bluuebunny/crossref_metadata_2025 huggingface dataset:
Metabolism of the Herbicide Bromoxynil in Hordeum vulgare and Stellaria media
Authors: Schaller Barbara , Schneider Bernd , Schütte Horst Robert
Published: August 2018

The metabolism of [3,5-14C]3,5-dibromo-4-hydroxybenzonitrile (bromoxynil) was studied in Hordeum vulgare and Stellaria media.

In excised barley seedlings the time course of metabolism was followed over 48 h and the distribution of radioactivity to various metabolic fractions measured. The metabolites, separated by TLC and HPLC, were identified by chemical and spectrometric methods. Bromohydroquinone and 2,6-dibromohydroquinone were found, indicating partly debromination and replacement of the nitrile group by hydroxyl. The major parts of bromoxynil and of the metabolites were recovered in glucosidic conjugates.

In Stellaria media the same metabolites as in Hordeum vulgare were determined. Additionally, metabolites of unknown structures without bromine were detected.
How Many Ryanodine Binding Sites Are Involved in Caffeine Induced Calcium Release from Sarcoplasmic Reticulum Terminal Cysternae Vesicles?
Authors: Hasselbach Wilhelm , Migala Andrea
Published: August 2018

The inhibition by ryanodine of caffeine induced calcium release from actively loaded heavy sarcoplasmic vesicles has been studied in order to analyse the relation between the occupancy of the vesicular calcium release channels by ryanodine and channel function. Ryanodine binding was monitored with [3H]ryanodine under ionic conditions favouring the establishment of binding equilibrium. Binding follows 1 : 1 stoichiometry yielding dissociations constants between 7 - 12 nᴍ and 12-15 pmol ryanodine/mg vesicular protein as maximum number of ryanodine binding sites. When ryanodine labeling was monitored by measuring the decline of the amplitude of caffeine induced calcium release 50% inhibition occurred at a free ryanodine concentration of 1 nM. At this concentration less than 10% of the available ryanodine binding sites are occupied. Caffeine induced calcium release is completely abolished when 3 pmol ryanodine/mg have reacted. A corresponding divergence between ryanodine binding and its effect on caffeine induced calcium release was observed when the initial rate of ryanodine binding was measured either by labeling the vesicles with [3H]ryanodine or by following the decline with time of caffeine induced calcium release. Caffein induced calcium release declines four times faster than the fraction of unoccupied ryanodine binding sites, k = 4.3 x 104 ᴍ-1 s-1 versus 1.2 x 104 ᴍ-1 s-1. The observed interrelation between the occupation of ryanodine binding sites and its effect on caffeine induced calcium release indicates that the caffeine sensitive calcium channel functions as an assembly of at least 4 ryanodine binding sites whereby the occupation of one site suffices to abolish calcium release. The stoichiometric composition appears to be not fixed but might change according to the size of the fraction of ryanodine receptors exhibiting caffeine sensitivity. The reported data were evaluated according to the algorithm derived by H. Asai and M. F. Morales, J. Biol. Chem. 4, 830-838 (1965) for the activity of a macromolecule and the extent of an inhibiting reaction.
Umwandlung von [5' -3H]Riboflavin in 5,6-Dimethylbenzimidazol / Transformation of [5'-3H]Riboflavin into 5,6-Dimethylbenzimidazole
Authors: Kolonko Bernhard , Hörig Joachim A. , Renz Paul
Published: August 2018

The 5,6-dimethylbenzimidazole unit of vitamin B12 is formed from riboflavin via FMN in aerobic and some aerotolerant bacteria. Thereby C-1′ of the ribityl side chain gets C-2 of 5,6-dimethylbenzimidazole. Experiments with homogenates of Propionibacterium shermanii on the fate of C-atoms 2′ to 5′ of the ribityl side chain of riboflavin in this transformation are reported. It was found that [5′-3H]riboflavin leads to radioactive sugar phosphates. These were isolated, dephosphorylated, and separated. Thus 3H-D-fructose and 3H-D-glucose were detected. The degradation of 3H-D-glucose revealed that 14 per cent of the of the total radioactivity was located in C-1, and 86 per cent in C-6. This indicates that during 5,6-dimethylbenzimidazole biosynthesis a three carbon unit is formed from the ribityl side chain of riboflavin.
Hairy Root Cultures of Peganum harmala II. Characterization of Cell Lines and Effect of Culture Conditions on the Accumulation of ß-Carboline Alkaloids and Serotonin
Authors: Berlin J. , Kuzovkina I. N. , Rügenhagen C. , Fecker L. , Commandeur U. , Wray V.
Published: August 2018

Hairy root cultures of Peganum harmala established by genetic transformation with Agrobacterium

rhizogenes wild type strains A4, 15834 or carrying the binary vector pLTCgus 1, respectively, were analyzed with respect to their tryptophan-derived metabolites. Beside the previously detected β-carboline alkaloids harmine, harmol, harmaline and harmalol all hairy root cultures were found to contain the β-carboline glucoside ruine and serotonin. The appearance of the root cultures and the levels of β-carboline alkaloids were greatly affected by the nitrogen source of the medium. In the presence of higher levels of ammonium ions (as in MS medium) the roots were short and thick, while in B50 medium (low ammonium) they were thin and long. Ammonium ions had a negative effect on the levels of β-carbolines. The best root cultures accumulated on B50 1.5-2% β-carbolines on a dry mass basis and in the presence of 6% sucrose ca. 10 mg β-carbolines/L x d were formed. In the presence of phytohorm ones root cultures were converted into low producing suspension cultures, from which the highly productive roots were reinduced on phytohormone-free medium.
Pyoverdine aus Pseudomonas putida / Pyoverdins from Pseudomonas putida
Authors: Gwose I. , Taraz K.
Published: August 2018

The structures of two pyoverdins (Pp 1 and Pp 2) and one dihydropyoverdin (dihydro-Pp 2) from a strain of Pseudomonas putida have been elucidated by spectroscopic methods and degradation studies. The pyoverdins Pp 1 and Pp2 consist of a chromophore which was identified as (1 S)-5-amino-2,3-dihydro-8,9-dihydroxy-1 H-pyrimido[1,2-a]quinoline-1-carboxylic acid substituted at the amino group with a 3-carboxypropanoyl or a succinamoyl residue and at the carboxy group with the N-terminus of L-Ser-L-Thr-D-Ser-L-Orn-L-threo-(OH)Asp-[D-Gln + L-Dab]*-L-Ser-D-allo-Thr-L-c(OH)Orn.

Dihydro-Pp 2 differs from Pp 2 only in the chromophore, which is saturated at carbons 5 and 6. All compounds contain a tetrahydropyrimidine moiety ([D-Gln + L-Dab]*) resulting from the condensation of 2,4-diaminobutyric acid and glutamine.
Flavone-C-Glycosides from the Mosses Plagiomnium elatum and Plagiomnium cuspidatum
Authors: Anhut Siegbert , Biehl Jutta , Seeger Tassilo , Mues Rüdiger , Zinsmeister H . Dietmar
Published: August 2018

In Plagiomnium elatum the new di-C-glycosides 6-C-β-D-glucopyranosyl-8-C-α-L-rhamnopyranosyl- luteolin (Elatin) and 6-C-hexosyl-8-C-rhamnosyl-chrysoeriol were detected. Furthermore four known flavone-C-glycosides were identified. The main glycosides of Plagiomnium

cuspidatum are 6-C-glucosyl-7-O-glucosides of apigenin, luteolin and chrysoeriol respectively.
Sinapoylglucose: Malate Sinapoyltransferase Activity in Arabidopsis thaliana and Brassica rapa
Authors: Mock Hans-Peter , Vogt Thomas , Strack Dieter
Published: August 2018

Protein preparations from Arabidopsis thaliana and Brassica rapa catalyzed the formation of O-sinapoyl-ʟ-malate using 1-O-sinapoyl-β-glucose as acyl donor. The enzyme involved, 1-O-sinapoyl-β-glucose :ʟ-malate O-sinapoyltransferase (SMT; EC 2 .3 .1 .-), catalyzes in the cotyledons of the seedlings the key step in the conversion of the seed constituent sinapine (O-sinapoylcholine) to sinapoylmalate by way of the intermediate sinapoylglucose.
The Effect of Ecdysterone on the Cyanobacterium Nostoc 6720
Authors: Maršálek B. , Šimek M. , Smith R. J.
Published: August 2018

The insect hormone ecdysterone stimulated dinitrogen fixation, heterocyst formation, cell size and protein synthesis in suspension cultures of the cyanobacterium Nostoc 6720 within 48 h when added to the culture at concentrations between 10-9 and 10-7 м. In the presence of the hormone the volume of vegetative cells increased by 6-fold and that of heterocysts by nearly twice as compared to untreated controls. All the observed effects were inhibited by the calcium- calmodulin inhibitor, trifluoperazine. Cholesterol used as a null control had no significant effect.
Notes: Analysis of Phenolics of Bud Exudate of Populus laurifolia by GC-MS
Authors: Greenaway W. , May J. , Whatley F. R.
Published: August 2018

Analysis by GC-MS identified 30 phenolic components of the bud exudate of P. laurifolia. The majority of the exudate was composed of flavanones, flavanonols and chalcones, with pinobanksin-3-acetate being the major component. The bud exudate resembled that of the Asian Section Tacamahaca poplars P. cathayana and P. szechuanica but was unlike that of the North American Section Tacamahaca poplars, P. balsamifera and P. trichocarpa.
Notes: Isolation of the New (- )-(3 R,4S)-4-Hydroxymellein from the Fungus Septoria nodorum Berk
Authors: Devys Michel , Barbier Michel , Bousquet Jean-Frangois , Kollmann Albert
Published: August 2018

The new (-)-(3 R,4 S)-4-hydroxymellein (6) is isolated from the fungus Septoria (Phaeosphaeria) nodorum Berk, together with the previously reported isomer 5. The results so far obtained in this series of metabolites are discussed in relationship with biosynthetic considerations.
Artifacts and Pheromone Blends from Nezara spp. and Other Stink Bugs (Heteroptera: Pentatomidae)
Authors: Aldrich J. R. , Numata H. , Borges M. , Bin F. , Waite G. K. , Lusby W. R.
Published: August 2018

Isomeric compounds reportedly released by mature males of Nezara viridula as attractants for conspecific females are evidently artifacts formed by dimerization of (E)-4-oxo-2-hexenal. Additional analyses of the male-specific volatiles from Italian, Australian, Brazilian, and Japanese populations of N. viridula verify that at least two distinctive pheromone strains exist, but an active synthetic pheromone has not yet been developed. Analyses of volatiles from N. antennata and Acrosternum aseadum males are also reported showing that the native Japanese Nezara sp., and species in the sister genus Acrosternum, produce species-specific blends based on the same compounds as N. viridula: (Z)-α-bisabolene (1-methyl-4-(1,5-dim ethyl-(Z)-1,4- hexadienyl)-cyclohexene), and trans- and cis-1,2-epoxides of (Z)-α-bisabolene. The trans-/cis- 1,2-epoxide ratio of N. antennata is within the range found for most N. viridula populations, but the blend from Japanese N. viridula males deviates radically from those of other conspecific populations.
Interaction of Microsomal Cytochrome P-450 s and N-Phenylcarbamates that Induce Flowering in Asparagus Seedlings
Authors: Tanigaki Fumiaki , Ishihara Atsushi , Yoshida Kazuichi , Hara Takane , Shinozaki Masateru , Iwamura Hajime
Published: August 2018

n-Propyl N-(3,4-dichlorophenyl)carbamate, which induces flowering while it inhibits a step or steps in the phenylpropanoid metabolism in Asparagus officinalis L. seedlings, was found to retard the conversion of t-cinnamic acid to p-coumaric acid by high-pressure liquid chromatography of the metabolites in the shikimic acid pathway. The concentrations of the metabolites preceding t-cinnamic acid on the pathway in treated and untreated seedlings were the same, but those of p-coumaric acid and later metabolites were significantly lower in treated plants. The carbamate inhibited phenylpropanoid metabolism when used to treat stem segments that included a shoot apex primordium, where flowers are induced, and when added to a 100,000 × g microsomal fraction prepared from such segments. NADPH-cytochrome P-450 and NADH-cytochrome b5 reductases in the 100,000 × g fraction were not inhibited by the carbamate. The results showed that this compound has its site of action on the endoplasmic reticulum and that it inhibits cytochrome P-450s, including t-cinnamic acid 4-hydroxylase. We examined the flower-inducing activity of known cytochrome P-450 inhibitors, and found that piperonyl butoxide also causes flowering.
Understanding the Topography of the Photosystem II Herbicide Binding Niche: Does QSAR Help?
Authors: Huppatz John L. , McFadden Helen G.
Published: August 2018

For thirty years the study of Quantitative Structure Activity Relationships (QSAR) has been an active area of research aimed at developing an understanding of the interactions be­ tween inhibitors of photosynthetic electron transport and the herbicide binding site in the Photosystem II (PS II) reaction centre. Many QSAR studies of PS II inhibitors with diverse chemical structures have emphasized the hydrophobic nature of the binding domain, with lipophilicity being the dominant determinant of Hill inhibition activity. The cyanoacrylate classes of PS II inhibitors also show a diversity of active structures and considerable variation in inhibition potency with minor alterations to structure. QSAR analysis and examination of chirality in cyanoacrylate inhibitors has also shown the importance of steric factors in determining activity. Different modes of binding for different classes of cyanoacrylates have been identified; a classical urea-type relationship between activity and hydrophobicity and another type of interaction in which the lipophilicity or electronic nature of phenyl substituents plays little part and the size of the substituents is of primary importance. Because size and shape are parameters of great importance in determining the topography of a binding site, QSAR studies of flexible PS II inhibitors such as cyanoacrylates will continue to be important in elucidating the intricacies of inhibitor/PS II interactions.
Electron Transport from QA to Thymoquinone in a Synechococcus Oxygen-Evolving Photosystem II Preparation: Role of QB and Binding Affinity of Thymoquinone to the QB Site
Authors: Satoh Kazuhiko , Kashino Yasuhiro , Koike Hiroyuki
Published: August 2018

We have recently shown that binding affinities of benzoquinones can be estimated by two methods in photosystem (PS) II particles (K. Satoh et al., Biochim. Biophys. Acta 1102, 45-52 (1992)). Using these methods we calculated the binding affinity of thymoquinone (2-methyl-5-isopropyl-p-benzoquinone) to the QB site and studied how the quinone accepts electrons in oxygen-evolving PS II particles isolated from the thermophilic cyanobacteria, Synechococcus elongatus and S. vulcanus. The results are as follows: (1) The binding constant of thymoqui­ none to the QB site determined by several methods was around 0.33 mᴍ . (2) At low thymoquinone concentrations the quinone was supposed to accept electrons via QB-plastoquinone, whereas at high concentrations the quinone seemed to bind to the QB site and accept an electron directly from Q-
A. Lower rates of photoreduction of the quinone at high concentrations were attributed to a slower turnover rate of the quinone at the QB site than that of endogenous plastoquinone. (3) A model for the function of plastoquinone at the QB site, which can explain all the results, was presented. According to this model, the plastoquinone molecule at the QB site is not replaced by another plastoquinone molecule. Instead, it transfers electrons to pool plastoquinone molecules by turning over its head group but remaining its long side chain bound to the PS II complexes.
Bicarbonate-Reversible Inhibition of Plastoquinone Reductase in Photosystem II
Authors: Govindjee
Published: August 2018

In this paper the current status of the so-called bicarbonate effect is presented. Several chemicals (such as formate, azide, nitrite and nitric oxide) are known to inhibit the two-electron gate of photosystem II (PS II). A remerkable slowing down of QA
- reoxidation and an increase in equilibrium [QA
- ] have been observed after the second or the subsequent, but not the first, flash when thylakoid membranes are treated with formate, etc. And, significantly, these effects are totally and uniquely reversed upon bicarbonate addition. The current hypothesis is that bicarbonate functions as a proton shuttle that stabilizes the binding niche of QB
- and stimulates platoquinol formation. This bicarbonate effect must involve both the D 1 and D 2 proteins since various herbicide-resistant D 1 mutants (e.g., D 1 -S264A , D 1 -L275F), as well as some D 2 mutants (e.g., D 2 -R251S, D 2 -R 233Q) have been found to be differentially sensitive to formate. The D 2-arginine (233, 251) effects are specific since D 2 -R 139H mutant and an­ other mutant in which an extra arginine was inserted, between F 223 and E 224 , behaves like the wild type. Data in the literature suggest that the bicarbonate binding must also involve Fe in the PS II QA-Fe -QB complex. In contrast, the QA-Fe -QB complex and the two-electron gate of both green and purple photosynthetic bacteria, including the M -E 234 G , Q and V mutants, are insensitive to bicarbonate-reversible inhibitors. We will also address the question of the nature of the active species involved and the possible role of bicarbonate in vivo.
Differential Inhibition of Phytoene Desaturases from Diverse Origins and Analysis of Resistant Cyanobacterial Mutants
Authors: Sandmann Gerhard , Fraser Paul D.
Published: August 2018

Recent work on the molecular biology of carotenogenic genes and enzymes showed that there are two different and unrelated types of phytoene desaturase. One can be found in bacteria and fungi whereas the other is present in cyanobacteria, algae, and higher plants. Studies with herbicidal inhibitors showed that only the latter type of enzyme is affected by the bleaching herbicides norflurazon, fluridone, and flurtam one. I50 values have been determined for inhibition of phytoene desaturase in either solubilized membranes of the cyanobacterium Synechococcus, membrane preparation of E. coli in which the corresponding gene from Synechococcus was expressed or purified and reactivated phytoene desaturase from this E. coli transformant. The values differ by two orders of magnitude. The importance of the lipid environment of the integral membrane protein phytoene desaturase for its interaction with herbicides has been discussed. With the purified phytoene desaturase it could also be shown that the pyrimidine derivative J852 which is an inhibitor of ζ-carotene desaturase also inhibits phytoene desaturase with an I50 value which is about 2700 times higher than for inhibition of phytoene desaturation.
Structure-Activity Correlations of Substituted 3(2H)Furanones Chemically Related to the Bleaching Herbicide Flurtamone
Authors: Sandmann Gerhard , Böger Peter
Published: August 2018

The bleaching herbicide flurtamone shows a concentration-dependent inhibition of phytoene desaturase activity in a cell-free assay. Structure-activity studies were carried out with 26 derivatives. For this purpose, I50 values for inhibition of formation of colored carotenoids in cultures of Synechococcus and with some selected compounds in vitro inhibition data were measured. For meta-substituted 4-phenyl derivatives a quantitative structure-activity correlation was calculated. Regression analysis show ed a significant contribution of lipophilicity π and steric parameter B2 of the substituents to inhibitory activity of these derivatives. In addition, the stericrequirement of 4-phenyl substituents was further revealed by the substitution pattern at different positions. In general, mono substituents at the meta position were most favorable and only the very small fluoro group was allowed as a second substituent. When the ligands at position 2 of the furanone heterocycle were modified, phenyl or para-fluorophenyl groups were most advantageous. Among the available compounds with different alkyl substitutions of the 5-amino group, the ethyl derivative show ed the highest inhibitory activity whereas the one with the branched isopropyl group w as quite inactive.
Rare Flavonoid Aglycones from Anaphalis margaritacea and Two Gnaphalium Species
Authors: Wollenweber E. , Fritz H. , Henrich B. , Jakupovic J. , Schilling G. , Roitman J. N.
Published: August 2018

Anaphalis margaritacea, Gnaphalium chilense and G. microecephalum have been analyzed for flavonoid aglycones deposited externally on aerial parts. Anaphalis was found to produce, among others, several rare flavonoids, all of which are O-substituted in position 6 and mostly also in position 8. Both Gnaphalium species exhibit 3,5-dihydroxy-6,7,8-trim ethoxyflavone as the major exudate flavonoid.
Acylated Anthocyanins from Flowers of Cineraria, Senecio cruentus, Red Cultivar
Authors: Terahara Norihiko , Toki Kenjiro , Honda Toshio
Published: August 2018

The structures of the two pigments in the red Cineraria, Senecio cruentus, flowers have been identified as malonylcaffeylcyanidin 3,3′-diglucoside (2) and as its demalonyl compound (1), new anthocyanins, by using chromatographic and spectroscopic techniques involving UV-VIS, IR, FAB-MS and NMR . In a neutral aqueous solution, the acylated anthocyanins retained their colorings for a long time.
Reconstitution of Light-Harvesting Complexes from Chlorella fusca (Chlorophyceae) and Mantoniella squamata (Prasinophyceae)
Authors: Meyer Monika , Wilhelm Christian
Published: August 2018

Reconstitution experiments of light-harvesting complexes were performed with the green alga Chlorella fusca and the chlorophyll c-containing prasinophyte Mantoniella squamata using a modified method according to Plumley and Schmidt [Proc. N atl. Acad. Sei. U .S.A . 84, 146 -150 (1987)]. Changing the pigment supply quantitatively or qualitatively in the reconsti­tution mixture homologous and heterologous reconstitutes were obtained. In contrast to higher plants, light-harvesting polypeptides from green algae are able to bind the chlorophylls as well as the xanthophylls in different stoichiometries. Heterologous reconstitutes of M . squamata polypeptides give further evidence for a rather high flexibility of pigment recog­nition and binding. This is the first report of successful reconstitution of a chlorophyll c-binding protein. Contrary to chlorophyll c-less light-harvesting complexes, the reconstitution of M . squamata is strongly pH-controlled. In summary, the results give evidence for a high specificity of porphyrin ring recognition and variability in xanthophyll binding capacity. Therefore, it is suggested that at least in algal light-harvesting proteins chlorophyll organiza­tion may be determined by other mechanisms than xanthophyll binding.
Elicitor-Active Oligosaccharides from Algal Laminaran Stimulate the Production of Antifungal Compounds in Alfalfa
Authors: Kobayashi Akio , Tai Akihiro , Kanzaki Hiroshi , Kawazu Kazuyoshi
Published: August 2018

Natural polysaccharides were examined for their activity as elicitors of phytoalexins and flavonoids in alfalfa cotyledons. Only two polysaccharides, laminaran and pectic acid, had elicitor activity. Laminaran, which was more active than pectic acid, was hydrolyzed by tunicase and the hydrolysate was subjected to charcoal and gel filtration columns. Introduction of the pyridylamino group into the elicitor-active oligosaccharides was attempted in order to facilitate isolation. The pyridylamino derivatives were found to exhibit higher activity than the original oligosaccharides. Their liquid chromatography mass spectrometry (LC-MS) analysis revealed that the elicitor-active principles form two ion clusters with the same molecular weights, m/z 1070 and 1232. Their high performance liquid chromatography (HPLC) analysis showed three main peaks. The individual peaks (LN-1,2,3) were collected and subjected to the alfalfa cotyledon assay. LN-3 showed the highest activity (minimum effective concentration, 0.8 μg/ml).
X-Ray Studies on Phospholipid Bilayers. XIII. Interactions with Gentamicin
Authors: Suwalsky M. , Frías J.
Published: August 2018

This study deals with the structural perturbations that the aminoglycoside antibiotic gentamicin (GENT) can produce to phospholipid bilayers. Two multibilayer systems, one built-up of dimyristoylphosphatidylcholine (DMPC) and the other of dimyristoylphosphatidylethanolamine (DMPE) were allowed to interact with GENT. The experiments were performed in both a hydrophobic and a hydrophilic medium below the phospholipid main transition tem­peratures. X-ray diffraction techniques were used to determine the extent of the perturbation induced by GENT. The maximum effect was attained when GENT interacted with DMPC in the hydrophobic medium. On the other hand, GENT in aqueous solutions was unable to per­turb in any significant extent the structure of the phospholipids under study.
Electron Microscopical Morphology of Cytoplasmic Granules from Horse Eosinophil Leucocytes
Authors: Stockert J. C. , Trigoso C. I. , Tato A. , Ferrer J. M.
Published: August 2018

The structure of specific granules from horse eosinophil leucocytes is still largely unknown. In this work, electron microscopical studies of horse eosinophils reveal that the large cytoplasmic granules contain an external membrane, a m atrix o f less density, and a dense (non crystalline) core. Round vacuolar inclusions of matrix materials were often observed within the cores. Horse eosinophil granules showed a considerable heterogeneity, and three morphological types could be identified according to structural features of the core and matrix.
Fructose 1,6-Bisphosphatase in Chlorella kessleri Grown in Red or Blue Light
Authors: Grotjohann N.
Published: August 2018

Total activity of FBPase of Chlorella kessleri grown either in blue or in red light o f equal fluence rates differs (26.8 and 61.0 nmol · min-1 · mg protein-1) in crude cell extracts prepared at pH 8.5. The difference largely depends on FBPase II, an enzyme species assumed to be located in the chloroplast. FBPase II is strongly influenced by reducing agents. Addition of DTT, however, does not compensate for the difference in activities. Although it leads to a higher increase (197%) in the activity of the enzyme from blue than in that of the enzyme from red light conditions, the final activities (79.7 and 133.1 nmol · min-1 · mg protein-1) still differ by a factor of 1.67.

In contrast to alkaline conditions the activity is approx. equal when crude cell extracts are prepared at pH 6.0. It is 62.7 nmol · min-1 · mg protein-1 in blue light and 70.7 in red light. Under these conditions DTT enhances both activities equally (189 and 201 nmol · min-1 · mg protein-1). These results indicate that the observed difference in enzyme activity at pH 8.5 does not result from different enzyme quantities.

At pH 8.5 the mole mass of FBPase II is 88 kD a, while it is 1349 kD a at pH 6.0 under both light conditions. The smaller mole mass represents the monomeric form of the enzyme. The previously assumed pH-dependent oligomerization/dissoziation [8 ], which is generally proven, is therefore not responsible for the different activities of the enzyme from cells grown in red or in blue light. However, the monomeric form seems to possess a higher stability when prepared from cells from red light conditions.

The different stability and activity of FBPase II under alkaline conditions are discussed in context with an altered carbohydrate metabolism in Chlorella kessleri grown autotrophically in different wavelengths of light
Photoregulation of Nitrogen Metabolism and Protein Accumulation in the Red Alga Corallina elongata Ellis et Soland
Authors: Figueroa F. L.
Published: August 2018

Red and blue light pulses of 5 min applied together with 45 μM KNO3 stimulated the nitrate uptake and reduction and the assimilation of ammonium in darkness in the red alga Corallina elongata. Nitrate reductase and glutamine synthetase activities were increased in darkness after the application of both red and blue light pulses. Red light produced a dramatic increase in enzyme activities after the first hour in darkness but after 4 h the effect of blue light pulses was greater. The photostimulation of nitrogen metabolism was correlated with light-regulated accumulation of soluble proteins. Nitrogen incorporation, assimilation of ammonium, accu­mulation of total proteins and the increment in total intracellular nitrogen was greater in N-limited algae (C:N = 17.3) than in N-sufficient algae (C :N = 10.3) after the application of light pulses and nitrate. Because the stimulant effects of red and blue light on N-metabolism were partially reversed by far-red light, the possible involvement of the photoreversible red/ far-red photoreceptor, phytochrome, is proposed. In addition, the blue-light effect seems to be mediated by a specific B-light photoreceptor besides phytochrome due to the different time course of the response and the extent of the stimulation after blue compared to red light pulses.
Translocation of Adenine Nucleotides in the Mitochondria of Male Sterile and Male Fertile Sorghum
Authors: Arora J. , Nath P. , Sane P. V.
Published: August 2018

The translocation of ATP from the inside to the outside of the mitochondrial membrane has been studied in a male sterile (2219 A) and a male fertile (2219 B) line of sorghum. The translocation of ATP was found to be substantially lower in case of mitochondria from the male sterile line. The affinity of adenine nucleotides to the translocator proteins of the mito­ chondrial membrane was found to be almost one half in case of 2219 A as compared to 2219 B when the Km for ATP-ADP was determined by two different assays. It is proposed that the inadequate supply of ATP in the cytosol resulting from its inefficient translocation may con­ tribute to the male sterility in this line.
Inhibition of Dihydrofolate Reductase by Mofebutazon
Authors: Strehl Elke , Schneider Ingrid , Elstner Erich F.
Published: August 2018

Mofebutazon, Dihydrofolate Reductase, Non-Steroidal Antiinflammatory Drugs (NSAIDs) Mofebutazon, in contrast to phenylbutazon, inhibits dihydrofolate reductase in a concentration-dependent manner. An apparent for mofebutazon and dihydrofolate reductase in the presence of NADPH as electron donor and dihydrofolate as electron acceptor of approx­imately 0.2 mM was calculated.
Antitumoral Effect of Bleomycin + Dolomite Combination Treatment, in Mice Bearing Ehrlich Ascites Carcinoma
Authors: Scheller S. , Krol W. , Skirmuntt K. , Zydowicz G. , Shani J.
Published: August 2018

Dolomite, a mineral composed of magnesium and calcium carbonates, potentiates the antitumoral activity of bleomycin: While 40 days after inoculation, no mice survived the Ehrlich ascites tumor burden, 44% of them survived it after bleomycin treatment, and 63% after a simultaneous treatment of bleomycin and dolomite. The beneficial antitumor effect of dolomite is probably related to its high content (12.8%) of magnesium
Untersuchungen zur Struktur und Derivatisierung von Kondensationsprodukten der 2,4-Diaminobuttersäure mit anderen Aminosäuren / Investigations Regarding Structure and Derivatization of the Condensation Products of 2,4-Diaminobutyric Acid with Other Amino Acids
Authors: Filsak G. , Taraz K. , Budzikiewicz H.
Published: August 2018

Condensation of 2,4-diaminobutyric acid (Dab) with other amino acids yields tetrahydropyrimidine derivatives. Such condensation products can be constituents of the peptide chain of pyoverdins and ferribactins (the siderophors of fluorescent pseudomonads). Synthesis of several representatives and model substances allows to confirm earlier structural conclusions based mainly on NMR evidence. Apparent anomalies accompanying the derivatization for GC/MS analysis could be clarified.
Induced Accumulation and Potential Antioxidative Function of Rutin in Two Cultivars of Nicotiana tabacum L.
Authors: Steger-Hartmann Thomas , Koch Ulrich , Dunz Thomas , Wagner Edgar
Published: August 2018

The rutin (quercetin-3-rhamnosyl-glucoside) content of two tobacco cultivars (Nicotiana tabacum L.) which differ in their ozone-sensitivity was assayed after exposure to various rutininducing stimuli. In the growth-chamber, UV radiation in combination with white light led to the accumulation of similar amounts of rutin in both cultivars. Treatment with radical producing agents (tert-butylhydroperoxide and paraquat) also led to rutin accumulation. In this case, the rutin content was higher in the tolerant cultivar. The rutin content was also higher in the tolerant cultivar upon exposure of the plants on an out-door stand, even when the UV-part of the sun spectrum was excluded by cut-off filters.

The potential role of rutin as antioxidant was tested with an ion leakage assay. Plants with relatively high rutin content were less sensitive towards paraquat-induced ion leakage than plants without rutin. Thus, the higher rutin content of the ozone-tolerant cultivar Bel B may well contribute to its tolerance against oxidative stress.
Two Inhibitors of Platelet Aggregation from a Panus Species (Basidiomycetes)
Authors: Lorenzen Kirsten , Anke Timm , Anders Uwe , Hindermayr Herman , Hansske Fritz
Published: August 2018

Two inhibitors of platelet aggregation were isolated from fermentations of Panus sp. 9096. One inhibitor proved to be identical to naematolon (2), an antibiotic previously isolated by S. Backens et al. from several Hypholoma species. The other metabolite, panudial (1), is a new nordrimane (cis-annelation of the bicyclus) lacking the carbon atom in position 10 of the drimane skeleton. Panudial is a potent inhibitor of bovine and human platelet aggregation stimulated by different inducers.
Phototropism in Yeast: A New Phenomenon to Explore Blue Light-Induced Responses
Authors: Lazarova Galina , Ootaki Tamotsu , Isono Kunio , Kataoka Hironao
Published: August 2018

Although yeasts have been intensively investigated in photobiology, directional response of yeast growth to light has never been observed. The present data demonstrate for the first time phototropism in yeast, the basidiomycetous yeast Sporobolomyces salmonicolor. The effective spectral band is blue light - suggesting that a blue-light receptor similar to that in other plants is involved in yeast photophysiology. Further studies on yeast phototropism could help identification of the photoreceptor and throw new light on the mechanisms of signal transduction and response.
Involvement of Two Different Photoreceptors in the Light Regulation of Glutamine Synthetase Activity in a Chlorophyll-Free Chlorella Mutant
Authors: Meya Gudrun , Kowallik Wolfgang
Published: August 2018

Glutamine synthetase (EC 6.3.1.2) activity of a non-photosynthetic mutant of Chlorella kessleri is markedly enhanced under blue and slightly increased under red light. In both cases, the effect is largest after 6 h of irradiation. In blue light, saturation is reached at about 10 μEm-2 s-1; in red light, it is not even indicated at 62 μE m-2 s-1.

Semilogarithmic plots of both intensity dependencies reveal different slopes, indicating envolvement of two separate photoreceptors. This feature is supported by different effects of pulse irradiation: The response to 15 min of red light irradiation (λmax 650 nm) increases in subsequent darkness. It reaches the same value as in continuous light after 6 h. The response to 15 min of blue light irradiation (λmax 441 nm) increases also in subsequent darkness. However, after 6 h it reaches only 30% of the value obtained by continuous irradiation.

It is concluded that, glutamine synthetase of Chlorella is controlled by two different photoreceptors both independent of photosynthesis. There is evidence of two forms of glutamine synthetase, the intracellular distribution and specific light regulations of these are discussed.
Product Autofluorescence Activation in the Cytochrome P450 Monooxygenase System
Authors: Enoch Dieter Müller
Published: August 2018

The relative increase of the 7-ethoxycoumarin-O-deethylase and the 6,7-dimethoxycoumarin- O-demethylase activities were found 93 and 236% using a reconstituted cytochrome P 4502B 1 :NADPH-P450 reductase system by adding to the reaction mixtures their own products. The assays were irradiated during the reactions with the excitation wavelength maximum of their products umbelliferone (λE = 365 nm) or scopoletin (λE = 398 nm), respectively. Addition of the products to the reaction mixtures without irradiation (dark reaction) had no activating effect on the specific activities of the 7-ethoxycoumarin-O-deethylase or the 6,7-dimethoxycoumarin-O-demethylase. The relative increase of the specific activities is dependent on the excitation light intensities and was at maximum when the light intensity at the sample cuvette was 0.4 mW/cm2.

The activation energies of the P 4502B 1-dependent 7-ethoxycoumarin-O-deethylation reaction obtained from Arrhenius plots with and without added umbelliferone and irradiation with λE = 365 nm are 14.7 kJ/mol and 33.5 kJ/mol, respectively, in the temperature range of 27-37 °C. The irradiation energy of the fluorescent product umbelliferone change the catalytic mechanism, which has a two times lower activation energy in the presence of the irradiated product umbelliferone.

Umbelliferone and scopoletin have highest fluorescence intensities in the wavelength range of the blue light (440-480 nm). The photochemical action spectrum of the 7-ethoxycoumarin-O-deethylase of the P4502B 1:reductase system is also found to be in the wavelength range of 420-470 nm. No activation effect was seen with irradiating light lower than 400 nm. Obviously the fluorescence light of the products are due for the extremely high activation effect. This is the first report that the products umbelliferone and scopoletin are photoreceptors and phototransducers.
Partially N-Deacetylated Chitin Elicitor Induces Antimicrobial Flavonoids in Pea Epicotyls
Authors: Akiyama Kohki , Kawazu Kazuyoshi , Kobayashi Akio
Published: August 2018

Pisatin elicitors including fragments of chitosan and partially N-deacetylated chitins (DACs) strongly induced (+)-α,2′,4,4′-tetrahydroxydihydrochalcone, (-)-4′,7-dihydroxyflavanone, and 4,4′-dihydroxy-2′-methoxychalcone in Pisum sativum. These three flavonoids with moderate or weak antimicrobial activities were effectively induced by the treatment of pea with either the biotic elicitors or an abiotic elicitor CuCl2. The examination of chitosan derivatives with different molecular size and different N-acetylation for the flavonoidinducing activity in pea epicotyl assay revealed that the structural features required for the flavonoids induction were different from those required for (+)-pisatin induction. (+)-2- Hydroxypisatin, a possible intermediate in pisatin degradation pathway, which has been isolated from pea seedlings treated with the abiotic elicitor or infected by fungi was not induced by the chitosaccharides in pea epicotyl assay. These findings suggest that pea plants could distinguish invading pathogens by the difference of structural features of chitosaccharides derived from chitin, a major constituent of fungal cell walls. Thereby, the plant could accumulate antimicrobial compounds responsible for the chemical defense against invading pathogens.
Improved Preparation Procedure for the Endogenous 115 kb Plasmid of Rhodobacter capsulatus AD 2 and Analysis of Restriction Pattern
Authors: Koch Hans-Georg , Klemme Jobst-Heinrich
Published: August 2018

None of six published preparation procedures for circular bacterial plasmids was satisfactory to purify the endogenous plasmid of a nitrate-reducing strain (AD2) of the phototrophic bacterium Rhodobacter capsulatus. By modifying the method of N. T. Hu and B. L. Marrs (1979), Arch. Microbiol. 121, 61-69 , the 115 kb plasmid of the latter strain was prepared to a highly pure state. Digestion of the plasmid with restriction endonuclease Eco RI yielded 21 fragments with sizes ranging from 0.3 to 18.4 kb. Except for the three largest ones (18.4 kb, 16.9 kb and 11.2 kb), all fragments were cloned into the vector plasmid pU C 8, amplified in E. coli JM83 and characterized by H ind III restriction analysis.
7-Chloro-4-nitrobenzofurazan Inactivates Chloroplast H+-ATPase by Modification of Different Tyrosines, Depending on the Presence of ATP
Authors: Bickel-Sandkötter Susanne , Esser Kordula
Published: August 2018

The addition of 7-chloro-4-nitrobenzofurazan (NBD) to isolated CF1 at pH 7.5 leads to one tyrosine-bound NBD molecule per CF1 in one of the three β-subunits, concomittantly with the inhibition of the ATPase activity. Addition of ADP prior to NBD -incubation protected the ATPase activity and reduced binding of NBD to β-subunits. The addition of MgATP prior to modification did not result in protection against modification of the β-subunit as well as preservation of activity. Cleavage of the NBD -labelled subunits with cyanogen brom ide, follow ed by analysis of the labelled peptides, led to detection of a 14C-labelled peptide of 7 kDa in both cases (± ATP -preincubation). Sequence analysis of this peptide showed that in ATP-incubated CF1, tyrβ328 was modified with NBD-C1, whereas the ATP free sample contained no NBD bound to this tyrosine. Further digestion of the labelled peptide with protease V8 (Staphylococcus aureus) followed by sequence analysis of the radioactive labelled peptide, led to the detection of β-tyr362 as the modified amino acid in case of ATP-free CF1. Both tyrosines are closely related to a proposed nucleotide binding region of β
Partially N-Deacetylated Chitin Fragments are Strong Elicitors for (+)-Pisatin Induction in Epicotyls of Pea
Authors: Kobayashi Akio , Akiyama Kohki , Kawazu Kazuyoshi
Published: August 2018

Chitosan derivatives classed into three groups according to their molecular size were examined for the relationships between degree of N -acetylation and phytoalexin (+)-pisatin-inducing activity in pea epicotyl assay. Partially N-deacetylated chitin with degree of N-acetylation 56% (DAC 56%) was the most potent inducer of (+)-pisatin among sparingly water-soluble polysaccharides including chitosan (degree of N -acetylation 0%), DAC 32%, and chitin. Among the intermediate-sized molecules obtained from degradation of the chitosan and the DACs by NaNO2, the chitosan fragment was the most powerful elicitor for (+)-pisatin induc­tion. The NaNO2-degraded DAC 56% exhibited a com parable activity to the NaNO2 -degrad-ed chitosan at low concentrations. The NaNO2-degraded fragments as well as the native poly­mer induced a relatively high amount of (+)-pisatin, while the acetone precipitate of chitosan oligomers from the HCl-catalyzed hydrolysate and their partially N-acetylated derivatives ex­hibited a moderate (+)-pisatin-inducing activity. These findings suggest the possibility that partially N-deacetylated chitin fragments could be one of the most promising elicitors in the pea system.
Histone Acetylation is not Affected by Chloroacetamides in vitro
Authors: Kring Friedhelm , Böger Peter
Published: August 2018

The effects of chloroacetamides on the acetylation of histone protein in maize (Zea mays) were studied in an in vitro assay. Neither alachlor nor metazachlor showed any influence on both of the investigated acetylating enzymes, the nuclear histone acetyltransferase A and the cytoplasmic histone acetyltransferase B. Furthermore, an effect of these herbicides on deacetylation of histones could be excluded.
Natural Inhibitors of Germination and Growth, VII Synthesis of Ribulosebisphosphate Carboxylase in Darkness and Its Inhibition by Coumarin
Authors: Burghardt Helena , Brunner Harald , Oelmüller Ralf , Lottspeich Friedrich , Oster Ulrike , Rüdiger Wolfhart
Published: August 2018

Dedicated to Prof. Aloysius Wild on the occasion of his 65th birthday Lepidium sativum, Cruciferin, Ribulosebisphosphate Carboxylase, Inhibition of Transcription Cress (Lepidium sativum) seeds were germinated in darkness. Seedlings were investigated for soluble proteins by SDS-PAGE. Two proteins were identified by microsequencing: the small subunit of ribulosebisphosphate carboxylase (SSU) and the alpha subunit of the storage protein cruciferin. Net synthesis of small and large subunits of ribulosebisphosphate carboxylase (SSU and LSU) was investigated by Western blot. Net synthesis of both subunits was inhibited by coumarin. To the contrary, net synthesis of cruciferin was increased by coumarin. With specific cDNA probes, we determined steady state levels of the corresponding mRNAs (rbcS mRNA for SSU, rbcL mRNA for LSU). Both mRNAs can be detected in dry seeds; their amount increases during germination in the dark. Incubation with coumarin inhibits this increase. Inhibition of development by coumarin on the level of transcription is discussed.
Symbiotic Effectivity of Four Phaseolus vulgaris Genotypes after Inoculation with Different Strains of Rhizobium under Controlled Conditions
Authors: Epping Bernhard , Hansen Alexander P. , Djalali Bahman , Martin Peter
Published: August 2018

Four varieties of P. vulgaris L. were tested for their symbiotic nitrogen fixation effectivity in combination with nine different strains of Rhizobium leguminosarum bv. phaseoli and Rhizobium tropici. Plants were grown under controlled conditions and harvested 23 days after planting. Acetylene reducing activity, total N-content and dry weight of individual plant components were determined. Significant differences due to plant x bacterium interaction were assessed by ANOVA, especially for the total nodule mass per plant and the acetylene reducing activity per nodule dry weight. Data for acetylene reducing activity per plant correlated highly with the corresponding data for the total N-content. The comparison of the total N-content in symbiotically grown plants, lacking supply of mineral N, with plants luxuriously supplied with mineral N (relative N-accumulation rate) revealed high values (between 60% and 70% of maximal N-uptake) for some symbiotically active plant/bacterium combinations for this early developmental stage of the symbiosis N2 fixation potential for such symbioses.
Aggregation Pheromone of the African Rhinoceros Beetle, Oryctes monoceros (Olivier) (Coleoptera: Scarabaeidae)
Authors: Gries G. , Gries R. , Perez A. L. , Oehlschlager A. C. , Gonzales L. M. , Pierce H. D.
Published: August 2018

Coleoptera, Oryctes monoceros, African Rhinoceros Beetle, Aggregation Pheromone, Ethyl 4-M ethyloctanoate Ethyl 4-m ethyloctanoate is a male-produced aggregation pheromone of the African rhinoc­eros beetle, Oryctes monoceros (Olivier). It was identified by coupled gas chromatographic-electroantennographic detection (GC -EAD) and coupled GC-mass spectrometry (MS) of Porapak Q-trapped male-produced volatiles. Natural and synthetic ethyl 4-m ethyloctanoate elicited comparable antennal responses. In a field experiment (La Me Research Station, Côte d’Ivoire), synthetic ethyl 4-methyloctanoate released at 30 mg/day attracted both male and fem ale Oryctes, whereas the known, non-beetle-produced attractant, ethyl chrysanthemate, did not attract any Oryctes. Upon improvement of trap design and placement, and the identi­fication of synergistic (plant) volatiles, pheromone-based mass trapping may become an alternative and/or additional strategy to manage O. monoceros, one of the most destructive pests of commercial coconut, oil, and date palms in Africa.
Defensive Secretion of Ecdysteroids in Pycnogonum litorale (Arthropoda, Pantopoda)
Authors: Tomaschko Karl-Heinz
Published: August 2018

In response to disturbance, the pycnogonid Pycnogonum litorale discharges a mixture of eight ecdysteroids (ES). Repeated intensive molestation causes 99% secretion of the endogenous ES present. The concentration of the total ES in the defensive effluent is 1.0 × 10-3 mol · 1-1. 20-Hydroxyecdysone 22-acetate, the predominant ES, reaches 0.8 × 10-3 mol · 1-1. This is sufficient to deter significantly feeding by the common shore crab Carcinus maenas, a generalist predator in the habitat of the pycnogonid. There is evidence that the secreted ES of P. litorale contribute to its unpalatability. The present paper describes for the first time defensive secretion in marine arthropods.
External Flavonoids in Two Grindelia Species
Authors: Timmermann Barbara , Wollenweber Eckhard , Dörr Marion , Armbruster Sylvia , Valant-Vetschera Karin M. , Fuentes Eduardo R.
Published: August 2018

A series of methylated flavonols and two methyl flavones have been identified in the exudate of the American gumweed species Grindelia glutinosa and Grindelia robusta. They resemble the flavonoid patterns observed in other species of this genus, which thus shows a tendency for accumulation of methylated flavonols.