bluuebunny/crossref_metadata_2025 huggingface dataset:
Dicyano-bis(pyridin-2,6-dicarbothioato)-ferrat (II)/ferrat (III), ein weiteres eisenhaltiges Redoxsystem aus der Kulturlösung eines Pseudomonas-Stammes [1] / Dicyano-bis(pyridin-2,6-dicarbothioato)-ferrate (II)/ferrate (III), a Further Fe Containing Redox System from the Culture Medium of Pseudomonas sp.
Authors: Hildebrand U. , Taraz K. , Budzikiewicz H. , Korth H. , Pulverer G.
Published: August 2018

From the culture medium of Pseudomonas sp. a further Fe containing complex, viz. dicyano- bis(pyridin-2,6-dicarbothioato)-ferrate (III) (2) has been isolated which participates in a ferrate (II)/ferrate (III) redox system (normal potential of-0.013 V) in the range of the redox potentials of cytochromes. Pyridine-2,6-di(monothiocarboxylic acid) which originally has been considered to be characteristic for Pseudomonas putida has been found recently as a metabolite of other bacterial strains (two of which have been characterized in this paper) as well.
Differential Inhibition by Mevinolin of Prenyllipid Accumulation in Radish Seedlings
Authors: Schindler Sibille , Bach Thomas J. , Lichtenthaler Hartmut K.
Published: August 2018

We have studied in intact radish seedlings the effects of mevinolin (at concentrations of 0.25 to 5 μᴍ), a specific inhibitor of HMG-CoA reductase, and, therefore, of mevalonate biosynthesis, on the production of various isopentenoids and prenyllipids. Whereas the content of free desmethyl sterols was decreased steadily, only depending on the concentration of inhibitor present in the parts of seedlings investigated separately (e.g. roots, hypocotyls. and cotyledons), the effect on ubiquinone accumulation was different. Irrespective of the part of seedlings being analyzed, the maximal inhibition reached was 50%. Plastidic pigment accumulation, however, as well as that of chloroplast quinones (plastoquinone and phylloquinone), appeared even to be enhanced at low inhibitor concentrations and was not significantly lowered by application of 5 μᴍ mevinolin. α-Tocopherol showed a similar profile in the dose response to compounds known to be exclusively synthesized in the plastid.

The results indicate a differential accessibility of the mevalonate synthesizing enzymes presumably present in the cytoplasm, mitochondria and plastids in respect to the inhibitory action of mevinolin. If prenyllipid formation in the different cell compartments solely depended on cytoplasmic mevalonate biosynthesis, all prenyllipids should be affected to the same extent as the sterols, which are exclusively synthesized by cytoplasmic enzymes.
Adsorbent Filter — A Tool for the Selection of Plant Suspension Culture Cells Producing Secondary Substances
Authors: Knoop Bernd , Beiderbeck Rolf
Published: August 2018

Cells and cell aggregates from suspension cultures are plated onto selection plates, consisting of:

1. A layer of nutrient medium solidified with agar

2. A filter paper coated on the upper side with activated charcoal (AC) as an adsorbent

3. covered by a sheet of cellophane as cell carrier.

Substances produced migrate through the cellophane and are locally bound to the adsorbent layer. A fter transfer of the cells together with the cellophane to another dish the adsorbent filter is dried and the substances bound to the AC are eluted to the white side of the filter paper where they can be detected by m eans of standard methods of TLC and PC.

The substance pattern mirrors the pattern of cell material and allows to discover those cells with deviating substance production.

This method is used to recover cell aggregates of Nicotiana tabacum and Matricaria chamomilla from a mixture of both cultures.
The Influence of Low-intensity Millimeter-Wave Radiation on the Growth of Cress Roots
Authors: Kremer F. , Poglitsch A. , Santo L. , Sperber D. , Genzel L.
Published: August 2018

An inhibition of growth in cress roots (Lepidium sativum L.) by irradiation with low-intensity millimeter-waves was found using a computer controlled optical system which is capable of measuring nearly continuously the length of the roots to an accuracy of ± 2 jam. The effect is reversible and, for a power density of 6 mWcm-2, results in completely halting the root growth. It occurs within about 100 s after the onset of irradiation. The microwave-induced temperature increase at the surface of the root tip was found to be less than 0.3 °C at this power density. The effect did not show a sharp frequency dependence however it depended strongly on the polariza­tion of the microwaves with respect to the root orientation.

The sensitivity of the root growth to the ambient temperature was examined. Only a weak temperature dependence was found which could not explain the observed effects. However simulating the microwave-induced temperature increase at the surface of the root tip with (incoherent) far-infrared light (λ≥20 μm) resulted in similar effects as with microwaves. Hence one can conclude that the observed effects are primarily caused by the small local irradiation induced thermal gradients across the surface of the root tip.
A Small-Angle X-Ray Scattering Study on Pre-Irradiated Malate Synthase. The Influence of Formate, Superoxide Dismutase, and Catalase on the X-Ray Induced Aggregation of the Enzyme
Authors: Zipper P. , Wilfing R. , Kriechbaum M. , Durchschlag H.
Published: August 2018

The sulfhydryl enzyme malate synthase from baker’s yeast was X-irradiated with 6 kGy in air-saturated aqueous solution (enzyme concentration: ≃ 10 mg/ml; volume: 120 μl), in the absence or presence of the specific scavengers formate, superoxide dismutase, and catalase. After X-irradiation, a small aliquot of the irradiated solutions was tested for enzymic activity while the main portion was investigated by means of small-angle X-ray scattering. Additionally, an unir­radiated sample without additives was investigated as a reference. Experiments yielded the fol­lowing results:

1. X-irradiation in the absence of the mentioned scavengers caused considerable aggregation, fragmentation, and inactivation of the enzyme. The dose Dt
37 for total (= repairable + non­-repayable) inactivation resulted as 4.4 kGy. The mean radius of gyration was found to be about 13 nm. The mean degree of aggregation was obtained as 5.7, without correction for fragmenta­tion. An estimation based on the thickness factor revealed that about 19% of material might be strongly fragmented. When this amount of fragments was accordingly taken into account, a value of 7.1 was obtained as an upper limit for the mean degree of aggregation. The observed retention of the thickness factor and the finding of two different cross-section factors are in full accord with the two-dimensional aggregation model established previously (Zipper and Durchschlag, Radiat. Environ. Biophys. 18, 99 - 121 (1980)).

2. The presence of catalytic amounts of superoxide dismutase and/or catalase, in the absence of formate, during X-irradiation reduced both aggregation and inactivation significantly.

3. The presence of formate (10 or 100 mᴍ) during X-irradiation led to a strong decrease of aggregation and inactivation. This effect was more pronounced with the higher formate concen­tration or when superoxide dismutase and/or catalase were simultaneously present during X-irradiation. The presence of formate also reduced the amount of fragments significantly.

4. The results clearly show that the aggregation and inactivation of malate synthase upon X-irradiation in aqueous solution are mainly caused by OH·; to a minor extent O·̄
2 and H2O2 are additionally involved in the damaging processes.
Physiology of Nitrogen Fixation in Two New Strains of Anabaena
Authors: Chen Pei-Chung
Published: August 2018

Two different cyanobacteria, Anabaena CH 1 and CH2, were isolated from Taiwan paddy soils. Both strains can grow well with daily dilution method. Anabaena CH1 shows a blue-green color and Anabaena CH2 a green brownish one. Nitrogenase activity decreased as cultures were transferred from light to dark. When a darkened culture was placed again into the light, nitrogenase activity recovered within two hours, but not in the presence of chloramphenicol. Energy supply for nitrogenase within both strains was different. Nitrogenase activity of Anabaena CH1 was light-dependent and oxygen in heterocyst was exhausted through oxyhydrogen reaction. Except photosynthesis, respiration may be used as energy source for nitrogenase in Anabaena CH2. Respiration was the major one to protect nitrogenase against oxygen.
On the Role of Branched-Chain Amino Acids in Protein Turnover of Skeletal Muscle. Studies in vivo with L-Norleucine
Authors: Schott Klaus-Joachim , Gehrmann Jochen , Potter Ulla , Neuhoff Volker
Published: August 2018

1. The effect of ʟ-norleucine, an isomer of leucine, on protein metabolism in vivo was studied in suckling rats. Rats were injected subcutaneously with various doses of ʟ-norleucine (0.5 and 5.0 μmol/g body wt.) every 12 h from 3 to 15 days post partum. Protein concentration, amino acid concentrations, and incorporation of [3H]tyrosine into protein were analyzed in liver, muscles of thigh and small intestine. Amino acid concentrations and insulin levels in serum were also measured.

2. At 5 days of age, norleucine induced an increase in protein concentration of skeletal muscle with an increased incorporation of [3H]tyrosine into protein indicating an accelerated protein synthesis. Changes in protein metabolism were paralleled by alterations in the amino acid pattern of this tissue.

3. When protein concentration and protein synthesis were increased in skeletal muscle, protein concentration of small intestine was decreased, accompanied by elevated levels of amino acids in tissue. Protein synthesis of small intestine was not altered by the norleucine treatment. The results suggest a close interrelationship between skeletal muscle and small intestine with respect to protein turnover.

4. The effects of norleucine were less pronounced at 10 and 15 days of age, which indicates a metabolic adaptation to the treatment.

5. Alterations in amino acid concentrations of tissue due to changes in protein metabolism were not uniform but tissue-specific.

6. Current concepts for explaining the effects of branched-chain amino acids (BCAA) on protein turnover in skeletal muscle are based on the assumption that the BCAA or leucine alone might become rate-limiting for protein synthesis in muscle under catabolic conditions. The amino acid analogue norleucine, however, cannot replace any of the BCAA in protein. Additionally, norleucine affected protein metabolism in highly anabolic organisms.

Therefore, the present thoughts on this issue appear to be incomplete.
Regression of the Time-Keeping Ability in Carabid Beetles by Phylogenetic Adaptation to Cave Conditions
Authors: Martin Wolfgang , Weber Friedrich
Published: August 2018

Locomotor activity patterns of six cavernicolous carabid species representing the course of regressive evolution have been investigated under constant conditions. The analysis establishes new relationships between the circadian structure of the activity patterns observed under constant conditions (LL and D D) and the phylogenetic adaptation to cave conditions. This is due to the mathematical method used for investigating the activity patterns, i. e. the Wigner-Ville spectrum that enables the evaluation of nonstationarities. It overcomes the hypothesis of stationarity which was the base of previous examinations. The new method delivers a more refined gradual decrease of the stability of the circadian pattern of activity in cavernicolous beetles than could be achieved by classical periodogram analysis. It is also shown that the locomotion patterns of extremely evolved troglobitic clearly deviate from a purely signal-free (white noise) structure. Possible time­keeping mechanisms that may cause the measured stabilities and regressive lines of possible evolutionary development are discussed.
Comparison of pH Changes and Elicitor Induced Production of Glyceollin Isomers in Soybean Cotyledons
Authors: Osswald Wolfgang F. , Zieboll Sigrid , Elstner E. F.
Published: August 2018

During the incubation of soybean cotyledons with Pmg-elicitor for 22 hours the pH of the diffusion droplets increases from 7.2 to 8.3. This pH-shift is a precondition for the formation of the typical red colour of the diffusion droplet. After inhibiting the pH-shift by the use of 100 mм phosphate or Tris buffer instead of 10 mм buffer as solvent for the elicitor, the red colour is no longer formed with the exeption of 100 mM Ammediol buffer. However, the normal pattern of pterocarpan induction can be measured in the absence of the red colour in the diffusion droplet. Tris and Ammediol buffers exhibited a smaller pterocarpan induction as compared to phosphate buffer as solvent for the Pmg-elicitor.
Isoneorautenol and Other Pterocarpan Phytoalexins from Calopogonium mucunoides
Authors: Ingham John L. , Tahara Satoshi
Published: August 2018

Following inoculation with the fungus Helm inthosporium carbonum , excised leaflets of the tropical papilionate legume Calopogonium mucunoides have been found to produce isoneorautenol, a new dimethylpyrano-substituted isoflavonoid (pterocarpan) phytoalexin. This compound accumulates together with dem ethylm edicarpin, neodunol, tuberosin, sophorap-terocarpan A, and a sixth highly antifungal isoflavonoid (calopocarpin) characterised as 3,9-dihydroxy-2-(3,3-dimethylallyl)pterocarpan. Chromatographic and spectroscopic examination of ‘hom oedudiol’ (a pterocarpan from N eorautanenia edulis roots previously considered to possess the structure now assigned to calopocarpin) has shown that in reality this substance is identical with sophorapterocarpan A. The systematic relationship of Calopogonium to other genera within the legume tribe Phaseoleae is briefly discussed.
The Regulation of Acetyl Coenzyme A Synthesis in Chloroplasts
Authors: Treede Hans-Jürgen , Heise Klaus-Peter
Published: August 2018

The enzymatic activities of the pyruvate dehydrogenase complex (PDC) and acetyl-CoA synthetase (ACS) have been compared in extracts of plastids isolated from spinach leaves and from both green and etiolated pea seedlings. A ll plastid preparations were shown to be capable of synthesizing acetyl-CoA, not only via acetyl-CoA synthetase, but also via the pyruvate dehydroge­ nase complex, though, with different activities. Both pathways are apparently under metabolic control. Thus, the substrate levels in photosynthetically active spinach chloroplasts appear to favor acetyl-CoA synthesis via ACS (apparent Km for acetate of 0.1 mм) , because calculated stromal pyruvate levels (0.1 m M) appear to limit its formation via the PDC (apparent Km for pyruvate of 0.2-0.3 nм) . In spinach chloroplasts, therefore, the PDC pathway seems to be predominantly involved in providing precursors for branched-chain amino acid biosynthesis (vali­ne, leucine and isoleucine). Acetyl-CoA, synthesized via ACS, may additionally function as an inhibitor of the chloroplast PD C , because, as in mitochondria, relatively low concentrations of the end products NADH and acetyl-CoA strongly inhibit the PD C in chloroplast extracts. On the other hand, comparatively high concentrations of MgATP, a cofactor for ACS, inhibited the PDC complex. The pH optimum of about 8 and the high Mg-requirement distinguishes both enzymes from mitochondrial PDC and reflects an accomodation to stromal conditions in photosynthetically active chloroplasts.
Flavonoid Glycosides from Thymus membranaceus
Authors: Tomás Francisco , Hernández Luis , Barberán Francisco A. T. , Ferreres Federico
Published: August 2018

Thymus membranaceus is an endemism of southeastern Spain, which belongs to section Pseudothymbra of genus Thymus. In this work we have achieved an investigation of the flavonoid glycosides present in the aerial parts of this plant. Among the compounds identified are the rare luteolin-7-0-β-D-xyloside, luteolin-7-0-β-D-[rhamnosyl (1→2)glucoside] and luteolin-7-0-β-D-[xylosyl (1→2)glucoside] previously not known to occur in the Labiatae.
Synthesis of 1,2-Dipalmitoyloxypropyl-3-(2-ammoniumethyl) Phosphinate
Authors: Moschidis Michael C.
Published: August 2018

The total synthesis of 1,2-dipalmitoyloxypropyl-3-(2-ammoniumethyl) phosphinate, the phosphino-analog of phosphatidyl ethanolamine is described.

The phosphinate analog of phosphatidyl ethanolamine has been prepared by an Arbusov type of reaction between a diacyl-glycerol bromohydrin and 2-bromo-ethylphosphonic acid dimethyl ester for 48 h at 178 °C, followed by a reaction with aq. ammonia to yield the final product.

The product was characterized by elemental analysis, phosphono-phosphorus determinations and IR spectroscopy.
Physicochemical Characterization of Tetraetherlipids from Thermoplasma acidophilum
Authors: Blöcher Detlef , Gutermann Raymund , Henkel Birgit , Ring Klaus
Published: August 2018

By means of differential thermoanalysis, the miscibility of the main polar tetraether lipid of Thermoplasma acidophilum with two ester lipids, dipalmitoyl phosphatidylcholine and dipalmitoyl phosphatidylglycerol, resp., in the presence of excess water was studied. It is shown that with increasing fraction of tetraether lipid in the mixture, the transition range of dipalmitoyl phosphatidylcholine is broadened and the temperature of the maximum heat flow (Tm) is shifted to lower temperatures; furthermore, the enthaply change (ΔH) of the transition declines. Similar results were obtained with mixtures of tetraether lipid with dipalmitoyl phosphatidylglycerol. It is therefore concluded that the main polar tetraether lipid of Thermoplasma acidophilum , which essentially forms monomolecular layers, is able to form stable common phases with bilayer-forming ester lipids. Miscibility of the tetraether lipid with dipalmitoyl phosphatidylglycerol, which are both monovalent anions at neutral pH, is also observed in the presence of high proton or calcium ion concentrations.
Occurrence and Characteristics of Amino Alcohols and Cyclohexenone. Components of Fungal Mycosporines
Authors: Lemoyne F. , Bernillon J. , Favre-Bonvin J. , Bouillant M. L. , Arpin N.
Published: August 2018

After determination of hydrolysis conditions which allow the best recovery of the mycosporine components (cyclohexenone 1 and the amino alcohols 2 and 3), these compounds have been searched into mycelia of several fungi. In some of them, 1 was unambiguously detected, although in minute quantities, whilst the unknown natural 2 and 3 could not be identified. So, two alternative pathways of mycosporine biogenesis are under investigation.
Studies on Sporopollenin Biosynthesis: The Effect of Inhibitors of Carotenoid Biosynthesis on Sporopollenin Accumulation
Authors: Prahl A.-K. , Springstubbe H. , Grumbach K. , Wiermann R.
Published: August 2018

1. The unequivocal chemical composition of sporopollenin is unknown. Ir was often hypothesized that sporopollenin represents a derivative of carotenoids and/or carotenoid esters. Proceeding from this working hypothesis the influence of inhibitors of carotenoid biosynthesis (DPA, nicotine, Sandoz) on the sporopollenin accumulation was studied in order to test whether an intact carotenoid metabolism is involved.

2. Drastic changes in carotenoid spectra as well as in carotenoid patterns in pollen extracts were used as a “marker” for the uptake and transport of the inhibitors into the anther loculus, the site of sporopollenin biosynthesis. Of the three inhibitors of carotenoid metabolism, DPA, nicotine and Sandoz, only Sandoz appeared to influence carotenoid metabolism in the anthers.

3. After application of Sandoz the sporopollenin accumulation in anthers and pollen was only slightly affected. The amount of sporopollenin after treatment is similar to, or possibly even marginally higher than the control, if dry weight is chosen as reference. If the amount is expressed with respect to one pollen grain, the content is very slightly decreased in the case of pollen from treated plants.

Therefore, it is concluded that severe interference in carotenoid biosynthesis does not result in a subsequent drastic inhibition of sporopollenin biosynthesis.

4. A significant increase of PAL activity under the influence of Sandoz indicates that effects upon phenylpropanoid metabolism are possible.
Effects of Norfloxacin and Rifampicin on Growth and Streptolysin S Production in Hemolytic Streptococci
Authors: Taketo Akira , Taketo Yoriko
Published: August 2018

Norfloxacin, a nalidixic acid analogue, inhibited streptolysin S (SLS) production when added to young streptococcal culture. DNA synthesis was mainly affected, but increment of cell mass. RNA and protein was also significantly reduced in streptococci treated with norfloxacin. In stationary phase cells and in the washed resting bacteria, the toxin production was resistant to the drug. Pretreatment with norfloxacin did not abolish the cellular capacity to produce SLS. Although extracellular SLS was detectable at log phase of streptococcal growth, enhanced production of the toxin occurred upon cessation of coccal multiplication. In contrast to norfloxacin, lower concentration of rifampicin inhibited SLS production, even added at late log or early stationary phase. Roles of growth phase, medium and carrier in induction of SLS production were analyzed as well.
Mandibular Gland Secretions as Alarm Pheromones in Two Species of the Desert Ant Cataglyphis
Authors: Hefetz Abraham , Lloyd Helen A.
Published: August 2018

Mandibular gland secretion of two Cataglyphis species were chemically analyzed by combined gas chromatography mass spectrometry. The exudates produced by C. bombycina consisted of citronellol and geraniol while that of C. nigra contained only geraniol.

The reaction of both species to the glandular secretions was alarm and recruitment. While the reaction of C. bombycina was strong, that of C. nigra was relatively mild.
A Photoreversible 39 kDalton Fragment from the Pfr Form of 124 kDalton Oat Phytochrome
Authors: Reiff Ulrich , Eilfeld Peter , Rüdiger Wolfhart
Published: August 2018

Limited proteolysis of 124 kdalton oat phytochrome in the Pfr form is described which leads to a photoreversible 39 kdalton fragment. Whereas the absorption maximum of the Pr form is only slightly shifted (from 667 to 660 nm) no long-wavelength band is observed in the Pfr form. A “bleached” (i.e. low absorbing) form appears instead with a broad absorption maximum at 640 nm. This property corresponds with that of a 40.3 kdalton fragment obtained from pea phytochrome by limited proteolysis (Yamamoto and Furuya, Plant and Cell Physiol. 24, 713, 1983). Dark reversion of the bleached form to the Pr form is faster (t1/2 - 101 min) than dark reversion of 118 kdalton or 60 kdalton Pfr. Low temperature spectroscopy of the 39 kdalton fragment showed that the intermediates lumi-R and meta-Ra are formed like in intact phytochrome or 60 kdalton or 114/118 kdalton fragments. It is discussed that limited proteolysis removed that part of the peptide chain which is responsible for the interaction with the Pfr chromophore but that the site for interaction with the chromophore of Pr and the intermediates lumi-R and meta-Ra is still intact.
Potassium and Rubidium Effluxes in Saccharomyces cerevisiae
Authors: Ortega María D . , Rodríguez-Navarro Alonso
Published: August 2018

In growing cells, K+ and Rb+ effluxes followed first order kinetics, took place with slight differences between K+ and Rb+ and were stimulated at acidic pH values. In uncoupled cells and ATP-depleted cells, K+ efflux was higher than Rb+ efflux. In ATP-depleted cells, the effluxes were not stimulated at acidic pH values. Two different K+ effluxes are proposed: (i) the normal efflux, which may be a K+/H+ antiport and does not function in ATP-depleted cells, and (ii) the backward reaction of the uptake system, which can be high in depolarized cells. The role of the normal efflux system in K+ content and pH regulation is discussed.
Molecular Mechanics Investigation on Conformational Flexibility of 14β Steroids in Drug-Receptor Interactions
Authors: Bohl Martin , Wunderwald Manfred
Published: August 2018

The interaction between two 14 β steroids being still unsynthesized and a model receptor binding site is theoretically studied by a molecular mechanics scheme. Both com pounds containing seven-membered rings in the 17 β position are found to form stable hydrogen bonds to the receptor and can be attributed to be potential inhibitors of the Na +,K + -ATPase activity. Substantial steroid conformational changes necessary for an efficient receptor binding are calculated to reduce the interaction energy by only 10 kJ mol -1. Therefore, alterations in steroid structure should be generally taken into consideration in the investigation of steroid-receptor interactions.
The Anal Sac Secretion of Viverrids from the Genus Genetta
Authors: Jacob Jürgen , Schliemann Harald
Published: August 2018

The chemical composition of the secretions from the anal sacs of three species from the genus Genetta has been analysed by means of gas-liquid chromatography and mass spectrometry. The main constituents of the secretion are free fatty acids, hydrocarbons, mono- and diester waxes, triglycerides, alkane diols, and free alcohols. Composition of the secretion in the three species is fundamentally similar, but there are some remarkable quantitative differences of the components m entioned. Some of the alkane-1,2-diols in these secretions have never been found before in nature.
A Chemical Investigation of Pueraria mirifica Roots
Authors: Ingham John L. , Tahara Satoshi , Dziedzic Stanley Z.
Published: August 2018

Ten isoflavonoids including daidzein, daidzin (daidzein-7-O-glucoside), puerarin (daidzein-8- C-glucoside), genistein and coumestrol have been isolated from a methanolic extract of Pueraria mirifica roots. Apart from these known compounds and mirificin, a novel apioside derivative of puerarin, the roots have also been found to contain three minor coumestans and one 5-deoxyisoflavone for which only limited spectroscopic data are currently available.
Differential Regulation of Two Genes Controlling the Biosynthesis of Isovitexin 7-O-Galactoside in Silene Plants
Authors: Steyns Jan M.
Published: August 2018

The expression of the allelic isovitexin 7-O-glycosylation genes gG (transfer of glucose) and gX (transfer of xylose) was studied in cotyledons, rosette leaves, stem leaves and petals of Silene plants. These studies revealed that gG is expressed in all ontogenetic stages, whereas its allele gX is only expressed in the petals. In the vegetative parts of gX individuals 7-O -xylosylation is replaced by 7-O-galactosylation. The possibility that gX encodes an enzyme activity that catalyzes different reactions in the petals and the vegetative parts resulting in the accumulation of the 7-O-xyloside and the 7-O-galactoside respectively, has been disproved. It is shown that there are two different enzymes catalyzing the biosynthesis of isovitexin 7-O-galactoside. These 7-O -galactosyl-transferase activities differ with respect to heat inactivation, pH optimum , flavone acceptor specificity and Michaelis-Menten enzyme kinetic parameters. The genes controlling these enzyme activities are regulated differentially, with gene O7g (described previously by Steyns et al. [11]), expressed in the cotyledons and the rosette leaves and Xgal in the stem leaves and petals.
Flavin Nucleotide-Dependent 3-Hydroxylation of 4-Hydroxyphenylpropanoid Carboxylic Acids by Particulate Preparations from Potato Tubers
Authors: Boniwell Jeremy M. , Butt Vernon S.
Published: August 2018

Particulate preparations from potato tubers, extracted in 4 mᴍ 2-m ercaptoethanol, catalyze the 3-hydroxylation of 4-hydroxyphenylpropanoid carboxylic acids, including p-coumaric acid and tyrosine, in the presence of NADH (or NADPH) and FAD (or FMN); ascorbate could not substitute for these electron donors. Among a range of 4-hydroxylated C6-C2 and C6-C1 compounds tested, only 4-hydroxyphenylacetic acid and p-cresol were hydroxylated. The hydroxylase was sensitive to KCN and diethyldithiocarbam ate and showed some features of phenolase hydroxylation, but no DOPA oxidase nor chlorogenic acid oxidase activity was exhibited under these conditions. It is suggested that the phenolase complex, which is confined to potato tuber particles, in whole or part catalyzes the hydroxylation.
Properties of Vinorine Synthase — the Rauwolfia Enzyme Involved in the Formation of the Ajmaline Skeleton
Authors: Pfitzner Artur , Polz Leo , Stöckigt Joachim
Published: August 2018

Vinorine synthase, a key enzyme in the formation of the Rauwolfia alkaloid ajmaline and its derivatives, has been isolated from Rauwolfia serpentina cell suspension cultures. The new enzy­me has been 160-fold purified and characterized in detail. The synthase catalyses a single step in the biosynthesis of ajmalan alkaloids by the acetyl-coenzyme A and 16-epi-vellosimine dependent formation of vinorine, which shows the basic ajmaline skeleton. Besides a characteristic substrate specificity the major properties of the enzyme are a relatively high pH optimum (pH 8.5), a temperature optimum of 35 °C, an isoelectric point of pH 4.4, and a relative molecular weight of 31000 ± 8%. The apparent Km values for 16-epi-vellosimine and acetyl-coenzyme A were 19.4 μm and 64 μm resp. for the formation of vinorine. Kinetic data of the catalysed reaction indicate that 17-deacetylvinorine is not involved as a free intermediate during the vinorine biosyn­thesis. Vinorine was proved by in vivo feeding experiments to be the biosynthetic precursor of the alkaloids in the final stages of the ajmaline pathway, vomilenine (21-hydroxyvinorine), 17-O-acetylnorajmaline and 17-O-acetylajmaline.
Partial Purification and Characterization of S-Adenosyl-ʟ-Methionine: Norreticuline N-Methyltransferases from Berberis Cell Suspension Cultures
Authors: Wat Chi-Kit , Steffens Paul , Zenk Meinhart H.
Published: August 2018

Two new N-methyltransferases (NMT-I and NMT-II) were found to occur in Berberis vulgaris cell suspension cultures. One of these enzymes (NMT-I) was partially purified (100-fold) and characterized. This enzyme is specific for tetrahydrobenzylisoquinoline alkaloids and S-adenosyl-ʟ-methionine serves as the methyl donor. The apparent molecular weight of the enzyme is 68,000. The pH optimum of the enzyme is 7.6, the temperature optimum 35 °C. Apparent KM values for (R)-tetrahydropapaverin as substrate were 0.2 mᴍ and for SAM 0.04 mᴍ. The preparation of the same type of enzyme from B. wilsoniae var. subcaulialata was utilized as an efficient enzymatic system for the synthesis of stereochemically pure (R)-as well as (S)-reticuline labelled with tritium or 14C at the N-CH3 group. Enzymes catalyzing this type of reactions are named S-adenosyl-ʟ-methionine: norreticuline N-methyltransferases.
Green Algae (Scenedesmus obliquus) Contain Three Thioredoxins of Regular Size
Authors: Langlotz Petra , Wagner Wolfgang , Follmann Hartmut
Published: August 2018

A comprehensive thioredoxin profile of Scenedesmus obliquus has been established by chromatography of heat-stable protein extracts on five different ion exchange, gel permeation, and affinity chromatography columns and using three different assay systems including homolo­gous S. obliquus ribonucleotide reductase, chloroplast fructose-bis-phosphatase, and NADP malate dehydrogenase. Four different thioredoxins were purified to homogeneity. Besides the large chloroplast thioredoxin f described previously, the algae contain three proteins of molecular weight 12,000 designated thioredoxin I, II, and III. They bind specifically to antibodies against E. coli thioredoxin. Chloroplast-free mutant algae (strain C-2A′) lack thioredoxin f but contain all three regular thioredoxins. Species I and II have very similar amino acid composition and enzyme-stimulating activities. They are considered cytoplasmic thioredoxins which serve as hydrogen donors in algal deoxyribonucleotide biosynthesis. Thioredoxin III is of low activity towards all the presently tested enzymes and its physiological role remains unknown; its role as a glutaredoxin could be excluded. All non-photosynthetic plant cells analyzed so far (mutant algae, seeds, and roots) contain a set of three regular-size thioredoxins.
Changes in Levels of Cellular Constituents in Suspension Culture of Catharanthus roseus Associated with Inorganic Phosphate Depletion
Authors: Ukaji Toshiko , Ashihara Hiroshi
Published: August 2018

Changes in growth and the level of various cellular constituents were monitored for 96 h after transfer of stationary phase cells of Catharanthus roseus to fresh complete (“+Pi”) or phosphate deficient (“-Pi”) Murashige-Skoog medium. In the cultures transferred to “+Pi” medium, cell number and fresh weight increased rapidly after an initial lag period, while little or no increase in cell number or fresh weight was observed in cultures transferred to “-Pi” medium. The levels of ATP, glucose-6-phosphate (G6P), fructose-6-phosphate (F6P), RNA and protein, increased in the cultures in “ + Pi” medium, while the levels of free amino acids decreased. In contrast, we found a decrease in the levels of ATP, G6P and F6P and an increase in the levels of free amino acids in the cultures in “-Pi” medium. Appreciable DNA synthesis was observed only in cells growing in “+Pi” medium, at 72 h after cell transfer. The rate of RNA synthesis in the “+Pi” culture was generally higher than that in the “-Pi” culture. The levels of ethanol soluble-phenolic compounds increased transiently in the cells grown in both media just after cell transfer, but the level in the “+Pi” culture decreased progressively with cell division.

The metabolic role of inorganic phosphate in metabolism of Catharanthus roseus cells is discussed.
C9 Aliphatic Aldehydes: Possible Sex Pheromone from Male Tropical West African Shield Bug, Sphaerocoris annulus
Authors: Gough A. J. E. , Games D. E. , Knight D. W. , Olagbemiro T. O.
Published: August 2018

By gas chromatography-mass spectrometry, 1H NMR , and synthesis of authentic standards, the secretion from the abdominal dorsal scent gland of male adults of Sphaerocoris annulus has been found to contain a mixture of C9 aliphatic aldehydes: nonanal (3%), (Z)-4-nonenal (13%), (E)-4,8-nonadienal (23%) and (Z)-4,8-nonadienal (56%). A further component was tentatively iden­tified as 8-nonenal (5%).
Individual Variation in the Sex Pheromone Components of the False Codling Moth, Cryptophlebia leucotreta (Lepidoptera: Tortriciade)
Authors: Attygalle Athula B. , Schwarz Jürgen , Vostrowsky Otto
Published: August 2018

Analysis of individual pheromone glands of the false codling moth Cryptophlebia leucotreta Meyr. originating from South Africa, was performed by capillary gas chromatography. During the calling period, the pheromones are concentrated in the dorsal part of the intersegmental membrane between the abdominal segments V III and IX . The average amount of pheromones and related compounds present in the gland was 412 ng/♀ . This total amount was highly variable from individual to individual (200-740 ng/♀). However, the relative amounts of (Z)- and (E)-8- dodecenyl acetates showed a narrow variance. The coefficients of variance values of these two components, 10 and 19 respectively, were significantly lower than those of other components present in the gland.

The results infer that the different isomer ratios of (Z)- and (.E)-8-dodecenyl acetates reported for C. leucotreta cannot be due to individual variations. Hence, the presence of different geographical strains can be expected.
Relative Potencies of Antagonists of the Luteinizing Hormone Releasing Hormone with Lys8 and Arg8 and Substitutions in Positions 3 ,5 ,6 ,7 and 8
Authors: Folkers Karl , Bowers Cyril , Tang Pui-Fun L. , Kobota Minoru , Shao-bo Xiao , Bender Wolfgang , Yin-Zeng Liu
Published: August 2018

Antagonists of the luteinizing hormone releasing hormone (LHRH) of increased potency is a goal for control of ovulation. In the design and synthesis of 26 decapeptides, emphasis was given to analogs with Lys8 and Arg8 and with various substitutions in positions 3, 5, 6, 7 and 8. Two antagonists, [N-Ac-ᴅ-2-Nal1,ᴅ-pClPhe2,ᴅ-3-Pal3,Ser4,Tyr5,ᴅ-Arg6,Leu7,Lys8,Pro9,ᴅ-Ala10] - NH2 and [N-Ac-ᴅ-2-Nal1.ᴅ-pClPhe2,ᴅ-3-Pal3,Ser4,Arg5,ᴅ-3-Pal6,Leu7,Arg8,Pro9,ᴅ-Ala10]-NH2 showed 80-85% antiovulatory activity (AOA) at 0.25 μg in the rat. The latter antagonist showed 60% AOA at 0.125 μg. Of four pairs of analogs with Arg8 and Lys8, respectively, two pairs favored Lys8 over Arg8 for potency. One pair showed negligible difference and another pair favored Arg8 over Lys8. There is specificity of substitution for potency. In other antagonists, ᴅ-3- Pal3, Tyr5 or Phe5, ᴅ-Arg6 and Leu7 or Nle7 or Val7 and Arg8 were variously effective substitutions for increase of potency and reduction of histamine release.
Vorarbeiten zu einer Monographie der Flechtenfamilie Roccellaceae Chev. VII. Inhaltsstoffe und Verwandtschaftsbeziehungen der Gattungen Combea de Not. und Schizopelte T. M. Fries / Preliminary Studies towards a Monograph of the Lichen Family Roccellaceae Chev. VII. Secondary Products and Relationships of the Genera Combea de Not. and Schizopelte T. M. Fries
Authors: Follmann Gerhard , Geyer Mechthild
Published: August 2018

The spectra of secondary products of Combea mollusca (Ach.) de Not. (Namibia) and Schizopelte californica T. M. Fries (California) proved to be qualitatively and quantita­tively identical. Lecanoric acid (depside) and schizopeltic acid (dibenzofuran) are first records for the genus Combea. For chemical, morphological, anatomical, ontogenetical, and ecological reasons both genera should be united: Com­bea (incl. Schizopelte, Roccellaceae, Arthoniales, Locu-loascolichenes).
An Improved Procedure for the Quantitative Estimation of the Rust Fungus in Infected Plant Tissue
Authors: Wiese Gertrud , Hugo-Wissemann Doris , Grambow Hans J.
Published: August 2018

A quantitative estimation of the rust fungus in infected wheat leaves was possible following enzymatic hydrolysis of the chitin and colorimetric determination of the N-acetyl-glucosamine released. The apparently complex cell wall structure of the fungal structures made it necessary, however, to use an enzyme mixture of chitinase and cellulase in order to make accessible the chitin of the cell wall for diges­tion by chitinase. In applying this method the measurement is not appreciably influenced by already formed uredio-spores as would otherwise be the case were the chitin to be determined on the basis of glucosamine after chemical hydrolysis.
Low Molecular Mass Inhibitors from Calf Thymus Selective for T-Lymphocyte Proliferation
Authors: Matthiessen H. Peter , Maurer H. Rainer
Published: August 2018

Endogenous factors preferentially inhibiting T-lymphocyte proliferation were prepared from the acetone precipi­tate of a 60% ethanol extract from calf thymus and their biochemical properties examined. By ultrafiltration the strongest lymphocyte-selective inhibition was found in the molecular mass range between 1 and 5 kDa. Fast protein liquid chromatography (FPLC) of this fraction on an anion exchange column eluted the lymphocyte inhibitors at 205-265 mᴍ ammonium acetate. Staining procedures following IEF and TLC suggested, that the inhibitors may not be glycoconjugates or amines but small weakly acidic peptides (< 3 kDa).
Changes in Fructose-2,6-bisphosphate Level during the Growth of Suspension Cultured Cells of Catharanthus roseus
Authors: Ashihara Hiroshi
Published: August 2018

The level of fructose-2,6-bisphosphate (F2,6BP), a potent regulator of carbohydrate metabolism , varied from 23 to 448 pmol·g fresh weight-1 during the growth of the cells of Catharanthusroseus in suspension culture. The maximum F2,6BP level was found in the cells at the lag phase of the growth, and its level decreased with cell division and enlargement.
Biosynthesis of Pyoluteorin: A Mixed Polyketide-Tricarboxylic Acid Cycle Origin Demonstrated by [1,2-13C2]Acetate Incorporation
Authors: Cuppels D. A. , Howell C. R. , Stipanovic R. D. , Stoessl A. , Stothers J. B.
Published: August 2018

The incorporation of [1,2-13C2]acetate into the bacterial phytotoxin pyoluteorin (1) as determined by 13C NMR spectroscopy occurs in a pattern consistent with the biosynthesis of the molecule as a tetraketide in which proline, or an equivalent precursor derived from the TCA cycle, serves as the starter unit.
Stimulation of Photorespiration by the Carbonic Anhydrase Inhibitor Ethoxyzolamide in Chlorella vulgaris
Authors: Shiraiwa Yoshihiro , Schmid Georg H.
Published: August 2018

Ammonia was excreted at high rates in the presence of L-methionine sulfoximine (L-MSO) from Chlorella cells which have been grown and analyzed at normal CO2 partial pressure (330 ppm ). If these cells are analyzed at high CO2-concentration (3% CO2 in air) only little ammonia is excreted in the presence of L-MSO. In the absence of L-MSO no ammonia is excreted under either condition. In agreem ent with this observation Chlorella cells grown under high CO2 partial pressure (3% CO2 in air) but tested under normal CO2 partial pressure excreted only very little ammonia. Under these conditions neither “High CO2-cells” nor “Low CO2-cells” exhibited any glycolate excretion. However, glycolate excretion was observed in the presence of a-HPMS (a-hydroxy-2-pyridyl methanesulfonate) an inhibitor of glycolate dehydrogenase or INH (isonicotinyl hydrazide) an inhibitor of the glycine-serine am inotransferase, irrespective of the presence or absence of L-M SO. INH inhibited ammonia excretion. The above described high ammonia excretion in “Low CO2-cells” in the presence of L-MSO was suppressed or substantially reduced by 0.1 mм ethoxyzolamide an inhibitor of carbonic anhydrase which, however, at the same time caused a substantial excretion of glycolate into the medium. The same qualitative effect of ethoxyzolam ide was observed in “High CO2-cells” (tested under normal CO2 partial pressure) although the amount of glycolate excreted in this type of culture was very small. It was generally noted that glycolate excretion caused by ethoxyzolamide was stoichiometrically always more important than the rate of ammonia excretion which was inhibited. This shows that excretion and therefore most probably also the formation of glycolate are enhanced by ethoxyzolamide. The experiments seem to show that due to the inhibition of carbonic anhydrase the affinity of the ribulose-1,5-bisphosphate carboxylase/oxygenase system is increased towards oxygen, which leads to a stimulation of the photorespiratory carbon cycle.
The Photosynthetic Apparatus of Ectothiorhodospira halochloris 2. Accessibility of the Membrane Polypeptides to Partial Proteolysis and Antenna Polypeptide Assignments to Specific Chromophores
Authors: Steiner R. , Angerhofer A. , Scheer H.
Published: August 2018

E. halochloris thylakoids and spheroplasts were treated with trypsin, thermolysin or proteinase K to determine which proteins are exposed at the different membrane surfaces. Based on SDS polyacrylamide analysis, all 9 polypeptides are exposed on the cytoplasmic side. Only one (28 kDa) is accessible from the periplasmic side. This polypeptide is generally isolated as the H-subunit of the reaction centers of photosynthetic bacteria, but is in the case of E. halochloris rather isolated with the antenna (B 800/1020) (Steiner and Scheer, Biochim . Biophys. Acta 807, 278, 1983).

Proteolysis is accompanied by a shift of the absorption band at longest wavelengths from 1020 to 960 nm (B 800/960), which upon standing is shifted further to 680 nm (“B” 800/680). The spectral changes are similar to the ones reported earlier for treatment with acid, and are also inducible with urea. The correlation of SDS-PAGE and absorption spectroscopy shows, that the chroophores absorbing at 1020 nm are transformed sim ultaneously with the degradation of the 6.5 kDa (=α) polypeptide.
Effects of Pyridazinone Herbicides during Chloroplast Development in Detached Barley Leaves III. Effects of SAN 6706 on Photosynthetic Activity and Chlorophyll-Protein Complexes
Authors: Laskay G. , Lehoczki E. , Dobi A. L. , Szalay L.
Published: August 2018

The photosynthetic activities of barley leaves in vivo and of thylakoids, isolated from the leaves, in vitro were studied during greening in the presence or absence of 2 × 10-4 м SAN 6706. The degree of chlorophyll bleaching increased from 32% at 24 h of greening to 60% at the final stage. Treated leaves were unable to carry out 14CO2-fixation, their fluorescence induction properties showed very limited, if any, photosystem II-activity, and the thylakoids isolated from the leaves were also inactive in mediating ferricyanide Hill reaction. The leaves, however, exhibited lightinduced quenching of fluorescence revealed by slow fluorescence induction measurements; and the thylakoids were active in mediating photosystem I-specific in vitro Mehler reaction. Thylakoid membranes of the chloroplasts isolated from treated leaves contained CP 1 and LHCP3 bands as revealed by polyacrylamide gel electrophoresis. From these results it is concluded that i) greening in the presence of SAN 6706 leads to the formation of inactive photosystem -II units; that ii) photosystem-I per se is active in vitro, and can, possibly, mediate cyclic electron transport in vivo coupled to the formation of ATP; and that iii) the presence of xanthophyll pigments is required for the assembly of the light-harvesting complex.

The experiments were repeated with the application of SAN 9789, another pyridazinone compound, and yielded practically the same results as those obtained with SAN 6706. For practical reasons, only the results obtained with SAN 6706 are demonstrated throughout this communication.
Structure Investigations of Agonists of the Natural Neurotransmitter Acetylcholine, V [1]. Structure-Activity Correlations for Cholinergic Stimulants Derived from Crystal Structures of Their Halides
Authors: Gieren Alfred , Kokkinidis Michail
Published: August 2018

General features of crystal structures of halide salts of cholinergic stimulants can be interpreted in terms of substrate-receptor interactions. The monoatomic counterions in the crystal structures are discussed as models for the binding site of the receptor with respect to the ammonium group of the cholinergic neurotransmitters. In the crystal structures the anions occupy the tetrahedral faces of the quaternary trimethylammonio methyl or related groups in a specific geometry. Crystallographic and pharmacological evidence indicates that these groups should preferentially interact with the receptor via a specific face type (B-type face). The directionality of the interaction is derived from the vectors joining N+ with the anions occupying B-type faces. So called “activity triangles”, formed by the nitrogen of the ammonium group, a second polar centre of the neuro-transmitter cation and a counterion occupying a B-face of the ammonium group, provide a structural criterion for the differentiation between muscarinic and nicotinic activity. It is shown that structure-activity relationships of cholinergic stimulants do not depend on the conformational details of the neurotransmitter cations, but primarily on the relative positions of the polar centres of the cations with respect to the anionic binding site of the receptor.
Antipeptide Antibodies: Do They Distinguish HLA-Alloantigens?
Authors: Chersi Alberto , Houghten Richard A. , Zelaschi Daniela , Cenciarelli Cristina
Published: August 2018

Three immune sera, raised in rabbits against synthetic peptides corresponding in sequence to predetermined regions of the HLA-DQ histocompatibility antigens, were tested for their ability to recognize phenotypicallv distinct human lymphoblastoid cell lines.

The immune sera readily recognize the immunogen. When tested on the cells, they react poorly but seem to exhibit a certain degree of specificity.

The possibilities in developing true selective reagents for HLA-alloantigens are considered and discussed.