bluuebunny/crossref_metadata_2025 huggingface dataset:
Biosynthesis of Acridone Alkaloids. A Cell-Free System from Ruta graveolens Cell Suspension Cultures
Authors: Baumert A. , Schneider G. , Gröger D.
Published: August 2018

A cell-free extract of Ruta graveolens cell suspension cultures, strain R-20, was prepared which synthesizes 1,3-dihydroxy-N-methylacridone from N-methylanthranilic acid and malonylcoenzyme A. The reaction is strongly dependent on the presence of ATP. After adding of coenzyme A to the assay mixtures a second compound X2 is accumulated to a considerable extent. The structure of this substance has not yet been clarified. Apparently X2 is a precursor of 1,3-dihydroxy-N-methylacridone, the key intermediate in the pathway leading to more complex acridones.
Plant Biochemistry of Xenobiotics. Mineralization of Chloroaniline/Lignin Metabolites from Wheat by the White-Rot Fungus, Phanerochaete chrysosporium
Authors: Arjmand Masood , jr. Heinrich Sandermann
Published: August 2018

The lignin metabolites formed in wheat plants from [ring-u-14C]-4-chloroaniline and -3,4-dichloroaniline were isolated by a Björkman-type procedure and characterized by gel permeation chromatography and chemical degradation. The isolated metabolite fractions were then incubated with the white-rot fungus, Phanerochaete chrysosporium.

Mineralization to [14C]carbon dioxide occurred in high yields, about 65% of the initial radio­activity of the lignin-bound chloroanilines being trapped as CO2 after an incubation period of 32-33 days. The lignin metabolites with the 14C-label in the aromatic ring of the chloroanilines were mineralized as readily as a non-xenobiotic control lignin with a 14C-label in the aromatic ring of coniferyl alcohol.

It is concluded that the white-rot fungus studied has an unusually high capacity for the removal of chloroanilines and possibly other xenobiotic contaminants from the environment.
Biosynthesis of Flavor Compounds by Microorganisms 6. Odorous Constituents of Polyporus durus (Basidiomycetes)
Authors: Berger R. G. , Neuhäuser K. , Drawert F.
Published: August 2018

The neutral volatile constituents produced by shake flask cultured mycelium of Polyporus durus comprise aliphatic and aromatic alcohols, lactones and various carbonyl compounds, and sesquiterpenoids. The occurrence of five 2,3-unsaturated 4-olides (γ-lactones), some of which were identified for the first time in nature, is characteristic of the fungus. The presence of a synthetic triglyceride in the nutrient medium strongly favors the formation of lactones and other volatile flavor compounds.
Content and Metabolism of Indole-3-acetic Acid (IAA) in Healthy and Rust-Infected Wheat Leaf Segments
Authors: Wiese Gertrud , Grambow Hans J.
Published: August 2018

The content of IAA in stem rust-infected susceptible wheat leaves shows a highly pronounced maximum 5-6 days after inoculation, shortly prior to the onset of sporulation. This auxin increase can not only be caused by a reduced degradation of IAA. Considerable amounts of IAA are also found in urediospores and germlings; the IAA is in part released by them into the germination medium.

IAA applied exogenously to wheat leaves is channelled into two different degradation path­ways: (a) into the peroxidase-catalysed decarboxylation which leads to indole-3-methanol and subsequent products as well as into (b) a non-decarboxylative path which leads to a number of oxindolic compounds. Furthermore, IAA conjugates such as IAAglc and IAAsp are formed. The formation of the products is characteristically dependent upon the concentration of the IAA applied.

In rust fungus-infected wheat leaves, all IAA metabolites occur which are known in healthy leaves. The mode of their formation after “feeding” of radioactively-labelled IAA leads to the conclusion that the main part of the IAA in the infected leaves is present in a pool which does not permit a rapid exchange with the IAA taken up. The results lead to the hypothesis that IAA is present, to a major extent, in the structures of the fungus and is probably also produced by it.
The Production of Pyrenocines A and B by a Novel Alternaria species
Authors: Tal Beni , Robeson David J.
Published: August 2018

A previously undescribed species of Alternaria was isolated from the leaves of Helianthus tuberosus bearing necrotic lesions. When this isolate was grown in liquid medium two phytotoxic metabolites were produced. These compounds were identified as pyrenocine A and pyrenocine B. The former metabolite was found to be lethal to both isolated protoplasts and whole leaf tissue of Helianthus.
Screening and Use of Sex Attractants in Monitoring of Geometrid Moths in Bulgaria
Authors: Subchev Mitko A. , Ganev Julius A. , Vostrowsky Otto
Published: August 2018

Four candidate sex attractants for geometrid moths have been screened individually and in mixtures. As a result, in addition to the confirmation of the known sex attractants of Operophtera brumata L. and Alsophila aceraria Denis & Schiff (= A. quadripunctata Esper), possible sex attractants for five other geometrid species have also been established. For O. brumata and A. aceraria an inhibitor has been found. For the same species the possibility for seasonal monitoring by means of sex pheromone traps was demonstrated.
Evidence for the Presence of Glycerophosphonolipids in the Land Snail Eobania vermiculata
Authors: Moschidis Michael C.
Published: August 2018

Total phosphonolipids from the land snail have been iso­lated by thin-layer chromatography (TLC) using the sol­vent system methanol-water (2:1) and have been sub­jected to silicic acid column chromatography. The fraction eluted with 40% methanol in chloroform has been ob­tained, the single species isolated by these means has been identified as the phosphono analog of phosphatidyl choline and has been fully characterized by TLC, IR spectroscopy, elemental analysis and phosphono-phosphorus determina­tions.
Specificity of Rabbit Antibodies Elicited by Related Synthetic Peptides
Authors: Chersi Alberto , Houghten Richard A. , Chillemi Francesco , Zito Romano , Centis Dora
Published: August 2018

Three 17-residue peptides, presenting from 65% to 70% sequence homology, and one endecapeptide, with no apparent homology with the first three, were chemically synthesized and investigated in their ability to elicit rabbit antipeptide antibodies.

The complex crossreactivities of the antisera were investigated by testing the binding of the antibodies to the intact peptides, to their enzymatic fragments, and by the use of specific immunoadsorbents.

Antipeptide antibodies may or may not crossreact with related “parent” peptides, this depending upon number, distribution, and localization of amino acid differences in low or high antigenicity regions of the immunogen.

Related peptides may elicit antibodies that crossreact almost completely, and therefore not specific for one or the other “parent” peptide. Those the selective recognition of closely related structures.
Is the Calcium Pump Involved in Calcium Release?
Authors: Ungeheuer Martina , Migala Andrea , Hasselbach Wilhelm
Published: August 2018

The blockage of all thiol residues accessible to the mercurial mersalyl in the sarcoplasmic reticulum membranes resulting in complete inactivation of the membranes’ calcium transport system does interfere neither with caffeine- nor calcium-induced calcium release from actively loaded membrane vesicles.
The Sensitivity of the Ventral Nerve Photoreceptor of Limulus Recovers after Light Adaptation in Two Phases of Dark Adaptation
Authors: Claßen-Linke I. , Stieve H.
Published: August 2018

The time course of the recovery of the sensitivity of the Limulus ventral nerve photoreceptor was measured during dark adaptation following light adaptation by a bright 1 or 5 s illumination. The stimulus intensity ICR of a 300 μs light flash evoking a response of criterion amplitude (receptor potential or receptor current under voltage clamp conditions) was used as measure of sensitivity.

The time course of dark adaptation shows two phases with time constants in the range of 5-9 s and 300-500 s (15 °C). Only the first of the two phases is significantly changed when the extracel- lular Ca2+-concentration is varied.

The power function ICR = a·Io-tDA
-b gives a good data fit for each of the two phases of dark adaptation. In the first phase the factor ax and the exponent bx are decreased when the external calcium is lowered from 10 mmol/1 to 250 μmol/1. Conversely a1 and b1 are increased when the Ca2+-concentration is raised to 40 mmol/1. For the second phase neither a2 nor b2 is changed significantly upon the changes in calcium concentration in the same experiments.

The two phases of dark adaptation reflect the behaviour of the two components C1 and C2 of the electrical light response (receptor potential or receptor current). Under the conditions described here C, determines the size of the light response during the first phase of dark adaptation whereas C2 mainly influences the size of the response during the second phase.

Interpretation: The fast first phase of dark adaptation is determined by the change in intracellu- lar Ca2+-concentration. The slower second phase of dark adaptation is not primarily calcium- controlled.
A Furanoheliangolide in Helianthus debilis; Implications for a Chemotaxonomy of the Genus Helianthus
Authors: Spring Otmar , Klemt Volker , Albert Klaus , Hager Achim
Published: August 2018

Leaves from Helianthus debilis subsp. cucumerifolius yielded the furanoheliangolide 17,18-dihydrobudlein A . The same compound has been previously isolated from Viguiera hemsleyana, V. procumbens and Helianthus strumosus. 17,18-dihydrobudlein A revealed strong antimicrobial, insecticidal and plant growth inhibiting activity. Its distribution within the plant is restricted to the leaves. Implications for the chemotaxonomy of the genus Helianthus are discussed.
Substrate-Dependent Arylsulfatase Activity in the Cyanobacterium Plectonema 73110
Authors: Müller Sonja , Schmidt Ahlert
Published: August 2018

Plectonem a, Arylsulfatase. Thiosulfate R eductase, Substrate Induction, Cyanobacteria Arylsulfatase activity of the cyanobacterium P lectonem a 73110 is detected during growth on p-nitrophenyl sulfate as only sulfur source. A 60-fold purification of the soluble arylsulfatase yields a protein with an pH-optim um around 10 and K m data for p-nitrophenyl sulfate of 9.5 × 10" 5 and for nitrocatechol sulfate of 3.4 × 10-5. The enzym atic activity is not effected by the cations Mg2-, M n2+, K 2+ or Na + used as chloride salts. The anions SO3
2- and SO4
2-did not inhibit this activity, how ever EDTA , thiols and triton X -100 decreased this activity to about 25% w here­ as SDS inhibited com pletely. Sulfate limitation is necessary for the developm ent of arylsulfatase activity in the presence of its substrate p-nitrophenyl sulfate. This arylsulfatase activity is partly bound to m embranes.
Biochemical Properties and Crystal Structure of Ethylmethylglyoxal Bis(guanylhydrazone) Sulfate — an Extremely Powerful Novel Inhibitor of Adenosylmethionine Decarboxylase
Authors: Elo Hannu , Mutikainen Ilpo , Alhonen-Hongisto Leena , Laine Raija , Janne Juhani , Lumme Paavo
Published: August 2018

Ethylmethylglyoxal bis(guanylhydrazone) (EMGBG) sulfate, an analog of the well-known antileukemic drug methylglyoxal bis(guanylhydrazone), was synthesized. It was shown to be an extremely powerful competitive inhibitor of eukaryotic S-adenosyimethionine decarboxylase, with an apparent Ki value 12 nᴍ. Thus, it appears to be the most powerful known inhibitor of the enzyme, being almost an order of magnitude more powerful than the corresponding ethylglyoxal derivative. It neither inhibited the proliferation of mouse L1210 leukemia cells in vitro, nor did it potentiate the growth inhibition produced by α-difluoromethyl ornithine. In this respect, its properties are closely related to those of dimethylglyoxal, ethylglyoxal and propylglyoxal bis(guanylhydrazones), while in striking contrast to those of the antiproliferative glyoxal and methylglyoxal analogs. EMGBG also inhibited intestinal diamine oxidase activity (Ki 0.7 μᴍ). EMGBG sulfate was crystallized from water, giving orthorhombic crystals (space group Pbcn). Their crystal and molecular structure was determined by X-ray diffraction methods. The carbon-nitrogen double bonds between the ethylmethylglyoxal part and the aminoguanidine moieties were found to have the same configuration as they are known to have in the salts of glyoxal. methylglyoxal and propylglyoxal bis(guanylhydrazones). The glyoxal bis(guanylhydrazone) chain of the EMGBG cation deviated strongly from planarity, thus differing dramatically from the corresponding chains of the glyoxal, methylglyoxal and propylglyoxal analogs.
Diethyldithiocarbamate, a New Photosystem I Electron Donor of Mehler-Type Hill Reactions
Authors: Upham Brad L. , Hatzios Kriton K.
Published: August 2018

Diethyldithiocarbamate (DEDTC) does not accept electrons from the photosynthetic electron transport (PET) but can donate electrons to a photosystem I (PSI) Mehler reaction in the pres­ence of the following PET inhibitors: DCMU. DBMIB, and bathophenanthroline. It cannot photoreduce PSI in the presence of cyanide, a PET inhibitor. These data indicate that the site of electron donation is after the plastoquinone pool. Ascorbate is not required for the ability of DEDTC to donate electrons to PSI. There is no photoreductant activity by DEDTC inferredoxin/NADP Hill reactions. Superoxide dismutase inhibits DEDTC/DCMU or bathophenanthroline→methylviologen/O2 Mehler reaction. Catalase does not recover the consumed O2 from a DEDTC/DCMU→methylviologen/O2 Mehler reaction, indicating O2
- has not been dismutating into H2O2. These results indicate that superoxide is required for DEDTC ability to donate electrons, therefore DEDTC is limited only to Mehler-type reactions.
Phenolic Herbicides: Correlation between Lipophilicity and Increased Inhibitory Sensitivity of Thylakoids from Higher Plant Mutants
Authors: Durner Jörg , Thiel Andreas , Böger Peter
Published: August 2018

Pheonlic herbicides, being quite hydrophilic as compared to classical photosystem-II inhibitors do not exhibit a correlation between inhibitory activity and partition coefficient. Sensitivity against phenolic herbicides, however, as observed with atrazine-resistant thylakoids from higher plants mutants (Brassica napus) is increased by higher partition coefficients.
On the Direct Observation of Water-FIuxes in Tissues and Leaves
Authors: Hirth Ulrich-Andreas , Lawaczeck Rüdiger
Published: August 2018

Based on the different absorption spectra of H2O and D2O in the near infrared (NIR, 800-2200 nm) a strategy is developed to measure H2O/D2O-fluxes in thin sections. The physical background of the method is presented. Results on the H2O/D2O-fluxes in filter paper and plant leaves together with both the physical and biological limitations of the new method are discussed.
Induction and Characterization of a NADPH-Dependent Flavone Synthase from Cell Cultures of Soybean
Authors: Kochs Georg , Grisebach Hans
Published: August 2018

Microsomal preparations from osmotically stressed soybean cells catalyze the conversion of (2S)-naringenin to apigenin in presence of NADPH. In contrast, such preparations from normal soybean cells or from elicitor-challenged cells catalyze the conversion of (2S)-naringenin to genistein (isoflavone synthase). It is concluded that osmotic stress of the cells causes a switch from isoflavone to flavone synthesis. The flavone synthase from osmotically stressed cells corresponds in its properties to the microsomal flavone synthase found in several flowers (G. Stotz and G. Forkmann, Z. Naturforsch. 36c, 737-741 (1981)) and differs from the flavone synthase I from parsley cell cultures which is a soluble Fe2+ and 2-oxoglutarate dependent dioxygenase.

Flavone synthase II from soybean has an absolute requirement for NADPH and oxygen. It is inhibited by carbon monoxide in presence of oxygen and this inhibition is reversed by light. It is also inhibited by cytochrome c and by a number of cytochrome P-450 inhibitors. This and other properties show that flavone synthase II is a cytochrome P-450 dependent monooxygenase.
Fermentation of D-Xylose to Ethanol by Bacillus macerans
Authors: Schepers Hans-Jürgen , Bringer-Meyer Stephanie , Sahm Hermann
Published: August 2018

In the absence of oxygen Bacillus macerans is able to ferment xylose. The principal products are ethanol, formate,CO2, acetone and H2. The yield of ethanol was 61% based on the theoretical value of 0.51 g per g xylose consumed. The cells could grow in the presence of up to 4% (v/v) of added ethanol but the growth rate was already reduced to about 50% by 1% (v/v) of alcohol. Glucose and the pentoses arabinose and xylose were sequentially utilized when initially present as a mixed substrate. Enzymatic studies indicate that xylose was metabolized via the pentosephos-phate and Embden-Meyerhof pathways. At an oxygen concentration of 1-2% air saturation 42 g/l xylose were completely fermented within 160 h and 10 g/l ethanol were produced.
Site Directed Antisera to the D-2 Polypeptide Subunit of Photosystem II
Authors: Geiger R. , Berzborn R. J. , Depka B. , Oettmeier W. , Trebst A.
Published: August 2018

Three synthetic oligopeptides were used for preparation of antibodies against the D-2 polypeptide of thylakoid membranes. Their sequence was chosen from a model of the folding of the amino acid sequence of the D-2 polypeptide subunit through the membrane that predicted these sequences to be exposed at the membrane surface. For the Merrifield solid-phase method on a fully automated synthesizer the Na-amino group was protected by a fluorenyl-9-methylcarbonyl group. The oligopeptides were coupled to serum albumin by EDAC for immunizations in rabbits.

Antisera with high titer were obtained for the two oligopeptides that contained the amino acid sequence of the D-2 protein from amino acid 230 to 235 and from 235 to 241. The antisera reacted with the D-2 polypeptide, separated on SDS gel and agglutinated the thylakoid membrane.

It is known that certain photosystem II functions are impaired by short time trypsin treatment of the membrane. The antisera were used to show that under these conditions the D-2 polypeptide in the membrane is very sensitive. The trypsination yielded two cleavage products detected by the two antisera, a 20 kDa fragment blotted by antiserum against amino acids 230 to 235 and a 10 kDa fragment blotted by the antiserum against amino acids 235 to 241. As the polypeptide cleavage occurs between the two epitopes, the trypsin cut is therefore at arginine 234. This supports the prediction that the sequence containing this arginine is the most exposed part of the D-2 polypeptide on the membrane (matrix) surface. It is proposed that the high sensitivity of the D-2 polypeptide accounts for the known effect of membrane trypsination on QA accessibility in photosystem II.
Über die ätherischen Öle von Chrysanthemum balsamita L. / On the Essential Oils from Chrysanthemum balsamita
Authors: Strobel Harald , Knobloch Karl , Ziegler Erich
Published: August 2018

The production of essential oil in Chrysanthemum balsamita L. reveals a seasonal dependence. – We conclude that, in blossoms, a dominant influence due to the ontogenetic development of head flowers regulates the production of essential oil. – Freshly harvested head blossoms produced 5 times the amount of oil when compared to fully developed head flowers. Dried leaves contain 5 to 7 times the amount of oil compared to fresh leaves. The composition of the oil from leaves changes more distinctly during the season than the oil from head flowers. Main components of the oil from flowers and leaves are carvon and thujon. During spring and fall, the percentage of sesquiterpenoid hydrocarbons is increased mainly in the oil from leaves. The component β-cubeben can no longer be detected in dried leaves.
Epoxy-trans-isodihydrorhodophytin, ein neuer Metabolit aus Laurencia obtusa / Epoxy-trans-isodihydrorhodophytin, a New Metabolit from Laurencia obtusa
Authors: Imre Sedat , Lotter Hermann , Wagner Hildebert , Thomson Ronald H.
Published: August 2018

Laurencia obtusa, Red Algae, Rhodomelaceae, Acetylenic Ether Epoxy-trans-isodihydrorhodophytin, a new halogenated acetylenic bicyclic ether, has been isolated from a Laurencia obtusa variety, collected in the Marmara sea. Its structure was determined by spectroscopic methods and X-ray diffraction analysis.
Tetraponerine-8, an Alkaloidal Contact Poison in a Neoguinean Pseudomyrmecine Ant, Tetraponera sp.
Authors: Braekman J. C. , Daloze D. , Pasteeis J. M. , Hecke P. van , Declercq J. P. , Sinnwell V. , Francke W.
Published: August 2018

The sting of the Neoguinean pseudomyrmecine ant, Tetraponera sp. (group punctulata) is modified in a structure resembling a drawing pen. These ants do not sting, but smear upon enemies a contact poison. The venom which originates from the poison gland is a mixture of eight alkaloids with an original tricyclic ring system. The structure of the major component, tetra-ponerine-8, has been determined by X-ray diffraction analysis. The poison of Tetraponera is highly efficient in deterring aggressive sympatric ants and tetraponerine-8 shows toxic properties against Myrmica rubra when applied topically, with a LD50 of 5 × 10-4 mg/mg of ants.
Interference by Herbicides with the Transmembrane Potential of Thylakoids
Authors: Moreland Donald E. , Novitzky William P.
Published: August 2018

Interferences expressed by herbicides classified as inhibitory uncouplers were measured on the induction and maintenance of ΔpH and ΔΨ, the chemical and electrical components, respectively. of the proton motive force (pmf) generated by light-induced cyclic electron transport in spinach thylakoids. Maintenance of the pmf is required for the synthesis of ATP. The inhibitory uncouplers arc known to inhibit photophosphorylation, but the mechanisms involved remain to be identified. The dinoseb types (dinitrophenols. benzimidazoles. benzonitriles. bromophenoxim. perfluidone. thiadiazoles) of inhibitory uncouplers, most of which contain dissociable protons, were found to discharge ΔpΗ at low concentrations and to collapse ΔΨ at high concentrations. Collapse of ΔpΗ can be attributed to the protonophoric (proton shuttling) action of the herbicides. However, collapse of ΔΨ can be caused by alterations induced to the integrity and loss of semipermeability of the thylakoid membrane. As a result the membrane bccomes permeable to protons and other cations, and the electrical charges across the membrane are neutralized. The non-ionic dicryl types of inhibitory uncouplers (acylanilides. dinitroanilines. diphenylethcrs. bis-carbamates) collapsed ΔΨ at concentrations that were somewhat lower than those required for the collapse of ΔpΗ. These herbicides appear only to alter the integrity and permeability of the thylakoid membrane. Inhibition of photophosphorylation by the inhibitory uncouplcrs correlated with their ability to dissipate the pmf.
Sequence Analysis of Mutants from Rhodopseudomonas viridis Resistant to the Herbicide Terbutryn
Authors: Sinning I. , Michel H.
Published: August 2018

Several mutants resistant to terbutryn (2-thiom ethyl-4-ethylamino-6-t-butylamino-s-triazine) from the purple bacterium Rhodopseudom onas viridis have been isolated. The sequence analysis of that part of the DNA coding for the herbicide binding site in the photosynthetic reaction centre showed that only two genetically different mutant strains were obtained. The sequence data are discussed with respect to recent crystallographic results.
Isolation and Characterization of Herbicide Resistant Mutants in the Cyanobacterium Synechococcus R2
Authors: Hirschberg Joseph , Ohad Nir , Pecker Iris , Rahat Ana
Published: August 2018

A variety of mutants which are resistant to triazine - and urea - classes of herbicides have been isolated in the cyanobacterium Synechococcus R2.

All the mutants that have been analyzed, show some cross-resistance to different herbicides suggesting that these herbicides share a common binding site in photosystem II.

Three psbA genes have been identified in Synechococcus R2. The psbA-copy I gene was cloned from three mutants and used in DNA-mediated genetic transformation. It was found that in all three mutants this gene could transfer the mutation for herbicide resistance indicating that this gene codes for the herbicide resistant protein.
Site-Directed Mutations of Two Histidine Residues in the D2 Protein Inactivate and Destabilize Photosystem II in the Cyanobacterium Synechocystis 6803
Authors: Vermaas Wim F. J. , Williams John G. K. , Arntzen Charles J.
Published: August 2018

Site-directed mutations were created in the cyanobacterium Synecliocystis 6803 to alter specific histidine residues of the photosystem II (PS II) D2 protein. In one mutant (tyr-197). the his-197 residue was replaced by tyrosine, in another mutant (asn-214). his-214 was changed into asparagine. The tyr-197 mutant did not show any low-temperature fluorescence attributable to PS II. but contained a PS II chlorophyll-protein. CP-47, in significant quantities. Another PS II chlorophyll-protein. CP-43, was absent, as was PS II-related herbicide binding. The asn-214 mutant showed a blue-shifted low-temperature fluorescence maximum around 682 nm. but did not have a significant amount of membrane-incorporated CP-43 or CP-47. Herbicide binding was also absent in this mutant. These data indicate a very important role of the his-197 and his-214 residues in the D2 protein, and are interpreted to support the hypothesis that the D2 protein and the M subunit from the photosynthetic reaction center of purple bacteria have analogous functions. According to this hypothesis, his-197 is involved in binding of P680, and his-214 forms ligands with Qᴀ and Fe2+. In absence of a functional D2 protein, the PS II core complex appears to be destabilized as evidenced by loss of chlorophvll-proteins in the mutants.
Structure-Function-Relationship in Thylakoids Influenced by the Pyridazinone BAS 13–338 (SAN 9785)
Authors: Graf Josef A. , Strasser Reto J. , Kull Ulrich
Published: August 2018

The pyridazinone BAS 13-338 (SAN 9785) inhibits the desaturation sequence leading to polyunsaturated fatty acids, mainly of glycolipids. Parallel to the inhibition of fatty acid desaturation in the presence of the pyridazinone, changes in energy-distribution parameters have been observed. These data indicate that the amount of polyunsaturated fatty acids in glycolipids is strongly correlated with excitation, trapping, grouping and dissipation, but not with spillover. Functional changes in energy distribution induced by BAS 13-338 are interpreted as a consequence of structural changes in the lipid matrix, which may imply a structure-function relationship between pigment protein complexes and the surrounding lipid environment in thylakoids.
A Non-Metabolic Model of Acifluorfen Activity
Authors: Duke Stephen O. , Kenyon William H.
Published: August 2018

The para-nitro substituted diphenyl ether herbicides which cause rapid plant pigment photo- bleaching can be divided into two categories: 1. those that have a photosynthetic requirement for activity (e.g. oxyfluorfen) and 2. those that have no apparent metabolic requirement for activity (e.g. acifluorfen). A model is presented for the latter category, in which the diphenyl ether herbicide interacts with carotenoids and/or chlorophyllide in plastid membranes to form a complex which photochemically generates singlet oxygen or lipid-peroxidizing radicals.
Methylation of Guanine in vivo by the Organophosphorus Insecticide Methamidophos*
Authors: Zayed Salah M . A . D . , Mahdi Fathya M.
Published: August 2018

The methylating capability of methamidophos, assayed by the formation of [7-14C]methylguanine in mouse liver, was investigated using a 14C-insecticide labelled at the O -CH3 group. Following i.p. administration of the toxicant, [7-14C]methylguanine could be isolated from liver nucleic acids of treated mice. The amount of 14C-label reached its maximum 6 h follow ing administration of the insecticide. At maximum 14C-labelling, the amount of 7-methylguanine calculated as fraction of applied dose, was 20-22 × 10-4 and 98 -104 x-4, for DNA and RNA , respectively. The results obtained indicate also, that an appreciable amount of I4C-activity is incorporated via the C-1 pool.
Biotransformation of Humulene by Fungi and Enantioselectivity of the Strains Used
Authors: Abraham Wolf-Rainer , Stumpf Burghard
Published: August 2018

Humulene was transform ed by strains of Chaetomium cochlioides and Diplodia gossypina ATCC 10936 affording 33 new humulanes. The first step is a non-enantioselective epoxidation of the 1,2-double bond, whereas the subsequent hydroxylations were performed preferably at the 1R ,2R -epoxide. To proof these results the anti-1,2;8,9-diepoxide was synthesized and used as substrate. While the 1R ,2R ,8S,9S-antipode of this diepoxide was hydroxylated the other one was recovered unchanged. Diplodia gossypina ATCC 10936 gave the same products but differing in relative and absolute configurations.
PAPS-Reductase from Escherichia coli: Characterization of the Enzyme as Probe for Thioredoxins
Authors: Schwenn Jens D . , Schriek Ulrich
Published: August 2018

PAPS-reductase from Escherichia coli was em ployed to detect thioredoxins from pro- and eukaryotic organisms. A simple method for the isolation of this enzyme and properties of the enzymatic assay were described. A comparison betw een thioredoxins detected by the PAPS-reductase and the Fructose-bisphosphatase or NADP malate dehydrogenase was used to assess the validity of the test. The high cross-reactivity of the bacterial enzyme was useful in the purification of heterologous thioredoxins from spinach, Synechococcus, and Saccharomyces cerevisiae.
A GC/MS Study of the Propolis Phenolic Constituents
Authors: Bankova V. , Dyulgerov Al. , Popov S. , Marekov N.
Published: August 2018

Silylated phenolic fraction from two propolis samples was investigated by capillary GC/MS. Fifteen phenolic acids (seven of them new for propolis), two ketones, new for propolis, eight esters of phenolic acids, new for propolis, six flavanones and two flavonols, were tentatively detected.
Stereoisomere Aromastoffe XIX: Asymmetrische Reduktion von 4(5)-Oxocarbonsäuren mit Bäckerhefe / Asymmetric Reduction of 4(5)-Oxocarboxylic Acids by Baker's Yeast
Authors: Gessner Martin , Günther Claus , Mosandl Armin
Published: August 2018

Asymmetric reduction of 4(5)-oxocarboxylic acids (esters)by baker’s yeast and cyclizationin acidic media yield soptically active γ(δ)lactones. The evaluation of their chirality and optical purity was carried out by HPLC (HRGC)analysis of the corresponding 1,4(1.5)-diols via diastereomeric esters with(R)-Mosher acid(MTPA) and (S)-O-acyllactic acids respectively. By increasing the 4(5)alkyl side chain 4R(5R) configurated γ(δ)-lactones with high ee-values are generated.
Natural Inhibitors of Germination and Growth IV Compounds from Fruit and Seeds of Mountain Ash (Sorbus aucuparia)
Authors: Oster Ulrike , Bios Inge , Rüdiger Wolfhart
Published: August 2018

Extracts from ripe fruit and seeds of Sorbus aucuparia inhibit germination of other seeds, tested with Amaranthus caudatus and Lepidium sativum. The main compound of the “neutral fraction” of fruit extracts is the lactone compound parasorbic acid (4 -7 mg/g fresh weight) which inhibits germination at concentrations ≧ 5 × 10-4 ᴍ. The “acid fraction” contains abscisic acid (1.3-2.5 µg/g fresh weight) and isopropylmalic acid (1.0-1.5 µg/g fresh weight) as germination inhibitors. Whereas abscisic acid inhibits germination of L. sativum at concentration ≧ 5 × 10-7 ᴍ, germination of A. caudatus is inhibited only at concentrations ≧ 10-5 ᴍ. This is probably due to differences in uptake of the acid because abscisic acid methylester inhibits germination of both species at concentrations ≧ 5 × 10-7 ᴍ. Isopropylmalic acid belongs to a structural type of germination inhibitors which had already been detected in oat extracts.
The v versus v[I] Plot
Authors: Borstlap Adrianus C.
Published: August 2018

Data of the velocity (v) of an enzyme-catalyzed reaction at a fixed concentration of substrat (S) and various concentrations of an inhibitor (I) may be presented in a v versus v[I] plot. This plot is the counterpart of the Eadie-Hofstee plot (v versus v/[S]) which may be used to present data of the velocity at various substrate concentrations.
Radiochemical Methods for Studying Lipase-Catalyzed Interesterification of Lipids
Authors: Schuch Ricardo , Mukherjee Kumar D.
Published: August 2018

Reactions involving lipase-catalyzed interesterification of lipids, which are of commendable interest in biotechnology, have been monitored and assayed by radiochemical methods using 14C-labeled substrates. Medium chain (C12 plus Cu) triacylglycerols were reacted in the presence of an immobilized lipase from Mucor miehei and hexane at 45 °C with methyl [1-14C]oleate. [1-14C]oleic acid, [carboxyl-14C]trioleoylglycerol. [1-14C)octadecenyl alcohol, and [U-14C)glycerol, each of known specific activity. The reactions were monitored and the rate of interesterification determined by radio thin layer chromatography from the incorporation of radioactivity into acyl moieties of triacylglycerols (from methyl oleate, oleic acid, and trioleoylglycerol), alkyl moieties of wax esters (from octadecenyl alcohol), and into glycerol backbone of monoacylglycerols and diacylglycerols (from glycerol).
Recognition of HLA Class II Molecules by Antipeptide Antibodies Elicited by Synthetic Peptides Selected from Regions of HLA-DP Antigens
Authors: Chersi Alberto , Houghten Richard A. , Morganti Maria C. , Muratti Eleonora
Published: August 2018

Repeated immunizations of rabbits with chemically synthesized peptides from selected regions of HLA-DP histocompatibility antigens resulted in the production of specific antibodies that were then isolated from the immune sera by chromatography on Sepharose-peptide immunoadsorbents.

The purified antibodies, when tested with an enzyme-linked immunosorbant assay, specifically bound to the inciting fragments; moreover, two of them recognized glycoproteins extracted by nonionic detergents from human chronic lymphocytic leukemia cells, as revealed by binding assays.

The results suggest that amino acid stretches 51 - 61 of the alpha chain and 80-90 of the beta chain of HLA-DP histocompatibility antigens are likely exposed on the surface of the protein molecule.

The specific recognition of DP regions is strongly suggested by the difference in the binding of those antibodies to soluble membrane proteins, as compared to the binding of monomorphic anti-Class II monoclonal antibodies to the same antigens.
Evidences for Circadian Rhythmicity in the per° Mutant of Drosophila melanogaster
Authors: Helfrich Charlotte , Engelmann Wolfgang
Published: August 2018

per° Mutants of Drosophila melanogaster which are exposed to light-dark cycles (LD) with different Zeitgeber period (T) have a limited range of entrainment. Entrained flies show a characteristic phase relationship of activity to the LD which depends on the period of the driving cycle as expected by oscillator theory. Both facts are taken as evidence that per° possesses endogenous oscillators and that the per gene product is not concerned with central clock structures but rather might be responsible for the mutual coupling between the individual oscillators in a multioscillatory system controlling locomotor activity.
Notes: (Z)-5-Dodecen-1-ol, Another Inhibitor of Pheromonal Attraction in Coleophora laricella
Authors: Priesner Ernst
Published: August 2018

Sex Pheromone, A ttraction-Inhibitor, (Z)-Alkenols, C oleoph ora laricella, Coleophoridae
Notes: Inhibition of the Acetyl-CoA Carboxylase of Barley Chloroplasts by Cycloxydim and Sethoxydim
Authors: Focke Manfred , Lichtenthaler Hartmut K.
Published: August 2018

The effect of the three cyclohexane-1,3-dione derivatives cycloxydim, sethoxydim and clethodim on the incorpora­tion of 14C-labelled acetate, malonate. acctyl-CoA or malonyl-CoA into fatty acids was studied in an enzyme preparation isolated from barley chloroplasts (Hordeum vulgare L. var. “Alexis”). The herbicides cycloxydim, clethodim and sethoxydim block the de novo fatty acid biosynthesis from [2-14C]acetatc and [1-14C]acetyl-CoA, whereas that of [2-14C]malonatc and [2-14C)malonyl-CoA is not affected. The data indicate that the mode of action of the cyclohexane-1,3-dione derivatives in the sensitive bar­ley plant consists in the inhibition of de novo fatty acid biosynthesis by blocking the acetyl-CoA carboxylase (EC 6.4.1.2.).
Notes: Schmelzpunkt, Volumen und Beständigkeit von Blut unter hohem Druck / Melting Pressure, Volume and Stability of Blood at High Pressure
Authors: Kluge A. , Lentz H.
Published: August 2018

The melting pressure and the specific volume of human blood was measured up to pressures of 1000 bar or more. The melting pressure curve has a slope of -138 bar K-1. The compressibility of blood is nearly twice the value of blood scrum. After application of high pressure the blood exhibits some haemolysis most probably due to the effect of the steel surface of the autoclave.
A Novel Caffeic Acid Derivative and Other Constituents of Populus Bud Excretion and Propolis (Bee-Glue)
Authors: Wollenweber Eckhard , Asakawa Yoshinori , Schillo Detlef , Lehmann Ulrich , Weigel Heidrun
Published: August 2018

The bud exudates of Populus nigra, P. trichocarpa, and P. grandidentata × tremuloides were analyzed for the presence of phenolics and flavonoids. A novel natural product, caffeic acid y.y-dimethylallyl ester, was identified from P. nigra, along with further phenolics such as ρ-hydroxy-acetophenone, dimethyl caffeic acid, cinnamoyl cinnamata and vanillin. The flavonoid aglycones correspond to those reported earlier. Propolis samples from the Sonoran Desert were shown to exhibit the flavonoid pattern that is typical for poplar bud exudates, thus confirming this material as the major source for bee-glue. Only a single flavonoid might originate from the leaf exudate of a desert shrub.
Polyunsaturated Pheromones: Semi-Synthesis of-(Z,Z)-6,9-Alkatrienes and (Z,Z,Z)-3,6,9-Alkatrienes from Naturally Occurring Fatty Acids
Authors: Mangold H. K. , Becker H . , Schulte E.
Published: August 2018

Chain elongation of the methyl esters of linoleic and linolenic acids by one, two, or three methylene groups followed by elimination of the functional groups leads to (Z,Z)-6,9-alkadienes and (Z,Z,Z)-3,6,9-alkatrienes that function as pheromones in various insects. All of the simple reactions involved proceed in excellent yield, they do not require expensive reagents, high pressure or high temperature. The route of synthesis is applicable on a large scale. Rigorous analyses prove the purity of the hydrocarbons prepared.
Fungal Metabolism of the Prenylated Isoflavone 2,3-Dehydrokievitone
Authors: Tahara Satoshi , Ingham John L.
Published: August 2018

The prenylated isoflavone, 2,3-dehydrokievitone [5,7,2′,4′-tetrahydroxy-8-(3,3-dimethylallyl)- isoflavone, 1], was metabolized by both Aspergillus flavus and Botrytis cinerea to yield the same three compounds, a dihydrofurano-isoflavone (DK-M1, 2), a dihydropyrano-isoflavone (DK- M2, 3), and a glycol (DK-M3, 4). Although structure 3 has previously been assigned to lunatone, an isoflavone from CuCl2-stressed lima bean (Phaseolus lunatus) seedlings, a comparison of spectroscopic (MS, 1H NMR) data indicated that the Phaseolus compound was not identical with metabolite DK-M2 found in Aspergillus and Botrytis cultures. Evidence is presented to suggest that lunatone is probably identical with the furano-substituted metabolite DK-M 1 (2).
Extrachloroplastic Site of Synthesis of Three Chloroplast Proteins in Maize (Zea mays)
Authors: Kleczkowski L. A. , Zeiher C. A. , Randall D. D.
Published: August 2018

Activities of acetyl-CoA synthetase (EC 6.2.1.1), adenylate kinase (EC 2.7.4.3) and glycerate kinase (EC 2.7.1.31) were found in leaf extracts of iojap mutant maize (Zea mays) which lacks the protein-synthesizing apparatus in plastids. These activities represented at least one-half of the rates observed for normal maize plants. Since the proteins studied are localized either preferen­tially (adenylate kinase) or exclusively (acetyl-CoA synthetase, glycerate kinase) in chloroplasts, the high activities seen for iojap mutant can not be attributed to some outerchloroplastic isoforms of these enzymes. The data indicate that in maize the three proteins are synthesized by an outerchloroplastic translation system.
Topography of the phytochrome molecule as determined from chemical modification of sh-groups
Authors: Eilfeld Petra H. , Widerer Gabriele , Malinowski Heike , Rüdiger Wolfhart , Eilfeld Peter G.
Published: August 2018

From Antitrichia curtipendula and Racomitrium lanuginosum 5′,3‴-dihydroxyrobustaflavone and 5′, 8″-biluteolin were isolated. In Plagiomnium elatum the new biflavone 5′-hydroxyamentoflavone was detected
Dimers of Altersolanol A from Alternaria solani
Authors: Lazarovits George , William R. , Stoessl Albert
Published: August 2018

Weakly phytotoxic, water-soluble pigments from culture filtrates of the potato early blight organism Alternaria solani have been identified by 1H NMR, UV, mass spectrometric, and acetylation studies as the pair of rotamers represented by structure 1a.
Chemical Analysis of Peptidoglycans from Species of Chromatiaceae and Ectothiorhodospiraceae
Authors: Meißner Joachim , Jürgens Uwe J. , Weckesser Jürgen
Published: August 2018

Rigid layer (sodium dodecylsulfate(SDS)-insoluble cell wall) and peptidoglycan fractions were obtained from the Chromatiaceae (Thiocysüs violacea and Chromatium tepidum) and from Ectothiorhodospira vacuolata. Chemical composition of rigid layers from all three species indicated the presence of peptidoglycan-bound protein.

Qualitative and quantitative composition of isolated peptidoglycan indicate an Aly-type. meso-Diaminopimelic acid was the only diamino acid found. Direct cross-linkage of peptide sidechains was confirmed by separation of respective dipeptides (M-A;pm-D-Ala) from partial acid hydrolysates of peptidoglycan. GlcN and MurN of the sugar strands are completely N-acetylated. All peptidoglycan fractions contained small amounts of Gly.
Enzymatic Studies on the Reversible Synthesis of Nicotinic Acid-N-glucoside in Heterotrophic Parsley Cell Suspension Cultures
Authors: Upmeier Barbara , Thomzik Jürgen E. , Barz Wolfgang
Published: August 2018

A soluble enzyme catalyzing the transfer of the glucose moiety from UDP-glucose to the nitrogen atom of nicotinic acid was detected in protein preparations from heterotrophic cell suspension cultures of parsley (Petroselinum hortense Hoffm.). Enzyme activity was enriched 22-fold by ammonium sulfate precipitation, gel filtration and ion exchange chromatography. The UDP-glucose : nicotinic acid-N-glucosyltransferase showed a pH-optimum at pH 7.8-8.2 and a temperature optimum at 30 °C. The apparent KM values were determined to be 170 μM for nicotinic acid and 1.2 mM for the cosubstrate. The native enzyme had a molecular mass of about 46 kDa. The glucosyltransferase reaction was shown to be reversible. The transfer of the glucose molecule from nicotinic acid-N-glucoside to uridinediphosphate yielding uridinediphosphoglucose and nicotinic acid could be demonstrated indicating that nicotinic acid-N-glucoside has a high group-transfer potential.
Secondary Sex Pheromone Components of Choristoneura murinana Hb. (Lepidoptera: Tortricidae)
Authors: Priesner Ernst , Bogenschütz Hermann , Löfstedt Christer
Published: August 2018

The alkenyl acetates E9-12:Ac, Δ11-12:Ac and Zll-14:Ac were identified as minor components of the C. murinana female pheromone blend by chemical analyses of volatile pheromone gland constituents and potential pheromone precursors, electrophysiological recordings from single receptor cells, and field trapping tests. Gland washes from virgin females contained these compounds at 3%, 10% and 5%. respectively, the amount of the primary pheromone component Z9-12:Ac already reported. A 0.3% addition of either Δ11 - 12 : Ac or Z11-14:Ac significantly raised trap captures over Z9-12:Ac alone and a 3-30% addition of either minor component revealed maximum captures, not increased further by including both synergists within the same blend. A functional role of the E9-12: Ac could not be established during this study; 3% of it when combined with the pheromonal ratio mixture of the three other components tended to increase trap captures further whereas in various other mixture combinations the E9-12:Ac strongly reduced captures. These inhibitory effects were more pronounced with attractant blends based on Δ11-14:Ac rather than Δ11-12:Ac. Each blend component activated its own type of antennal receptor cell.
Do Monoclonal Antibodies Recognize Linear Sequential Determinants?
Authors: Camera Matildé , Muratti Eleonora , Trinca Maria Luisa , Chersi Alberto , Elena Regina
Published: August 2018

A group of 19 anti-class II monoclonal antibodies produced in different laboratories were tested in ELISA for their ability to bind to a panel of synthetic peptides selected from HLA-DQ alpha and beta chains. No one of the antibodies tested was found to react with the synthetic fragments, thus confirming the common finding that MoAbs generally fail to recognize fragments of the native antigen. The possibility that this result might be partly due to the procedure used for screening hybridoma supernatants is discussed.
A Competitive Inhibition Enzyme Immunoassay for Detection and Quantification of Organophosphorus Compounds
Authors: Schmidt Peter , Kühlmann Reiner , Lösch Uli
Published: August 2018

A sensitive and specific method for detection and quantification of methyl phosphonic acid, paminophenyl 1,2,2,-trimethyl-propyl diester (MATP) as a model substance for organophosphorus compounds is described.

Different procedures for coupling the haptenic group for immunization, purification and immobilization allowed the detection of hapten-specific antibodies.

The competitive inhibition enzyme immunoassay (CIEIA), using purified chicken and rabbit IgG-antibodies, was able to detect MATP-concentrations as low as 10-10 mol/1.

Based upon our results, we postulate that the CIEIA represents a good alternative to the customary diagnosis of organophosphate intoxications, measuring blood Cholinesterase activity.
Phytochemical Investigation of Roots of Pterocarpus marsupium. Isolation and Structural Studies of Two New Flavanone Glycosides
Authors: Tripathi J. , Joshi T.
Published: August 2018

From the roots of Pterocarpus marsupium 7-Hydroxy-6, 8-dimethyl flavanone-7-O-α-L-arabinopyranoside and 7,8,4′-trihydroxy-3′, 5′-dimethoxy flavanone-4′-O-β-ᴅ-glucopyranoside have been isolated and their structure elucidated.
The Influence of the Proton Gradient on the Activation of Ferredoxin-NADP+-oxidoreductase by Light
Authors: Pschorn Roland , Rühle Wolfgang , Wild Aloysius
Published: August 2018

Ferredoxin-NADP+-oxidoreductase (FNR, EC 1.18.1.2) has been shown to be activated by light within a few seconds during dark-light transitions and inactivated in the dark. In previous papers this could be pointed out by the correlation of cytochrome f induction kinetics to the rate of NADP-photoreduction and the variable fluorescence. The present study deals with the role of the proton gradient during the activation process. The transition from an inactive to an active form is followed continuously in an in situ system. The steady-state rate of NADP-photoreduction is affected only by ionophores which inhibit a formation of the proton gradient, but not by inhibitors of the electric field. It correlates to the 9-aminoacridine fluorescence quench and the light scattering signals at 535 nm. The perception of the pH-gradient through the enzyme is still a matter of discussion.