bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phytochemische Untersuchungen an westeuropäischen Lasallia-Arten Phytochemical / Investigations on Western European Lasallia Species
Authors: Posner Birgit , Feige Guido Benno , Huneck Siegfried 
Published: August 2018

Abstract
The secondary product pattern of 38 specimens of Lasallia brigantium (Zsch.) Llano, L. hispanica (Frey) Sancho & Crespo and L. pustulata (L.) Merat were investigated by HPLC. A c­ cording to previous publications gyrophoric acid, lecanoric acid and umbilicaric acid were detected. Additionally two further unknown depsides were found. The presence of the anthraquinone skyrin, new to Lasallia, was shown for L. hispanica and L. pustulata. Skyrin is not equally distributed within the thalli but mainly concentrated in the umbilicus. In L. hispanica skyrin is located in the epihymenium, too. A correlation between secondary product pattern and thallus size or light supply does not exist.
Antifungal Antibiotics from Calcarisporium thermophilum: A New Source of 15-Azahomosterol Derivatives
Authors: Chrisp Paul , Dewick Paul M. , Boyle F. Tom 
Published: August 2018

Abstract
Two antifungal metabolites isolated from Calcarisporium thermophilum were identified as 15-azahom osterols related to the compounds previously isolated from Geotrichum Jlavo-brun-neum. By full spectral comparison with authentic 15-aza-24-methylene-D-homocholesta-8,14-dien-3 β-ol (A 25822 B) from G. flavo-brunneum, the Calcarisporium metabolites were characterized as the 4a-m ethyl-and 4,4-dimethyl-analogues of A 25822 B. Several minor members of the series were also detected, and tentatively identified by MS analysis. The 15-azahom osterols exhibited good antifungal activity towards Candida parapsiliosis, though the activities were somewhat lower than that of the 4-demethyl derivative A 25822 B. Calcarisporium thermophi­lum is the second microorganism known to synthesize these unusual 15-azahomosterol deriva­tives.
A Photosynthetic Antenna System which Contains a Protein-Free Chromophore Aggregate
Authors: Holzwarth Alfred R. , Gnebenow Kai , Gnebenow Kai , Schaffner Kurt 
Published: August 2018

Abstract
The interior of chlorosomes, the main antenna system of the photosynthesizing bacterium Chloroßexus aurantiacus, is shown to contain no proteins in a fixed ratio to BChl c and in amounts that could be significant of direct chromophore-protein complexes. This excludes non-covalent chromophore-protein complexing -that has so far been found in all other antennae -as the main organizational principle of the interior architecture for chlorosom es of chlorophyll C. aurantiacus. Rather, these antennae constitute the first case of a chromophore-chromophore aggregate functioning as a photosynthetic light harvesting system.
Phosphohydrolase Activities in Developing and Mature Dental Tissues
Authors: Warth Edda , Jeck Reinhard 
Published: August 2018

Abstract
In the course of the odontogenesis of bovine incisors several clearly distinguishable phosphohydrolase activities are observed in the pulp and in dental hard tissues. Using various substrates and inhibitors, unspecific alkaline phosphatase, two isoenzymes of acid phosphatase, Ca2+-activated ATPase and inorganic pyrophosphatase are characterized. The enzymatic activity of alkaline phosphatase in pulp and hard tissues is significantly high at the beginning of dentine and enamel mineralization. The specific activity of this enzyme decreases quite fast with the beginning of root formation, then more slowly, until it reaches a constant final value. Histochemical studies show that during mineralization the maximum of alkaline phosphatase activity is in the subodontoblasts. Lower enzyme concentrations are found in the stratum intermedium and in the outer enamel epithelium during that process.
The specific activities of ATPase, acid phosphatases and pyrophosphatase show little temporal variation during tooth development, but they also appear in a characteristic spatial pattern in the dental tissues.
Monophosphates and Cyclic Phosphates of Some Antiviral Acyclonucleosides: Synthesis, Conformation and Substrate/Inhibitor Properties in Some Enzyme Systems
Authors: Stolarski Ryszard , Ciesla Jaroslaw M. , Shugar David 
Published: August 2018

Abstract
Chemical and enzymatic procedures are described for the synthesis of the monophosphates and cyclic phosphates of the antiviral acyclonucleoside 9-(1,3-dihydroxy-2-propoxym ethyl)-guanine (DHPG), its 3-hydroxymethyl-4-hydroxybutyl analogue, the (/?)-and (S)-epimers of 9-(3,4-dihydroxybutyl)guanine, and 9-(2,3-dihydroxypropyl)guanine.
The structures, and some conformational features, of all the foregoing, were determined by 1H and 31PNMR spectroscopy. Their substrate/inhibitor properties have been examined in several enzyme systems, including ribonucleases, snake venom phosphodiesterase, beef heart and higher plant cyclic nucleotide phosphodiesterases, nuclease P1, and 3′-and 5′-nucleo-tidases. The enzymatic results are considered in relation to the mechanism of the antiviral ac­tivity of the cyclic phosphate of DHPG .
Developmental and Seasonal Variations in the Epicuticular W axes of Beech Leaves (Fagus sylvatica L.)
Authors: Prasad R. B. N. , Giilz Paul-Gerhard 
Published: August 2018

Abstract
The leaf cpicuticular waxes of beech trees (Fagus sylvatica L.) were analyzed continuously all over one vegetation period with preparations every week from April 24 to November 15. The folded leaves in buds contained hydrocarbons, wax esters, benzyl acyl esters, alcohols and fatty acids from the beginning, but not aldehydes. Aldehydes were identified only after 10 days of leaf unfolding. The biosynthesis of wax lipids was rapid in the first three to five weeks till May 30. During this time the wax lipids were doubled quantitatively and the chain length spccifity has also changed in all wax lipid classes. From June to October the composition of the wax lipid classes and also the chain length specifity remained constant with the exception of fatty acids. The biosynthesis of wax lipids was found to be very dynamic in the first five weeks and correlated with the leaf development and growth.
A Further Investigation of Phytoalexin Formation in the Genus Trifolium
Authors: Ingham John L. 
Published: August 2018

Abstract
An earlier study of phytoalexin formation in the genus Trifolium has now been extended to include a further 61 species and subspecies. Using the drop-diffusate method, isoflavonoid phytoalexins were isolated from the fungus-inoculated leaflets of 55 accessions, whilst four others produced the stilbene derivative resveratrol. Phytoalexins could not be obtained from the leaflets of two species, T. billardieri and T. grandiflorum. The pterocarpan medicarpin was the most commonly encountered phytoalexin, occurring alone or in various combinations with the known Trifolium isofjavonoids maackiain (pterocarpan), vestitol, isovestitol, sativan, isosativan and arvensan (all isoflavans). Two additional pterocarpans, 4-methoxymedicarpin from T. cherleri and T. pallescens, and 4-hydroxyhomopterocarpin also from T. pallescens, were recognized for the first time as Trifolium phytoalexins. Re-examination of T. aureum re- vealed that this species produced resveratrol as a phytoalexin and not the isoflavan vestitol as previously described.
The Herbicide Command Does Not Inhibit the Prenyl Diphosphate-Forming Enzymes in Plastids
Authors: Lützow Manfred , Beyer Peter , Kleinig Hans 
Published: August 2018

Abstract
The herbicide Comm and (2-(2-chlorophenyl)methyl-4,4-dimethyl-3-isoxazolidinone) does not affect the in vitro activities of the plastid enzymes catalyzing the steps leading from isopen­ tenyl diphosphate to geranylgeranyl diphosphate and phytoene, i.e. the isopentenyl diphos­ phate isomerase, prenyl transferase and phytoene synthase. The extractable activities of these enzymes in herbicide-treated seedlings are also not affected. Nevertheless, the synthesis of chlorophylls and carotenoids in treated seedlings is severely inhibited in vivo. The mode of action of Comm and remains still unknown.
3-Hydroxy-3-methylglutaryl Coenzyme A Reductase from Spruce ( Picea abies). Properties and Regulation
Authors: Boll Meinrad , Kardinal Angelika 
Published: August 2018

Abstract
HM GCoA reductase was identified in seedlings, callus cultures, cell suspension cultures and in needles of spruce ( Picea abies) (L.) (Karst). Activity was found in both the 18 K pellet and in the 105 K pellet with different ratios between the two fractions from the various sources. The enzyme has a pH-optimum of 7.9 and an absolute requirement for NADPH . The presence of a thiol reagent such as dithiothreitol is required for activity. Km for HM G CoA is 20 -25 μM. Detergents have differential effects on the activity.
In seedlings, enzyme activity was considerably higher in the hypocotyls than in the cotyledons. Enzyme activity was high in dark-grown and low in light-grown seedlings. When the light conditions were reversed, levels of activity adapted to the respective new conditions (increase or decline of specific activity).
Aerobic incubations of seedlings, callus cultures or needles in medium containing a carbon source, resulted in a large (up to 20-fold) transient increase of HMGCoA reductase activity. Transfer of stationary phase cell suspension cultures into new medium caused a similarly large increase of activity. A number of carbohydrates induced the enzyme, glucose, fructose and sucrose being most effective. The increase of activity was prevented by cycloheximide. All changes of activity were much more pronounced in the 18 K pellet HMG CoA reductase
Hypothesis for Structure and Oxidation State of Manganese Cluster in Oxygen-Evolving Center Deduced from Their Magnetic Properties
Authors: Nishida Yuzo , Nasu Miyuki 
Published: August 2018

Abstract
Magnetic Interaction, Manganese C om pounds, Photosystem II, Manganese Clusters Based on the investigations for the magnetic interaction in the synthetic binuclear man­ganese com pounds of (μ-oxo bridge and for results by magnetic measurements and EXA FS studies on the native enzyme, it was concluded that there are two dimeric manganese units in the oxygen-evolving center of the photosystem II. One of them is a di-(μ-oxo-bridged dimer with M n -M n distance of 2.7 Å, and it has a Mn2(III/III) oxidation state in both the S1,-and S2-states. A second binuclear unit, which we will call as X-pair, is assumed to have a Mn2(II/III) oxidation state in the S1-state, and is oxidized in the S,-to S2-state transition. The multiline ESR signal observed for the S2-state has been attributed to be due to a partially oxidized (Mn2-(III/IV) oxidation state) of the 2.7 A-pair, which should be formed through the interac­ tion between the 2.7 A-pair with Mn-,(III/III) state and the X-pair of Mn2(III/III) which is gen­ erated in the S1-to S2-state transition.
Direct Measurement of the Flight Behavior of Male Moths to Calling Females and Synthetic Sex Pheromones
Authors: Witzgall Peter , Arn Heinrich 
Published: August 2018

Abstract
The approach of male Lobesia botrana (Lepidoptera: Tortricidae) in the wind tunnel to a source of sex pheromone was studied using two video cameras connected to image processing equipment. Three-dimensional records demonstrate that the flight to calling females is quite direct compared to the zigzag flight reported for other species. Convoluted paths displaying bimodal distribution of track and course angles were only obtained with a synthetic pheromone blend consisting of E-7,Z-9-dodecadienyl acetate, E-7,Z-9-dodecadien-l-ol and Z-9- dodecenyl acetate at the proportions of 1 /0.2/0.05. This suggests that this blend is still suboptimal and that zigzag flight may be due to a lack of precision in upwind motion caused by inadequate composition of the stimulus
Enantioselective Multidimensional Gas Chromatography of Some Secondary Alcohols and Their Acetates from Banana
Authors: Schubert Vera , Diener Renate , Mosandl Armin 
Published: August 2018

Abstract
Using enantioselective MDGC the enantiomeric distribution of alkan-(alken-)2-yl-acetates from bananas is achieved. After simple acetylation their corresponding alcohols 2-pentanol, 2-hexanol, 2-heptanol an d (Z)-4-hepten-2-ol respectively are also exactly stereodifferentiated by the same method.
All compounds investigated -esters as well as alcohols -exhibit a remarkable excess of the (S)-enantiomers.
Local Anesthetic Binding to Thylakoid Membranes. Relation to Inhibition of Light-Induced Membrane Energization and Photophosphorylation
Authors: Günther Gabriele , Laasch Henrik 
Published: August 2018

Abstract
The association of the lipophilic tertiary amine and local anesthetic dibucaine with osmotically shocked chloroplasts of Spinacia oleracea L. cv. Monatol was investigated. Dibucaine, known as an effective inhibitor of thylakoid membrane energization and ATP synthesis, ex­hibited three distinct binding classes with chloroplasts: partitioning in the lipid phase of the membranes, electrostatic screening of negative electrical charges on the thylakoid surface and light-induced association of an as yet unknown nature. Evidence is presented that the mecha­nism of inhibition of the transthylakoid pH gradient, ∆pH, by dibucaine is distinct from ‘classical’ amine-type uncoupling: The inhibitory effect of dibucaine on ∆pH was independent of the initial strength of ∆pH. Light-induced dibucaine binding was independent of the volume of the intrathylakoid space and of the strength of ∆pH as varied by medium pH. Judged from a comparison of the data on dibucaine binding and on inhibition of ∆pH and photophosphorylation, dibucaine bound via partitioning in the membrane lipid phase is responsible for the uncoupler-like effects of the local anesthetic. A mechanism for the inhibition of thylakoid energization by local anesthetic amines is discussed.
Inhibitory Effect of Crown Compound on Photoelectron Transport Activity of Beet Spinach Thylakoid Membranes
Authors: Sabat S. C. , Vijayavergiya V. , Tripathy B. C. , Mohanty Prasanna 
Published: August 2018

Abstract
The effect of K-picrate-18-crown-6 (crown) on the photoelectron transport activity of beet spinach thylakoid membranes was investigated. Addition of micromolar concentration of crown to thylakoid preparation inhibited p-benzoquinone, chloride-indophenol, methyl viologen supported Hill activities maximally by 75 per cent in a concentration dependent manner. However, the photosystem I catalyzed reaction remained insensitive to crown suggesting that crown specifically inhibits photosystem II electron transport. Addition of exogenous electron donors like hydroxylamine or diphenylcarbazide failed to restore the crown induced inhibition of photosystem II electron transport and lowering of steady state chlorophyll a fluorescence yield. These observations suggest that crown also inhibits photosystem II catalyzed electron transport after the donation sites of these exogenous donors. Washing of the crown pre-treated thylakoids with isolation buffer, relieved the crown inhibited electron transport activity, indicating that this inhibition is reversible. Furthermore, in hydroxylamine washed thylakoids which are devoid of O2 evolution capacity, the hydroxylamine induced increase in chlorophyll a fluorescence of variable yield was quenched by the addition of crown. These observations suggest that crown affects the oxygen evolution and inhibits at a site close to photosystem II reaction centres.
Iridoids from Plantago carinata Schrad
Authors: Saadi Houcine , Handjieva Nedjalka , Ivanova Antoaneta , Popov Simeon 
Published: August 2018

Abstract
The new iridoid 10-acetylaucubin and the well known iridoids aucubin. melittoside and monomelittoside as well as the rare 6-epiaucubin and 3,4-dihydroaucubin were isolated from aerial parts of Plantago carinata Schrad. This is the first isolation of 6-epiaucubin from Planta-ginaceae plants and of 3,4-dihydroaucubin and monomelittoside from P. carinata Schrad.
New Triterpenes from the Frond Exudate of the Fern Notholaena rigida
Authors: Arriaga-Giner F. J. , Rullkötter J. , Peakman T. M. , Wollenweber E. 
Published: August 2018

Abstract
Two new triterpenoids, isolated from the frond exudate of the fern Notholaena rigida, have been identified as 3 β, 12 β,25-trihydroxy-(20 R-24 R)-epoxy-dammarane- 12-acetate (1), and 24 R,25-diO-isopropyliden-9(19)-cyclolanostan-3 β-ol (5), based on NMR spectroscopic studies.
New Isoflavone Glucosides from White Lupin (Lupinus albus L.)
Authors: Shibuya Yusuke , Tahara Satoshi , Kimura Yutaka , Mizutani Junya 
Published: August 2018

Abstract
Further investigation of polar constituents in white lupin roots revealed the presence of genistein 7-O-β-glucoside (1 a), genistein 4′-O-β-glucoside (1 b), 2′-hydroxygenistein 7-O-β-glucoside (2 a) and 2′-hydroxygenistein 4′-O-β-glucoside (2 b) as simple isoflavone gluco­ sides; luteone 7-O-β-glucoside (3 a), licoisoflavone A 7-O-β-glucoside (4 a) and licoisoflavone A 4′-O-β-glucoside (4 b) as prenylated (= 3,3-dimethylallyl-substituted) isoflavone glucosides; and genistein 7-O-β-(6′-O-malonyl)glucoside (1 am) and 2′-hydroxygenistein 7-O-β-(6″-O-malonyl)glueoside (2 am) as malonylated isoflavone glucosides. Six compounds (2 a, 2 b, 3 a, 4 a, 4 b, and 2 am) are new naturally occurring isoflavone glucosides.
Identification of Tropane Alkaloids in Hairy Root Cultures of Hyoscyamus albus
Authors: Doerk Katja , Witte Ludger , Alfermann A. Wilhelm 
Published: August 2018

Abstract
Tropane alkaloids are typical natural products of solanaceous plants. The patterns of these alkaloids from hairy roots of Hyoscyamus albus were determined by GC-MS analysis. 18 alka-loidal compounds were detected, six of them only in trace amounts. Some of these alkaloids, namely hygrine, 3a-acetoxytropane, 3 β-acetoxytropane and 6-hydroxylittorine as well as the trace compounds N-methylpyrrolidinylhygrine, phenylacetoxytropane and two isomers of feruloyloxytropane were not previously reported to be components of this species. The major compounds formed were found to be hyoscyamine and littorine.
Control by Light Quality of Chlorophyll Synthesis in the Brown Alga Desmarestia aculeata
Authors: López-Figueroa F. 
Published: August 2018

Abstract
The chlorophyll synthesis in the brown algae Desmarestia aculeata is affected by light quality and by the nutrient state in the medium before the illumination. Pulses of 5 min of red, green and blue light together with 200 μM nitrate in plants growing under natural conditions deter­ mined similar induction of chlorophyll synthesis. However, when the plants were incubated previously under starvation conditions the light effect was different. The induction of chlorophyll synthesis was greater after blue and green light than after red light pulses. Red-light photoreceptor was only involved in the chlorophyll synthesis under no nutrient limitations and under starvation conditions after previous illumination with blue light followed by far-red light. The induction of chlorophyll synthesis by green and blue light pulses applied together with nitrate was greater when the algae were incubated in starvation conditions than in natural conditions (normal nutrient state).
Because all light effects were partially reversed by far-red light the involvement of a phyto-chrome-like photoreceptor is proposed. In addition, a coaction between blue-and a green-light photoreceptors and phytochrome is suggested.
Photoautotrophic Cultured Plant Cells: A Novel System to Survey New Photosynthetic Electron Transport Inhibitors
Authors: Sato Fumihiko , Yamada Yasuyuki , Kwak Sang Soo , Ichinose Katsunori , Kishida Mitsuhiro , Takahashi Nobutaka , Yoshida Shigeo 
Published: August 2018

Abstract
The responses of photoautotrophic (PA) cultured cells of tobacco (Nicotiana tabacum cv. Samsun NN) and liverwort (Marchantia polymorpha L.) to thirty-eight cyclohexanedione derivatives were surveyed. Each derivative was also tested for inhibitory activity on photosynthetic electron transport (PET), using isolated thylakoids, and herbicidal activity, using seed­ lings and mature plants. Comparison of the results from the different assays showed that the responses of PA cells to each com pound correlated more closely with the responses of seed­ lings and mature plants than did the results of the Hill reaction assays. Our findings suggest that PA cultured cells would be a suitable screening material for identifying potential herbicides with PET-inhibiting activity.
Long-Term Effect of Diuron on Chlorophyllous Callus of Bromus erectus: Lipid Composition
Authors: El Kaoua Mimoun , Duval Evelyne , Laval-Martin Danielle 
Published: August 2018

Abstract
The selection of plants resistant to photosynthetic herbicides is limited by the low rate of success in obtaining a photosynthetic callus. An attempt was made to induce diuron tolerance with chlorophyllous tissue strains of Bromus erectus: growth, chlorophyll contents and total fatty acids were studied during four months of photoheterotrophic growth in the presence or absence of 6 μM diuron. The presence of the herbicide, which reduced the fresh weight by 40%, provoked increases in chlorophyll levels by 2-or 3-fold, and in galactolipids (especially DGDG) which were enriched in linolenic acid content. These results, closely related to already described characteristics of herbicide-resistant material, suggest that callus of Bromus erectus could constitute an interesting photosynthetic in vitro material.
Effect of Azide on the ATPase Activity of Isolated CF1
Authors: Minkov Ignat B. , Strotmann Heinrich 
Published: August 2018

Abstract
The effect of azide on M g2+-and Ca2+-dependent ATPase of differently activated CF1 isolated from spinach chloroplasts was studied. It is shown that Mg2+-ATPase activity is sensitive towards azide irrespective of the applied method of enzyme activation. Heat-or trypsin-acti-vated Ca2+-ATPase is also inhibited, whereas methanol-and octylglucoside-stimulated or DTT-activated Ca2+-ATPase is not affected by azide. Preincubation of the DTT-activated enzyme with low concentrations of Mg2+ induces azide susceptibility of the Ca2+-dependent ATPase.
Phenotypic Traits and Regulatory Role of RNA Folding in Molecular Selection
Authors: Fernández Ariel 
Published: August 2018

Abstract
We concentrate on instances in which the phenotypic expression of information encoded in an RNA primary sequence might be revealed by the folding of the RNA itself. We have discov­ered that this situation finds concrete realization in the design of RNA molecules capable of maximizing the rate of autocatalytic synthesis when incubated with viral Qβ-replicase. This requires that we introduce the notion of phenotypic traits at the molecular level. Thus, the problem of finding RNA sequences whose phenotype favorably influences propagation amounts to finding RNA sequences which fold so as to optimize enzymatic performance and are in addition endowed with the proper recognition sites. The proof that these two problems are indeed equivalent has two steps: First we predict the metastable folded structures formed as a template RNA chain grows by sequential incorporation of nucleotides. The transient folded states appear to be involved in the regulation of the enzyme activity and they occur in a manner which is “oblivious” of thermodynamic time scales. Secondly, we compute the time-dependent activation energy for relaxation of each intermediate structure. This is done to establish constraints necessary for optimization of the regulatory role of RNA folding. The search for prospective template sequences is subject to such constraints. Our results aim at elucidating an optimization process realized by molecular selection in de novo (template-free) RNA synthesis by Qβ-replicase. We argue that the phenotype which mediates selection is given by metastable folding which emerges together with the printing of the genotype, that is, within the time span of a replication turnover.