bluuebunny/crossref_metadata_2025 huggingface dataset:
Inter-and Intraspecific Variation of the Nucleotide Sequence of the Cytochrome b Gene in Cory's (Calonectris diomedea), Manx Shearwater (Puffinus puffinus) and the Fulmar (Fulmavus glacialis)
Authors: Wink M. , Heidrich P. , Kahl U. , Swatschek I. , Witt H .-H , Ristow D.
Published: August 2018

Cytochrome b, DNA Sequence, Polymerase Chain Reaction (PCR), Molecular Evolution, Procellariidae The cytochrome b gene of three European taxa of the family of Procellariidae was amplified from total DNA and sequenced. The sequence comparison shows that the Fulmar (Fulmarus glacialis) is significantly distinct from shearwaters, whereas Cory’s (Calonectris diomedea) and Manx Shearwater (Puffinus puffinus) are closely related. Although the populations of C. dio­medea can be distinguished morphologically, the sequences of cyt b differ only slightly between the Atlantic and Mediterranean subspecies (i.e. C. d. borealis versus C. d. diomedea) and do not reveal other population differences within subspecies.
Pheromone 92 [1]. Duftstoffe aus den abdominalen Haarbüscheln des männlichen Totenkopfschwarmers Acherontia atropos L. (Lepidoptera: Sphingidae) / Pherom ones 92 [1], Odorous Substances from the Abdominal Hair Brushes of the Male Sphingid Moth Acherontia atropos L. (L epidoptera: Sphingidae)
Authors: Bestmann Hans Jürgen , Erler Joachim , Vostrowsky Otto , Wasserthal Lutz Th.
Published: August 2018

Duftstoffe aus den abdominalen Haarbüscheln des männlichen Totenkopfschwarmers Acherontia atropos L. (Lepidoptera: Sphingidae) Pherom ones 92 [1], Odorous Substances from the Abdom inal Hair Brushes of the Male Sphingid Moth Acherontia atropos L. (L epidoptera: Sphingidae) Hans Jürgen Bestm ann, Joachim Erler, Otto Vostrowsky From abdominal hair brushes of male hawk moths Acherontia atropos (Lepidoptera: Sphingidae) 24 volatiles have been detected and identified by GC-MS analysis, caryophyllene (17), humulene (18), linalool (6), linalyl propionate (12) and geranic acid methylester (9) comprising the main constituents. Analyzing the terpenoid composition of volatiles from insects reared on different host plants as well as that of the essential oils from these plants it could be demon­ strated, that most components of the odour blend are not derived from the food plants but can be de novo synthesized by the insects.
Photoregulation of Carotenoid Biosynthesis in Mutants of Neurospora crassa: Activities of Enzymes Involved in the Synthesis and Conversion of Phytoene
Authors: Sandmann Gerhard
Published: August 2018

Synthesis of carotenoids is photoregulated in many fungi including Neurospora crassa. In order to investigate the regulatory mechanism at the enzyme level, several carotenoid mutants of Neurospora were used to determine the activities of enzymes involved in the carotenoid bio synthetic pathway after growth under illumination or in darkness. Light stimulation of carotenoid formation was due to enhanced activities of three subsequent enzymes, geranylgeranyl pyrophosphate synthase, phytoene synthase, and phytoene desaturase indicating a coordinated regulation at the enzyme level. Farnesyl pyrophosphate synthase and lycopene cyclase were not involved in light regulation. Immunological studies showed that in the case of phytoene desaturase higher activity in the light originated from an increased amount of this enzyme in light-grown cultures.
Molecular Modelling of the Interaction of Cyanoacrylate Inhibitors with Photosystem II Part 1. The Effect of Hydrophobicity of Inhibitor Binding
Authors: Mackay Simon P. , O’Malley Patrick J.
Published: August 2018

Cyanoacrylate Inhibitors, Photosystem II, Hydrophobicity The secondary quinone binding site of photosystem II is also the binding site for many dif­ ferent herbicides. The 2-cyanoacrylate inhibitors are a potent class of electron transfer inhibi­tors which bind at this site and are extremely sensitive to minor structural variation. In order to understand their mode of binding, we have studied the interaction between the inhibitors and receptor in the D1 protein binding region (residues Leu 210 to Val 280) in terms of non­ bonded intermolecular forces. The intermolecular energy was calculated by van der Waals and electrostatic interactions after energy minimization of the combined structures to reduce inter and intramolecular strain. We have identified specific amino acid residues within the binding protein which are instrumental in binding the herbicide and have shown that the spatial arrangement of the herbicide functional groups within the binding site rather than their lipo­philicity is the determining factor in binding efficiency.
New Three- and Tetraoxygenated Coumarin Glucosides from the Mosses Atrichum undulatum and Polytrichum formosum
Authors: Jung M. , Zinsmeister H. D. , Geiger H.
Published: August 2018

Atrichum undulatum as well as Polytrichum formosum are containing each six different coumarin glycosides of which three are common to both species. From the nine different glycosides eight are new natural compounds. The structures have been elucidated spectroscopically.
Phenolic Composition of Propolis from China and from South America
Authors: Bonvehí Josep Serra , Coll Francesc Ventura
Published: August 2018

Flavonoids and other phenolic compounds were determined in 15 samples of propolis originating from China, from Brazil, and from Uruguay. A total of 24 compounds were identified using mainly HPLC and a few other analytical methods. The most abundant compounds found were benzoic acid and benzaldehyde derivatives, flavones, flavonols. and flavanones. 80% of the samples contained at least 22 g/100 g of flavonoids, primarily acacetin, isorhamnetin, apigenin, and pinocembrin. The flavonoid patterns were sufficiently distinctive to permit discrimination between propolis from China, from Uruguay, and from Brazil.
On the Expression of Several Lhc Genes in Garden Cress (Lepidium sativum L.)
Authors: Brunner Harald , Rüdiger Wolfhart
Published: August 2018

The polymerase chain reaction was used to prepare gene-specific probes for several Lhc genes coding for chlorophyll a/b-binding proteins of cress (Lepidium sativum L.). Due to the presence of about 150 basepairs of the coding region, the isolated clones could be attributed to Lhc a3 (1 clone), Lhc b1 (5 clones), Lhc b2 (1 clone) and Lhc b3 (1 clone) genes. Probes prepared from the 3′ non-coding regions of the clones did not cross-hybridize; they were specific for 3 different Lhc b1 transcripts and one each of Lhc b2, Lhc b3 and Lhc a 3 transcripts. The transcript levels were higher in leaves than in cotyledons of light-grown seedlings; they decreased significantly in cotyledons from week 1 to week 4. The levels of 2 Lhc b1 transcripts (detected with probes cd 1 and cd 2) changed from 1 week old cotyledons (30% c d l, 28% cd 2) to 3 months old leaves (14% c d l), 44% cd 2), stems (11% c d l, 56% cd 2) and fruits (15% cd 1, 62% cd 2, all values percent of total transcripts), whereas transcript levels of another Lhc b1 gene (detected with probe cd 3) and of a Lhc a 3 gene remained nearly constant. The level of Lhc b2 and Lhc b3 transcripts were 1 - 2 orders of magnitude smaller than those of the other Lhc transcripts. The data obtained with cress plants are compared with published data from other plants.
Preparation of Ureidonucleosides of the Threonine Isomers
Authors: Martin Dierk , Schlimme Eckhard
Published: August 2018

The hypermodified ureidonucleoside N6[((9-β-ᴅ-ribofuranosyl-9H-purine-6-yl)amino)carbonyl]- ʟ-threonine (5) is a constituent of transfer ribonucleic acid (tRNA) and is secreted as a tRNA catabolite in body fluids such as blood, milk and urine. Compound 5 and the isomeric ureidonucleosides bearing ᴅ-threonine (9), ʟ-allo- (7) and ᴅ-allo-threonine (11) as side chain moieties were synthesized on a preparative scale. The amido protons of 5 and 9 cause two separate 1H NMR signals whereas 7 and 11 cause multiplets. The 13C NMR signals of all carbon atoms of the allo-amino acid side chains (7, 11) are shifted downfield of the corresponding signals in compounds 5 and 9. The chemically protected intermediate compound adenosine urethane (3) is potentially of interest in the analysis of amino acids because it may be converted to nucleosides of the ureido type by reaction with amino acids in biological matrices.
Biotinylated Carbohydrate Markers -A Novel Tool for Lectin Research
Authors: Lauc Gordan , Flögel Mirna , Müller Werner E. G.
Published: August 2018

One of the key obstacles in lectin research is the lack of specific techniques for their detection. Novel markers, biotin-labeled carbohydrates, could contribute to overcome this problem. Being at least 10 times more sensitive than neoglycoproteins in the membranescreening assays, they also enable direct detection of lectins in complex mixtures. The markers were synthesized by linking biotin to one, and a carbohydrate (galactose or glucose) to the other amino group of (the amino acid) lysine. After synthesis the markers were chromatographically purified on lectin (RCA for galactose marker, ConA for glucose marker) and avidin affinity columns. The applicability of the markers to detect lectins was demonstrated e.g. with sponge extracts (from Geodia cydonium). Following incubation with biotin-labeled carbohydrates covalent cross-linking between lectins and markers was induced by UV radiation. After transfer to the blotting membrane, lectins were detected with deglycosylated antibiotin antibody labeled with alkaline phosphatase. Besides for the cross-linking technique, the biotinylated carbohydrate markers were also used for detection of lectins on the nitrocellulose membrane in gene library screening and slot blotting.
Intersexual Transfer of a Toxic Terpenoid during Copulation and Its Paternal Allocation to Developmental Stages: Quantification of Cantharidin in Cantharidin-Producing Oedemerids (Coleoptera: Oedemeridae) and Canthariphilous Pyrochroids (Coleoptera: Pyrochroidae)
Authors: Holz C. , Streil G. , Dettner K. , Dütemeyer J. , Boland W.
Published: August 2018

In whole body extracts of the canthariphilous pyrochroid Schizotus pectinicornis and the cantharidin-producing oedemerid Oedemera femorata cantharidin contents were determined by means of quantitative gas chromatography. Adults and all developmental stages of both species contain this terpenoid, but in considerably different amounts. Cantharidin contents differ significantly between the sexes of adult O. femorata: 8.4 μ,g/female, 3.5 μg/male. Values for Sch. pectinicornis are more than 30-fold lower than those of O. femorata and no intersexual difference in the cantharidin content could be detected. Eggs of O. femorata contained cantharidin and larvae of this species are capable of synthesizing this terpenoid. The total amount of cantharidin increases in successive instars. In Sch. pectinicornis, the content of cantharidin decreases from egg to first instar.

Feeding and copulation experiments with [2H2]cantharidin indicate that in O. femorata no or only very small amounts of cantharidin are transferred from males to females at copulation. Thus, males do not invest in the protection of their offspring by cantharidin gifts to the mate. For Sch. pectinicornis an intersexual transfer of labelled cantharidin during copulation was detected. About 45% of the entire cantharidin content in mated females derived from fed males. Analyses of eggs and first instar larvae show that a paternal allocation of 2[H2]cantharidin to developmental stages exists for this canthariphilous pyrochroid.
Different Mode of Incorporation of o-Succinylbenzoic Acid into the Naphthoquinones Juglone and Lawsone in Higher Plants
Authors: Chung Dong-O. , Maier Ulrich H. , Inouye Hiroyuki , Zenk Meinhart H.
Published: August 2018

[1-13C]o-Succinylbenzoic acid is incorporated to approximately 50% into each of the keto groups of the quinone ring of juglone in JugIans regia. The same labelled precursor is transformed into the keto group of position 1 in lawsone, the pigment of Impatiens balsamina, suggesting two different intermediates in the biosynthesis of these simple 2- or 5-hydroxy-1,4-naphthoquinones.
Aloe Plants Accumulate Anthrone-Type Anthranoids in Inflorescence and Leaves, and Tetrahydroanthracenes in Roots
Authors: Sigler Anette , Rauwald Hans W.
Published: August 2018

The accumulation and distribution of characteristic secondary products in the different organs of an Aloe plant (A. succotrina Lam.) were studied by high performance liquid chromatography for the first time. In the leaves of the Aloe plant, only anthrone-C-glycosyls of the 7-hydroxyaloin type and, for the first time in plant material, the free anthraquinone 7-hydroxyaloeemodin were found. In contrast to previous reports on the distribution of secondary products in Aloe plants, anthrone-C-glycosyls were also detected in flowers, bracts and the inflorescence axis of the species examined. Aloesaponol I, a tetrahydroanthracene aglycone, was only present in the underground organs and in the stem. The 2-alkylchromone-C-glucosyl aloeresin B showed no specific occurrence as it was found in every type of organ. Based on these results and the findings of recent studies on Aloe roots and flowers, a distri­bution scheme of polyketide types in the Aloe plant was established. It suggests a separate and independent anthranoid metabolism for underground Aloe organs and stem on the one hand, and for leaves and inflorescence organs on the other hand. In the latter structures anthranoid metabolism seems to be additionally compartmentalized as the anthranoid pro­ files of inflorescence organs and leaves differ in two points relevant to anthranoid biosynthe­ sis: firstly, the occurrence of anthrone aglycones and secondly, the individual content of corre­sponding anthrone-C-glucosyl diastereomers.
7-Chloro-4,6-dimethoxy-1(3H)-isobenzofurane and Basidalin: Antibiotic Secondary Metabolites from Leucoagaricus carneifolia Gillet (Basidiomycetes)
Authors: Huff Thomas , Kuball Hans-Georg , Anke Timm
Published: August 2018

Two antibiotic metabolites were isolated from cultures of Leucoagaricus carneifolia. Their structures were elucidated by spectroscopic methods. The first compound, 7-chloro-4,6-di-methoxy-1(3 H)-isobenzofurane (1) had to our knowledge not been described from natural sources whereas the second, basidalin (2), is a known metabolite of L. naucina (H. Iinuma et al., 1983). 1 exhibits antibiotic activities with minimal inhibitory concentrations of 20 μg/ml against Botrytis cinerea, the most sensitive microorganism
Acetylcholinesterase and Non-Specific Esterase Activities during the Regeneration of Planaria Dugesia tigrina (Girard)
Authors: De Simone S. Giovanni , Matta J. Torres da , Mattaa A. Nery da
Published: August 2018

Biochemical modification of the acetylcholinesterase (AChE) and non-specific esterases of a planarian species [Dugesia tigrina (Girard)] were studied as a function of regeneration. The enzymatic activities were measured in regenerating planarians at regular time intervals from the beginning of the regeneration process to the complete restoration of the animal. Both enzymatic activities were substantially altered during the regeneration process of caudal and cephalic segments. Polyacrylamide gel zymograms for soluble α-naphthyl acetate hydrolytic activity revealed four bands of activities. These activities were fractioned into two major on cation exchange high performance h between 6 and 7 and were inhibited by PMSF, TPCK, TLCK and n-ethyl maleimide.
Hyphodontal, a New Antifungal Inhibitor of Reverse Transcriptases from Hyphodontia sp. (Corticiaceae, Basidiomycetes)
Authors: Velten Robert , Gimenez Alberto , Steglich Wolfgang
Published: August 2018

In a search for inhibitors of RNA-directed DNA polymerases a new isolactarane sesquiterpenoid, hyphodontal (1), was isolated from fermentations of a Canadian Hyphodontia species. Its structure was elucidated by spectroscopic methods. Hyphodontal strongly inhibits the growth of several yeasts and is a non-competitive inhibitor of avian myeloblastosis virus (Ki 346 μᴍ) and Moloney murine leukemia virus (Ki 112 μᴍ) reverse transcriptases. In addition, cytotoxic and antifungal activities were observed.
Molecular Systematics of the Nepetoideae (Family Labiatae): Phylogenetic Implications from rbcL Gene Sequences
Authors: Kaufmann Martina , Wink Michael
Published: August 2018

Total DNA was extracted from 41 species (20 genera) of the subfamily Nepetoideae (family Labiatae). Using rbcL-specific primers, the rbcL gene was amplified by polymerase chain reaction (PCR) and sequenced directly. RbcL sequences were evaluated with character state (maximum parsimony; PAUP) and distance methods (neighbour-joining; MEGA). In agree­ ment with classical systematics all taxa studied cluster within the Nepetoideae and are clearly distinguished from members of the subfamily Lamioideae. A number of distinctive clades are apparent within the Nepetoideae:, and XIII -Perovskia. At least five main branches rep­ resenting the clades I, II, III to VII, VIII, and IX to XIII respectively, can be distinguished within the Nepetoideae studied. They might be considered representing the tribes (according to Cantino, 1992) Elsholtzieae (I), Lavanduleae (II), and Mentheae (III - XIII). The tribe Mentheae needs to be subdivided into at least three main groups (clades III-VII, VIII and IX -XIII). Major ana hortensis which is often classified as Origanum hortensis does not cluster with Origanum and deserves a generic status of its own.
New Emitter-Detector-Cuvette Assembly for Measuring Modulated Chlorophyll Fluorescence of Highly Diluted Suspensions in Conjunction with the Standard PAM Fluorometer
Authors: Schreiber Ulrich
Published: August 2018

A new emitter-detector-cuvette assembly for the standard PAM fluorometer is described which leads to substantial improvement of signal/noise ratio and increased flexibility with respect to the choice of excitation and emission wavelengths. These features are particularly useful for work with very dilute suspensions of unicellular algae and isolated chloroplasts. Instead of fiber optics perspex rods are applied for guiding excitation light to a mirrored 10×10×45 mm cuvette and from there at 90° angle to the photodetector, similarly as recently reported for a PAM fluorometer based on Xe-flash measuring light (Schreiber et al. (1993), Photosynth. Res. 36, 65-72). While the detection limit of the new system does not reach that of the Xe-PAM fluorometer, it is approximately two orders of magnitude higher than that of the standard system. Rapid induction kinetics can be measured at low chlorophyll concen­ trations down to 0.1 μg · ml-1. Satisfactory quenching analysis for detection of active chloro­ phyll concentration is still possible at 5 μg chlorophy · l-1 . The various optical factors con­ tributing to the improved sensitivity are analyzed. An accessory device is described by which the frequency of the measuring light pulses generated by the PAM fluorometer is lowered in order to reduce the actinic effect of the measuring light. The performance of the new system using different excitation and emission wavelengths is demonstrated in measurements with green algae, cyanobacteria and leaves. Applying a newly available blue light-emitting diode with 450 nm peak emission, short wavelength fluorescence enriched in PS II emission can be measured, which is characterized by high values of variable fluorescence relative to maximal fluorescence. Using measuring light covering five different wavelength ranges the fluorescence contributions from cyanobacteria and green algae can be distinguished on the basis of distinct differences in their excitation spectra. This approach should become useful for an estimation of content and activity of different types of phytoplankton in natural surface waters.
Further Flavonoids and Other Phenolics of Thymus webbianus Rouy
Authors: Blázquez María Amparo , Máñez Salvador , Zafra-Polo María Carmen
Published: August 2018

Seven different flavonoids from the aerial parts of Thymus webbianus were isolated. They were identified by UV spectra, TLC and HPLC-DAD as luteolin, api­genin, eryodictiol, naringenin, luteolin-7-O-glucoside, apigenin-7-O-glucoside and apigenin-6,8-di-C-glucoside. Other phenolics characterized by HPLC-DAD analysis were: protocatechuic, chlorogenic, syringic, p-coumaric and 3,5-dicaffeoylquinic acids.
Kuehneromycins A and B, Two New Biological Active Compounds from a Tasmanian Kuehneromyces sp. (Strophariaceae, Basidiomycetes)
Authors: Erkel Gerhard , Lorenzen Kirsten , Anke Timm , Velten Robert , Gimenez Alberto , Steglich Wolfgang
Published: August 2018

In a search for new inhibitors of RNA-directed DNA-polymerases kuehneromycin A (1) was isolated from fermentations of a Tasmanian Kuehneromyces species. Its structure was elucidated by spectroscopic methods. Kuehneromycin A (1) is a non-competitive inhibitor of avian myeloblastosis virus (Ki 200 μᴍ) and moloney murine leukemia virus (Ki 40 μᴍ) reverse transcriptases. The second compound, kuehneromycin B (2) is a strong inhibitor of platelet aggregation stimulated with different inducers. In addition, both compounds exhibit cytotoxic and antimicrobial activities.
Chemical Structure-Odor Correlation in a Series of Synthetic n-Nonen-1-ols
Authors: Sakoda Yasunobu , Matsui Kenji , Kajiwara Tadahiko , Hatanaka Akikazu
Published: August 2018

In order to elucidate chemical structure-odor correlation in the all isomers of n-nonen-1- ols, an entire series of these alcohols were synthesized stereo-selectively in high purity. For unequivocal syntheses of them, geometrically selective hydrogenation of the respective acetylenic compound was adopted. The synthesized alcohols were converted to their 3,5-dinitrobenzoate derivatives with 3,5-dinitrobenzoyl chloride, and then purified by repeated recrystallization.

Chemical structure-odor correlations in all the isomers of n-nonen-1-ols were elucidated by introducing a novel method to evaluate odor characteristics and by treating the obtained data statistically with the principal component analysis method (Cramer et al., 1988). The odor profiles of the tested compounds were attributable largely to the positions of the carbon- double bond. The geometries of compounds had only a little effect. With the principal component analysis, the odor profiles of the series of compounds were successfully integrated into the first and the second principal components. The first component (PC-1) consisted of combined characteristics of fruity, fresh, sweet, herbal and oily-fatty, in which herbal and oily-fatty were conversely correlated each other to the position of double-bond of the tested compounds. Of these, only (6Z)-nonen-1-ol deviated markedly from the correlation, indicative of some special interaction between the spatial structure of this compound and the sensory machinery of human.
Chemical Composition and Antibacterial Activity of Brazilian Propolis
Authors: Bankova V. , Christov R. , Kujumgiev A. , Marcucci M. C. , Popov S.
Published: August 2018

Four samples of Brazilian propolis were investigated by GC/MS of different fractions. 32 volatile compounds, (10 of them new for propolis), as well as 12 more polar compounds (one of them new for propolis) were identified. Antibacterial activity was found in some propolis fractions.
Isomerization and Peroxidizing Phytotoxicity of Thiadiazolidine-thione Compounds
Authors: Iida Tetsuji , Senoo Satoshi , Sato Yukiharu , Nicolaus Beate , Wakabayashi Ko , Böger Peter
Published: August 2018

Eight 5-arylimino-3,4-tetramethylene-1,3,4-thiadiazolidine-2-thiones and eight 4-aryl-1,2- tetramethylene-1,2,4-triazolidine-3,5-dithiones were synthesized and their phytotoxic activities were investigated using sawa millet (Echinochloa utilis), green microalgae (Scenedesmus acutus) and protoporphyrinogen-IX oxidase isolated from etiolated corn (Zea mays) seedlings. 5-Arylimino-3,4-tetramethylene-1,3,4-thiadiazolidine-2-thiones showed strong phytotoxic activities and the same herbicidal mode of action as known for peroxidizing herbicides. 5-Arylimino-3,4-tetramethylene-1,3,4-thiadiazolidine-2-thiones were not or very little converted into 4-aryl-1,2-tetram ethylene-1,2,4-triazolidine-3,5-dithiones either with E. utilis seedlings present for 7 days, with S. acutus cells, or using glutathione 5-transferase (GST) and glutathione (GSH). The phytotoxic activities of 4-aryl-1,2-tetram ethylene-1,2,4-triazolidine- 3,5-dithiones were stronger than those of 5-arylimino-3,4-tetram ethylene-1,3,4-thiadiazolidine- 2-thiones [cf. Sato, Y., et al., Z. Naturforsch. 49c, 49-56 (1994)].
Endogenous Gibberellins from Three East Asian Stenophora Species of the Genus Dioscorea (Yams)
Authors: Tanno Noriaki , Nakayama Masayoshi , Kurosawa Hiroshi , Wakatsuki Masahiro , Tanno Masahiro , Abe Mamoru , Okagami Nobuo , Yokota Takao
Published: August 2018

Exogenous gibberellin A3 (GA3; 30 μm) promoted shoot elongation of germinated seeds of Dioscorea nipponica, an East Asian species of a taxonomic section Stenophora of the genus Dioscorea (yams). Endogenous gibberellins (GAs) were analyzed by combined gas chromatography-mass spectrometry (GC-MS) from growing shoots of three East Asian Stenophora species. Gibberellin A4, GA12, GA 19, GA24 and GA53 were identified by Kovats retention indices and by full spectra of GC-MS from D. quinqueloba. Gibberellin A19, GA24 and GA53 were also identified from D. nipponica and D. septemloba. These results suggest that two separate biosynthetic pathways of GAs, early 13-hydroxylation and non-13-hydroxylation pathways are functioning in the growth of shoots of these thee species.
Iron(III) Complexes with Hydrogen Peroxide which Can Discriminate Two Reaction Types; Oxidation (H-Atom Abstraction) and Oxygenation Reaction
Authors: Nishida Yuzo , Ito Sayo
Published: August 2018

Iron(III)-NTA (nitrilotriacetic acid) solution shows high activity for oxidative degradation of 2′-deoxyribose in the presence of hydrogen peroxide, whereas its activity of Fe(III)-TFDA (2-aminomethyltetrahydrofuran-N,N-diacetic acid) is negligible under the same experimental conditions; however the latter solution exhibits abnormally higher reactivity for oxygenation reaction at 8-position of 2′-deoxyguanosine than other iron(III) chelates examined. These results suggest that oxidative degradation of deoxyribose and the oxygenation of deoxyguanosine are caused by a different iron(III)-peroxide species.
Cell Wall Pigment Formation of in vitro Cultures of the Liverwort Ricciocarpos natans
Authors: Kunz Siegmund , Becker Hans
Published: August 2018

The liverwort Ricciocarpos natans has been cultivated on Gamborg B5 medium with different levels of ammonium, nitrate, phosphate and sucrose. The formation of the cell wall pigments riccionidin A and B was shown to be dependent on the level of these nutrients as well as on the intensity of light. A decrease in nitrogen supply (mainly nitrate) induced the formation of both wall pigments, whereas phosphate and high levels of sucrose inhibited the pigment synthesis. Decreasing the illumination rate led to lower anthocyanidin contents. Dedifferentiated cultures also produced wall pigments, but their amount was much lower compared to differentiated cultures.
Thermodynamic and Spectroscopic Characterization of the Berenil and Pentamidine Complexes with the Dodecanucleotide d(CGCGATATCGCG)2
Authors: Schmitz Hans-Uwe , Hübner Wigand , Ackermann Theodor
Published: August 2018

The dodecanucleotide d(CGCGATATCGCG)2 was characterized by thermodynamic and UV-spectrophotometric measurements. A van’t Hoff enthalpy of ΔHuv
v.H. ~ - 190 kJ/mol was determined for the thermal transition using UV spectroscopy. This value was confirmed by differential scanning calorimetry (DSC). In addition we obtained the thermodynamic data ΔHDSC = -405.1 kJ/mol, ΔSDSC = -1290 J/mol·K and ΔGDSC = -53.2 kJ/mol for the helix to coil transition of the dodecanucleotide. The association of berenil and the oligonucleotide was accompanied with a stabilization of the host duplex (increase in Tm) and an increase in the van’t Hoff enthalpy. The berenil binding parameters (ΔΔHDSC = -32.6 kJ/mol, ΔΔSDSC = -72 J/mol·K and ΔΔGDSC = -11.1 kJ/mol) revealed significant differences compared to those of the pentamidine aggregation (ΔΔHDSC = -23.7 kJ/mol, ΔΔSDSC = -53 J/mol·K and ΔΔGDSC = -7.8 kJ/mol). The transition of the pure oligonucleotide was characterized by a substantial amount of intermediate states (σDSC = 0.43) which decreased significantly upon binding of the drugs (σDSC ~ 0.80). The structural features of the complexes were analyzed by FT-IR spectroscopy. From these experiments we conclude that the configurations in the berenil and pentamidine complexes are different.
Polyphenol and Alkaloid Changes in Glyphosate-Treated Tobacco Regenerants Selected for Herbicide Tolerance
Authors: Bankova Vassya St. , Handjieva Nedyalka V. , Djilianov Dimitar L. , Vassileva Zarka Y. , Bachvarova Rositsa I. , Atanasov Atanas I. , Stefanov Kamen L. , Popov Simeon S.
Published: August 2018

In vitro a one-step selection for glyphosate tolerance of two Bulgarian tobacco cultivars Zlatna Arda and Nevrokop A24 was carried out. After treatment with glyphosate of the control plants and their regenerants polyphenol and alkaloid changes were determined. A decrease in the polyphenol concentrations and an increase in the alkaloid concentrations were registered only for Zlatna Arda.
Flavipucine and Brunnescin, Two Antibiotics from Cultures of the Mycophilic Fungus Cladobotryum rubrobrunnescens
Authors: Wagner Christian , Anke Heidrun , Besla Helmut , Sterner Olov
Published: August 2018

Two antimicrobial metabolites were isolated from submerged cultures of Cladobotryum rubrobrunnescens, a mycophilic fungus growing on a Inocybe species. One of the compounds proved to be identical to flavipucine (2), an antibiotic previously isolated from Aspergillus flavipes (Casinovi et al., 1968) and from a Macrophoma species (Sassa T. and Onuma Y. (1983), Agric. Biol. Chem. 47, 1155-1157). The other metabolite, brunnescin (1), is a new tetrasubstituted furan derivative which exhibits antibacterial, antifungal and cytotoxic effects.
Notes: Differential Alterations of Glutathione S-Transferase Enzyme Activities in Three Sorghum Varieties Following Viral Infection
Authors: Gullner Gabor , Kömives Tamás , Gáborjányi Richard
Published: August 2018

Activities of the enzyme glutathione S-transferase were determined in leaves of sorghum varieties of differential susceptibility to infection with sugarcane mosaic virus. Inoculation with the virus resulted in significant induction of the enzyme in the leaves of the immune host, while hitherto unpublished dramatic reductions were detected in the leaves of the systemic host sorghum varieties.
Enzymatic and Electrochemical Reactions of Catalase Immobilized on Carbon Materials
Authors: Horozova E. , Jordanowa Z. , Bogdanovskay V.
Published: August 2018

It has been shown that catalase immobilized on graphite and soot undergoes an oxidationreduction transformation. Some results on the effect of the potential sweep rate, temperature and pH on this transformation are presented. On the basis of the relationship established, it has been proved that the redox transformation is related to the iron in the heme of the active center of the enzyme and takes place with a transfer of one electron.
Mutants of the Cyanobacterium Anabaena variabilis Altered in Hydrogenase Activities
Authors: Mikheeva Lidia E. , Schmitzh Oliver , Shestakov Sergey V. , Bothe Hermann
Published: August 2018

Two mutants of the cyanobacterium Anabaena variabilis impaired in the utilization or formation of molecular hydrogen have been obtained by nitroso-guanidine mutagenesis. Cul­tures of both mutants did not show alterations in the growth characteristics or in the hetero­cysts frequency but evolved molecular hydrogen from nitrogenase with enhanced rates. Ac­tivity measurements in extracts showed that one mutant (PK84) did not perform Na2S2O4- dependent H2-formation and was, therefore, unable to express an active bidirectional hydro­genase. Both mutants (PK84, PK 17R) were characterized by lower activity of phenazine-methosulphate-dependent H2-uptake when extracts were assayed from younger cultures. In older cells, particularly when grown with nitrate in the medium , this H2-uptake activity was, how ever, enhanced. Both mutants are likely affected in regulatory hydrogenase genes. The mutant PK84 offers perspectives for potential applications in solar energy conversion programs.
Isolation and Partial Characterization of a Manganese Requiring ʟ-Arginine Metabolizing Enzyme Being Present in Photosystem II Complexes of Spinach and Tobacco
Authors: Gau Achim E. , Thole Hubert H. , Pistorius Elfriede K.
Published: August 2018

A low ʟ-arginine metabolizing enzyme (L-AME) activity leading to ornithine, urea and additional products not identified so far could be detected in photosystem II (PS II) membranes of spinach and of the chlorophyll deficient tobacco mutant Su/su. The detectable L-AME activity was very low in untreated PS II membranes, but increased significantly (about 10 fold) when the extrinsic peptides (psbO, P and Q gene products) were removed - suggesting that the L-AME is exposed at the lumen side of PS II. It was possible to isolate the detergent-solubilized protein from CaCl2-washed PS II membranes of spinach by a combination of anion and cation exchange columns. On the basis of SDS PAGE the protein was homogenous and had an apparent molecular mass of 7 kDa. N-terminal sequencing of the polypeptide gave a contiguous sequence of 20 amino acids showing no homologies to PS II polypeptides as yet sequenced. After chromatography of the L-AME on an anion exchange column at pH 9.5 (last purification step) a completely inactive enzyme was obtained. Maximal reactivation was achieved by dialyzing the protein against Hepes-NaOH buffer in the pH range of 6.5 to 7.5 containing 100 mᴍ chloride or sulfate (being the most effective anions). The L-AME activity was totally dependent on manganese added to the reaction mixture. Moreover, there were indications of a second cation binding site being more sequestered and requiring bound Ca2+ or Mn2+ for activity (Sr2+ was less effective and Mg2+ was ineffective). There are indications that the protein contains a redox active group - possibly an aminoacid- derived quinonoid (based on a redox cycling assay with glycine and nitroblue tetrazolium). The capability of this PS II associated protein to bind the cofactors of water oxidation and having a redox active group (preliminary results) suggests that this protein might be functional in photosynthetic water oxidation. This is further supported by the fact that the isolated L-AME has a low catalase activity
Plural Origins of the Molecular Homochirality in Our Biota
Authors: Dias Lins Roberto , Soares Thereza Amelia , Ferreira Ricardo
Published: August 2018

We describe results of computer simulation calculations of mixed and homochiral oligoribotides showing that it is possible to bind ʟ( D)-monomers at the term in al positions of chains built from D (L )-ribotides, but insertion at internal positions produces a large in stability of the chains. Coupled with aproposed new mechanism for the growth of these lin ear polymers in prebiotic conditions, our results imply that enantiomericcross-inhibition could have been bypassed to make all-D(ʟ) oligoribotidesdominant. We also show that racemic amino acids can form stable peptide β-strands, which rules out a similar origin for modern L -amino acids. Alternative schemes are proposed to account for the homochiralities of the amino acids and of other bio molecules.
External Flavonoids of 12 Species of North American Eupatorieae (Asteraceae)
Authors: Wollenweber Eckhard , Dörr Marion , Beyer Matthias , Schilling Edward
Published: August 2018

The flavonoid aglycones excreted by and deposited on aerial parts of 12 species of tribe Eupatorieae, including 10 species of Eupatorium (narrowly defined), Conoclinium coelestinum, and Brickellia eupatorioides, have been analyzed. The flavonoid pattern of Eupatorium is dominated by 6-O-methylated flavones, and there are relatively few differences between species including those of section Verticillata. In contrast, both Conoclinium and Brickellia were found to have significantly different flavonoid patterns. In Conoclinium, this included more highly O-methylated flavones, including the relatively rare compound 5,7,4′-triOH-6,3′,5′-triOMe flavone. In B. eupatorioides this consisted of O-methylated flavonols that are a feature previously reported to be characteristic of Brickellia and thus support the placement of the species in this genus.
Inhibition of Pancreatic Lipase by Phenolic Acids -Examination in vitro
Authors: Karamać Magdalena , Amarowicz Ryszard
Published: August 2018

The influence of addition 2, 4, 6, 8, and 10 μm of benzoic and cinnamic acids and selected phenolic acids (salicylic, p-hydroxybenzoic, gentisic, protocatechuic, vanillic, syringic, o-coumaric, p-coumaric, caffeic, ferulic, sinapic) on the activity of pancreatic lipase was examined in vitro. The strongest inhibition activities were observed with caffeic, ferulic and benzoic acid, while sinapic and gentisic acids produced the lowest inhibition.
Reduction of the Formyl Group of Zinc Pheophorbide b in vitro and in vivo: a Model for the Chlorophyll b to a Transformation
Authors: Scheumann Verena , Helfrich Michael , Schoch Siegrid , Rüdiger Wolfhart
Published: August 2018

The chemical reduction of the formyl group of pheophorbide b with sodium cyanoborohy­ dride in methanol leads to 71-methoxy-and 71-hydroxy-pheophorbide a. The same reaction with zinc pheophorbide b yields in addition zinc pheophorbide a. This was characterized by mass and 1H -NMR spectroscopy. Infiltration of zinc pheophorbides a and b and of zinc 71-hydroxy-pheophorbide a into etiolated oat leaves yielded phytylated products. The best yield in the esterification was obtained with 71-hydroxy-pheophorbide a. Analysis of the products revealed the formation of zinc pheophytin a from all infiltrated compounds. The significance for the transformation of chlorophyll b into chlorophyll a is discussed.
Antibacterial Diterpenic Acids from Brazilian Propolis
Authors: Bankova V. , Marcucci M.C. , Simova S. , Nikolova N. , Kujumgiev A. , Popov S.
Published: August 2018

Four labdane-type diterpenic acids and syringaldehyde were isolated and identified from Brazilian propolis. A ll the compounds exhibit antibacterial activity. The diterpenes, found for the first time in propolis, are typical for some Araucaria species and thus indicate a possible plant source of Brazilian propolis.
Two New Triterpenes from the Frond Exudate of the Fern Notholaena rigida
Authors: Arriaga Fco. Javier , Rumbero Angel , Wollenweber Eckhard
Published: August 2018

From the farinose frond exudate of the fern Notho­laena rigida two new triterpenes have been identified. They were found to be the C-24 epimers of 24, 25-diO-isopropylidene-3β, 12β, 20(S)-trihydroxy-dammarane.
Effect of Pulsed Magnetic Fields on Cholesterol and Tryglyceride Levels in Rats Study of Field Intensity and Length of Exposure
Authors: Bellossi A. , Pouvreau-Quillien V. , Rocher C. , Ruelloux M.
Published: August 2018

In a previous work a decrease in cholesterol and triglyceride plasma levels was observed in rats 24 hours after their exposure to a 12 Hz 6 mT pulsed magnetic field (PMF). This time, a study of intensity effects of a 12 Hz PMF for a sixty-minute exposure and of length of exposure for a 12 Hz 6 mT PMF took place. Non-linear effect-dose relationships were ob­ served for the PMF intensity as well as for the length of exposure used. The highest decreases in cholesterol and triglyceride levels were obtained after to a sixty-minute exposure with 1.5 mT and 12 mT.
Isolation of Two Cytotoxic Diterpenes from the Fern Pteris multifida
Authors: Woerdenbag Herman J. , Lutke  , Bos Rein , Stevens Jan F. , Hulst Ron , Kruizinga Wim H. , Zhu You-Ping , Elema Elizabeth T. , Hendriks Henk , Uden Wim van , Pras Niesko
Published: August 2018

From aerial parts of the fern Pteris multifida Poir. (Polypodiaceae) two diterpenes, entkaurane- 2β,16α-diol and ent-kaur-16-ene-2β,15α-diol, were isolated by repeated column chromatography using silica gel and silica gel impregnated with silver nitrate. The structures were confirmed by spectroscopic methods. Both compounds showed a moderate cytotoxicity to Ehrlich ascites tumour cells
Regulation of Fructose 1,6-Bisphosphatase Activity of Chlorella by Mole Mass Change
Authors: Grotjohann N.
Published: August 2018

Fast protein liquid chromatography on Superose 6 of partially purified FBPase II from Chlorella reveals a 1350 kDa-form at pH 6.0 and a 67 kDa-form at pH 8.5. Treatment of the large enzyme form with 5mᴍ concentrations of Mg2+, F1,6P2, DTT or ATP leads to dissociation into smaller ones of 215 -470 kDa.

Aggregation/dissoziation is a reversible process, as has been shown for the effect of F1,6P2 and of pH, by rechromatography.

The change in mole mass results in alterations of the activitiy and of the kinetic properties of the enzyme forms, obtained. Dissociation results in a 4 - 6 fold increase in activity, as can be shown for F1,6P2-treated samples.

Halfsaturation constants, as well as the degree of cooperativity of the 67- and the 1350- kDa form, are different for substrate affinity, activation by Mg2+ and DTT, and for inhibition by ATP. Both enzyme forms hydrolyse fructose 1,6 bisphosphate and seduheptulose 1,7 bisphosphate better than other phosphorylated compounds. The ratio of F1,6P2- to SDP-cleavage is 100:58 for the small enzyme form and 100: 84 for the large one.

Activation of FBPase II in the light and inactivation in the dark is discussed on the basis of different oligomeric forms of the enzyme, generated by changes in the concentration of intermediates and effectors in the chloroplast stroma, leading to dissociation or aggregation. The conclusion is drawn that oligomerization of key enzymes, resulting in enzyme forms with different activities and different kinetic properties, might provide an effective mechanism for enzyme regulation in vivo
Increase of Caryophyllene Oxide in Ageing Lemon Balm Leaves (Melissa officinalis L.) -A Consequence of Lipid Peroxidation?
Authors: Meyer Werner , Spiteller Gerhard
Published: August 2018

Oxidative processes, especially lipid peroxidation (LPO), are assumed to increase during ageing. In an attempt to provide experimental evidence for this assumption lemon balm plants (Melissa officinalis L.) of different age and location were analyzed for oxidatively caused changes in the etheric oil composition. The investigation revealed that the caryophyllene oxide (CarO) content of lemon balm plants - a main constituent - depends on two factors: age and habitat. The content of CarO increased with age continuously up to a factor of 3. Poor nutritive conditions, as growth on unfertilized soil, also caused an increase in CarO content. Addition of Fe2+/ascorbate - enhancing oxidative processes - promoted the formation of CarO. Hydroperoxides of unsaturated fatty acids (LOOHs) in the lipid extract of lemon balm leaves were converted to corresponding hydroxy acids (LOHs) by sodium borohydride reduction. These were hydrogenated and subjected to GC/MS analysis after derivatisation. A surplus of 9-hydroxy-octadecanoic acid over the 13 isomer indicated at least in part enzymatic lipid peroxidation. Polarographie determination of the oxygen consumption revealed a generally low but in ageing plants increased lipoxygenase activity. This indicates a contribution of lipid peroxidation in the epoxidation process of caryophyllene
Enhancing Effect of UV-Light on the Accumulation of Carthamine in Dyer's Saffron Florets
Authors: Saito Koshi , Utsumi Yoshifumi
Published: August 2018

UV-C (254 nm)- and UV-B (280-320 nm)-light were irradiated onto bright-yellow capitula of dyer’s saffron and their effects on carthamine accumulation compared. UV-C light promotes reddening of florets more prominently than UV-B light, yielding higher amounts of carthamine after the radiation process. The enhancement of carthamine synthesis by UV-C light was investigated on cellulose columns loaded with floret extracts under O2-sufficient or O2-deficient conditions. Externally charged O2 inhibits the UV-C- stimulated carthamine formation. The results are discussed in relation to light stimulation of carthamine synthesis in dyer’s saffron florets
The 1H-NMR Spectra of the Biflavones Isocryptomerin and Cryptomerin B - a Critical Comment on Two Recent Publications on the Biflavone Patterns of Selaginella selaginoides and S. denticulata
Authors: Geiger Hans , Markham Kenneth R.
Published: August 2018

Two recent reports from another laboratory on hinokiflavone and robustaflavone in S. selaginoides, and hinokiflavone, isocryptom erin, cryptomerin B and amentoflavone 7-methylether in S. denticulata are shown to be based on 1H -NMR data that are inconsistent with the biflavone structures proposed. In the current paper a comparison of the 1H -nmr spectra is made both with published data and with new data derived from authentic samples. It is concluded that in both reports, only for am entoflavone the NMR data provide convincing supportive evidence. These reports are considered therefore to merely confirm an earlier identification of am entoflavone in these species
Sterol and Fatty Acid Patterns in Wild and Cultivated Species of Lupinus (Leguminosae)
Authors: Fuentes Elsa , Planchuelo Ana M.
Published: August 2018

Seed oil components of wild and cultivated species of Lupinus were analyzed by gas liquid chromatography (GLC). The sterol and fatty acid patterns of Lupinus albescens and L. gibertianus that are considered important germoplasm resources of South America, are reported for the first time and compared with varieties of Lupinus albus, L. angustifolius and L. mutabilis. The taxonomic implication of seed oil composition was evaluated using a multivariate analysis system.
Subunit II (b') and Not Subunit I (b) of Photosynthetic ATP Synthases is Equivalent to Subunit b of the ATP Synthases from Nonphotosynthetic Eubacteria. Evidence for a New Assignment of b-Type F0 Subunits
Authors: Tiburzy Hans-Jürgen , Berzborn Richard J.
Published: August 2018

Subunit I of chloroplast ATP synthase is reviewed until now to be equivalent to subunit b of Escherichia coli ATP synthase, whereas subunit II is suggested to be an additional subunit in photosynthetic ATP synthases lacking a counterpart in E. coli. After publication of some sequences of subunits II a revision of this assignment is necessary. Based on the analysis of 51 amino acid sequences of b-type subunits concerning similarities in primary structure, iso­electric point and a discovered discontinuous structural feature, our data provide evidence that chloroplast subunit II (subunit b' of photosynthetic eubacteria) and not chloroplast subunit I (subunit b of photosynthetic eubacteria) is the equivalent of subunit b of nonphoto­ synthetic eubacteria, and therefore does have a counterpart in e.g. E. coli. In consequence, structural features essential for function should be looked for on subunit II (b').
Differential Processing of Homologues of the Small Subunit of ADP-Glucose Pyrophosphorylase from Barley (Hordeum vulgare) Tissues
Authors: Luo Cheng , Déjardin Annabelle , Villand Per , Doan Danny N. P. , Kleczkowski Leszek A.
Published: August 2018

ADP-glucose pyrophosphorylase (AGPase), a two-gene-encoded enzyme, is the key com­ponent of starch synthesis in all plants. In the present study, we have used an E. coli expression system for the (over)production of proteins derived from both full length and specifically truncated cDNAs encoding small subunits of AGPase from seed endosperm (AG Pase-Bl) and leaves (AGPase-B2) of barley (Hordeum vulgare). Based on immunoblot analyses, the molecular mass of the expressed A G Pase-Bl (52 kD) was similar to that from endosperm extracts, whereas the expressed AGPase-B2 (56 kD) was larger than that in barley leaves (51 kD). Expression of truncated cDNAs for both the seed and leaf proteins has allowed for a direct verification of molecular masses that were earlier proposed for mature AGPases in barley tissues. The data suggest that seed AGPase-B1 does not undergo any post-translational proteolytic processing in barley, whereas the leaf homologue is processed to a smaller protein. Possible implications of these findings are discussed.