bluuebunny/crossref_metadata_2025 huggingface dataset:
Occurrence of 3,4-Diacetoxybutinylbithiophene in Tagetes patula and Its Enzymatic Conversion
Authors: Pensl Rainer , Sütfeld Rainer
Published: August 2018

3,4-Diacetoxybutinylbithiophene was found to occur in considerable amounts in roots and hypocotyls of young Tagetes seedlings. This compound was converted enzymatically to 3,4-di- hydroxybutinylbithiophene by crude extracts from this plant. Experiments performed with enzyme preparations from plants of different stages of development supported the existence of two position-specific, subsequently working dithiophene acetate esterases. It is suggested that 3-hydroxy-4-acetoxybutinylbithiophene is the intermediate product, formed by an highly specific 3,4-diacetoxybutinylbithiophene: 4-acetate esterase.
Variabilität des "light-harvesting-systems" im Zellzyklus von Chlorella fusca / Variability of the Light-Harvesting-System during the Cell Cycle of Chlorella fusca
Authors: Brandt Peter , Gleibs Helene , Kohne Andrea , Wiessner Wolfgang
Published: August 2018

The seven chlorophyll-protein complexes CPIa, CPI, LHCP1, LHCP2, CPa, LHCP1 and LHCP11 known in part also from the chloroplasts of higher plants were isolated from Chlorella fusca. They were characterized by their molecular weight, their absorption maxima and their ratio of chlorophyll a/chlorophyll b. The composition of the chloropyhll-protein complexes changes during the cell cycle of Chlorella fusca. The ratio of LHCP/CPI decreases at the beginning of the light period and the ratio LHCP/CPa after the 2nd hour of the light period. Both quotients increase at the 5th hour of the light period, have a maximum at the 8th hour of the light period and decrease afterwards during the second part of the cell cycle. These altera­tions are no reflections of chlorophyll-accumulation, but cause modifications in the organization of the thylakoids and influence the photosynthetic efficiency of Chlorella fusca. The size of the PSI- and PSII-units during the cell cycle was estimated by these changes of the LHCP/CPI- and LHCP/CPa-ratios. In addition evidence is given that the assembly of LHCP1 and LHCP2 is no simple association of the monomeric forms of LHCPI or LHCPII.
Elimination of Ammonium Ion from the a-Hydroxyalkyl Radicals of Serine and Threonine in Aqueous Solution and the Difference in the Reaction Mechanism
Authors: Behrens Günter , Koltzenburg Günther
Published: August 2018

The zwitterionic radicals HO-ĊH-CH(COO-)NH3
+ (4a) and HO-Ċ(CH3)-CH(COO-)NH3
+ (4b) are the main species produced upon OH· radical attack in aqueous solutions at pH 3-7 at the amino acids serine, HO-CH2-CH(COO-)NH3
+, or threonine, HO-CH(CH3)-CH(COO-)NH3
+, respectively. Both radicals undergo elimination of NH4
+ ion to form the radicals O=CH-ĊH-COO- (7) or CH3-CO-ĊH-COO- (9) respectively.

The pKa of the serine-derived cationic radical HO-ĊH-CH(COOH)NH3
+ (3a) (3a ⇄ 4a + H+), was determined by ESR spectroscopy to 2.2 ± 0.1 at 276 K. From kinetic data the pKa(OH) of radical 4a (4a ⇄ O-ĊH-CH(COO-)NH3
+ (5a) + H+) was calculated to 7.0. The elimination of NH3 takes place from the ketyl radical 5a (type-B mechanism), the rate constant was calculated from kinetic data to 2.4 × 106 s-1 at 290 K.

The half-lives of radicals 4a and 4b were measured by time-resolved conductivity changes upon pulse radiolysis, 170 ± 10 μs for 4a and 26 ± 2 μs for 4b, at 290 K and pH 5.8 .

With the threonine derived radicals elimination of NH3 takes place at the stage of the α-hydroxyalkyl radical 4b (type-A mechanism). In this series the pKa of the product radical CH3-CO-ĊH-COOH (8) (8 ⇄ 9 + H+), was determined by ERS spectroscopy to 2.7 ± 0.1.

The reasons for the observed mechanistic differences (type-A versus type-B decay) are discussed. As further examples for a type-B decay some preliminary data on the elimination of HF from the radicals CF3-Ċ(OH)-CF3 and CF3-ĊH-OH have been added.
Enhanced Production of Cell-Bound and Extracellular Streptolysin S by Hemolytic Streptococci Pretreated with Proteases
Authors: Taketo Akira , Taketo Yoriko
Published: August 2018

The amount of streptolysin S produced by resting streptococci was considerably increased after incubation of the washed bacteria with trypsin or pronase. Production of both cell-bound and free forms of the toxin was enhanced by the protease treatment. By addition of trypsin, streptolysin S yield was considerably increased in growing culture as well. Treatment with lysozyme was ineffective, and the toxin production was only slightly promoted by preincubation with hyaluronidase or chymotrypsin. In contrast, pretreatment witn chymotrypsin caused in­creased production of an extracellular nuclease, whereas the yield of this enzyme was reduced after incubation of the cocci with pronase. Evidence was obtained indicating de novo synthesis of the exotoxin in the protease-treated bacteria.
Regulation of β-Galactosidase Synthesis in Wild Type and in a Succinate-Resistant Mutant of Rhizobium meliloti
Authors: Singh A. P. , Singh J. B.
Published: August 2018

The synthesis of β-galactosidase in Rhizobium meliloti WU60 was found to be inducible by lactose and its non-metabolizable analogue. isopropyl-β-ᴅ-thiogalactoside (IPTG). In contrast to Escherichia coli, galactose and melibiose were very weak inducers of this enzyme in R. meliloti. The maximum level of β-galactosidase in this bacterium is 2% of that in fully induced E. coli. In addition to glucose, the induced synthesis of this enzyme in R. meliloti was repressed by galactose, glycerol, and succinate. In comparison to E. coli, addition of cyclic AMP to the growth medium of R. meliloti did not alleviate the repressive effect of the above compounds on β- galactosidase synthesis.

High concentrations of sodium succinate (100 mᴍ) were inhibitory to the growth of R. meliloti. Spontaneous succinate-resistant mutants could be isolated at low frequency. In contrast to the wild type parent, in a succinate-resistant mutant, the synthesis of β-galactosidase was not repressed by succinate.
Soybean Root Response to Symbiotic Infection Glyceollin I Accumulation in an Ineffective Type of Soybean Nodules with an Early Loss of the Peribacteroid Membrane
Authors: Werner Dietrich , Mellor Robert B. , Hahn Michael G. , Grisebach Hans
Published: August 2018

A glyceollin I accumulation of about 6000 pmol · mg dry weight-, a tenfold increase above control root tissue, was found in one type of nodule from Glycine max which had been infected with a fix- strain (61-A-24) of Rhizobium japonicum. In nodules infected with one other ineffective (fix-) strain of Rhizobium japonicum (RH 31-Marburg) or with two fix+ strains of Rhizobium japonicum (61-A-101 and USD A 110) no increase in glyceollin I concentrations above control values was found at either 20 d or 34 d after infection. Nodules infected with Rhizobium japonicum 61-A-24 are distinguished by an early loss of the peribacteroid membrane in the infected host cell, whilst the bacteroids themselves remain stable.
Chemiluminescence in the Coupled Oxidation of Lecithin and Ascorbate
Authors: Lichszteld Krzysztof , Machoy Zygmunt , Stępińska Anna
Published: August 2018

Chemiluminescence (CL) that appears during oxidation of lecithin and ascorbate has been studied. A simple system consisting only of purified lecithin, which has one double bond, and ascorbate as a physiological reductant with a low redox potential, was used. The CL spectrum of lecithin contain a strong band lying in the near infrared, and three bands at 20 900 cm-1, 17 700 cm-1 and 15 800 cm-1, being characteristic of singlet molecular oxygen (1O2). The effect of 1O2 quenchers on both autooxidation processes has also been investigated. The obtained results indicate that the main emitter is the 1O2.

An addition of ascorbate to the system lecithin plus buffer causes a decrease of CL intensity. That is a result of stronger quenching properties of ascorbate and not due to efficiency of the generation of 1O2.
Sex Attractant Blends for Field Trapping of Agrotis segetum Males (Lepidoptera: Noctuidae) in Israel and Germany
Authors: Dunkelblum Ezra , Bestmann Hans Jürgen , Knauf Werner , Vostrowsky Otto
Published: August 2018

Lures for a monitoring system based on sex attractant trapping of Agrotis segetum males were elaborated for Israel and Germany. Various mixtures of (Z)-5-aecenyl acetate, (Z)-7-dodecenyl acetate, (Z)-9-dodecenyl acetate, (Z)-9-tetradecenyl acetate, decyl acetate and dodecyl acetate were tested in 20 different blends. From comparison of all the trap catches a four-component lure consisting of (Z)-5-decenyl, (Z)-7-dodecenyl, (Z)-9-tetradecenyl and dodecyl acetate is recommended for monitoring of A. segetum in both countries.
The Effect of Thiol Compounds on the Glutamate Affinity of the Chloroplastic Glutamine Synthetase from Mustard Leaves
Authors: Manderscheid Remigius , Wild Aloysius
Published: August 2018

The chloroplastic glutamine synthetase taken from mustard leaves shows a positive cooperative glutamate binding. The S0.5-value depends on the DTE concentration in the homogenization buffer. Normal glutamate satura­tion kinetics have been found with the root enzyme and the enzyme of etiolated cotyledons. These are not influ­enced by thiol compounds. The possible function of the allosteric behaviour of GS2 is discussed.
Flavonoids and Terpenoids from the Leaf Resin of Pluchea odorata
Authors: Wollenweber E. , Mann K. , Arriaga F. J. , Yatskievych G.
Published: August 2018

The chemical composition of the leaf resin of Pluchea odorata has been studied from material collected in Tamaulipas, Mexico. It mostly consists of triterpenes and phytosterols and an eudesmane type sesquiterpene. Very small amounts of ten different flavonol aglycones occur, dissolved in this resin; most of them are 6-methoxy compounds. A comparison with previous results on material from El Salvador shows that the latter contains a lesser number of triterpenes and especially of flavonoids, but more sesquiterpenes, while the n-alkane composition varies only quantitatively between both populations.
Acylchain Specificity and Kinetic Properties of Phospholipase A1 and A2 of Bone Marrow-Derived Macrophages
Authors: Flesch Inge , Schmidt Brigitte , Ferber Ernst
Published: August 2018

The fatty acyl specificity of phospholipase A1 and A2 in homogenates of mouse bone marrow-derived macrophages was determined using phosphatidylcholine and phosphatidylethanolamine of different acylchain composition. Phosphatidylcholine with arachidonoyl at position 2 was cleaved preferentially by an alkaline phospholipase A2 (pH-optimum 9.0) leading to selective liberation of arachidonic acid. In contrast, phosphatidylcholines with oleoyl or linoleoyl at posi­tion 2 were degraded mainly by an acid phospholipase A1 (pH-optimum 4 -5) resulting in a conservation of these fatty acids esterified in lysophosphatides. Substrate kinetics of the alkaline phospholipase A2 revealed a 30 fold higher affinity (Km = 3.8 x 10-7 ᴍ) for 1-acyl-2-arachidonoyl-glycerophosphocholine compared to 1-acyl-2-oleoyl-glycerophosphocholine. The kinetic data were not influenced by endogenous lipids indicating that exogenous substrates do not equilibrate with cellular lipids.

These results are suitable to explain a selective liberation of arachidonic acid from a mixture of phospholipids.
Prosomes are Involved in the Repression of Viral mRNA
Authors: Horsch Andrea , Köhler Kurt , Schmid Hans-Peter
Published: August 2018

Prosomes are small cytoplasmic RNP complexes. We present evidence that their RNA is a potential and selective inhibitor of viral mRNA translation while translation of normal cellular mRNA e.g. rabbit globin mRNA or HeLa cell mRNA is not affected.
New Flavone Glucoside Malonylesters from Bryum capillare
Authors: Stein Wolfgang , Anhut Siegbert , Dietmar H. , Mues Rüdiger , Barz Wolfgang , Köster Johannes
Published: August 2018

From Bryum capillare Hedw. a variety of flavone glucosides and their 6″ malonyl esters were isolated. Diosmetin 7-O-β-D-glucoside-6″-malonylester, luteolin 7-O-β-D-glucoside-6″-malonyl-ester and 6-OH-luteolin 7-O-β-D-glucoside-6″-malonylester are new flavone malonyl esters. This is the first report of flavone glucoside malonylesters in a non vascular plant. The flavonoid pattern of the gametophyte is different from that of the sporophyte. The chemotaxonomic relevance of these results is discussed.
Comparative Analysis of Epicuticular Waxes from Some High Alpine Plant Species
Authors: Lütz Cornelius , Gülz Paul-Gerhardt
Published: August 2018

Epicuticular waxes were extracted and analysed from leaves of 7 different high alpine plant species, with 3 species harvested at different altitudes: Salix herbacea (1950 m, 2825 m), Leucanthemopsis alpinum (1950 m, 3050 m), Loiseleuria procumbens (1950 m, 2660 m), Dryas octopetala (2400 m), Ranunculus glacialis (2800 m), Soldanella pusilla (2640 m), Oxyria digyna (2640m). Two main fractions obtained from waxes were investigated: hydrocarbons and wax-esters, -aldehydes plus -acetates. Individual wax compounds accumulated differently in the respective plant species. The gross composition did not indicate a strict altitude-dependent change in wax composition, though some single components like the C-29/C-31 alkanes (Loiseleuria) or the C-22/C-26 fatty acid methyl esters in Salix, changed significantly with increasing elevation of plant habitat. The evergreen leaves of Dryas and of Loiseleuria exhibited exceptionally high amounts of triterpenol esters.

The results indicate that the formation of epicuticular wax layers is not based on a special adaptation to altitude or high mountain habitats in general.
Diurnal Changes of Fructose-6-phosphate,2-kinase and Fructose-2,6-bis-phosphatase Activities in Spinach Leaves
Authors: Stitt Mark , Mieskes Gottfried , Söling Hans-Dieter , Große Heike , Heidt Hans W
Published: August 2018

Extracts have been rapidly prepared from spinach leaves, and the activity of fructose-6-phosphate, 2-kinase (Fru6P,2kinase) and fructose-2,6-bisphosphatase (Fru2.6P2ase) measured. The enzyme activities do not change during light-dark transitions, but there is an increase of Fru6P,2- kinase and decrease of Fru2,6P2ase activity over several hours in the light. This increase of the Fru6P,2kinase: Fru2,6P2:ase ratio shows that a previously unrecognized mechanism, which may include protein modification, controls Fru2,6P2 levels in leaves. It operates as sucrose accumulates in the leaf, and will be involved in regulating the partitioning of photosynthate.
Notizen: Oxygen Incorporation in Cleavage of 18-Labeled 13-HydroperoxylinoIeyl Alcohol into 12-Hydroxy- (3Z)-dodecenal in Tea Chloroplasts
Authors: Hatanaka Akikazu , Kajiwara Tadahiko , Sekiya Jiro , Toyota Hiromitsu
Published: August 2018

The oxygen atom in the hydroperoxy group of 13-hydroperoxylinoleyl alcohol was primarily incorporated into the carbonyl group of 12-hydroxy-(3Z)-dodecenal but scarcely into n-hexanal during the incubation with tea chloroplasts.
Notizen: Isolation of Beef Brain Phosphonolipids by Thin Layer Chromatography: Their Identification and Silicic Acid Column Chromatographic Separation
Authors: Moschidis Michael C.
Published: August 2018

The isolation and identification of the phosphonolipids from beef brain - right lobe, left lobe and cerebellum - is herein reported. The phosphonolipids were isolated by preparative thin layer chromatography (TLC) using the solvent system methanol/water (2:1, v/v) and identified preliminarily by TLC. The isolated phosphonolipids were subjected to silicic acid column chromatographic separation and the thus separated phosphonolipids were identified by TLC, nitrogen-phosphorus determinations and IR spectroscopy.
Biosynthetic Capacity of Stachys Seedlings for Verbascoside and Related Caffeoyl Derivatives
Authors: Andary Claude , Ibrahim Ragai K.
Published: August 2018

The caffeoyl derivatives of Stachys leaves (Labiateae) were identified as chlorogenic acid, verbascoside and stachyoside. The latter compound, reported here for the fist time, was shown to be a verbascoside derivative containing an extra glucose residue attached to C-2, C-3 or C-4 of rhamnose.

Cotyledonary leaves of Stachys accumulate high levels (8 -16 μmol/g dry tissue) of the three caffeoyl derivatives; all of which decrease significantly in amount during plant growth. Intact organs of the seedling were shown to efficiently incorporate the label from different precursors into caffeoyl derivatives. The biosynthesis of both verbascoside and stachyoside from labelled precursors revealed that the caffeoyl moiety was exclusively labelled from phenylalanine or cinnamic acid, whereas the 3,4-dihydroxyphenylethanol moiety was labelled from tyrosine, and better from tyramine.
Isolation and Separation of Epidermal and Mesophyll Protoplasts from Rye Primary Leaves — Tissue-Specific Characteristics of Secondary Phenolic Product Accumulation
Authors: Schulz Margot , Weissenböck Gottfried
Published: August 2018

We have develop ed a technique for the large-scale isolation of epidermal and mesophyll proto­plasts, as well as the vascular strands, of rye primary leaf blades.

Separation of the two types of protoplasts has been successful only from leaves harvested at the end of a 13-h light period, when chloroplasts were enriched in starch.

The occurrence of different flavonoid compounds, and amounts, in epidermal and mesophyll protoplasts can be used as criteria for protoplast purity and viability since C-glucosylflavone O-glycosides are characteristic of epidermal protoplasts whereas flavone O-glucuronides and anthocyanins are typical of mesophyll protoplasts. Several non-flavonoid phenolic compounds are found only in the epidermal protoplast. These patterns of secondary product accumulation reflect the high tissue specificity of the rye leaf.
Biosynthesis of 4-Formyl-4-imidazoIine-2-on, the Heterocyclic Base of Nikkomycin X
Authors: Schmidt Ralf-Michael , Pape Hermann , Junack Matthias
Published: August 2018

The nucleoside-peptide antibiotic nikkomycin X contains the unusual heterocyclic base 4-formyl-4-imidazoline-2-on. Investigations on the biosynthesis of this base were accomplished in a resting cell system which was optimized in respect to nikkomycin production.

Incorporation experiments with [2-14C]adenine, [8-14C]adenine, [2-14C]glycine, [2-14C]uracil, [U-14C]histidine, and [2-14C]histidine revealed that only [2-14C ]adenine, [U-14C]-and [2-14C]histidine were specifically incorporated into nikkomycin X. An incorporation experiment with [2-13C]adenine resulted in a 31-fold enrichment of the carbon atom 2 of 4-formyl-4-imidazoline-2-on. These results show that the heterocyclic base of nikkomycin X is a product of the histidine biosynthetic pathway.
Elicitor-Stimulated Furanocoumarin Biosynthesis in Cultured Parsley Cells: S-Adenosyl-ʟ-Methionine:Bergaptol and S-Adenosyl-ʟ-Methionine: Xanthotoxol O-Methyltransferases
Authors: Hauffe Karl Dietrich , Hahlbrock Klaus , Scheel Dierk
Published: August 2018

Cultured parsley cells (Petroselinum crispum) treated with an elicitor from the soybean patho­gen, Phytophthora megasperma f. sp. glycinea, were used as source for the separation, extensive purification and characterization of S-adenosyl-ʟ-methionine: xanthotoxol and S-adenosyl-ʟ-m ethionine: bergaptol O-methyltransferases. The products, xanthotoxin and bcrgapten, were among the most abundant coumarin derivatives accumulated in the culture fluid of elicitor-treated parsley cells. The latter enzyme also catalyzed the methylation of 5-hydroxyxanthotoxin to isopimpinellin, another major coumarin derivative in this system. The activities of both enzymes showed transient increases upon elicitor application prior to the accumulation of the products. No activity was detectable in untreated cells. Activity increases of the O-methyltransferases occurred a few hours later than those of phenylalanine ammonia-lyase and 4-coumarate:CoA ligase.
Flavonoid Constituents of Rhamnus lycioides L.
Authors: Payá Miguel , Máñez Salvador , Villar Angel
Published: August 2018

From the aerial part of Rhamnus lycioides, which is used in folk medicine in eastern Spain as an antihypertensive drug, seven free flavonoid aglycones were isolated. They were structurally eluci­dated as rhamnazin. rhamnocitrin, isorhamnetin, kaempferol, quercetin. quercetin-3-methylether and taxifolin. by applying the principal spectroscopic methods and TLC with authentic markers.
Effects of Low Frequency Magnetic Fields on Chick Embryos. Dependence on Incubation Temperature and Storage of the Eggs
Authors: Juutilainen Jukka P.
Published: August 2018

Chick embryos were exposed to sinusoidally oscillating 100 Hz magnetic fields during their first two days of development. The magnetic field strength was 1 A/m. Incubation temperatures of 36.3, 37.0, 38.0 and 38.5 °C were used and the duration of the storage of the eggs before incuba­tion was varied from 1 hour to 4 days. After the incubation, the embryos were examined for abnormalities. When the temperature was 36.3 or 37.0 °C and the eggs were stored for one day or less, the effect of the magnetic field was statistically significant. In these conditions, the percent­ age of abnormal control embryos was low, 8% in 36.3 °C and 5% in 37.0 °C. In the exposed groups the corresponding percentages were 23% (36.3 °C) and 25% (37.0 °C). However, higher temperature and storage of the eggs for 3 to 4 days increased the percentage of abnormal embryos in both the exposed and control groups. The difference between the exposed and control embryos was not significant in these conditions. The results demonstrate the importance of the handling of the eggs in this kind of experiments.
Chemistry and Morphology of Epicuticular Waxes from Leaves of Five Euphorbia Species
Authors: Hemmers Herbert , Gülz Paul-Gerhard , Hängst Kurt
Published: August 2018

The surface waxes of five Euphorbia species (Euphorbiaceae) were studied by chemical methods and by scanning electron microscopy. The yields of epicuticular waxes, expressed as percentages of the dry weights, differed from species to species. Qualitatively the five species showed the same wax composition but differences appeared in the amounts of single wax components and in their distribution patterns. The predominance of mainly saturated and long chained components as well as the high amounts of primary alcohols and triterpenols resulted in crystalline wax layers. The comparable chemical wax com position of all five species resulted in a quite similar morphological appearance of wax crystals.
Ergosterol as a Biochemical Indicator of Fungal Infection in Spruce and Fir Needles from Different Sources
Authors: Osswald Wolfgang F. , Höll Wolfgang , Elstner Erich F.
Published: August 2018

Different fungi are discussed to play a certain role in recent spruce decline in addition to different abiotic factors such as SO2, photooxidants (ozone) or unfavourable climatic conditions. Thus, ergosterol as a specific fungal sterol was used as a biochemical indicator for fungal infection in differently damaged spruce and fir needles. With its aid it could be demonstrated that the important needle pathogens Rhizosphaera kalkhoffii Bubak, Lophodermium piceae and Sirococcus Type II contain unsaponified ergosterol comparable with the ergosterol content of different edible m ushrooms. Furthermore it could be shown that all necrotic and also certain bleached and green needles exhibit fungal infection. However, fungal invasion seem s to be a secondary reaction after the needle is predamaged by different factors.
Changes in the Stoichiometry of Photosystem II Components as an Adaptive Response to High-Light and Low-Light Conditions during Growth
Authors: Wild Aloysius , Höpfner Matthias , Rühle Wolfgang , Richter Michael
Published: August 2018

The effect of different growth light intensities (60 W·m-2, 6 W·m-2) on the performance of the photosynthetic apparatus of mustard plants (Sinapis alba L.) was studied. A distinct decrease in photosystem II content per chlorophyll under low-light conditions compared to high-light conditions was found. For P-680 as well as for Oᴀ and Oв protein the molar ratio between high-light and low-light plants was 1.4 whereas the respective concentrations per chlorophyll showed some variations for P-680 and Oᴀ on the one and Oв protein on the other hand.

In addition to the study of photosystem II components, the concentrations of PQ, Cyt f, and P-700 were measured. The light regime during growth had no effect on the amount of P-700 per chlorophyll but there were large differences with respect to PQ and Cyt f. The molar ratio for Cyt f and PQ between high- and low-light leaves was 2.2 and 1.9, respectively.

Two models are proposed, showing the functional organization of the pigment system and the electron transport chain in thylakoids of high-light and low-light leaves of mustard plants.
Pflanzliche Insektizide, III [1], Pyrethrin I im etherischen Öl von Chrysanthemum balsamita L. / Herbal Insecticides III [1]. Pyrethrin I in the Essential Oil of Chrysanthemum balsamita L.
Authors: Bestmann Hans Jürgen , Claßen Beate , Kobold Uwe , Vostrowsky Otto , Klingauf Fred
Published: August 2018

From the leaves of Chrysanthemum balsamita L. an essential oil with insecticidal properties was isolated and the components were analyzed by gas chromatography and mass spectrometry. By means of TLC and HPLC the oil was divided into several fractions, which were examined for their insecticidal activity in a biotest. The activity could be contributed to pyrethrin I which was found for the first time in C. balsamita.
Interference of Dimethazone with Formation of Terpenoid Compounds
Authors: Sandmann Gerhard , Böger Peter , Sandmann Gerhard , Böger Peter
Published: August 2018

Dimethazone is a bleaching herbicide without any peroxidative activity. In addition to the inhibition of chlorophylls, carotenes, and xanthophylls, decreased formation of other prenyl lipids (phytol and α-tocopherol) can be observed in the presence of dimethazone. Application of this herbicide to pea plants results in the inhibition of longitudinal growth of the newly formed internodes which can be reversed by gibberellic acid. Apparently, dimethazone also decreases the endogenous gibberellin levels.

As the formation of all the compounds assayed is inhibited to the same extent and as I50 -values for chlorophyll and carotenoid biosynthesis are identical (about 10 µᴍ dimethazone), the various effects of dimethazone are explained by a single enzyme target in the terpenoid biosynthetic pathway between acetate and geranylgeranyl pyrophosphate.
Identification and Biosynthesis of Glucosylated and Sulfated Flavonols in Flaveria bidentis
Authors: Varin Luc , Barron Denis , Ibrahim Ragai
Published: August 2018

1.The flavonoid constituents of Flaveria bidentis have been identified as the 3-O-glucosides of kaempferol. 6-methoxykaempferol and 6-methoxyquercetin (patuletin), as well as six flavonol sulfate esters belonging to quercetin and isorhamnetin. The two latter glucosides are reported here for the first time in this species; whereas quercetin-3,7-disulfate, is a novel compound from nature.

2.The amounts of both glucosides and sulfate esters in young seedlings were highest in buds > stems > leaves on fresh weight basis, whereas they were undetectable in the root. There were striking quantitative differences in the flavonoid pattern of young seedlings, as compared with mature shoots, especially the flavonol sulfate esters which were predominant in seedlings.

3.The biosynthesis of both groups of flavonoids from [3H]cinnamate and [35S]sulfate showed that the former was predominantly incorporated into glucosides whereas the latter, into sulfate esters; thus indicating that sulfation is a later step in the biosynthesis of flavonol sulfate esters.

4.The significance of the glucosylation and sulfation reactions was discussed in relation to the regulation of biosynthesis and compartmentation of both groups of compounds.
Volatile Fragrance Compounds from the Fungus Gloeophyllum odoratum (Basidiomycotina)
Authors: Hanssen Hans-Peter , Sinnwell Volker , Abraham Wolf-Rainer
Published: August 2018

The accumulation of volatile metabolites in liquid cultures of the basidiomycete Gloeophyllum odoratum CBS 444.61 was studied after cultivation on defined synthetic liquid culture medium containing glucose (2%), asparagine (0.15%), and mineral salts. The composition of the steam volatile compounds differed distinctly from that obtained with another, previously investigated strain of this species. Two major constituents, the bicyclic sesquiterpene alcohol drimenol and a linalool derivative, 3,7-dimethyl-3-hydroxy-6-octenic acid methyl ester, could be identified by mass spectral data and 1H and 13C NMR spectroscopy. Besides several monoterpene alcohols, other minor constituents were trans-linalool oxide and 1-octen-3-ol. 3,7-Dimethyl-3-hydroxy-6-octenic acid methyl ester is described for the first time as a natural product.
An Elicitor of the Hypersensitive Lignification Response in Wheat Leaves Isolated from the Rust Fungus Puccinia graminis f. sp. tritici II. Induction of Enzymes Correlated with the Biosynthesis of Lignin
Authors: Moerschbacher B. , Heck B. , Kogel K. H. , Obst O. , Reisener H. J.
Published: August 2018

The genuine biotic elicitor from germ tube walls of Puccinia graminis f. sp. tritici (Pgt-elicitor) induces lignification, preceded by an increase in phenylalanine ammonia-lyase (PAL) activity, when injected into the intercellular space of primary wheat leaves. This increase in PAL activity is accompanied by an increase in other enzyme activities of the general phenylpropanoid pathway and the specific pathway of lignin biosynthesis: 4-coumarate :CoA ligase (4CL), cinnamyl alcohol dehydrogenase (CAD) and peroxidase (PO).

Total extractable activities of 4CL, CAD and PO do not differ significantly in resistant and susceptible near isogenic wheat lines, whereas the dose response curve of induced PAL activity shows significantly higher values in the resistant isoline. This difference is not observed after injection of other biotic and abiotic elicitors of the lignification response.

Although total induced PO activities 24 h after elicitor treatment are equal in both isolines, the PO isoenzyme pattern of resistant plants differs markedly from that of susceptible plants. The patterns of PO isoenzymes in the compatible and incompatible interaction 48 h after inoculation with Puccinia graminis f. sp. tritici also show differences, which closely resemble those seen after injection of the Pgt-elicitor. The patterns observed after injection of an artificial biotic elicitor clearly differ from those of the natural interaction.
Natural Waxes Investigated by Soft Ionization Mass Spectrometry
Authors: Schulten H .-R . , Murray K. E. , Simmleit N.
Published: August 2018

Field ionization (FI) and field desorption (FD) mass spectra of 35 aliphatic long-chain and branched long-chain compounds, representing the major six classes of constituents of natural waxes, are examined. In the FI mode the molecular ions are usually formed at comparatively low levels, while in FD such species are almost exclusively generated. In addition, some fast atom bombardment mass spectra, in the positive and negative ion mode, of selected lipids are recorded for comparison. In general, field ionization and field desorption techniques are found to be superior for mass spectrometric studies of low-polarity compounds.

Examination of several natural waxes, such as Jojoba wax, preen gland wax of goose, beeswax and epicuticular wax of Norway spruce, shows that field desorption mass spectrometry has a most promising role in the characterization of wax components. The intense molecular ions allow the identification of the constituents of complex lipid mixtures without the need for derivatization. Thus, for the first time, the carbon number distribution, especially of the high-mass wax con­stituents can be established for the natural waxes investigated. For identification of high-mass wax constituents the present results suggest that field desorption mass spectra could be best employed in conjunction with class and individual separation of constituents by chromatographic proce­dures.

The analysis of natural waxes is nowadays of major concern because of its importance in the problem of forest damage.
Epicuticular Leaf Wax of Euphorbia dendroides L., Euphorbiaceae
Authors: Gülz Paul-Gerhard , Hemmers Herbert , Bodden Jutta , Marner Franz-Josef
Published: August 2018

Quantity and composition of epicuticular leaf wax of Euphorbia dendroides L. was examined. The wax contained rt-alkanes, wax esters, aldehydes, fatty acids and primary alcohols. In addition to these common epicuticular wax constituents several triterpenoids and benzoic acid esters were found. The triterpenols β-amyrin and lupeol occurred free as well as esterified with long chain fatty acids. The ketones Δ 12-oleanen-3-one and lupen-3-one have also been identified.
Characterization and Amino Acid Composition of a Hypertrehalosaemic Neuropeptide from the Corpora cardiaca of the Cockroach, Nauphoeta cinerea
Authors: Gäde Gerd
Published: August 2018

Nauphoeta cinerea corpora cardiaca contain peptide material which is capable of eliciting strong hypertrehalosaemia (maximum increase: 27 mg carbohydrates/ml haemolymph) and fat body glycogen phosphorylase-activation (maximal: 70% of the total phosphorylase activity in the a-form) in the American cockroach, Periplaneta americana. It appears that comparable amounts of bioactive material are stored in the corpora cardiaca of N. cinerea and P. americana. Purifica­tion of a methanolic extract of corpora cardiaca from N. cinerea by reversed-phase HPLC revealed that the hypertrehalosaemic phosphorylase-activating activity is concentrated in a single peak. The amino acid composition of the purified neuropeptide material was determined after acid hydrolysis with HCl and methanesulfonic acid. The analyses demonstrated that the N. cinerea hypertrehalosaemic factor is a decapeptide which contains the following amino acid residues: Asp, Thr, Ser, Glu, Pro, Gly (2), Val, Phe, and Trp.
Proposal for the Mechanism of Action of Urocanase. Inference from the Inhibition by 2-Methylurocanate
Authors: Gerlinger Erich , Rétey János
Published: August 2018

Incubation of urocanase with 2-methylurocanate leads, after an initial normal reaction, to a time dependent inactivation of the enzyme. It is suggested that a tautomeric form (1) of the product, 2-methyl-imidazolone propionate, is the actual inhibitor. On the basis of these and of published experimental data a novel mechanism is proposed for the urocanase reaction. The crucial and initial step is the electrophilic addition of enzyme-bound NAD to the 2-position of the imidazole nucleus of urocanate.
Derepression of Arylsulfatase Activity by Sulfate Starvation in Chlorella fusca
Authors: Niedermeyer Inge , Biedlingmaier Susanne , Schmidt Ahlert
Published: August 2018

Arylsulfatase activity was detected in the green alga Chlorella fusca 211-8b during sulfur starvation. No activity was present during growth on sulfate, whereas activity was found with sulfur sources as growth-limiting factor including L-cysteine and L-methionine. Arylsulfatase activity was found after transfer to sulfate starvation conditions after a lag-period of about 3 h; addition of cycloheximide prevented arylsulfatase formation, suggesting the participation of protein synthe­ sis. Addition of sulfate to cultures with active arylsulfatase led to a decay of this enzyme, whereas addition of sulfate and cycloheximide prevented this decay suggesting that protein synthesis is also needed for degradation of arylsulfatase activity. The Km for p-nitrophenyl sulfate was determined to be 0.8 mм. The activity of the arylsulfatase is not affected by sulfate or phosphate, however it is inhibited strongly by sulfite, cyanide and boric acid and therefore is classified according to Dogson and Spencer (Meth. Biochem. Anal. 4, 211-254 (1957) as an arylsulfatase of type I.
Substrate Flow from Photosynthetic Carbon Metabolism to Chloroplast Isoprenoid Synthesis in Spinach Evidence for a Plastidic Phosphoglycerate Mutase
Authors: Schulze-Siebert Detlef , Heintze Adolf , Schultz Gernot
Published: August 2018

The carbon flow from 3-phosphoglycerate to pyruvate and acetyl-CoA within the chloroplast as well as the pathway for the formation of β-carotene, plastoquinone-9 etc. as plastidic isoprenoids from photosynthetically fixed CO2 hitherto remained unclear because the presence of the phos- phoglycerate mutase in chloroplasts had not unequivocally been proven. To clarify this question, the incorporation of 14CO2, [2-14C]acetate, [2-14C]pyruvate, [2-14C]glycine, [3-14C]serine and [2-14C]mevalonate into β-carotene, plastoquinone-9, sterols and fatty acids was studied using spinach and barley protoplasts and barley seedlings. In protoplasts as well as in seedlings under conditions of CO2 fixation, the largest portion of the acetyl-CoA derived compounds formed was β-carotene and plastoquinone-9 rather than fatty acids and sterols. High rates of fatty acid synthesis were obtained by supplying acetate as well. Mevalonate was incorporated into sterols but not into β-carotene and plastoquinone-9. Direct evidence was obtained for the hitherto questioned plastidic phosphoglycerate mutase. Low activities were found in spinach chloroplasts which were substantiated by the criteria of latency method. Substrate flow from 3-phosphoglycerate to pyruvate via 2-phosphoglycerate and phosphoenolpyruvate was shown by applying [1-14C]- glycerate and following its incorporation. From this the following conclusions were drawn: (i) The plastidic IPP synthesizing system is strongly separated from the cytosolic-ER one. (ii) As the formation of β-carotene and plastoquinone-9 is favoured under conditions of photosynthetic CO2 fixation, a direct carbon flow from 3-phosphoglycerate to isoprenoids via acetyl-CoA by a low- capacity pathway, which shows high affinities for the substrates, is suggested.
Nitrate Reductase from Sphagnum Species: Isolation, in vitro Assays and Partial Purification
Authors: Deising Holger
Published: August 2018

Nitrate reductase (EC 1.6.6.2) has been isolated from 11 Sphagnum (Bryophyta) species and purified up to 500-fold by a procedure involving (NH4)2SO4 precipitation and blue sepharose affinity chromatography.

The purest fraction showed a nitrate reductase activity of 7.7 nkat mg protein-1 with NADPH as the electron donor. Beside NADPH and NADH, FMNH2 and - after blue sepharose affinity purification of the enzyme - MVH2 were used as electron donors in different assays.
Photosynthetic Properties and Cross-Resistance to Some Urea Herbicides of Triazine-Resistant Conyza canadensis Cronq (L.)
Authors: Pölös E. , Laskay G. , Szigeti Z. , Pataki Sz. , Lehoczki E.
Published: August 2018

A comparison of the photosynthetic activities, chloroplast ultrastructures and sensitivities to some urea herbicides of atrazine-resistant (R) and suspectible (S) biotypes of Conyza canadensis Cronq (L.) (horseweed) in the rosette stage showed that: I) The light-intensitv dependences of the rates of CO2 reduction in intact leaves of the R and S plants are very similar. 2) The rate of the Hill reaction of the R chloroplasts at 25 0C is 15 - 20% lower at all light intensities than that of the S chloroplasts. 3) The rates of the Hill reactions of the R and S chloroplasts exhibit different temperature-dependences. The activation energy for the S chloroplasts in the temperature range 10-40 0C was found to be 15.3 kJ mol-1. For the R chloroplasts. the discontinuity in the Arrhenius plot was found at around 20 °C: the activation energy was 20.1 kJ mol-1 at below 20 0C. and decreased to 8.2 kJ mol-1 at higher temperatures. 4) The R plants have a better adaptive capacity than the S plants at low temperatures. 5) The chloroplast ultrastructure in the R plants was not reminiscent of that of plants grown under low light intensity. 6) The R biotype exhibited cross- resistance to chlorbromuron and metobromuron. and tolerance to linuron. The R and S biotypes, however, were equally sensitive to diuron. The results permitted conclusions on the properties of the triazine-resistance and urea cross-resistance.
Evolution of E. coli tRNAIle: Evidence of Derivation from Other tRNAs
Authors: Staves Mark P. , Bloch David P. , Lacey James C.
Published: August 2018

Two E. coli tRNAIle sequences were compared against those of 36 other E. coli tRNAs. tRNAIle 1 was found to bear high similarity with tRNAVal 1 (E = 1.11 x 10-18) while tRNAIle 2 had the greatest match ( E = 3 .4 0 x 10-19) with tRNALysl (E is the expected number of such matches, per search, based on coincidence). These matches, which we consider to represent homologies, extend from base 7 to base 67 in the former and base 7 to the end (76) in the latter pair. These results coupled wim otners on tne lower activity ot isoleucine in reactions postulated to be important in primitive protein synthesis (i.e. esterification reactions and non-enzymatic activation by ATP [1-3]) lead us to propose that isoleucine was included among the proteinaceous amino acids, and received its anticodonic assignment, relatively late in evolution through mutation of tRNAs previously employed for other amino acids.
The Polyphasic Rise of Chlorophyll Fluorescence upon Onset of Strong Continuous Illumination: I. Saturation Characteristics and Partial Control by the Photosystem II Acceptor Side
Authors: Neubauer Christian , Schreiber Ulrich
Published: August 2018

Applying a rapid modulation system for measurement of chlorophyll fluorescence yield (U. Schreiber. Photosynth. Res. 9. 261-272 (1986)) the induction kinetics upon onset of strong actinic illumination previously studied by Delosme (Biochim, Biophys, Acta 143, 108-128 (1967)) are reinvestigated. With increasing actinic intensity the fluorescence rise is changed from the typical O-I-P characteristic to a more complex rise curve with two intermediary levels I1 and I2 both of which show saturation at high intensity. The typical kinetics at saturating light intensity (O-I1-D-I2-P) are observed in a variety of plant species. The properties of the kinetics with respect to light intensity, temperature, electron acceptors and PS II inhibitors suggest that the O-I1 phase is controlled by photochemical charge separation (photochemical phase), while the I1-D-I2-P transients are limited by dark reactions (thermal phases). Dichlorophenyl-dimethylurea (DCMU) eliminates the thermal phases by raising I, to the original I level. While in principal the previous findings by Delosme are confirmed, there, is the new aspect of two distinct components in the thermal part of the rise curve, which display different properties. Electron acceptors suppress only the I2-P phase, which appears to parallel the reduction of the plastoquinonc pool, which is a fluorescence quencher when oxidized. While the DCMU effect suggests quenching control during I1-I2 by reoxidation of PS II acceptors, this suggestion is contradicted by the observed saturation of I1 with light intensity and at low temperatures. The relevance of these results with respect to quenching analysis of chlorophyll fluorescence by the saturation pulse method is discussed.
NMR Spectra of Flavone Di-C-glycosides from Apometzgeria pubescens and the Detection of Rotational Isomerism in 8-C-Hexosylflavones
Authors: Markham Kenneth R. , Mues Rüdiger , Stoll Marina , Zinsmeister H. Dietmar
Published: August 2018

1H and 13C NMR spectra are documented for the novel flavone-6,8-di-C-glycosides isolated from the liverwort, Apometzgeria pubescens. The existence of rotational isomerism evident from these spectra is shown to be general for 8-C-monohexosylflavones and of possible diagnostic value.
In vivo synthesis of [14C]Dilinoylgalactosylglycerol by gametophytes of the fern anemia phyllitidis
Authors: Klose Eckard , Gemmrich Armin R.
Published: August 2018

Blue light-grown gametophytes of Anemia phyllitidis were used for the in vivo synthesis of radioactively labeled dilinoylgalactosylglycerol, a potential intermediate in the synthesis of linolenic acid. Optimal yield was obtained by incubating gametophytes with [14C]linoleate first for 2 h under anaerobic conditions followed by 46 h under aerobic conditions. As product [14C]dilinoylgalactosylglycerol was identified
Synthesis of Racemic [2-14C]Jasmonic acid*
Authors: Knöfel Hans-Dieter , Gross Dieter
Published: August 2018

(±)-[2-14C)Jasmonic acid has been synthesized in nearly 50% yield via the route of the Michael addition starting from 2-(2Z-pentenyl)-2-cyclopenten-1-one and diethyl [2-14C]malonate followed by saponification and decarboxylation of the Michael products in one step
Fatty-acid biosynthesis and acetyl-coa carboxylase as a target of diclofop, fenoxaprop and other aryloxy-phenoxy-propionic acid herbicides
Authors: Kobek Klaus , Focke Manfred , Botanisches K. Lichtenthaler
Published: August 2018

The effect of the herbicides and aryloxy-phenoxy-propionic acid derivatives diclofop, fenoxaprop, fluazifop and haloxyfop and their ethyl, methyl or butyl esters on the de novo fatty-acid biosynthesis of isolated chloroplasts was investigated with intact chloroplasts isolated from sensitive grasses (Poaceae) and tolerant dicotyledonous plants (Pisum, Spinacia). The 4 herbicides (free-acid form) block the de novo fatty-acid biosynthesis ([2-14C]acetate incorporation into the total fatty-acid fraction) of the sensitive Avena chloroplasts in a dose-dependent manner. The I50- values (a 50% inhibition of the [14C]acetate incorporation) lie in the range of 10-7 to 2 x 10-6 ᴍ. The ethyl or methyl esters (diclofop, fenoxaprop, haloxyfop) and butyl ester (fluazifop) do not affect the de novo fatty-acid biosynthesis of isolated chloroplasts or only at a very high concentration of ca. 10-4 ᴍ. In contrast, the de novo fatty-acid biosynthesis of the tolerant dicotyledonous species (pea, spinach) is not affected by the 4 aryloxy-phenoxy-propionic acid herbicides. In an enzyme preparation isolated from chloroplasts of the herbicide-sensitive barley plants the de novo fatty-acid biosynthesis from [14C]acetate and [14C]acetyl-CoA is blocked by all 4 herbicides (free acids), whereas that of [14C]malonate and [14C]malonyl-CoA is not affected. This strongly suggests that the target of all 4 herbicides (free-acid form) is the acetyl-CoA carboxylase within the chloroplasts. The applied ester derivatives, in turn, which are ineffective in the isolated chloroplast test system, have equally little or no effect on the activity of the acetyl-CoA carboxylase. It is assumed that the acetyl-CoA carboxylase of the tolerant dicot plants investigated is modified in such a way that the 4 herbicides cannot bind to and affect the target
The complete amino acid sequences of the b 800—850 antenna polypeptides from rhodopseudomonas acidophila strain 7750
Authors: Bissig Iwan , Brunisholz René A. , Suter Franz , Cogdell Richard J. , Zuber Herbert
Published: August 2018

Spectrally pure B 800-850 light harvesting complexes of Rhodopseudomonas acidophila 7750 were prepared by chromatography of LDAO-solubilised photosynthetic membranes on Whatmann DE-52 ion exchange resin. Two low molecular mass polypeptides (α, β) have been isolated by organic solvent extraction of the lyophilised B 800-850 light harvesting complexes. Their primary structures were determined by liquid phase sequencer runs, by the sequence analyses of C-terminal o-iodosobenzoic acid fragments, by hydrazinolysis and by carboxypeptidase degradation.

B 800-850-a consists of 53 amino acids and is 45.3% and 50.9% homologous to the B 800-850- a antenna polypeptides of Rhodobacter sphaeroides and Rhodobacter capsulatus, respectively. The second very short polypeptide (B800-850-β, 41 amino acids) is 61.0% and 56.1% homologous to the corresponding polypeptides of Rb. sphaeroides and Rb. capsulatus. The molar ratio of the two polypeptides is about 1:1. Both polypeptides show a hydrophilic N-terminal domain, a very hydrophobic central domain and a short C-terminal domain. In both polypeptides the typical His residues, identified in all antenna polypeptides of purple nonsulphur bacteria as possible bacteriochlorophyll binding sites, were found