old cell suspensions to a 10-fold volume of a 8% sucrose solution. The alkaloid accumulation started two days after the transfer and reached a plateau after ten days. Furthermore an enhanced level of phenolic compounds was found, whereas growth of the culture was low. The accumulation of both, alkaloids and poly­phenols was stimulated by high concentrations of sucrose and low concentrations of nitrogen con­taining salts and phosphate. When these minerals were added to the sucrose solution in con­centrations commonly used for cell culture media, the accumulation of alkaloids and phenolic compounds was largely suppressed.
Complex Formation of Carnosine with Purine Nucleotides in Aqueous Solution
Authors: Neurohr Klaus J. , Mantsch Henry H.
Published: August 2018

This 1H-NMR study provides experimental evidence for an intermolecular interaction between the dipeptide camosine (β-alanyl-ʟ-histidine) and the purine nucleoside 5′-monophosphates 5′-AMP, 5′-IMP and 5′-GMP. From the observed upfield shifts of the purine nucleotide and imidazole proton resonances it is concluded that the interaction is of the stacking type and that it involves the purine base of the nucleotide and the histidine moiety of camosine. Apparent microscopic equilibrium constants and complex shifts are obtained with a microscopic model, which considers the formation of both 1:1 and 1:2 complexes. The stacking pattern for complex formation between the histidine moiety of camosine and the adenine moiety of 5′-AMP is constructed by Fitting the experimental 5′-AMP complex shifts to the calculated isoshielding contours for histidine.
Some Aspects Concerning Conformation of Polypeptide Chains in Proteins
Authors: Gieren Alfred , Dederer Bernhard , Schanda Friedrich
Published: August 2018

The structure of (S)-N,N′-di-tert-butyl-2-[N-(1-phenylethyl)benzamido] malonamide contains two fragments of a polypeptide chain. This compound therefore can be taken as a model substance for details of protein conformation. In the crystalline state one peptide chain of the model molecule incorporates a hydrogen bond between two adjacent nitrogen atoms in the backbone. The acceptor for the hydrogen is the pz-orbital at the proton accepting nitrogen. The occurence of such hydrogen bonds in proteins might explain some correlations found between φ and ψ torsion angles. In addition a correlation between torsion angle ψ and the bond angle τ at Cα in the backbone of polypeptide chains could be established. The model substance also contains a “frozen” back side attack of a C = O group on the tetrahedrally coordinated Cα in analogy to the SN2 substitution reaction of the Walden inversion with a trigonal bipyramidal transition state.
3-D Analysis of the Flight Trajectories of Flies (Drosophila melanogaster)
Authors: Buelthoff Heinrich , Poggio Tomaso , Wehrhahn Christian
Published: August 2018

We have developed a computer system for reconstructing and analyzing three dimensional flight trajectories of flies. Its application to the study of the free flight behaviour of the fruitfly Drosophila melanogaster is described. The main results are: a) Drosophila males only occasionally track other flies; b) in such cases the fly’s angular velocity is a function of the error angle under which the leading fly is seen; c) body saccades can be demonstrated during cruising flights; d) high angular velocities are strongly correlated with low forward velocities, probably reflecting an aerodynamic constraint of flight. The 3-D technique described may provide an adequate tool for studying the organization of the systems present in flies and for relating the free flight behaviour to previous analyses of tethered flies.
Three Dimensional Structure of the Carbohydrate Moiety of a Lipopolysaccharide. Computer Calculations
Authors: Formanek Helmut , Weidner Hermann
Published: August 2018

The cell wall of the mutant R 595 of Salmonella minnesola contains a lipopolysaccharide in which only a trisaccharide consisting of three KDO * residues is linked to a lipid termed lipid A. Considering the sterical requirements of fourteen rotation angles, we have calculated allowed conformation of this trisyccharide unit and its linkage to lipid A. The calculations have been based on averaged crystallographic data of pyranose rings, ester-, N-acetyl-, phosphate-and carboxylgroups.

Because of considerable sterical hindrance, there are unique positions for the rotation around the axes O3-C3 of the glucosamine residue and O1-C1 of KDO residue 1 as well as for the rota­tion of the N-acetylgroup at the C2-atom of glucosamine. Similarly, the rotation angle of the carboxylgroup on KDO residue 1 and the rotation angles of the phosphategroup linked to glucos­ amine are highly restricted, while a large range of angles is allowed for the bond of the ester group to glucosamine.

Chemical sequence analysis yields two possibilities for the linkage between the KDO residues 1 and 2. Linkage of O4 of KDO 1 in equatorial position is restricted to a narrow range of angles, whereas the linkage to O4 in axial -and to O3 in axial and equatorial position is unfavourable. Furtheron chemical sequence analysis suggests two ways how to link KDO residue 1 and 3. The linkage to the oxygen atom on C7 of KDO residue 1 can be described by four, the linkage to the oxygen on C6 with three rotation angles. In either case two of the rotations are highly restricted. In the first case the two remaining angles have large rotational freedom, while the second case is sterically unfavorable.

The feasibility of the computer calculations has been demonstrated by the construction of a three-dimensional atomic model.
Stimulation of Wound Reactions in Potato Tubers by Thiabendazole
Authors: Elstner E. F. , Niehuss M. , Pils I.
Published: August 2018

Thiabendazole (TBZ), an antifungal and antihelmintic benzimidazole derivative, after 6 min treatment with a 0.1 mᴍ aqueous solution enhances CO2 release in intact potato tubers for up to two hours. There are also indications for a reduced water permeability of isolated periderm layers from TBZ - treated potato tubers. Potato slices (ca. 3 mm thick) or discs (with ca. 5 mm diameter) from potato slices show enhanced ethane formation after TBZ - treatment exhibiting maximal rates ca. two hours after treatment, indicating enhanced unsaturated fatty acid peroxidation. This lipid peroxidation is not enhanced by TBZ in potato homogenates or in isolated potato mitochondria. The results of this communication might partly explain macroscopically observable, preservative effects of treatment of freshly harvested potatoes by a stimulation of certain metabolic responses after mechanical wounding.
Solution Conformation of Benzimidazole Nucleosides with the Aid of Model Analogues
Authors: Kazimierczuk Zygmunt , Stolarski Ryszard , Dudycz Lech , Shugar David
Published: August 2018

The 4,6-dibromo-and 5,7-dibromo-derivatives of 1-β-ᴅ-ribofuranosylbenzimidazole, and the 4,6-dibromo-derivative of 1-α-ᴅ-arabinofuranosylbenzimidazole, have been synthesized by condensation of the trimethylsilylated derivative of 4,6-dibromobenzimidazole with the appro­priate protected sugar in the presence of SnCl4. Application of the fusion method led to the β-ribofuranoside of 2-methyl-5,6-dichlorobenzimidazole. Two additional analogues of the biologi­cally active ribofuranoside of 5,6-dichlorobenzimidazole, viz. the 2′,3′-O-isopropylidene and the 5′-chloro-5′-deoxy derivatives have been synthesized.

Analyses of the 1H NMR spectra of the foregoing, and of previously synthesized 5(6)-mono-halogeno and 5,6-dihalogeno derivatives, were employed to determine solution conformations of these nucleosides. Conformations of the sugar rings and exocyclic groups were evaluated from vicinal proton-proton coupling constants, as for purine nucleosides. The conformation of the benzimidazole ring about the glycosidic bond was determined from the chemical shifts of the sugar protons, principally H(2′), with the aid of model analogues in fixed syn and anti conforma­tions; and, independently, from the chemical shifts of the benzimidazole ring protons, principally H(4) and H(7). The halogenated benzimidazole ribofuranosides exhibit conformations of the sugar ring similar to those for purine β-nucleosides, but differ from the latter in their preference for the conformation syn about the glycosidic bond.
Rotation of Cells in an Alternating Electric Field: the Occurrence of a Resonance Frequency
Authors: Zimmermann U. , Vienken J. , Pilwat G.
Published: August 2018

Cells suspended in a low-conducting medium were exposed to an alternating electric field whose frequency was altered between 1 kHz and 2 MHz. A resonance frequency was observed at which all suspended cells rotated about an axis normal to the field lines (when the electric field strength was larger than a threshold value of about 400 V/cm). This resonance frequency varied from species to species of cells (mesophyll protoplasts of Avena sativa = 20-40 kHz, human erythrocytes and ghost cells = 80-100 kHz, yeast cells = 140-180 kHz, Friend cells = 30-40 kHz, at room temperature).

The resonance frequency of cell rotation was observed only under specific experimental conditions which excluded interference by reversible electrical breakdown of cell membranes and by gravitational forces.

Glutardialdehyde fixed and heated cells exhibited no rotation in the frequency and field range investigated.

The phenomenon of rotation is discussed in terms of dipole orientation within the membrane.
Properties of an ATP-Fueled, Cl--Dependent Proton Pump Localized in Membranes of Microsomal Vesicles from Maize Coleoptiles
Authors: Hager A. , Helmle M.
Published: August 2018

Vesicles prepared from the microsomal membrane fraction of maize coleoptiles possess an ATP-fueled H+-transport into the vesicles. It is highly possible that the vesicles from the microsomal membrane fraction actually are unchanged, native vesicles (originating from the ER or Golgi-apparatus) that can fuse with the plasmalemma or the vacuole. Therefore, they can reflect properties of the vacuole or the plasmalemma.

The energy dependent acidification within the vesicles, which can be completely reverted through the addition of CCCP, was determined on the basis of photometric difference spectra using NR (Hager et al., Z. Naturforsch. 35 c, 794-804 1980).

The proton pumps possess a very high substrate specificity; only ATP (+ Mg2+) can be used as substrate, while GTP, ITP, UTP and CTP or other nucleoside tri- or diphosphates cannot be used.

DCCD and DES inhibit H+-ATPase completely, oligomycin has only a slight, orthovanadate no inhibitory effect at all.

The energy dependent transport of H+ across the membrane takes place only in the presence of Cl- or Br- (not as well in the presence of I-). Other anions (F-, NO-
3, SO2-
4, SCN-, IDA-, H2BO-
3 cannot cause an intravesicular acidification through ATP if chloride (or Br-) is not present.

In the presence of chloride, however, some of these anions inibit the H+/Cl--symport (J-, NO-
3, SO2-
4, SCN-, H2BO-
3). They obviously are in competitive interaction with Cl- ions for Cl--binding sites on a carrier or channel without being able to be transported themselves.

Pi, which renders the acidification of the vesicles at a low rate possible without Cl-, is the only tested anion which can augment the Cl- dependent acidification.

This supports the idea that either Pi functions as a positive effector on the Cl-transport or that a Cl-/Pi-antiporter exists which reduces Cl- accumulation and therefore facilitates the Cl- coupled H+ transport into the vesicles also.

The anion transport inhibitor, DIDS, blocks the ATP-dependent H+-transport. This again supports the idea of a relatively tight coupling between H+ and Cl- transport in a possibly electroneutral system.

The presence of monovalent cations, such as K+, Na+, Li+ and choline+, are not important for H+ transport.

The dependence of the ATP-fueled acidification of the vesicles on the same anion pattern which seems to regulate elongation growth and stomata aperture speaks for the eminent importance of the H+-pump and vesicles described in this report for growth and turgor of plant cells.
Flüchtige Terpene aus Ceratocystis fimbriata Volatile / Terpenes from Ceratocystis fimbriata
Authors: Hanssen Hans-Peter , Sprecher Ewald
Published: August 2018

The volatile metabolites of three strains of Ceratocystis fimbriata (Ascomycetes) have been investigated. In the steam distillates of Strain 835 C several monoterpene hy­ drocarbons and alcohols as well as other metabolites could be identified. Mycelial growth and accumulation of the main components have been analyzed throughout the culture period on a defined synthetic cultural medium.
New Cembranoids from Burley Tobacco
Authors: Bruemmer Ursula , Paulsen Christian , Spremberg Gunda , Seehofer Friedlieb , Heemann Volker , Sinnwell Volker
Published: August 2018

The liquid CO2-extract of aged burley tobacco was investigated for its content of diterpenoids, which are considered as important precursors of flavour constituents. Among several cembranoids, already known from various tobacco types, 4,8-dimethyl-8-hydroxy-11-(1-methyl-ethyl)-14-oxo-pentadeca-5,9-diene-4-olide, a new natural product, could be identified, evidently originating from 2,6,11-cembratriene-4,8-diol by oxidative cleavage of the 11,12-double bond with subsequent cyclization to the seco-lactone 14.
Das cyanogene Glykosid von Holcus mollis / The Cyanogenic Glycoside of Holcus mollis
Authors: Zinsmeister H. D. , Erb N. , Nahrstedt A. , Hegnauer R. , Fat L. Tjon Sie
Published: August 2018

From leaves of Holcus mollis L. the structure of the cyanogenic glycoside could be elucidated as 2-β-ᴅ-glucopyranosyloxy- 2S-butyronitrile (Heterodendrin) by means of chromatography, hydrolysis and 1H-NMR-spectroscopy. By that another example for grasses is given where obviously the general assumed biogenetic pathway starting with tyrosine is not used
Ein Programmpaket zur rechnerischen Konfor- mationsanalyse von Peptiden auf dem TR 440 / A Program Package for the Analysis of Peptide Conformations on the TR 440
Authors: Knack I. , Rohm K.-H.
Published: August 2018

The “Empirical Conformational Energy Program for Peptides (ECEPP)” by Scheraga and coworkers which calculates the conformational energies of given peptide conformations was adapted for use with the CGK TR440 computer system. New programs for energy minimization, statistical data analysis and graphical display of peptide conformations were added. In this way the range of application of the original ECEPP program was considerably extended. At the same time, its handling was greatly simplified by an improved data input/output
Analysis of Phenolic Acids by High Performance Liquid Chromatography Using a Step-Wise Gradient
Authors: Proksch Peter , Wisdom Charles , Rodriguez Eloy
Published: August 2018

A high performance liquid chromatographic method for analyzing phenolic acids on reverse phase C-18 is described. Twelve substituted benzoic and cinnamic acid derivatives as well as the parent acids were resolved in less than 25 min. Separation was achieved by using a step-wise gradient of three different solvent systems and by adding ammonium acetate for preventing intramolecular hydrogen bonding of the acids.

The applicability of the described m ethod to crude plant extracts is demonstrated with Adenostoma fasciculatum, Adenostoma sparsifolium and Phyllospadix scouleri. The percent composition of the phenolic acids within the three extracts is given.
The Pressure Dependence of the Rotation of the N-Aralkyl- pyridinium Moiety in a Synthetic NAD+ Model System Studied by High Pressure HRNMR
Authors: Hauer Johann , Lüdemann Hans-Dietrich , Verhoeven J. W.
Published: August 2018

High Pressure, NMR, NAD +-Model, Activation Volume The activation volume ⊿V* for the rotation of the N -aralkylpyridinium moiety in a synthetic NAD + model was studied by high pressure HRNMR. From the pressure dependence of the proton spectra a negative ⊿V* of -3 cm3 · mol-1 is derived. It is concluded from this result, that the rotation of the N -aralkylpyridinium ring occurs in a complex geared m otion and not in 180°-flips.
Über die Komponenten des ätherischen Öls aus Artemisia absinthium L. / On the Essential Oil Components from Artem isia absinthium L
Authors: Vostrowsky Otto , Brosche Thorolf , Ihm Helmut , Zintl Robert , Knobloch Karl
Published: August 2018

By use of 13CNM R, GC and GC-MS analysis, 60 compounds, mainly mono-and sesquiterpenes, were identified structurally from the essential oil of Artemisia absinthium L. The specific appli­ cation of 13CNMR spectroscopy enabled the structure elucidation of the components. Actually for the first time trans-sabinylacetate could be identified in the essential oil from Artemisia absinthium; it even represents a main component of the oil.
Distribution of Phenylalanine Ammoma-Lyase and 4-Coumarate: CoA Ligase in Oat Primary Leaf Tissues
Authors: Knogge Wolfgang , Beulen Christa , Weissenböck Gottfried
Published: August 2018

4-Coumarate: CoA ligase (CL) isolated from oat primary leaves shows two activity maxim a in 5 and 7 day old seedlings, the first of which corresponds with the highest flavone accumulation rate. In this plant stage most of L-phenylalanine ammonia-lyase (PAL) is located in the epidermal tissues, whereas CL dominates in mesophyll protoplasts and in the vascular elements. In the older leaves, in which PAL is only detectable in the epiderm is and in vascular elements, most of CL is located in the latter. The CL from different tissues varies significantly in substrate specificity. Investigations of intact chloroplasts from isolated protoplasts revealed that approximately half of the PAL activity can be extracted from this organelle, whereas there is no direct evidence for the existence of CL in plastids.
A Thioredoxin Activated Glutamine Synthetase in Chlorella
Authors: Schmidt Ahlert
Published: August 2018

Glutamine synthetase was partly purified from Chlorella pyrenoidosa. This enzyme activity was stimulated by dithioerythritol and 2′-3′-dim ercaptopropanol (BAL). Full activation was obtained by thioredoxins isolated from the cyanobacterium Synechococcus 6301, from spinach and by heated Chlorella extract. The apparent Km for the purified thioredoxin B from Synechococcus 6301 was determined to be 0.022 (22 × 10-9 M), suggesting a specific role for thioredoxins in regulating glutamine synthetase activity in this alga.
Isolation and Partial Characterization of the Membrane-Bound NADH Dehydrogenase from the Phototrophic Bacterium Rhodopseudomonas capsulata
Authors: Ohshima Toshihisa , Drews Gerhart
Published: August 2018

Chemotrophically grown cells of Rhodopseudomonas capsulata contain at least three different pyridine nucleotide dehydrogenases,

i) a soluble, found in the supernatant (144000 × g) of cell free extracts, NADH-dependent,

ii) a mem brane-bound, NADH-dependent, and

iii) a soluble, found in the supernatant N AD PH dependent.

The membrane-bound NADH dehydrogenase (E.C. 1.6.99.3) has been solubilized by sodium deoxycholate treatm ent of m em branes and purified 75 fold by column chrom atography on Sephadex G-150 and DEAE cellulose in the presence of sodium cholate. The native enzyme has an apparent molecular mass (Mr) of 97 000, containing polypeptides of Mr of about 15 000. The pH optim um was at 7.5. The enzyme was specific for NADH. The Michaelis constant for NADH and DCIP were 4.0 and 63 μm, respectively.

The enzyme was inactivated by FMN, riboflavin and NADH. In contrast, the soluble NADH-dehydrogenase (i) was activated by FMN.
Structure and Biosynthesis of Vitexin 2″-O-Xyloside in Silene alba
Authors: Brederode Jan van , Kamps-Heinsbroek Ria
Published: August 2018

In petals of Silene alba plants of Armenian populations, vitexin 2″-O-xyloside was demonstrated to be present. The enzyme, catalyzing the transfer of the xylose moiety of UDP-xylose to vitexin, has its optimal activity at pH 7.8. Mg2+ and Mn2+ stimulated the reaction.

The Km values were 2 × 10-5 M for vitexin and 3 × 10-5 M for UDP-xylose.
Discrimination of Two Fusogenic Properties of Aqueous Polyethylene Glycol Solutions
Authors: Krähling Hermann
Published: August 2018

Investigations on the dose response of cell fusion, induced by ionfree aqueous polyethylene glycol (PEG) solutions, reveal distinct lowest fusogenic PEG concentrations for different permanently growing mammalian cell lines. Part of the requisite PEG can be replaced by carbo­ hydrates, preserving the fusogenity of the solutions. This discriminates two effects of PEG solutions causing cell fusion: a) cell shrinkage, the required hyperosmolality of the solutions may be provided by PEG or by carbohydrates, is supposed to cause intracellular processes necessary for consolidating polycaryons; b) membrane alterations, which can not be induced by carbo­ hydrates, enable intimate cell-cell contact via particle-free membrane areas. Depending on cell line salts can not only raise the osmolality of PEG solutions but are able to co-operate with PEG in generating membrane alterations.
Effect of Isobutylmethylxanthine and Related Drugs on the Receptor Response (ERG; a-Wave) of the Frog Retina at Various Extracellular Calcium Concentrations
Authors: Leser Karl H.
Published: August 2018

Various drugs known or expected to increase the levels of cyclic nucleotides in cells were applied to isolated superfused frog retinae, and their influence on the aspartate-isolated a-wave was studied. Isobutylmethylxanthine (IBMX), triacetylguanosine (TAG), and dimethylaminopurine (DAMP) strongly influenced the responses elicited from dark-adapted retinae by flashes of light With all three drugs the response amplitude was increased, and latency and time to peak were prolonged. If, on the other hand, the retinae were light-adapted by background light of various intensities, the drugs showed different effects on the response amplitude: IBMX either did not influence the amplitude at all or even caused a decrease (4 of 6 experiments), DAMP decreased the amplitude and TAG caused an increase of the amplitude in 2 of 3 experiments. But latency and time to peak were still prolonged by all three drugs. When dark-adapted retinae were superfused with IBMX or TAG Ringer solution and simul­ taneously calcium concentration was raised, different effects of calcium on the three measured parameters of the a-wave were observed: By increasing the extracellular calcium concentration the increase of the amplitude caused by the drugs was reversed, down or even below the control level, whereas latency and time to peak remained prolonged. Thus, both an increased calcium level and light adaptation had the same effect, namely to reverse only that part of the drug effect concerning the amplitude but not latency or time to peak of the response. The data suggest that calcium and cyclic nucleotides act through different ways in the rod cells.
Unusual Flavanones from a Rare American Fern
Authors: Wollenweber Eckhard
Published: August 2018

Notholaena fendleri, Polypodiaceae, Farinose Exudate, Novel Flavanone Notholaena fendleri is a rare representative of the genus, growing mainly in Colorado/USA. The white farinose exudate on the lower surface of its pinnules is composed partly of waxy material and partly of flavonoid aglycones. The flavonoid moiety consists mainly of methyl derivatives of the flavanones naringenin and eriodictyol. The eriodictyol methyl ethers are rare compounds; eriodictyol-7 methyl ether is a novel natural flavanone. Three flavones and two flavonols are found as trace constituents only. — The farina flavonoids of N. fendleri form a very typical pattern that is characteristic for this species.
Subcellular Compartmentation of Indole-3-acetic Acid in Mesophyll Cells of Spinacia oleracea
Authors: Heilmann B. , Hartung W. , Gimmler H.
Published: August 2018

A compartmental analysis of the distribution of the plant hormone indole-3-acetic acid (IAA) was performed with mesophyll cells of spinach leaves. The results indicated that up to about 45% of the total amount of free IAA in the laminae of spinach is localized within the chloroplasts, although these organelles occupy only about 7% of the tissue volume. This distribution is due to the dissociation properties of IAA which has a pK a of 4,7. The chloroplast envelope is easily permeable for the undissociated acid (IAAH) and less permeable for the anion (IAA"). The rate of uptake of LAA by chloroplasts was linearly dependent on the IAAH concentration gradient between medium and stroma. Uptake was increased by lowering the extraplastidic pH or by alkalization of the stroma during illumination. In illuminated chloroplasts, IAA was accumulated up to 4 fold compared to the surrounding medium owing to the pH gradient between the medium (pH 7.6) and the stroma (pH 8.0). The unexpectedly high plastidic IAA concentration observed in the dark (concentration ratio stroma/medium was about 2) suggested binding of IAA to chloroplast components. Due to this binding, the IAA distribution between medium and chloroplasts must not be used for calculating the stroma pH, as is possible with ABA. However, from the different distribution of IAA in light and darkness the light-induced alkalization of the chloroplast stroma can be calculated.
Drosophila Males Produce a Pheromone which Inhibits Courtship
Authors: Tompkins Laurie , Hall Jeffrey C.
Published: August 2018

Normal Drosophila males produce a volatile pheromone which inhibits courtship. This chemical cue is not identical to the pheromone made by mated female flies, which also inhibits male sexual behavior. Mutant olfC males, which fail to respond to several organic compounds, are not inhibited by the pheromone made by males; hence, unlike normal sexually mature males, olfC males court each other vigorously.
Isolierung und Morphologische Charakterisierung des Kartoffelblattrollvirus (PLRV) / Isolation and Morphological Characterization o f the Potato Leafroll Virus (PLRV)
Authors: Blessing J. , Sarkar S.
Published: August 2018

In spite of its very low concentration, the potato leafroll virus (PLRV) can be enriched from leaf-homogenates of the infected host plant Physalis floridana by a series of separation steps and purified by ultracentrifugation through layers of cesium chloride of defined density. U nder the present experimental conditions the virus accumulates as an invisible band in a region where the density of CsCl is 1.39 ± 0.01 g/cm 3. In negatively stained preparations, the virions show a diam eter of 23 nm and some morphological criteria indicate an icosahedral symmetry.
9(11)-Fernene and Its 21-Epimer as an Epicuticular Layer on Ferns
Authors: Wollenweber Eckhard , Malterud Karl Egil , Gómez P. Luis D.
Published: August 2018

The glaucous epicuticular layer on the undersurface of the leaves of Polypodium glaucinum and the white exudate material on the lower surface of the sterile pinnae of Plagiogyra formosana is shown, mainly by spectroscopical methods, to consist of a mixture of 9(ll)-femene and 21-epi-9(l l)-femene, in both instances in a ratio of ca. 4:1. The 13C-NMR spectrum of 9(ll)-femene has been re­ corded and partially assigned.
Zur Phytochemie südamerikanischer Nephroma-Arten / The Phytochemistry of South American Nephroma-Species
Authors: Renner Bernd , Henssen Aino , Gerstner Ernst
Published: August 2018

New results on the phytochemistry of Nephroma, a genus of the lichen family Peltigeraceae are presented. Further eight species occuring in South America have been studied. Including earlier results, nine groupings of secondary metabolites within the genus are defined: The phytochemistry of pattern I is represented by N. analogicum containing ergochromes (ergochrome AB and AA), hitherto found only in members of the Parmeliaceae; pattern II: tenuiorin, methylgyrophorate, gyrophoric acid, 4-O-methyl gyrophoric acid, methylevernate, lecanoric acid, zeorin and usnic acid (represented by N. gyelnikii and N. pseudoparile); pattern III: Zeorin, 15α-acetoxy-22- hydroxyhopane and 15α-22-dihydroxyhopane (represented by N. parile and N. expallidum); pat­tern IV: stictic, constictic, hypostictic, hyposalazinic and usnic acid, zeorin and one unknown depsidone [PQ 4] (represented by N. antarcticum and N. lobuligerum); pattern V: no lichen metabolites (represented by N. resupinatum and N. plumbeum); pattern VI: perlatolic, stenosporic and glomelliferic acid, zeorin and five further metabolites being most likely O-methyl-derivatives of stenosporic and perlatolic acid (represented by N. cellulosum and N. lepidophyllum); pattern VII: usnic acid and phenarctin, including three further unknown depsides (represented by N. microphyllum and N. kuehnemanii); pattern VIII: usnic acid, phenarctin, nephroarctin and zeorin (represented by N. arcticum); pattern IX: usnic acid and 6oc-7β-22-trihydroxyhopane (represented by N. chubutense). A considerable variation in accessory compounds exists in pattern II, IV and VI which does not correlate with the variation in morphological characters.

N. patagonicum Kremp. is placed to synonymy with N. analogicum Nyl.
Spectrophotometric Isolation of Kinetically Different Pools of P-700 and Their Correlation to the Reduction of NADP by Isolated Chloroplasts *. I. The Effect of Light Quality and Intensity
Authors: Rurainski Hans J. , Gerhardt Richard , Mader Gerhard
Published: August 2018

Excitation of isolated chloroplasts in the presence of ferredoxin and NADP by repeated short flashes yields a polyphasic absorption change at 700 nm. Assuming first-order reactions, the signal may be resolved into three distinct components with average relaxation times of approxi­mately 20 μs, 150 μs and 20 ms. Their relative magnitude is dependent on experimental conditions; their spectral characteristics indicate that all three components may be ascribed to P-700.

Concurrent measurements of Y-NADPH, the flash yield of NADP reduction with an enzymatic recycling method, allowed Y-NADPH to be compared to the magnitude of each of the three P-700 components and to total P-700. In general, the data show a good correlation of NADP reduction with the sum of the μs-phases but not with the ms-phase or total P-700.

Analysis of light intensity curves (blue or far red flashes) with a mathematical model which yields maximum values for all parameters at infinite light intensity shows that in both cases approximately two moles of the microsecond component of P-700 turn over for each mole of NADPH formed. In contrast, the molar ratio of the ms-component to the yield of NADP reduction is approx. 0.2 in blue and approx. 6.3 in far red light. The data suggest that only that portion of the P-700 pool which relaxes in the microsecond range may be involved in the reduction of NADP while the ms-component is funtionally isolated from linear electron transport.
1H-NMR - und ESR -Messungen zur Struktur der Dehydroascorbinsäure und des Semidehydroascorbatradikals / 1H-NMR- and ESR-Investigations on the Structures of Dehydroascorbic Acid and the Semidehydroascorbate Radical
Authors: Sapper Helmut , Pleyer-Weber Anita , Lohmann Wolfgang
Published: August 2018

By comparing proton and electron spin resonance spec­tra of twofold and single oxidized ascorbate and acetylated derivatives therefrom it can be concluded that semidehy- droascorbate as well as dehydroascorbate are of bicyclic structure due to the formation of a furanose ring of their side chain.
Indole Alkaloids from Cell Suspension Cultures of Stemmadenia tomentosa and Voacanga africana
Authors: Stöckigt Joachim , Pawelka Karl-Heinz , Rother Ana , Deus Brigitte
Published: August 2018

Cell suspension cultures of Stemmadenia tomentosa synthesized under normal growth condition the eight major indole alkaloids: (-)-tabersonine, (-)-minovincinine, (+)-conoflorine (voaphyl-line), condylocarpine, (+)-tubotaiwine (dihydrocondylocarpine), (-)-norfluorocurarine (vin-canine), (-)-vinervine, and (-)-coronaridine. These alkaloids consist of the three different types, Aspidosperma, Strychnos and Iboga. In contrast, cultures o f Voacanga africana produced mainly one alkaloid group (Aspidosperma-type) represented by (-)-tabersonine, lochnericine and (-)-minovincinine. Therefore this cell culture seems to be qualified for investigation concerning the biosynthesis of Aspidosperma alkaloids.
A Steroid-Binding Protein from Insect Haemolymph Isolated by PhotoafTinity Labelling and Immunoadsorption
Authors: Reum Lutz , Käuser Gerd , Enderle Ulrike , Koolman Jan
Published: August 2018

Endogenous ecdysteroids as well as radiolabelled exogenous ecdysone were crosslinked to a protein when haemolymph from blowfly larvae was irradiated with UV-light under optimized conditions. This indicates that larval haemolymph of blowflies contains an ecdysteroid-binding protein.

The crosslinked ecdysteroid-protein complex was shown to form a ternary complex when mixed with ecdysteroid-specific antibodies. Formation of the ternary complex was due to a specific interaction of the binding sites of the antibodies with the steroid. This specific interaction was used to isolate the ecdysteroid-protein complex from irradiated crude larval haemolymph by immunoadsorption. The method described here represents a rapid approach for the isolation of steroid-binding proteins by a combination of photoaffinity labelling and immunoadsorption.
Tl+-Ions: Effects on the Automaticity of Sinoatrial Tissue and on dV/dtmax and iK2 of Cardiac Purkinje Fibres
Authors: chenbach C. , Wiemer J. , Ziskoven R. , Winter U.
Published: August 2018

The disrhythmic effects of thallium were investigated in various cardiac tissues to determine the primary site of intoxication with respect to ensuing arrhythmias. In isolated cardiac tissue Lameijer and van Zwieten [1] had contended that arrhythmias arise from the sinus node after thallium poisoning. To test this hypothesis we administered concentrations of Tl+ between 10"7 and 10-4 ᴍ to guinea pig sino-atrial preparations, to guinea pig papillary muscles and to sheep cardiac Purkinje fibres. In sino-artial preparations thallium provoked increases and decreases of spontaneous beat frequency which were not linked to corresponding changes in contractile force. In conductive tissue, Purkinje fibres, the inactivation kinetics of the fast sodium current and the pacemaker current iK2 were investigated by voltage clamp experiments. Here, thallium was seen to be essentially without toxic effects which could account for arrhythmias. In ventricular muscle actions potentials and contractile force were recorded simultaneously. Here again, ventricular arrhythmias are not to be expected from thallium intoxication in rather high concentrations. The findings support the view that arrhythmogenic effects of thallium are restricted to the sinus node.
Biliverdin IX α, Intermediate and End Product of Tetrapyrolle Biosynthesis
Authors: Köst Hans-Peter , Benedikt Eva
Published: August 2018

Dark-grown cells of the unicellular rhodophyte Cyanidium caldarium were incubated with 17 mmol/l 5-aminolevulinic acid in the dark. The excreted pigments were extracted with chloroform and butanol. The presence of biliverdin IX α in the chloroform-extract (besides phycocyanobilin and other pigments) was demonstrated using TLC, HPLC and chromic acid degradation. A pathway leading to phycocyanobilin is discussed. A green pigment from egg shells of Turdus merula (black bird) was also identified as biliverdin IX α with small amounts of protoporphyrin IX, using the same methods as above.
The Oxidative Degradation of ʟ-Ascorbic Acid via an α-Ketoaldehyde
Authors: Kang Sa-Ouk , Sapper Helmut , Lohmann Wolfgang
Published: August 2018

Dehydro-ʟ-ascorbic acid, the oxidation product of L-ascorbic acid, is unstable in aqueous solution and decomposed by a hydrolytic disruption of its ring structure to 2,3-diketo-ʟ-gulonic acid. It is shown by means of UV, 1H-, and 13C-NMR spectroscopy that after decarboxylation 3,4,5-trihydroxy-2-keto-ʟ-valeraldehyde, an α-ketoaldehyde, is formed. This substance is oxidized further to ʟ-erythroascorbic acid, coupled with a reduction of 2,3-diketo-ʟ-gulonic acid to L-ascorbic acid.
Separation, Partial Purification and Characterization of a Fatty Acid Hydroperoxide Cleaving Enzyme from Apple and Tomato Fruits
Authors: Schreier P. , Lorenz G.
Published: August 2018

A membrane-bound enzyme catalysing the cleavage of 13-hydroperoxy-(Z)-9,(E)-11-oc-tadecadienoic acid (13-LHPO) and 13-hydroperoxy-(Z)-9,(E)-11,(Z)-15-octadecadienoic acid (13-LnHPO) to C6-aldehydes was isolated and partially purified from apples and tomatoes. Attempts to employ Ultrogel AcA 34 and AcA 22 in a gel chromatographic purification step were partially frustrated by reaggregation phenomena. However, by using Sepharose CL-4 B an enzyme fraction (MW 200 000 Da) with lipoxygenase and fatty acid hydroperoxide cleaving activity could be separated from a high molecular-weight active eluate. By applying preparative isoelec­ tric focussing to the tomato protein we succeeded in separating the fatty acid cleaving activity from the lipoxygenase, because o f their different isoelectric points of pH 5.8 -6 .1 and pH 5.0, respectively, An 8.4-fold purification of the fatty acid cleaving activity was achieved. A pH-optimum of 5.5 and a Km-value of 2.6 × 10-5 м/1 for the 13-hydroperoxide of linoleic acid were measured. p-Chloromercuribenzoic acid (1 mм) showed significant inhibitory effect on the fatty acid hydroperoxide cleaving enzyme, but no evidence o f inhibition was found with 1 mм H2O2, KCN, DABCO and EDTA or superoxide dismutase (270 U). The maximum amount of fatty acid hydroperoxide decomposition (C6-aldehyde formation) was determined to be 59%.
Peptidoglycan and Protein, the Major Cell Wall Constituents of the Obligate Halophilic Bacterium Rhodospirillum salexigens
Authors: Tadros Monier Habib , Drews Gerhart , Evers Dierk
Published: August 2018

The obligate halophilic member of Rhodospirillaceae, Rhodospirillum salexigens, does not contain lipopolysaccharide in its thin and delicate gram-negative type cell wall. Major constituents are protein (approximately 70% of dry weight) and peptidoglycan (murein).
Growth Characteristics of in vitro Cultured Ehrlich Ascites Tumor Cells under Anaerobic Conditions and after Reaeration
Authors: Merz Reiner , Schneider Friedh
Published: August 2018

The effects of deprivation of oxygen on proliferation kinetics of in vitro grown Ehrlich ascites tumor cells were studied by means of flow cytometry. The flow cytometric results obtained by applying the BUdR-H 33 258 technique showed that 6 -8 hours after establishment of anaerobiosis cells lose their capacity for proliferation and accumulate in the late G1-phase; during this time late S cells enter the G2 compartment but do not divide while cells, which are in G2+M at the beginning of anaerobiosis divide and enter G1. Cell cycle distribution remained constant up to about 20 hours, thereafter G1-cells enter the S-phase. Up to 24 hours of anaerobiosis cell number does not change and viability of the cells was not severely affected. Recultivation under aerobic conditions of 12 hours anaerobically treated cells revealed, that the cytokinetic properties of G1 cells were not impaired, while S-phase cells after reaeration did not enter G2 but began again to synthesize DNA forming cells with a DNA content greater than 4c. S-phase cells are most sensitive to deprivation of oxygen.
Nachweis von Actinioerythrin in der Roten Seebarbe (Mullus bar bat us L.) (Pisces; Teleostei; Mullidae) / Actinioerythrin in Mullus barbatus L. (Pisces; Teleostei; Mullidae)
Authors: Czygan Franz-C. , Krüger Almuth
Published: August 2018

Actinioerythrin has been isolated together with asta-xanthin-esters and β-carotene from different samples of Mullus barbatus for the first time.
Possible Orientation of the Fatty Acid Chains in Lipopolysaccharide
Authors: Formanek Helmut
Published: August 2018

The fatty acid chains of the lipid A component of lipopolysaccharides are hexagonally packed with a lattice periodicity of 4.1 Å. The smallest subunit of this lattice consists of a disaccharide to which seven fatty acid chains are linked representing the hydrophobic part. Carbohydrates and substituted phosphate residues linked to them form the hydrophilic part of the molecule.

Because of sterical reasons and because of the necessity of a separation of hydrophobic and hydrophilic part, we could derive that the angles of the hydrocarbon chains with the planes of the two sugar residues should be as vertical as possible and the planes of both sugar residues should be approximately coplanar forming an angle of about 180° with one another.

Conformation angles for all the theoretically possible linkages of the disaccaride and of the linkages of the fatty acid residues have been calculated. Between the two-N-acylglucosamine residues theoretically β-1,4, α -1,6 or β-1,6 linkages are possible. The experimentally found β-1,6 linkage has the largest degrees of freedom for its conformation angles.
Anomalous Reduction of Cytochrome b in Highly Purified Complex III from Baker’s Yeast
Authors: Rosa Francisco F. de la , Palmer Graham
Published: August 2018

In highly purified bc1-complex from baker’s yeast, the reduction of cyt c1 and partial reduction of cyt b is obtained by catalytic amount of succinate dehydrogenase and succinate in the presence of 7 μᴍ antimycin. After the addition of ferricyanide the c1 is re-oxidized and a increase in the reduction of b is observed. Using stopped-flow we established that the oxidation of c1 by ferricyanide proceeds as a pseudo-first order reaction and the reduction of b is faster and with two phases. Our observation suggests that these two processes are not directly interconected and that other component than c1 must be the “control factor” in the anomalous reduction of cyt b. This component must be, by exclusion, the iron-sulfur protein.
Studies of Photosynthesis Inhibition by Phytoluminography
Authors: Blaich R. , Bachmann O. , Baumberger Iris
Published: August 2018

Inhibition of photosynthesis by simazine or diuron, as well as disturbance brought about by darkness, fungal infections, heat, high concentrations or lack of CO 2, lead to a luminescence of chloroplasts after irradiation with photosynthetically active light. This effect is the basis of phytoluminography, a new method which may replace in many cases the tedious procedures used at present to determine the photosynthetic capacity of living plant tissue. Both qualitative analyses of luminescence images produced by an image intensifier as well as quantitative measurements using a photomultiplier are possible.

Autoradiographic studies have shown that luminescence images of herbicide-damaged leaves are identical with autoradiographs of the same leaf obtained after labelling with radioactive CO 2. In contrast to autoradiography, phytoluminography does not damage the tested parts of plants nor is there danger of contamination. There is no need for expensive chemicals and skilled technicans, and immediate results are obtained.

Quantitative measurements of phytoluminescence after the application of simazine and diuron (DCMU) to Elodea canadensis in submersed culture showed that approximately 1 ᴍ of inhibitor per 20 ᴍ of chlorophyll (a + b) is needed to obtain maximal luminescence, which indicated total inhibition of photosynthesis.

Both luminescence and inhibition are reversible if the inhibitor is removed by dialysis.
Protochlorophyllide Photoconversion Initiates the Transformation of Reaggregated Prolamellar Body Tubules in vitro
Authors: Müller M. , Nisius A.
Published: August 2018

Completely dissolved components of native prolamellar body/primary thylakoids PLB/PT were induced to reaggregate into tubular structures in vitro. Incubation of these pchlide containing PLB-like tubules under red light with NADPH : pchlide oxidoreductase led to a specific association of the enzyme protein to the tubules. Photoconversion of the pigment initiates the dispersal of reaggregated PLB-tubules as indicated by changes in the content of their main constituent saponin.
The Sarcoplasmic Reticulum of Smooth Muscle Fibers
Authors: Raeymaekers L.
Published: August 2018

The ability of the sarcoplasmic (endoplasmic) reticulum (SR, ER) of smooth muscle cells to accumulate Ca was demonstrated by measuring the uptake of 45Ca in fibers which were chemically skinned with saponin, and by electron cytochemistry of the accumulated Ca. The Ca uptake was dependent on ATP and it was stimulated by oxalate, as it is the case in SR of striated muscle. Electron microscopy of the skinned smooth muscle preparations revealed the presence of calcium oxalate deposits in the reticulum.

The SR vesicles were isolated from several smooth muscles. The purification was carried out by taking advantage of the density increase of the SR vesicles after loading with calcium in the presence of oxalate. Among the muscles investigated the smooth muscle of the pig stomach was found to be the most suitable and it was selected for further biochemical and morphological characterization of the SR vesicles. These vesicles, which contain calcium oxalate crystals, were able to accumulate an additional amount of Ca. The Ca uptake was supported by several energy yielding substrates. Their order of potency was ATP > dATP ≃ UTP > ITP > GTP ≃ CTP. The rate of Ca uptake was two orders of magnitude slower than that in SR of skeletal muscle. The measurement of the level of phosphorylated Ca transport intermediate showed that this difference is due to smaller number of calcium transport sites per vesicle. The distribution of intramembrane particles in freeze-fractured specimens is in agreement with this conclusion.