bluuebunny/crossref_metadata_2025 huggingface dataset:
Isoflavone Dimers from Yeast Extract-Treated Cell Suspension Cultures of Pueraria lobata
Authors: Hakamatsuka Takashi , Shinkai Kenji , Noguchi Hiroshi , Ebizuka Yutaka , Sankawa Ushio
Published: August 2018

Two new isoflavone dimers, kudzuisoflavone A and B have been isolated from yeast extracttreated cell suspension cultures of Pueraria lobata (Leguminosae). Their structures were characterized by spectral data, and they were considered to be formed by phenol oxidative coupling of two isoflavone moieties through C -C ortho-ortho and ortho-para couplings, respectively.
Surface Structures and Chemical Composition of Epicuticular Waxes during Leaf Development of Fagus sylvatica L.
Authors: Gülz P.-G. , Prasad R. B. N. , Müller E.
Published: August 2018

The surface structures of beech ( Fagus sylvatica) leaf waxes were studied by SEM and correlated with chemical compositions of the extracted wax lipids during one vegetation period. The very young leaflets just unfolding from buds contained already a wax layer without any wax sculptures or crystalloids. This wax layer is quite different in yield and composition to that of mature leaves. With the unfolding of beech leaves, a dynamic biosynthesis of several wax lipids was started, but the biosynthesis of wax esters was not continued further.

Ten days after leaf unfolding the de novo biosynthesis of aldehydes could be detected for the first time. Aldehyde amount increased rapidly to about 13% of the wax. The predominant individual wax lipids synthesized were aldehydes, alcohols and fatty acids with C28 and hydrocarbons with C27 chain lengths, respectively. The biosynthesis of wax lipids in beech leaves was completed at the end of May and remained nearly constant in quantity and com position during the remaining season.

At the same time when aldehydes were found for the first time, wax sculptures were observed on beech leaf waxes coming out of the continuous wax layer, exclusively on the upper leaf side. These wax sculptures increased in size and quantity in the following time and were present on the upper leaf side all over the season, only some wax sculptures show a trend to crystalline forms.
The Stereoisomers of Nerolidol: Separation, Analysis and Olfactoric Properties
Authors: Schubert Vera , Dietrich Armin , Ulrich Thomas , Mosandl Armin
Published: August 2018

The sesquiterpenoic alcohol nerolidol was separated into its 4 stereoisomers by MPLC of the diastereomeric (1 S, 4 R)-camphanoates.

An analytical GC method was found by which both the enantiomeric pairs of (Z)- and (E)-nerolidol are resolved on a chiral cyclodextrin stationary phase. The olfactoric properties of the nerolidol stereoisomers were investigated.
Chemical Constituents of the Lichen Stereocaulon azoreum
Authors: González Antonio G. , Rodríguez Pérez Elsa M. , Hernández Padrón Consuelo E. , Barrera Jaime Bermejo
Published: August 2018

Column chromatography of the acetone extract of the lichen Stereocaulon azoreum afforded several substances identified by chemical and spectral means; α-amyrin, lupeol, taraxerol, ursolic acid, ergosterol peroxide, brassicasterol, cerevisterol, stictic acid and an acetone-condensation derivative, lobaric acid. Furthermore atranorin, methyl β-orsellinate, atranol and, for the first time from the genus Stereocaulon, cryptostictic acid and the dibenzofuran, strepsilin were isolated.
New Triterpenes from the Frond Exudates of Some Notholaena Species
Authors: Arnaga-Gmer F. J. , Rumbero A. , Wollenweber E.
Published: August 2018

Several triterpenes were isolated from the lipophilic frond exudates of three Notholaena species. In the terpenoid portion of N. Candida we identified two novel cycloartane type triterpenes. N. rigida yielded protolyofoligenic acid, a cycloartane type product that has been reported once before from a higher plant. From N. schaffneri, a novel dammarane type compound was isolated. These products were identified by spectroscopic methods.
Chemical Composition and Surface Structures of Epicuticular Leaf Waxes of Ginkgo biloba, Magnolia grandiflora and Liriodendron tulipifera
Authors: Gülz P.-G. , Müller E. , Schmitz K. , Marner F.-J. , Güth S.
Published: August 2018

Epicuticular leaf waxes of Ginkgo biloba, Magnolia grandiflora and Liriodendron tulipifera contain homologous series of hydrocarbons, wax esters, benzyl acyl esters, aldehydes, primary alcohols, and fatty acids. None of these lipid classes is found to contain any main component dominating. In addition to these usual wax lipids, in G. biloba leaf wax a secondary alcohol namely nonacosan-10-ol (15.0%), γ-tocopherol (1.7%) and acetates (0.3%) is also present. The wax of L. tulipifera, however, contains hentriacontan-16-one (23%) and several triterpenols (10%), additionally.

On G. biloba leaves a dense arrangement of tubular wax crystalloids are found on the lower as well as on the upper leaf surface. The openings of the tubules can be seen very well in the SEM figures at a magnification of 20000. The small tubules are a clear indication for the presence of nonacosan-10-ol as also reported previously for conyferyl waxes.

Leaves of M . grandiflora have an abaxial epidermis with a continuous wax layer without any crystalloids or sculptures. The adaxial epidermis also shows a continuous wax layer but with little irregular granular sculptures.

L. tulipifera leaves show an abaxial epidermis with a continuous wax layer superimposed by a dense arrangement of crystalloids in shape of angular rodlets which are composed of several piled up layers. The adaxial leaf surface is also superimposed with wax crystalloids, the rodlets of which, however, are not sculptured in such definite way. They usually appear melted up and also form granular sculptures. The wax crystalloids in shape of angular rodlets on the abaxial surface are formed by hentriacontan-16-one. The abaxial and adaxial leaf surfaces show most different micromorphological wax ultrastructures, as shown for all trees studied.
Further Studies on the Induction of Nitrate Reductase by Arginine in the Filamentous Cyanobacterium Oscillatoria chalybea
Authors: Bednarz J. , Schmid G. H.
Published: August 2018

In an earlier publication we reported on the role of arginine for the development of nitrate reductase activity in cells of the filamentous cyanobacterium Oscillatoria chalybea (Bednarz and Schmid, Z. Naturforsch. 46c, 591 (1991)). In the present paper we present further evidence that arginine is the natural inducer for nitrate reductase activity. Thus, we show that the induction is regulated by transcription, probably related to the apoprotein or the molybdenumcofactor. We also examined the influence of arginine on nitrate reductase activity in the filamentous cyanobacterium Anabaena PCC7120. In contrast to Oscillatoria chalybea this cyanobacterium forms heterocysts and shows nitrogen fixation activity. Like in Oscillatoria chalybea nitrate reductase activity in Anabaena PCC7120 is stimulated in the presence of arginine as the sole nitrogen source. However, this stimulation is limited to an early growth stage. Subsequently, nitrogen fixation activity appears and nitrate reductase activity decreases.
Thermoluminescence Investigation of Photoinhibition in the Green Alga, Chlamydobotrys stellata and in Pisum sativum L. Leaves
Authors: Janda T. , Wiessner W. , Páldi E. , Mende D. , Demeter S.
Published: August 2018

During photoinhibitory light treatment of the green alga, Chlamydobotrys stellata and Pisum sativum leaves the amplitude of the B thermoluminescence band (S2OB
- charge recombination) decreased faster than that of the Q band (S2QA
- charge recombination). Consistently, in the alga cells the electron transport rate from water to oxidized diaminodurene (electron acceptor after Q B) was also diminished faster than that measured from water to phenyl- p-benzoquinone (electron acceptor after QA). These observations suggest that in intact photosynthetizing organisms at high light intensities on the acceptor side of photosystem II photoinhibition is initiated at the binding site of the secondary quinone acceptor, QB.
In situ Localization of Phenylpropanoid-Related Gene Expression in Different Tissues of Light- and Dark-Grown Parsley Seedlings
Authors: Wu Sheng-Cheng , Hahlbrock Klaus
Published: August 2018

Using in situ RNA hybridization and immunohistochemical techniques, we investigated the tissue-specific and light-dependent expression of four genes involved in phenylpropanoid metabolism in various parts of parsley (Petroselinum crispum) seedlings. The genes encode phenylalanine ammonia-lyase (PAL) and 4-coum arate: CoA ligase (4CL), two enzymes of general phenylpropanoid metabolism; chalcone synthase (CHS), the key enzyme of flavonoid biosynthesis; and bergaptol O-methyltransferase (BMT), a late enzyme of the furanocoumarin pathway. In young leaves, PAL and 4 CL genes were expressed predominantly and in a coordinated fashion in epidermal cells, young xylem cells of vascular bundles, and epithelial cells of oil ducts. The gene(s) encoding BMT was active exclusively in the epithelial cells of oil ducts, whereas CHS gene expression was largely confined to the epidermis. In shoot and root apices, PAL, 4CL and CHS m RNAs were detectable at low levels without distinct patterns. The corresponding proteins, however, accumulated preferentially in the protoderm and pith meristem of the shoot apex and in root-cap cells. A gene encoding pathogenesis-related protein 1 (PR 1) was analyzed in roots for comparison and was found to be expressed predominantly in the cortical cells of root tips. The expression of all genes investigated was, to a greater or lesser extent, dependent on light conditions and tissue age, with highest levels occurring in newly differentiated, light-exposed tissue. In the leaf epidermis of seedlings illuminated for 20 h, PAL and CHS mRNAs and proteins, as well as 4CL protein, were particularly abundant.
Resonance Effect of Microwaves on the Genome Conformational State of E. coli Cells
Authors: Belyaev Igor Ya. , Alipov Yevgeny D. , Shcheglov Victor S. , Lystsov Vitaly N.
Published: August 2018

The effect of low intensity microwaves on the conformational state of the genome of X-irradiated E. coli cells was studied by the method of viscosity anomalous time dependencies. It has been established that within the ranges of 51.62-51.84 GHz and 41.25-41.50 GHz the frequency dependence of the observed effect has a resonance nature with a resonance halfwidth of the order of 100 MHz. The power dependence of the microwave effect within the range of 0.1-200 (μW/cm2 has shown that a power density of 1 μW/cm2 is sufficient to suppress radiation-induced repair of the genome conformational state. The effect of microwave suppression of repair is well reproduced and does not depend on the sequence of cell exposure to X-rays and microwave radiation in the millimeter band. The results obtained indicate the role of the cell genome in the resonant interaction of cells with low intensity millimeter waves.
Composition of Propolis from Two Different Spanish Regions
Authors: García-Viguera C. , Greenaway W. , Whatley F. R.
Published: August 2018

Propolis and propolis balsam from two different Spanish Regions were analyzed by GC-MS. The majority of the compounds were typical of poplar bud exudate of P. nigra. No significant differences were found between the balsam and the entire propolis analyzed, apart from the components of beeswax added to the plant exudate by the bees.
Extracellular Production of Abscisic Acid by Soil Algae under Salt, Acid or Drought Stress
Authors: Maršálek Blahoslav , Zahradníčková Helena , Hronková Marie
Published: August 2018

The common soil green algae Chlorella vulgaris and Stichococcus hacillaris increase extracellular abscisic acid (ABA) production under salt, acid or drought stress 5 - 10 times. Production of ABA also increases from young to senescent cultures 2 - 3 times.

The relationship between age of cultures and reaction to stress factors was found. Extracellular ABA levels are 1 - 2 times higher than cellular ones.

Possible influence of ABA to soil microbial associations, growth of plants and soil fauna is discussed from an ecological point of view.
Notes: Analysis of Phenolics of Bud Exudate of Populus violascens by GC-MS
Authors: Greenaway W. , May J. , Scaysbrook T. , Whatley F. R.
Published: August 2018

Analysis of bud exudate of Populus violascens by GC-MS identified 26 phenolic components. The bulk of the exudate was composed of caffeic acid esters.
Studies on Sporopollenin Biosynthesis in Cucurbita maxima I: The Substantial Labeling of Sporopollenin from Cucurbita maxima after Application of [14C]Phenylalanine
Authors: Gubatz Sabine , Wiermann Rolf
Published: August 2018

The results of tracer experiments performed with anthers of Tulipa cv. Apeldoorn have already shown that a high level of incorporation into the sporopollenin fraction was achieved, when [14C]phenylalanine was applicated as a precursor. In order to investigate whether the substantial incorporation of [14C]phenylalanine is a unique phenomenon restricted to Tulipa, tracer experiments were carried out on anthers of Cucurbita maxima.

The sporopollenin fraction was isolated and purified by a gentle method including extractions with various solvents, incubations with hydrolysing enzymes and fractionated saponifications. The remaining, as well as the released radioactivity, was determined after each purification step. After the application of [U-14C]phenylalanine, a substantial incorporation into the sporopollenin fraction was determined. The values were clearly higher than those obtained with [1-14C]glucose or those from corresponding experiments on Tulipa anthers.

After potash fusion of sporopollenin fractions labeled via [U-14C]phenylalanine, p-hydroxybenzoic acid was shown to be the main com ponent among the ether soluble acids; moreover it showed the highest level of radioactivity.

No radioactivity was detected in the degradation products oxalic acid, benzoic acid, phthalic acid and terephthalic acid or octanedioic acid- and decanedioic acid-dimethylester.
Presence of Both Hemidiscoidal and Hemiellipsoidal Phycobilisomes in a Phormidium Species (Cyanobacteria)
Authors: Westermann Martin , Reuter Wolfgang , Schimek Christine , Wehrmeyer Werner
Published: August 2018

Hemidiscoidal and hemiellipsoidal phycobilisomes have been determined in cells of the complementary chromatically adapting cyanobacterium Phormidium sp. C86 . They could be isolated from red and green light-adapted cells, respectively. Hemidiscoidal red light phycobilisomes show molar pigment ratios of allophycocyanin: phycocyanin of 1:4.5 with phycoerythrin lacking. Hemiellipsoidal phycobilisomes induced by green light present allophycocyanin: phycocyanin: phycoerythrin ratios of 1:1:6.8. The differences between the two phycobilisome types could additionally be demonstrated by their ultrastructure and sedimentation values. Isolated red light phycobilisomes have six rods, show dimensions of 70×30×15nm and a sedimentation value of 66 S whereas green light phycobilisomes are nearly twice larger. They contain ten rods and present dimensions of 70×40×25nm and a sedimentation value of 98 S. The number of phycobilisomes in red light cells is almost twice as large as in green light cells. There is evidence that cells grown under white light contain both types as well as “intermediate” forms.
Changes of Excitation Spectra of in vivo Chlorophyll Fluorescence during Induction of Photosynthesis
Authors: Gruszecki Wieslaw I. , Krupa Zbigniew
Published: August 2018

Excitation spectra of chlorophyll fluorescence from intact rye leaves were registered at different steps of the induction of photosynthesis after dark adaptation. Analysis of these spectra indicates that at least two processes related to spectroscopic features are responsible for a fluorescence quenching. The first one, active during the first 100 s of illumination, was interpreted to consists in an overall decrease of the fluorescence quantum yield of antenna pigments and chlorophylls, in particular close to the reaction centers. The second type of a fluorescence decrease (between 100 s and 300 s of illumination) was found to be in large extent related to decrease of the rate of an excitation energy transfer between accessory xanthophyll pigments and chlorophylls emitting fluorescence. This latter molecular mechanism is discussed as being related to violaxanthin availability to de-epoxidation in the xanthophyll cycle.
New Biologically Active Compounds from the Nematode-Trappmg Fungus Arthrobotrys oligospora Fresen
Authors: Stadler Marc , Sterner Olov , Anke Heidrun
Published: August 2018

The isolation, structural elucidation and biological activities of oligosporon (1), oligosporol A(2) and oligosporol B(3), three new antibiotics from cultures of the predacious deuteromycete, Arthrobotrys oligospora, are reported. The structures were elucidated by means of high resolution mass and high field NMR spectroscopy. The compounds exhibited weak antimicrobial, cytotoxic and hemolytic effects, but were not active towards the nematode Caenorhabditis elegans. Other Arthrobotrys species were also found to produce these or similar compounds.
Occurrence of Vesicular-Arbuscular Mycorrhizal Fungi in Alberta, Canada
Authors: Boyetchko S. M. , Tewari J. P.
Published: August 2018

Three V A mycorrhizal fungal species were isolated from soils in Alberta, Canada and examined by scanning electron microscopy and energy-dispersive X-ray microanalysis. Mature spores of Glomus aggregatum developed an outer hyaline wall which contained lower levels of calcium than the middle wall. Examination of G. pansihalos spores revealed a lower level of calcium in the outer evanescent wall as compared to the ornamented wall. When spores of Entrophospora infrequens were examined, the wall of the vesicle was found to contain similar levels of calcium as the ornamented wall of the spore. The significance of the results concerning the presence of calcium in mycorrhizal spore walls is discussed, as is the occurrence of the mycorrhizal species.
Characterization of the Light-Induced Oxygen Gas Exchange from the IC 2 Deletion Mutant of Synechocystis PCC 6803 Lacking the Photosystem II 33 kDa Extrinsic Protein
Authors: Boichenko V. A. , Klimov V. V. , Mayes S. R. , Barber J.
Published: August 2018

The absence of the extrinsic Mn-stabilizing 33 kDa protein in the IC 2 mutant of Synechocystis PCC 6803 disturbs the redox cycling of the water splitting system and retards the formation of its higher S-states (I. Vass, K. Cook, S. Deak, S. R. Mayes, and J. Barber, Biochim. Biophys. Acta 1102, 195-201 (1992)). We have performed analyses of the flashinduced oxygen exchange in the mutated cyanobacterium to clarify further the role of the 33 kDa protein. Under aerobic conditions, both the wild type and IC2 mutant show a relatively slow signal of oxygen rise on the first flash which is increased about twice by the addition of 10 μᴍ DCMU and significantly diminished by lowering the oxygen concentration in the medium. According to action spectra measurements, this mode of apparent oxygen release is mediated by PS I and can be attributed to a light induced inhibition of respiratory activity. In contrast to the wild type, having the usual oxygen evolution flash pattern with a periodicity of four, the IC2 mutant shows a binary oscillation pattern of flash-induced respiratory oxygen exchange at a flash frequency 10 Hz, being dampened with DCMU or by a lower flash frequency (< 1 Hz). Oxygen evolution due to water splitting is clearly seen in the IC2 mutant when background far-red illumination is applied to saturate the signal due to respiratory inhibition, but a quadruple oscillatory component of flash-induced oxygen evolution appears only in the presence of artificial electron acceptors under partial aerobic conditions. The mutant possesses a higher PS I/PS II ratio compared to the wild type, as judged from both the flashinduced yields and quantum efficiencies of the steady-state rates of the oxygen exchange reactions. Estimates of antenna sizes indicate about a 20% decrease of optical cross-section at 675 nm of the PS II unit in IC2 mutants in comparison with the wild type. It is suggested that the absence of the 33 kDa protein leads to a modification of the PS II assembly and because of the slowing down of the S-state cycle, the rate of cyclic electron flow around PS II is enhanced. It seems that the absence of the 33 kDa protein in Synechocystis 6803 also disturbs energy transfer between adjacent PS II core complexes and may also alter their association with the phycobilisomes.
Studies on the Inhibition of Biotin-Containing Carboxylases by Acetyl-CoA Carboxylase Inhibitors
Authors: Motel Anja , Günther Simone , Clauss Martin , Kobek Klaus , Focke Manfred , Lichtenthaler Hartmut K .
Published: August 2018

In higher plants the biosynthetic machinery of de novo fatty acid biosynthesis, measured as [14C]acetate incorporation into fatty acids, is predominantly located in plastids. A key enzyme in this pathway is the biotin-containing acetyl-CoA carboxylase (ACC , EC 6.4.1.2) which catalyzes the ATP-dependent carboxylation of acetyl-CoA to malonyl-CoA. The ACC from Poaceae is very efficiently blocked by two herbicide classes, the cyclohexane-1,3-diones (e.g. sethoxydim, cycloxydim) and the aryloxyphenoxy-propionic acids (e.g. diclofop, fluazifop). It is shown that within the Poaceae not only different species but also different varieties exist which exhibit an altered sensitivity and tolerance towards both herbicide classes, which points to a mutation of the target enzyme ACC. In purifying the ACC we extended our research to the possible presence of other biotin-containing plant enzymes. In protein preparations from maize, oat, barley, pea and lentil we were able to demonstrate the carboxylation of acetyl-CoA, propionyl-CoA and methylcrotonyl-CoA. The two herbicide classes not only block the ACC, but also the activity of the propionyl-CoA carboxylase (PCC ), whereas the methylcrotonyl- CoA carboxylase (MCC ), a distinct biotin-containing enzyme from mitochondria, is not affected. MCC may play a role in isoprenoid catabolism. Whether PCC is a separate plastid enzyme or only a side activity of ACC is under current investigation. The efficiency of the graminicides in sensitive Poaceae is then not only determined by the inhibition of ACC, malonyl-CoA and fatty acid biosynthesis, but also by the exclusion of the PCC-catalyzed metabolic pathways of the plant cell.
Molecular Mobility of Sucrose in Aqueous Solution Studied by 13C NMR Relaxation
Authors: Girlich D. , Lüdemann H.-D
Published: August 2018

From the temperature and concentration dependence of the 13C spin lattice relaxation times of the 12 carbon atoms of the sucrose molecule the rotational dynamics of the sugar molecules are determined. No indication for conformational mobility of the rings is found. The exocyclic hydroxymethyl groups possess extra mobility. The models used for the description are critically discussed. The temperature dependence of the rotational mobility is described by a VTF equation. The concentration dependence of the ideal glass transition temperature To for this mobility is derived.
Uptake and Transport of Quinolizidine Alkaloids in Cuscuta reflex a Parasitizing on Lupinus angustifolius
Authors: Bäumel P. , Jeschke W. D. , Witte L. , Czygan F.-C. , Proksch P.
Published: August 2018

Cuscuta reflexa, Lupinus angustifolius, Quinolizidine Alkaloids, Parasitism During parasitism on Lupinus angustifolius the phanerogamic parasite Cuscuta reflexa takes up quinolizidine alkaloids from L. angustifolius via haustoria that tap xylem and phloem ves­sels of the host. The alkaloid pattern of the haustorial region of C. reflexa as revealed by GLC as well as by GLC-M S closely resembles that of infested lupin stems. With increasing distance from the haustoria towards the apex of C. reflexa the complex alkaloid pattern of the host is significantly reduced. Whereas alkaloid esters such as 13-benzoyloxylupanine and 13-cinnamoyloxy-lupanine are prominent peaks in the alkaloid profiles of the host as well as of the haustorial region of the parasite they are not detected in the apex of C. reflexa but are replaced by their respective alcohol com ponent 13-hydroxylupanine. This change of alkaloid profiles is accompanied by a strong decline of alkaloid concentration which drops from ap­ proximately 11 m g/g dry wt. in the haustorial region of C. reflexa to 0.2 m g/g dry wt. in the apex. Alkaloid analyses of xylem sap and phloem exudate from L. angustifolius suggest that uptake of host plant alkaloids by C. reflexa is mainly via the phloem even though a contribu­tion of xylem sap to the supply of alkaloids to the parasite can not be excluded.
Partial Purification and Characterization of Membrane-Associated 3-Hydroxy-3-methylglutaryl-Coenzyme A Lyase from Radish Seedlings
Authors: Weber Thomas , Bach Thomas J.
Published: August 2018

We solubilized from radish membranes and purified by 154-fold 3-hydroxy-3-methyl-glutaryl-CoA lyase (HMGL, EC 4.1.3.4) catalyzing the conversion of 3-hydroxy-3-methyl-glutaryl-(HMG -)CoA into acetyl-CoA and acetoacetate. The apparent molecular mass under non-denaturating conditions is 70 kDa. The enzyme has a broad pH optimum around 8.0 and its activation energy as determined from the linear part of an Arrhenius plot is 137.1 kJ/mol. The Km with respect to (5)-H MG-CoA is 40 μM . The enzyme is extremely unstable and rapidly loses activity even when kept on ice, but retains some activity over several weeks when stored at -80 °C.
Synthesis of Protoheme via Both, the C5-and the Shemin-Pathway, in the Pigment Mutant C-2 A′ of Scenedesmus obliquus
Authors: Drechsler-Thielmann Beate , Dörnemann Dieter , Senger Horst
Published: August 2018

During greening of pigment mutant C-2A′ of Scenedesmus obliquus the iron tetrapyrrole protoheme is synthesized via 5-aminolevulinic acid (ALA). In this organism ALA can be formed either via the C5- or the Shemin-pathw ay. [14C]labeling with precursors of both pathways led to radioactive protoheme. [1-14C]glutamate, the substrate of the C5-pathway, labeled protoheme 7 times more efficiently than [2-14C ]glycine, a substrate most effective for the Shemin-pathway. Labeling experiments in the presence of different inhibitors were carried out to prove the specificity of the observed labeling. Gabaculine, a highly effective inhibitor of glutamate-1-semialdehyde aminotransferase, one of the enzymes of the C5-pathway, led to a decrease in [1-14C ]glutamate incorporation, and to an increase in [2-14C]glycine label, showing that the pathways work independently from each other. With DCMU only the incorporation of [1-14C ]glutamate was reduced, indicating that the C5-pathway activity is depending on plastidic energy supply.

The presented data confirm the existence of both pathways to 5-aminolevulinic acid in the pigment mutant C-2A′ of Scenedesmus and their involvement in protoheme formation. It is concluded that the C5-pathway provides the bulk of protoheme for the plastidic electron transport chain and the Shemin-pathway for the minor part of the hemes needed for the electron transport in the mitochondria.
Factors Controlling Medium-Chain Fatty Acid Synthesis in Plastids from Maturing Cuphea Embryos
Authors: Fuhrmann Jochen , Heise Klaus-Peter
Published: August 2018

The colorless embryos of Cuphea wrightii A. Gray accumulate capric (about 30%) and lauric acid (about 50%) in their storage lipids. Fractionation studies show that the capacities for the synthesis of these medium-chain fatty acids (MCFA) from [1-14C]acetate were strictly bound to intact plastids. These, in turn, obligately required the addition of ATP. ATP could partially be substituted by ADP. Reduction of the pyridine nucleotide pool, required for opti­mum MCFA formation within the plastids, was driven by glucose 6-phosphate. Under these conditions the plastids were capable of synthesizing MCFA like the intact tissue. The presence of CoA in the incubation medium induced acyl-CoA formation.

The observed accumulation of unesterified capric and lauric acid in the absence of CoA suggests that acyl-ACP thioesterase activity is involved in the chain termination. Treatment with cerulenin led to an unexpectedly small reduction of total fatty acid synthesis while the chain elongation of capric acid was clearly inhibited. A similar accumulation of capric acid at the expense of longer chain fatty acids has been observed after replacing ATP by ADP. These findings implicate that even the condensing enzymes are involved in the control of chain ter­mination.
Ion Transport through Gramicidin A. Water Structure and Functionality
Authors: Poxleitner M. , Seitz-Beywl J. , Heinzinger K.
Published: August 2018

Dynamics (MD) simulations were performed on a gramicidin A dimer model representing a transmembrane channel. Different from previous simulations the peptide was in contact with bulk water at both ends of the dimer to guarantee a realistic description of the hydration of the biomolecule. The flexible BJH model for water was employed in the simula­tions and the gramicidin-water, gramicidin-ion and ion-water potentials used are based on molecular orbital calculations. The water structure near the gramicidin was investigated first by a simulation without ions, while for the energy profiles of the ion transport through the channel a potassium or a sodium ion was added. These investigations provide a detailed and conclusive picture on a molecular level of the role of water in the ion transport through a gramicidin A channel and can explain the experimental results on the selectivity between alkali ions, their double or even triple occupancy, the exclusion or permeability of anions depending upon cation concentration and the consequences of differences in the ionic charge. The investi­gation demonstrate that the water molecules around the gramicidin behave as an integral part of the peptide and the functionality is the result of the whole complex biomolecule-water.
Metabolie Reduction of Phenylpropanoid Compounds in Primary Leaves of Rye (Secale cereale L.) Leads to Increased UV-B Sensitivity of Photosynthesis
Authors: Reuber S. , Leitsch J. , Krause G. H. , Weissenböck G.
Published: August 2018

In the epidermal layers of rye primary leaves two flavone glycosides and several hydroxycinnamoyl esters are localized, whereas the mesophyll contains two flavone glucuronides and two anthocyanins. The concentrations of all these potential UV-B protective phenylpropanoid compounds could be reduced by application of 2-aminoindan-2-phosphonic acid (AIP), an efficient inhibitor of phenylalanine ammonia-lyase (EC 4.1.3.5). Photosystem II in the primary leaves of seven-days-old plants, grown in the presence of 20 μm AIP up to an age of 80 h, was more severely affected by UV-B than in control plants with the normal concentration of phenylpropanoid compounds. Damage of photosystem II in vivo was estimated by measuring the chlorophyll a fluorescence (parameter FJFm) of PS II. The results indicate an essential role of phenylpropanoid com pounds as UV-B protectants in rye primary leaves
Oxidative Stress of Crops Monitored by EPR
Authors: Stegmann Hartmut B. , Schuler Paul
Published: August 2018

Treatment of leaves of spinach, corn, and peas with the herbicides paraquat, amitrole or acifluorfen leads to oxidative stress resulting in a light driven drastically increased production of ascorbic acid radical (m̱onoḏehydroa̱scorbic acid, MDAA) which could be demonstrated by in vivo EPR analysis. A discrimination of the MDAA formation between the action of elec­tron uncouplers and catalase inhibitors can be achieved by observation of the radical rise kinetics. Significant MDAA signal intensities are detected in the darkness likewise. These signals are probably due to the action of ascorbic acid oxidase activated by membrane destruction.
Purification, Characterization and N-Terminal Sequence of Phosphoserine Aminotransferase from the Green Alga Scenedesmus obliquus, Mutant C-2 A′
Authors: Stolz M. , Dörnemann D.
Published: August 2018

Phosphoserine aminotransferase (EC 2.6.1.52), an enzyme of the “phosphorylated pathway” leading to the formation of serine, was purified from Scenedesmus obliquus, mutant C-2 A′. Purification started from the soluble supernatant of a crude cell homogenate and included different affinity and DEAE chromatographic techniques, as well as gel filtration. The purified phosphoserine aminotransferase was enriched 1537-fold and identified to be a homodimer with subunit molecular masses of 40 kDa, each. The absorption spectrum is consistent with the presence of pyridoxal-5-phosphate as cofactor. From the purified enzyme 18 amino acids of the N-terminus could be determined, showing at least 67% homology with the serC gene encoding phosphoserine aminotransferases from bacterial organisms.
Stimulatory Effects of an Ammonium Salt Biocide on Photosynthetic Electron Transport Reactions
Authors: Bader Klaus P. , Höper Susanne
Published: August 2018

Alkylbenzyldimethylammonium chloride (ABDAC, zephirol) has been shown to improve the functioning of the photosynthetic apparatus of the filamentous cyanobacterium Oscillatoria chalybea (Bader, K. P. (1989) Biochim. Biophys. Acta 975, 399-402). This biocide exerts stimulatory effects on various electron transport reactions in Oscillatoria chalybea and chloroplasts from higher plants. By means of oxygen evolution measurements and of repetitive flash-induced absorption spectroscopy we were able to demonstrate an impact of the drug on the major complexes of photosynthetic membranes, i.e. the water splitting complex, photosystem II and photosystem I. Both, P820- and X320-absorption change signals were enhanced by the addition of ABDAC. Along with the quantitative analysis we investigated the relaxation kinetics of the signals and observed a substantial stabilization of the oxidized states of the respective redox components in the presence of the ammonium salt. Under appropriate conditions the relaxation kinetics of the absorption signals were significantly slowed down. ABDAC also affects photosystem I in Oscillatoria chalybea, but only under conditions, where a donor/acceptor system i.e. an isolated photosystem I reaction with photosystem II being disconnected was measured. Electron transport through the whole chain i.e. with water as the electron donor yielded no effect of the quaternary ammonium salt. It is suggested that this is due to an extremely bad linkage between the two photosystem, each of which, however, shows good reaction rates, when separately measured. The described interactions of the biocide with photosynthetic membranes are not restricted to Oscillatoria chalybea but are also observed with higher plant chloroplasts. In these systems, ABDAC enhances X320- and P700-signals to a comparable extent. In this case the P700-signal is stimulated in assays with electrons which are furnished from water which hints at good coupling between the two photosystems in our tobacco chloroplast preparations.
Aromatic Components of the Essential Oils of Four Chinese Medicinal Plants (Asarum petelotii, Elsholtzia souliei, Eupatorium adenophorum, Micromeria biflora) in Yunnan
Authors: Ding Jingkai , Xuejian Yu , Yu Wu , Ding Zhihui , Chen Zonglian , Hayashi Nanao , Komae Hisasi
Published: August 2018

The volatile components of the essential oils of four Chinese medicinal Plants (Micromeria biflora, Elsholtzia souliei, Eupatorium adenophorum, Asarum petelotii) were investigated by GC and GC-MS. Large amounts of terpenes (geranial, naginataketone, p-cymene, β-himachalene), or phenol ethers (apiole, elemicin, 1,2,3,4-tetramethoxy-5-allyl-benzene) were identified in the oils.
Protoporphyrin Accumulation Induced by Peroxidizing Herbicides is Counteracted by Safeners
Authors: Böger Peter , Miller Roswitha
Published: August 2018

A number of safeners like naphthalene-1,8-dicarboxylic acid anhydride (naphthalic anhydride) or dichloroacetyl-hexahydro-3,3,8-α-trimethylpyrrolo-[1 ,2 α]-pyrimidine-6-(2H̲)-one (BAS 145138) drastically decreased the accumulation of protoporphyrin IX induced by a peroxidative cyclic imide (chlorophthalim, N-(4-chlorophenyl)-3,4,5,6-tetrahydrophthalimide), or p-nitrodiphenyl ether (acifluorfen methyl, 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoicmethylester). This effect was observed with etiolated maize and cress seedlings during a 16-h illumination period with these herbicides and 0.1 to 1 mᴍ safener present. The safeners did not affect the inhibition of protoporphyrinogen oxidase, the target enzyme of peroxidative herbicides. Mixed function oxidase inhibitors did not influence this safening effect. A microsome preparation from safener-treated maize seedlings did neither degrade protoporphyrin IX nor protoporphyrinogen IX.
Quantitative Computerized Analysis of Silver-Stained and Coomassie Blue-Stained Two-Dimensional Protein Maps
Authors: Hillebrandt Sonja , Streffer Christian
Published: August 2018

Using the two-dimensional gel electrophoresis and two systems for computer analysis of the resulting maps, we obtained a good quantitative reproducibility of individual spots of silver-stained and Coomassie Blue-stained gels from mouse fetus liver samples. The GelScan- XL system was established for the evaluation of silver-stained gels. The Gel-Image software has shown to be capable of the analysis of Coomassie Blue-stained gels and autoradiographs. For these systems the linear relationship between defined concentrations of protein loaded on the gel and the resulting integrated intensities of spots were examined. The results show that both systems are efficient to detect quantitative changes in protein expression correlated with malformations in mouse fetuses.
Antioxidative Effect of Extracts from Erodium cicutarium L.
Authors: Sroka Zbigniew , Bodalska Halina Rządkowska , Mażol Irena
Published: August 2018

Extracts from Erodium cicutarium L. (EC) and some standard substances present in EC extracts were tested for their antioxidative properties during Fe2+-induced triglyceride oxidation. Hydrophobic fractions such as petroleum ether (PEE), benzene (BE) and chloroform I (ChE I) extracts as well as hydrophilic fractions i.e. water (WE) and ethyl acetate (EAE) showed an antioxidative effect. Among the tested substances vitamin C and some polyphenolic compounds; tannin, (+)-catechin and gallic acid exhibited antioxidative activity, stronger than the one of the mentioned extracts.
The Structure of a New Dipeptide from the Mushroom Clitocybe acromelalga
Authors: Yamano K. , Shirahama H.
Published: August 2018

From the poisonous mushroom Clitocybe acromelalga, a new glutam ate-containing dipeptide was isolated. Its structure was deduced to be N-(γ-aminobutyryl)-ʟ-glutamic acid (10) based on spectral data and was confirmed by synthesis
Differential Expression of Chitinase and ß-1,3-Glucanase Genes in Various Tissues of Potato Plants
Authors: Garcia-Garcia Francisco , Garcia-Garcia Francisco , Schmelzer Elmon , Hahlbrock Klaus , Roxby Robert
Published: August 2018

We have analyzed the tissue-specific expression of chitinase, β-1,3-glucanase and, for com parison, phenylalanine ammonia-lyase genes in healthy, unstressed potato (Solanum tuberosum) plants by using RNA -RNA hybridization and immunostaining techniques to localize the respective mRNAs and proteins in situ. Preparations of leaf, flower, shoot tip, node and axillary bud revealed that chitinase exhibited a distinctive and characteristic expression pattern in being confined to the epidermal cell layer, while β-1,3-glucanase and phenylalanine ammonia-lyase were present to varying extents in most tissues of these organs. These distinctive patterns of expression suggest fundamentally different roles for the two glucanohydrolases in the metabolism of unstressed plants
Tawny Owl (Strix aluco) and Hume's Tawny Owl (Strix butleri) Are Distinct Species: Evidence from Nucleotide Sequences of the Cytochrome b Gene
Authors: Heidrich Petra , Wink Michael
Published: August 2018

The cytochrome b gene of the Tawny Owl (Strix aluco), Hume’s Tawny Owl (Strix butleri) and the African wood owl (Strix woodfordii) was amplified by polymerase chain reaction (PCR) and partially sequenced (300 base pairs). Sequences differ substantially (9 to 12% nucleotide substitutions) between these taxa indicating that they represent distinct species, which is also implicated from morphological and biogeographic differences. Using cytochrome b sequences of S. aluco, S. butleri, S. woodfordii, Athene noctua and Tyto alba phylogenetic relationship were reconstructed using the “maximum parsimony” principle (PAUP 3.1.1) and the neighbour-joining method (MEGA)
4-Epidihydrocochlioquinone B and 14-Epicochlioqumone B, Antibiotics from Fermentations of the Ascomycete Neobulgaria pura: Structure Elucidation and Effects on Platelet Aggregation
Authors: Lorenzen Kirsten , Anke Timm , Anders Uwe , Hindermayr Hermann , Hansske Fritz
Published: August 2018

14-Epicochlioquinone B (1) and 14-epidihydrocochlioquinone B (2) were isolated from sub­ merged cultures of Neobulgaria pura (Pers. ex Fr.) Petrak. 14-Epicochlioquinone B is a potent inhibitor of hum an and bovine platelet aggregation stimulated by different inducers. 14-Epidihydrocochlioquinone B does not inhibit the aggregation of platelets. In addition, both 1 and 2 exhibited cytotoxic and antimicrobial activites.
Zn2Mg Alkaline Phosphatase in an Early Ptolemeic Mummy
Authors: Kaup Yoka , Baumer Ursula , Koller Johann , Hedges Robert E. M. , Werner Herbert , Hartmann Hans-Jürgen , Etspüler Hedwig , Weser Ulrich
Published: August 2018

Bone samples of a ptolemeic mummy have been employed to study the mode of conservation on the intactness of Zn2Mg alkaline phosphatase in both structure and catalytic activity. A protein of Mr = 190 ± 10 kDa being identical to the 200 kDa enzyme of fresh human bones was successfully isolated. Regardless of age 200 kDa protein bands and a distinct sub­ unit at 60 kDa were seen in SDS-PAGE electrophoresis. The 200 kDa band was also monitored by activity staining. The specific activity was 120 mU/mg and 65% of the respective activity obtained in the identical preparation using fresh human tibia or rib. The enzymic activity was inhibited in the presence of 1,10-phenanthroline and ʟ-homoarginine. Radiocarbon dating supported the assignment of the mummy to the early ptolemeic period. Among the many bactericidal and fungicidal components employed for mummification were aromatic alcohols, mono-and sesquiterpenes. Pistachio resin was the major balm resin used. The microbiological sterility of the bone surface was ascertained by independent bacterial and fungal examinations
Diurnal Changes in Murine Spermatogenesis
Authors: Hacker-Klom Ursula Beate
Published: August 2018

We analysed testicular samples of NMRI mice every 2 h of a day in order to determine whether there is a circadian rhythm in spermatogenetic activity. We used flow cytometry after staining the DNA with DAPI. The highest proportion of DNA synthesizing cells (mainly spermatogonia and preleptotene spermatocytes) was seen at 8 p.m. and especially at 10 p.m.; the lowest proportion was observed at 2 p.m. At 6 a.m., the percentage of round spermatids increased significantly, whereas the fraction of 4c-cells decreased at that time. Our results of a diurnal rhythm of spermatogenic DNA synthesis rate are in contrast to another publication of other authors (Oakberg and Crosswait, 1983)
Phylogeny and Biotransformation. Part 5*: Biotransformation of Isopinocampheol
Authors: Abraham Wolf-Rainer
Published: August 2018

Biotransformation of isopinocampheol with 100 bacterial and fungal strains yielded 1-, 2-, 4-, 5-, 7-, 8 - and 9-hydroxy-isopinocampheol besides three rearranged monoterpenes, one of them bearing the novel isocarane skeleton. A pronounced enantioselectivity between (+)- and (-)-isopinocampheol was observed. The phylogenetic position of the individual strains could be seen in their ability to form the products from (+)-isopinocampheol. The formation of 1,3-dihydroxypinane is a domain of bacteria, while 3,5- or 3,7-dihydroxypinane was mainly formed by fungi, especially those of the phylum Zygomycotina. The activity of Basidiomycotina towards oxidation of isopinocampheol was rather low. Such informations can be used in a more effective selection of strains for screening.
Spermatozoid Chemotaxis in Laminaria digitata (Phaeophyceae). III. Pheromone Receptor Specificity and Threshold Concentrations
Authors: Maier Ingo , Müller Dieter G. , Boland Wilhelm
Published: August 2018

The pheromone receptor specificity and threshold concentrations have been determined for spermatozoid chemotaxis in Laminaria digitata in structure-activity studies. The results are in agreement with the current concept on the pheromone receptor interaction in brown algae, which is based on mutually-induced dipole-dipole interaction, dispersion forces and hydrophobic forces. Comparison with the receptor specificity in pheromone-induced spermatozoid release in the same species indicates that different pheromone receptors are involved in these two functions.
Composition of the Epicuticular Wax Esters of Picea abies (L.) Karst
Authors: Sümmchen Peter , Markstädter Claus , Wienhaus Otto
Published: August 2018

The long-chain alkyl esters homologues of the cuticular needle wax of Picea abies consist of a series of isomers, which are formed by different n-fatty acids and n-alkanols of various chain lengths. Even-numbered esters are dominating. Methyl esters range from C27 to C37, even-numbered esters are only minor components. Furthermore, a new class of homologue wax esters was isolated. Examination by gas chromatography, mass spectroscopy and chemi­cal studies resulted in identification of pentenyl esters of triacontanoic, dotriacontanoic, tetratriacontanoic and hexatriacontanoic acid.
Changes in the Content of Chlorophyll and Redox Components of the Thylakoid Membrane during Development and Senescence of Beech (Fagus sylvatica) Leaves
Authors: Zhu Hua , Wild Aloysius
Published: August 2018

Leaves from 145-year-old and 44-year-old beech trees were harvested during 1991-1993. Chlorophyll (Chl) and redox components of the thylakoid membrane, including P-700, cytochrome f (Cyt f) and D1 protein, were determined with the following results. Chl a + b, P-700 and Cyt f per unit of fresh weight (FW), dry weight (DW) and leaf area (LA) increase significantly during leaf development. This can be attributed to a massive membrane syn­thesis and new thylakoid formation in the cells. The Chl a/Chl b ratio decreases with the synthesis of Chl during the development of beech leaves and is reduced further with Chl breakdown in the stage of senescence. When expressed on the basis of Chl, a reduction in the amount of P-700 and Cyt f is observed during the growth stage, indicating a marked enlargement of the functional photosynthetic unit. During senescence of beech leaves, Chl breaks down, and P-700 and Cyt f per unit of FW, DW and LA decrease dramatically with the decline in Chl levels. However, when expressed on the basis of Chl, P-700 remains rela­tively constant, while Cyt f shows a pronounced increase. The uncommon pattern of Cyt f change in senescent beech leaves and the relationship between the amount of Chi and the content of Cyt f throughout an entire growth period of beech leaves are discussed.
A New Clerodane Diterpenoid Isolated from Propolis
Authors: Matsuno Tetsuya
Published: August 2018

A physiologically active substance has been isolated from Brazilian propolis and charac­terized as a new clerodane diterpenoid, as indicated by human hepatocellular carcinoma HuH 13 cell cytotoxicity assays. This compound inhibited growth of the hepatoma cells at a concentration around 10 μg/ml and arrested the tumor cells at S phase as revealed by flow cytometry. At higher concentrations it exerted lethal damage. The compound showed cyto­toxicity on human lung carcinoma HLC-2, HeLa, KB and rat W3Y cells, whereas human diploid foreskin and primary rabbit kidney cells were less affected.