bluuebunny/crossref_metadata_2025 huggingface dataset:
Complex Flavonoids from Pityrogramma Frond Exudates: Synthesis of Two Flavones with C—C-Linked Dihydrocinnamoyl Substituents
Authors: Iinuma Munekazu , Hamada Koji , Mizuno Mizuo , Asai Fujio , Wollenweber Eckhard
Published: August 2018

Complex flavonoids that are typical for the frond exudate in ferns of the genus Pityrogramma are surveyed to demonstrate their close structural relation. Two such compounds, isolated earlier from the exudate of Pityrogramma calomelanos var. aureoflava are prepared by an unambiguous synthesis. Direct comparisons of the synthetic products, namely P-(5,7.4′-trihydroxy-8-yl)-β- phenylpropionic acid and its methyl ester, show them to be identical with the natural products. The structures deduced previously for these compounds by spectroscopic methods are thus confirmed.
Occurrence of 2-(2-Hydroxy-4,7-dimethoxy-2H-1,4-benzoxazin-3-one)- β-ᴅ-glucopyranoside in Triticum aestivum Leaves and Its Conversion into 6-Methoxy-benzoxazolinone
Authors: Grambow Hans J. , Lückge Johanna , Klausener Alexander , Müller Edwin
Published: August 2018

Cyclic hydroxamic acids occurring in the Gramineae have been reported to be involved in the resistance of cereals to fungi and insects. Here we describe the occurrence, in wheat leaves, of 1,4- benzoxazinone derivatives and their glucosylated forms, a major representative of which was found to be 2-(2-hydroxy-4,7-dimethoxy-2H -1,4-benzoxazin-3-one)-β-ᴅ-glucopyranoside. Owing to its spontaneous conversion into 6-methoxy-benzoxazolinone the corresponding aglucone could not be isolated following enzymic cleavage. We propose a plausible mechanism for this reaction which also explains the higher stability of other members of the 1.4-benzoxazinone family.
Comparative Enzymatic Degradation of H1 Subfractions from Syrian Hamster Tissues
Authors: Hrabec Elżbieta , Płucienniczak Anna , Panusz Henryk
Published: August 2018

An additional hydrolysis site recognized by thrombin on histone H1 molecules was found. Snakes venom proteases from Agkistrodon rhodostoma, Bothrops marajoensis and Bothrops moojeni were further used for the analysis of H1 histones. The presence of the main cleavage site on H1 histone molecules has been established. This site is localized on main N-terminal thrombin peptide. The main venom protease peptides obtained from different H1 subfractions preserve differences of electrophoretic mobility in acid-urea polyacrylamide gels typical for the initial H1 subfractions.
Proliferation Kinetics and Metabolic Features of in vitro Grown Ehrlich Ascites Tumor Cells in the Presence of Exogenous Pyruvate
Authors: Kroll Werner , Postius Stefan , Schneider Friedhelm
Published: August 2018

The proliferation of in vitro grown Ehrlich ascites tumor cells is inhibited by pyruvate concen­trations >2 mᴍ. In the presence of 4-5 mᴍ pyruvate the growth is reduced to about 50%, in the presence of 20 mᴍ to about 5 - 10%. Viability of the cells is not severely affected. Increase of DNA corresponds to the cell growth. On recultivation in pyruvate free standard medium, growth is nearly normal. Flow cytometric analyses of the proliferation kinetics of the cells in the presence of 20 mᴍ pyruvate revealed a retardation of the passage of all phases of the cell cycle. No phase specific effects could be detected though the S- and G2M-phase are more afflicted than Gl. The growth inhibition of EAT cells by pyruvate seems to depend on the presence of glucose.

Exogenous pyruvate (>1-2 mᴍ) causes an activation of pyruvate dehydrogenase, a reduction of lactate production from glucose and a stimulation of lipid biosynthesis; the NAD/NADH ratio of the cells is reduced and a rise of glycolytic intermediates beyond glyceraldehyde-3-phosphate dehydrogenase is observed. Maximal activation of pyruvate dehydrogenase by non toxic concen­trations of dichloroacetate is also accompagnied by an inhibition of cell growth. It is suggested that an increase of glyceraldehyde-3-phosphate level and the changes in the redox state of the cells are of relevance for the inhibition of cell growth by pyruvate. 100-500 μᴍ exogenous glycer-aldehyde-3-phosphate strongly inhibited cell growth.
Interaction between Spin Labels and DPPC Vesicles
Authors: Lohmann W. , Kiefer B. , Schmehl W.
Published: August 2018

1H NMR studies on DPPC vesicles labeled with the spin labels (1,14) or (12,3) have shown that both of the spin labels influence the fatty acid side chains as well as the choline head groups. The spin label (12,3) affects, natural­ly, the head groups stronger than the spin label (1,14), while the reversed effect can be observed at the side chains. This effect progresses with time after vesicle preparation and is fully developed after about 24 h. Addition of Na- ascorbate, at this time, seems to reverse the effect indicat­ing a stabilizing effect of the vitamin on the membrane. These results could be confirmed by ESR investigations according to which the high-field signal seems to be indica­tive for changes occurring at the side chains, while the low-field signal seems to reflect modifications of the head groups. Since the spin label (1,14) affects considerably the head groups at temperatures <6 °C, in which case the spec­trum is very similar to that obtained with spin label (12,3) at 24 °C, one might conclude that there might be a phase transition in regard to the head groups.
Characterization of Volatile Constituents from Heterotrophic Cell Suspension Cultures of Ruta graveolens
Authors: Jordan Michael , Rolfs Claus H. , Barz Wolfgang , Berger Ralf G. , Kollmannsberger Hubert , Drawert Friedrich
Published: August 2018

Heterotrophic cell suspension cultures of Ruta graveolens were established by reversion of photomixotrophic cultures without any change in the chemical composition of the growth medium. The heterotrophic cultures were qualitatively and quantitatively analyzed by gas- chromatography and mass spectroscopy for volatile compounds. The terpenoid hydrocarbons geijerene and pregeijerene, C6-C8 ketones, acetic acid n-butylester and a series of aliphatic C4-C9 primary and secondary alcohols were found as main constituents. Two isomeric sabinene hydrates were also isolated as new constituents of rue cells. The data are discussed in comparison to results obtained with photomixotrophic cell suspension cultures.
Metabolie Conversions of Trichothecene Mycotoxins: Biotransformation of 3-AcetyldeoxynivaIenoI into Fusarenon-X
Authors: Baldwin Nigel C. P. , Bycroft Barrie W. , Dewick Paul M. , Gilbert John
Published: August 2018

The trichothecene mycotoxin 3-acetyldeoxynivalenol was transformed by cultures of the diace- toxyscirpenol producer Fusarium sp. strain C37410-90 into four compounds, identified as deoxy- nivalenol, 15-acetyldeoxynivalenol, 3,15-diacetyldeoxynivalenol and fusarenon-X. The major transformations are the result of specific esterification and de-esterification processes, but the production of fusarenon-X involves in addition a novel 4p-hydroxylation of the trichothecene ring system itself.
Soluble and Insoluble Rat Liver Chromatin is Different in Structure and Protein Composition
Authors: Brust Rüdiger
Published: August 2018

Rat liver chromatin has been fractionated by different solubility in solvents of 155 mᴍ ionic strength in soluble S and insoluble I-chromatin. Histone H1 content is lower in S as compared to I-chromatin. The HMG1/2 nonhistone proteins are observed in S-chromatin and in the nuclear pelleted residue from the chromatin isolation procedure, but no amount can be detected in I-chromatin. Thermal denaturation profiles and CD-spectra are different for S and I-chromatin indicating distinct interactions between DNA and proteins in the chromatin molecules. Both effects, differing protein content and distinct DNA-protein interactions, can be correlated with solubility and insolubility being the result of charge-charge interactions between chromatin molecules and ionic components of the solvent.
New Flavonoids from the Exudate of Baccharis bigelovii (Asteraceae)
Authors: Arriaga-Giner Francisco J. , Wollenweber Eckhard , Hradetzky Dagmar
Published: August 2018

Four flavonoids have been identified from the leaf and stem resin produced by Baccharis bigelovii (Asteraceae) in addition to twelve previously described aglycones. A flavonol (alnusin) and a dihydroflavonol (alnustinol) with 3,5,7-trihydroxy substitution had both been reported only twice before. The novel compound 2β,5,7-trihydroxy-flavanone is remarkable for its 2β-substitution at the heterocyclic ring. 7-Benzoyl-chrysin is the first flavone aglycone found as ester and the first flavonoid aglycone at all that is esterified with an aromatic acid.
Antiproliferative Activity of Derivatives of trans-Bis(salicylaldoximato)copper(II) in vitro. Some in vivo Properties of the Parent Compound
Authors: Elo Hannu , Lumme Paavo
Published: August 2018

Several derivatives and analogs of the recently reported antiproliferative and antitumor agent trans-bis(salicylaldoximato) copper(II) (CuSAO2) have been prepared and tested for antiproliferative activity against L1210 leukemia cells in vitro. The salicylaldimine analog of CuSAO2 had a very strong antiproliferative activity, the 2-day IC50 value being lower than 3 μg/ml- The 2,3-dihydroxybenzaldoxime analog was equally active with CuSAO2, while the corresponding 2,5-dihydroxy derivative had a slightly lower activity. The 2,3,4-trihydroxybenzaldoxime derivative had a much lower activity than had the dihydroxybenzaldoxime derivatives. The zinc(II) analog of CuSAO2 had only a low antiproliferative activity. The ligand of CuSAO2, salicylaldoxime, resembles pyridoxal oxime, a vitamin B6 antagonist and a powerful inhibitor of pyridoxal kinase. An attempt to reduce the toxicity of CuSAO2 in vivo with pyridoxal hydrochloride led to increased toxicity.
Comparison of the Solid State CPMAS and Solution Carbon-13-NMR Spectra of Humic Acids Extracted from Composted Municipal Refuse
Authors: Fründ R. , Gonzalez-Vila F. J. , Lüdemann H .-D . , Martin F.
Published: August 2018

The solution and CPM AS spectra of humic acids extracted from the composted municipal refuse of three Spanish cities (Sevilla, G ranada and Puerto Real) have been obtained at 75.4 MHz.

The spectra are discussed qualitatively and the signals assigned to the various chemical struc­ tures forming the humic acids.

It is attempted to learn the limits for the quantitative determination of signal areas for the different chemical structures.

It is concluded, that aliphatic-and carbohydrate structures contribute most to these compounds.
Phosphate Accumulation by Muscle in vitro and the Influence of Vitamin D3 Metabolites
Authors: Bellido Teresita , Boland Ricardo
Published: August 2018

Phosphate accumulation by muscle in vitro and the effects of vitamin D3 metabolites thereupon were studied in cultures of chick embryo skeletal muscle myoblasts and intact chick soleus mus­cles. A significant proportion of phosphate accumulation by the cells was Na+-dependent, satu­rable with respect to phosphate, energy-dependent and inhibited by ouabain and arsenate, in agreement with the operation of a Na+-phosphate cotransport system in the muscle cell plasma membrane as has been described for intestine and kidney. This was further supported by the demonstration of substrate-saturable phosphate uptake in sarcolemma vesicles isolated from chick skeletal muscle. Preincubation of myoblast and soleus muscle cultures with physiological levels of 25-hydroxy-vitamin D3 resulted in a significant stimulation of phosphate accumulations by cultures. 1,25-dihydroxy-vitamin D3 had no effects on the differentiated tissue whereas it marked­ly increased phosphate accumulation by embryonic muscle cells. In addition, it could be shown that 25-hydroxy-vitamin D3 affects the Na+ -linked component of cell phosphate uptake through a mechanism dependent on de novo protein synthesis.
Distant Precursors of Benzylisoquinoline Alkaloids and their Enzymatic Formation
Authors: Rueffer Martina , Zenk Meinhart H.
Published: August 2018

The incorporation rates of labelled tyrosine, DOPA. tyramine. and dopamine have been inves­tigated during the in vivo formation of the protoberberine alkaloid, jatrorrhizine, in callus cul­tures of Berberis canadensis. While tyrosine was equally well incorporated into both the iso­quinoline (54%) and benzyl (46%) portions of the alkaloid, DOPA was almost exclusively (91%) transformed into the isoquinoline moiety. However, tyramine (25%) and to a lesser extent, dopamine (15%) were incorporated into the aldehyde-derived, benzylic half of the isoquinoline molecule as well. In order to investigate further the precursory roles of these compounds, select enzymes involved in tyrosine metabolism in alkaloid-producing cell cultures have been studied. The occurrence of tyrosine decarboxylase, phenolase, transaminase, p-hydroxyphenylpyruvate decarboxylase, amineoxidase and methionine adenosyl transferase was demonstrated in suspen­sion cells of Berberis. These enzymes were partially purified and a preliminary characterization was performed. In the light of these and previous data, the differential metabolism of tyrosine and DOPA in the early steps of isoquinoline alkaloid biosynthesis is discussed. Conclusive evidence as to the biosynthetic origin of the phenylacetaldehydes which furnish the benzylic moiety of the alkaloids is precluded by the presence of both amineoxidase and phenylpyruvate decarboxylase activities in these cultures.
Characterization of 2β(R)-17-O-AcetylajmaIan: Acetylesterase — a Specific Enzyme Involved in the Biosynthesis of the Rauwolfia Alkaloid Ajmaline
Authors: Polz Leo , Schübel Helmut , Stoekigt Joachim
Published: August 2018

A novel enzyme was isolated, partially purified (217-fold) and characterized from cell suspen­sion cultures of Rauwolfia serpentina Benth. The enzyme catalyzes one of the late biochemical reactions in the biosynthesis of ajmaline by hydrolysis of 17-O-acetylated alkaloids of the ajmalan group forming the appropriate deacetylated compounds. This esterase exhibits an unusually high substrate selectivity and exclusively accepts acetylated ajmaline derivatives with the naturally occurring 2β(R)-configuration. The properties of the enzyme were determined showing an optimum pH at 7.5, an isoelectric point of pH 4.9 and a relative molecular weight of 33 ± 2 kDa. Inhibition studies of enzyme activity point to the necessity of SH-groups. The esterase seems not to be inhibited by ajmaline. the end product of the pathway. The highest enzyme activities were observed in leaves and cell suspension tissues of the tribe Rauwolfieae which are known to synthe­size ajmaline and its congeners. The specific function of the esterase in the biosynthesis of the later alkaloids was established.
Microbial Hydroxylation of Cedrol and Cedrene
Authors: Abraham Wolf-Rainer , Washausen Peter , Kieslich Klaus
Published: August 2018

Biotransformation of cedrol with 5 different strains afforded 8 previously undescribed hydroxy-cedrols. The attack came from a hemisphere centered at C-12 approximately. At two positions epimeric pairs were formed, which could be avoided by using different strains. Contrary to previous studies of other groups we found the 2-and 12-hydroxylations as main reactions. Cedrene needed prolonged fermentation and gave lower yields than cedrol. Apart from allylic hydroxylations the oxidation pattern by Corynespora cassiicola DSM 62474 of cedrene and cedrol was the same. The structures of the metabolites were elucidated by 2D NMR techniques.
Bausteine für Oligonucleotid-Synthesen mit einheitlich fragmentierbaren β-halogenierten Schutzgruppen /Building Blocks for Oligonucleotide Syntheses with Uniformly Fragmentable β-Halogenated Protecting Groups
Authors: Lemmen Peter , Karl Rosmarie , Ugi Ivar , Balgobin Neil , Chattopadhyaya Jyoti
Published: August 2018

5′-Dimethoxytrityl-3′-phosphite amides of deoxynucleosides are synthesized. Phosphite/phosphate is protected by the 2,2,2-trichloro-1,1-dimethyl-ethyl (TCB) group, heterocyclic bases by the 2,2,2-trichloro-2,2-dimethyl-ethoxycarbonyl (TCBOC) group. Deoxyguanosine is also block­ ed by 6-O-trichloroethyl thus avoiding the difficulties observed with monoprotected guanine residues.
Structure Elucidation of Kwakhurin, a New Prenylated Isoflavone from Pueraria miriflca Roots
Authors: Tahara Satoshi , Ingham John L. , Dziedzic Stanley Z.
Published: August 2018

An isoflavonoid obtained from dried roots of the Thai legume Pueraria mirifica has been identified by chemical and spectroscopic methods as 7,2′,4′-trihydroxy-5′-methoxy-6′-(3,3-dimethylallyl)isoflavone (kwakhurin).
Root Hair Specific Proteins in Glycine max
Authors: Werner Dietrich , Wolff Andreas Bernd
Published: August 2018

In root hairs from seedlings of Glycine max cultivars, isolated from the root system and com­ pared with the complete organ, specific soluble proteins have been found. By FPLC chromatography and SDS gel electrophoresis root hair specific proteins with molecular weights of 13, 21, 34, 38 and 42 kDa were separated. Additionally, proteins with molecular weights of 12, 20, 69 and 74 kDa were significantly enriched in root hairs compared to roots without root hairs. By using CNBr activated Sepharose with antibodies against the root system without root hairs, the pres­ ence of root hair specific proteins was confirmed in extracts from isolated root hair cells. Enrichment of Fe and Ca in some of the proteins from the root hairs is demonstrated. The present knowledge of the biochemical specificity of legume root hairs, the target cells of Rhizobium and Bradyrhizobium infection, is discussed.
Embryotoxicity Induced by Alkylating Agents. Some Methodological Aspects of DNA Alkylation Studies in Murine Embryos Using Ethylmethanesulfonate
Authors: Platzek T. , Bochert G. , Rahm U. , Neubert D.
Published: August 2018

Synthesis and spectroscopic analysis of some alkylated DNA purine bases are described. HPLC separation methods are developed for the determination of DNA alkylation rates in mammalian embryonic tissues. Following treatment of pregnant mice with the ethylating agent ethyl-methanesulfonate (EMS), an appreciable amount of alkylation (ethylation and methylation) was found in the nuclear DNA of the embryos during organogenesis. The results are discussed in context of our thesis that a certain amount of DNA alkylation in the embryos is correlated to the teratogenic potential of alkylating agents.
Free Amino Acids in Cytosol of Rat Brain after Intraventricular Administration of 5,6-Dihydroxytryptamine and 6-Hydroxydopamine
Authors: Konecki Janusz , Gabrys Janusz , Brus Ryszard , Szkilnik Ryszard , Shani Jashovam
Published: August 2018

Levels of 24 free amino acids were estimated in the brain after administration of 5,6-dihydroxy-tryptamine and 6-hydroxydopamine into the lateral brain ventricles of male Wistar rats. These neurotransmitters caused serotoninectomy and sympathectomy in the diencephalon, striatum, brain stem and medulla, thalamus and hypothalamus, cerebral cortex and cerebellum. The most abundant amino acids in these brain structures were: glutamic acid, serine, aspartic acid, cystine, gamma-aminobutyric acid, glycine, tryptophan and alanine. We detected and quantified changes in the levels of these and other amino acids in the investigated regions of the rat central nervous system, under the influence of these two neurotransmitters.
Pressure Effects on the Interactions of the Sarcoplasmic Reticulum Calcium Transport Enzyme with Calcium and para-Nitrophenyl Phosphate
Authors: Hasselbach Wilhelm , Stephan Lore
Published: August 2018

The effect of hydrostatic pressure on calcium dependent p-nitrophenyl phosphate hydrolysis of the sarcoplasmic reticulum calcium transport enzyme has been investigated at different degree of enzyme saturation by calcium and Mg-p-nitrophenyl phosphate to distinguish between activation and binding volumes. The enzyme saturated by both ligands displays a significant dependence of the activation volume on pressure, rising from 20 ml/mol at atmospheric pressure (0.1 MPa) to 80 ml/mol at 100 MPa. At subsaturating concentration of Mg-p-nitrophenyl phosphate an activation volume of 35 ml/mol prevails between 0.1 and 40 MPa. At subsaturating concentration of calcium the activation volume approximates 80 ml/mol in the same pressure range. The binding volume for both substrates is likewise pressure dependent falling from 20 ml/mol to 0 ml/mol for Mg-p-nitrophenyl phosphate and rising from 67 ml/mol to 155 ml/mol for calcium. The pressure dependence of activation and binding volumes is analysed on account of a simplified reaction scheme yielding activation volumes and rate constants for individual reaction steps.
The Role of Chirality in the Activity of Photosystem II Herbicides
Authors: Gardner Gary , Sanborn James R.
Published: August 2018

Although significant differences in activity between optical isomers have been recognized in many types of pesticides, the role of stereoselectivity has not been fully characterized for one of the most important classes of commercial herbicides, those that inhibit photosynthetic electron transport. This report describes experiments in which optically active α-methylbenzylamine or sec-butylamine was used as starting material for the synthesis of optically active triazine and urea herbicides. The biological activities of the compounds were determined in two in vitro chloroplast assays - competition for specifically bound [14C]atrazine and inhibition of photosystem II-medi- ated dye reduction - as well as in whole plant phytotoxicity. In both in vitro assays the (-)-isomer of the N-a-methylbenzyl triazine was about 15-fold more active than the (+)-isomer, and the racemate fell in between and was of about the same potency as atrazine. The same relative activities were also seen for in vivo phytotoxicity. The a-methylbenzyl urea derivatives were much less herbicidally active, but the in vitro assays were able to discriminate between the optical isomers. In both assays, the (-)-isomer of the urea was much more active than the (+)-isomer, with the racemate intermediate. Steric factors play a critical role in the degree of this chiral discrimination, since in both the corresponding triazines and ureas, the optically active molecules synthesized from the enantiomers of 2-butylamine showed only slight differences in activity. Saturation of the phenyl ring of the a-methylbenzyl triazines resulted in molecules which still showed substantial differences in activity related to chirality, further supporting the importance of steric factors, rather than electronic, in this chiral discrimination.
Cyanoacrylate Inhibitors of the Hill Reaction V. The Effect of Chirality on Inhibitor Binding
Authors: Huppatz John L. , Phillips John N.
Published: August 2018

Optically active α-methylbenzylamino 2-cyanoacrylic esters were synthesized and assayed as inhibitors of the Hill reaction in isolated pea chloroplast fragments. The 5-isomers were more potent inhibitors than the S-isomers with discriminations of from ten to greater than 100-fold being observed. A β-alkyl substituent in the cyanoacrylate molecule affected both the level of activity and the difference in activity between the isomers. An α,α-dimethylbenzylamino derivative was also active at about the same level as the corresponding α-methylbenzylamino racemate. This result could be explained in terms of the orientation of the phenyl ring in the receptor site.

Replacement of the α-methylbenzylamino group by other α-alkyl and α-phenyl substituents had little effect on activity. However, an α-benzyl group was beneficial.
Interaction of Halogenated 1,4-Benzoquinones with System II of Photosynthesis
Authors: Renger Gernot , Kayed Angela , Oettmeier Walter
Published: August 2018

The interaction of halogenated p-benzoquinones with PS II has been analyzed by measurements of fluorescence induction curves and the average oxygen yield per flash in isolated class II chloroplasts. It was found:

1)The normalized area over the fluorescence induction curve in the presence of DCMU. A/Fmax, markedly increases if halogenated p-benzoquinones are added before DCMU. The effect is eliminated by DCMU addition prior to that of the quinones.

2)The extent of A/Fmax increases with increasing dark time between the additions of 2,3.5-tri- bromo-6-methyl-1,4-benzoquinone (TBTO) and DCMU. respectively.

3) Some of the halogenated p-benzoquinones were found to act as efficient electron acceptors under repetitive excitation at low flash frequency (2 Hz). In the case of TBTO and 2,3-di-chloro-5-t-butyl-1,4-benzoquinone (TBU 13) the sensitivity of the average oxygen yield per flash was shifted towards higher concentrations of DCMU.

4) Halogenated p-benzoquinones can also affect the stability of oxidizing redox equivalents in the water oxidizing enzyme system Y. This effect depends on the nature of the substituents.

The present results are interpreted by the assumption of a covalent binding of halogenated p-benzoquinones in the vicinity of Qᴀ. This binding is prevented by DCMU. The possibility of allosteric interaction between the donor and acceptor side of PS II is discussed.
A Role of the Qв Binding Protein in the Mechanism of Cyanobacterial Adaptation to Light Intensity?
Authors: Koenig Friederike
Published: August 2018

Growth of the unicellular blue-green alga Anacystis nidulans in media containing sublethal concentrations of DCMU-type inhibitors of photosynthetic electron transport in strong white light gave rise to shade type appearance in this organism, as characterized by an increased ratio of phycocyanin to chlorophyll and reduced ratios, both, of carotenoids to chlorophyll and of total chlorophyll to P700. Shade type in Anacystis was caused neither by phenolic inhibitors tested nor by those known to bind to the cytochrome b6/f-complex. Surprisingly enough, the molar ratio of phycocyanin to chlorophyll in artificially shade adapted Anacystis1 grown in strong white light in the presence of 10-6 м atrazine, was found to increase with temperature for a given light intensity and with light intensity for a given temperature.

Mutants of Anaeystis with a reduced binding capacity for DCMU-type herbicides due to an amino acid exchange in the 32 kDa Qв-binding polypeptide, also called D-1 protein, were ob- served to show shade type appearance in strong light, to respond very little to changes in light intensity and to show a reduced capability to further change their appearance to shade type by binding of competitors of Ob to the 32 kDa polypeptide.

In Anaeystis a concentration of atrazine (10-7 м), ten times lower than the one causing the highest rate of shade adaptation (10-6 м), was shown to induce an optimum in cell density, which in turn resulted in an optimum in light-dependent O2 evolution. Both factors together might be responsible for the so-called greening effect observed in higher plants treated with sublethal concentrations of DCMU-type inhibitors of photosynthetic electron transport.
Expression of the psbA Gene in E. coli
Authors: Johanningmeier Udo
Published: August 2018

A psbA gene fragment has been cloned into an expression vector in frame with the 3′ end of the beta-galactosidase gene. Expression of this construct in E. coli results in an overproduction of a hybrid protein consisting of part of the herbicide binding protein and beta-galactosidase. An antiserum raised against this fusion protein specifically detects a 34 kDa polypeptide within the complex mixture of spinach thylakoid membrane proteins.
A Temporal Phase Mutation of Chlorophyll Fluorescence in Triazine-Resistant Brassica napus
Authors: Dekker Jack , Westfall Barbara
Published: August 2018

The objectives of this study were to determine if there were variations in triazine-resistant and -susceptible Brassica napus leaf disc chlorophyll fluorescence (LCF) intensity in terms of: age of leaf on the plant and time of day. In growth room and field experiments triazine-susceptible B. napus cv. “Tower”, and triazine-resistant B. napus cv. OAC Triton” were used. Chlorophyll fluorescence intensity measurements were made 30 min after disc removal. In both environments, two periods of reduced photosynthetic efficiency occurred in the diurnal. The times that these periods occurred during the diurnal differed between biotvpes. A phase shift in LCF maxima between resistant and susceptible biotypes resulted in two periods, early and late in the light period of the diurnal, of increased LCF in resistant tissue. This differential pattern in LCF is support for the hypothesis that triazine resistance chloroplast alterations could imply an alteration in the temporal organization of chloroplast physiological function.
Counteraction of Paraquat Toxicity at the Chloroplast Level
Authors: Upham Brad L. , Hatzios Kriton K.
Published: August 2018

Six pyridyl derivatives [benzylviologen, 2-anilinopyridine, 1,2-bis(4-pyridyl)ethane, 1,2-bis(4-pyridyl)ethylene, 2-benzoylpyridine, and 2-benzylaminopyridine] and five heme-iron derivatives [hemoglobin, hemin, hematin, ferritin, and ferrocene] were screened for their potential to counteract paraquat (1,1′-dimethyl-4.4′-bipyridinium ion) toxicity on pea (Pisum sativum L.) isolated chloroplasts. The H2O → methylviologen(MV)/O2 and H2O → ferredoxin(Fd)/NADP+ were two Hill reactions assayed with these compounds. Antagonists of paraquat toxicity should inhibit the first Hill reaction but not the latter. AU pyridyl derivatives examined did not inhibit the reaction H2O → MV/O2. Ferritin and ferrocene were also ineffective as inhibitors of this reaction. Hemoglobin inhibited the reaction H2O → MV/O2 without inhibiting the reaction H2O → Fd/NADP+, providing protection to pea chloroplasts against paraquat. Hemin and hematin inhibited both Hill reactions examined. They also inhibited H2O → diaminodurene(DAD)ox and durohydro- quinone → MV/O2 Hill reactions but not the dichlorophenol indophenolred → MV/O2 and DADred → MV/O2 Hill reactions. These results suggest that hemin and hematin are inhibiting the photo- synthetic electron transport in the plastoquinone-pool region.
The Effects of Photosystem I Electron Acceptors on Leaf Discs
Authors: Camilleri P. , Bowyer J. R. , McNeil P. H.
Published: August 2018

A leaf-disc chamber has been used to measure changes in photosynthesis by soybean leaf discs which have been supplied with photosystem I (PS I) electron acceptors via the transpiration stream. The uncharged heteropentalenes induce an inhibitory effect on CO2 fixation which is de­pendent on the n-octanol-water partition coefficient of these molecules. Paraquat, which carries a di-positive charge, was ineffective under the same conditions and at a concentration of 10-4 м. Cationic species such as K+, Ca2+ and Mg2+ greatly enhanced the effect of paraquat on CO2 fixation while the presence of these ions did not affect inhibition by the heteropentalenes. Such differences between uncharged and charged PS I electron acceptors have been explained in terms of electrostatic interactions encountered by paraquat on its way to the site of action within the chloroplast, via the transpiration stream.
n-Alkylphenole aus Schinus terebinthifolius RADDI (Anacardiaceae) / n-Alkylphenols from Schinus terebinthifolius RADDI (Anacardiaceae)
Authors: Skopp G. , Opferkuch H.-J. , Schwenker G .
Published: August 2018

The isolation of n-alkylphenols from the drupes of Schinus terebinthifolius is described for the first time. The 1H -NMR parameters, especially those for the triolefinic and monoolefinic components, are presented. Structures were proved by calculated spectra. Skin irritating activities were determined
Reactions of Substituted Arenediazonium Chlorides with Methylamine- Formaldehyde Premix Revisited: Reactivity and Transformations of Methylolamine Intermediates and Their Biological Significance
Authors: Kolar George F. , Schendzielorz Michael
Published: August 2018

Modulation of the N-azo coupling betw een ring-substituted arenediazonium chlorides and premixed m ethylam ine-form aldehyde leads not only to 1-aryl-3-hydroxymethyl-3-methyltriazenes and their dimers, but also to unexpected cyclic and com plex products. The syntheses comprise reactions with arenediazonium chlorides bearing both - M and + M substituents at para and ortho/para positions of the phenyl ring. One of the major constituents isolated from a mixture of products is the O-acetate ot 3-hydroxymethyl-3-methyl-1-(2,4,6>-trichlorophenyl)triazene. This product was obtained from the reaction of 2,4,6-trichlorobenzenediazonium chloride and methylamine- formaldehyde mixture which was then stabilized by acetylation.

The structures of the isolated products could be derived from reactive methylolamines and electrophilic intermediates that possibly occur in vivo and thereby offer a plausible mechanistic explanation for the carcinogenic and tumour-inhibitory activity associated with the open-chain triazene com pounds in the living cell.
Protein Transport in Chloroplasts: ATP is Prerequisit
Authors: Schindler Christine , Hracky Ruth , Soll Jürgen
Published: August 2018

The energy requirement for protein transport into chloroplast was assayed under conditions that perm it to distinguish whether the posttranslational translocation is dependent on ATP or whether a membrane potential across the chloroplast envelope can drive this transport event.

A membrane potential is not required for translocation. ATP can support protein transport in the presence of protonophores and ionophores. Non-hydrolyzable ATP analogues and GTP, CTP, UTP cannot serve as ATP substitutes. Translocation could be observed when an ATP generating system was used to supply ATP. In contrast ATP degrading systems completely abolished translocation.

The inner envelope mem brane localized ATP-ase is probably not involved in the transport event. The results suggest that ATP is needed at the outer chloroplast envelope.

Inhibition of protein transport by ADP, pyrophosphate and NaF is studied and its consequences discussed.
Epicuticular Leaf Wax of Cistus albanicus, Cistaceae
Authors: Vogt Thomas , Gülz Paul-Gerhard
Published: August 2018

The epicuticular wax of Cistus albanicus was investigated. Homologous series of alkanes, wax esters, alcohols and long chain fatty acids were identified. The alcohol fraction consisted of primary and most probably of secondary alcohols.
Entwicklung neuer Plattentests zum Nachweis mikrobieller Hydrolysen von Estern und Oxidationen von 2-Hydroxycarbonsäuren / Development of New Plate Tests for the Detection of Microbial Hydrolysis of Esters and Oxidations of 2-Hydroxycarboxylic Acids
Authors: Yamazaki Y. , Kula M.-R.
Published: August 2018

The application of the thin-agar-layer coated filter culture technique (Z. Naturforsch. 42c, 1082 (1987)) has been extended to the detection of ester hydrolysis and 2-hydroxyacid oxidation by microbial colonies. The former was performed by spraying with bromocresol purple and the latter with a salicylhydrazide reagent. Under the optimized conditions, the hydrolysis activity of more than 20 µmol/h·g-wet cells and the oxidation activity of more than 40 µmol/h·g-wet cells were usually detected directly on the filter-plate cultures of bacteria, yeasts and molds.
The Separation of Two Different Enzymes Catalyzing the Formation of Hydroxycinnamic A dd Glucosides and Esters
Authors: Bäumker Paul Alfred , Jütte Michael , Wiermann Rolf
Published: August 2018

Protein extracts from anthers of Tulipa cv. Apcldoorn catalyze the formation of glucosidcs and glucose esters of hydroxycinnamic acid with UDP-glucose as the glucosyl donor. By chromatofocusing and by HPLC (anion exchange chromatography) it could be demonstrated for the first time that two different enzymes are involved in these reactions. By using the molecular sieving (HPLC) a molecular weight of about 45000 D was determined for the GT (E) (= catalyz­ing the formation of esters) and of about 25000 D for the GT (G) (= catalyzing the formation of glucosidcs). Both enzymes exhibit a high spezificity for free hydroxycinnamic acids.

It is assumed that these transferases arc involved in the formation of feruloylglucose and ferulic acid glucoside, the latter of which can be isolated from anthers at early developmental stages. Furthermore, it is hypothesized that feruloylglucose functions as a starter molecule for the transacylation reaction by which di- and triferulovlsucrose are formed.
Twisted Fibrils are a Structural Principle in the Assembly of Interstitial Collagens, Chordae Tendineae Included
Authors: Folkhard Waltraud , Christmann Daniela , Geercken Werner , Knörzer Ernst , Koch Michel H. J. , Mosler Erika , Nemetschek-Gansler Hedi , Nemetschek Theobald
Published: August 2018

X-ray diffraction analysis of connective tissue samples, which contain type I and type III collagen shows that twisted collagen fibrils are a general principle of assembly. The occurrence of twisted fibrils in native wet Chordae tendineae, skin and Aorta is combined with a shorter axial periodicity of about 65 nm. This shorter D period is shown to be directly related to the tilt of the molecules, which have to be curved to build-up twisted fibrils.
Notes: Thermal Lability of Membrane Proteins of Age Separated Erythrocytes as Studied by Electron Spin Resonance Spin Label Technique
Authors: Bartosz Grzegorz , Christ Gabriele , Bosse Harald , Stephan Roland , Gärtner Helmut
Published: August 2018

Thermal lability of bovine erythrocyte membrane proteins was studied by electron spin resonance using maleimide spin label. The temperature of the sample during measurements could be varied for the first time be­ tween 0 and 60 °C with an accuracy of ± 0.1 °C. Our results show that “old” erythrocyte membrane proteins are less stable against thermal denaturation then “young” cells.
Notes: Lipids in the Gular Gland Secretion of the American Alligator (Alligator mississippiensis)
Authors: Weldon P. J. , Shafagati A. , Wheeler J. W.
Published: August 2018

Lipids from the gular glands of the American alligator (Alligator mississippiensis) were examined by gas chromatography-mass spectroscopy. C14, C16, and C18 fatty acids, squalene, and α-tocopherol (vitamin E) were detected in nearly all samples. Cholesterol was detected clearly in several samples.
Notes: Mammalian Pheromone Studies, VI. Compounds from the Preorbital Gland of the Blue Duiker, Cephalophus monticola
Authors: Burger B. V. , Pretorius P. J.
Published: August 2018

Forty five volatile compounds, mostly straight- and branched-chain alcohols and ketones, as well as derivatives of two of these alcohols, two y-lactones, an aromatic thiol ester and other simple aromatic compounds, have been identified in the preorbital secretion of the blue duiker, Cephalophus monticola.
Notes: Cellular Spin Resonance of Yeast in a Frequency Range up to 140 MHz
Authors: Hölzel Ralph , Lamprecht Ingolf
Published: August 2018

Rotation of living and dead yeast cells with and without buds was examined in rotating electric fields through a frequency range of 90 Hz to 140 MHz. For living yeast maximum rotation was observed in co-field direction at 30 MHz as predicted from model calculations, but with an unexpected sharp second resonance at 80 MHz for nonbud­ding cells. Also in the high frequency range the rotation rate was found to be proportional to the square of the applied field strength. The resonance of dead cells lies at 4 MHz; at lower frequencies these cells spin against the field analog to living cells, but without any resonance.
Trichothecene Mycotoxins from Fusarium culmorum Cultures
Authors: Bycroft Barrie W. , Baldwin Nigel C. P. , Dewick Paul M. , Marsh David C. , Gilbert John
Published: August 2018

Chemical analysis of the culture filtrates of Fusarium culmorum CMI 14764 has demonstrated the presence of seven trichothecene mycotoxins. Major metabolites are 3-acetyldeoxynivalenol and 7α,8α-dihydroxycalonectrin. with 3,15-diacetyldeoxynivalenol, deoxynivalenol. calonectrin, isotrichodermin and 12,13-epoxytrichothec-9-ene (EPT) as minor products. The occurrence of the rarely encountered unsubstituted trichothecene EPT is significant in that this compound may function as a common intermediate in the biosynthetic pathways to all natural trichothecenes. The structures of the known trichothecenes isolated from F. culmorum suggest a route in which EPT is sequentially oxygenated to the more complex deoxynivalenol derivatives.
Geraniol-10-hydroxylase Activity and Its Relation to Monoterpene Indole Alkaloid Accumulation in Cell Suspension Cultures of Catharanthus roseus
Authors: Schiel Otmar , Witte Ludger , Berlin Jochen
Published: August 2018

The activity of geraniol- 10-hydroxylase was greatly increased when Catharanthus roseus cells were transferred to a production medium for monoterpene indole alkaloids. Its activity pattern showed a closer relationship than tryptophan decarboxylase to the pattern of indole alkaloid accumulation. The intermediate accumulation of tryptamine and its later incorporation into ajmalicine indicated that the coordination of the two precursor pathways for the monoterpene indole alkaloid formation was not synchronized under the chosen culture conditions. A better tuning of these two pathways may shorten the time period for induction of indole alkaloid biosynthesis.
Ein neues Verfahren zum direkten Nachweis mikrobieller Aminoacylaseaktivität auf Agarplatten mit o-Phthalaldehyd / A New Detection Procedure for Aminoacylase Activity of Microorganisms Directly on Plate Culture with o-Phthalaldehyde
Authors: Yamazaki Y. , Hummel W. , Kula M.-R.
Published: August 2018

Not less than 1 nmol of methionine and phenylalanine were detected as fluorescent spots on agar plates with ophthalaldehyde reagent under UV light. Microorganisms were grown on thin- agar-layer coated filter papers placed on nutrient agar plates, and then transfered onto new plates lacking nutrients by moving the papers. After the background amino compounds were removed by the diffusion to the bottom plates, the paper cultures were moved and incubated on assay plates containing N-acetylmethionine or N-acetylphenylalanine. The amino acids formed around the colonies were visualized by the ophthalaldehyde procedure to indicate aminoacylase activity of microorganisms. The substrate- and stereospecificity of the enzyme was shown for some strains on the agar plates by this procedure.
Cell wall-bound phenolics from norway spruce (picea abies) needles
Authors: Strack Dieter , Heilemann Jürgen , Klinkott Eva-Susan , Wray Victor
Published: August 2018

Insoluble phenolics have been isolated and identified from Norway spruce (Picea abies [L.] KARST.) needles as cell wall-bound astragalin (kaempferol 3-O-β-glucoside) and p-coumaric acid as major components, and ferulic acid as a minor one. They probably mainly occur as lignincarbohydrate complexes
Nucleotide binding and atpase activity of membrane bound chloroplast coupling factor (cf1)
Authors: Huchzermeyer Bernhard
Published: August 2018

It has been found that the decay of light triggered ATPase activity is paralleled by nonexchangeable type of binding of one ADP per mol of CF1. Inactivation of light triggered ATPase activity is a continuous process. It can be described mathematically as shown in this paper. Three simplified reaction schemes are described, each of them describing the mode of ATPase inactivation in a mechanistic way. A computer simulation of each model was performed and the results were compared to the observed experimental data. In the presence of phosphate our results were explained best by a model assuming that there is at first a rapid binding of ADP to “exchangeable” sites. Due to a slowly occurring change in the CF1 protein with prolonged incubation, an increasing portion of the nucleotides can be found bound in a non-exchangeable way after some seconds of incubation. Our model does not rule out that this reaction sequence might be a part of a catalytic cycle in vivo. - Another result was the finding that there is an additional diminution of ATPase activity when phosphate is lacking
The structure and function of grana-free thylakoid membranes in gerontoplasts of senescent leaves of vicia faba l.
Authors: Schmidt H. Oskar
Published: August 2018

In the course of yellowing (senescence) the leaves of Vicia faba L. lose 95% of their chlorophyll. Gerontoplasts develop from chloroplasts and aggregate with the pycnotic mitochondria and the cell nucleus in the senescent cells (organelle aggregation). The gerontoplasts contain only a few, unstacked thylakoid membranes but a large number of carotinoid-containing plastoglobuli, which after the degration of chlorophyll presumably assume the light protection of the cells. The thylakoid membranes of the gerontoplasts were isolated by means of a flotation method. Their polypeptide composition is characterized by a high proportion of light-harvesting complex. Evidence of relatively high photochemical activity shows that functional thylakoid membranes are present in the premortal senescence state of leaves and this suggests that there is functional compartmentation of the hydrolytic processes in this stage of the leaves’ development
Major Flavanones from Lonchocarpus guatamalensis
Authors: Ingham John L. , Tahara Satoshi , Dziedzic Stanley
Published: August 2018

The flavanones 2 S-lupinifolin and 2R:3R-lupinifolinol have been isolated as major components from a methanolic extract of Lonchocarpus guatamalensis root bark. These known compounds occur together with a minor flavanone (2R:3R-3-O-methyl-lupinifolinol) not previously recognized as a natural product.
Glutaric Acid as a Catabolite of Nicotinic Acid in Parsley Cell Suspension Cultures
Authors: Komoßa Dieter , Barz Wolfgang
Published: August 2018

A degradation product of nicotinic acid representing the pyridine carbon skeleton was isolated and purified from parsley cell suspension cultures after incubation with [6-14C]nicotinic acid for 70 h. The catabolite was identified as glutaric acid by means of spectroscopic (GC-MS and 1H NMR) and chromatographic (TLC, HPLC) techniques. Glutaric acid when applied to parsley cell cultures was readily degraded to CO2 but intermediate products could not be identified.
Acetolactate Synthase from Barley (Hordeum vulgare L.): Purification and Partial Characterization
Authors: Durner Jörg , Böger Peter
Published: August 2018

Acetolactate synthase (EC 4.1.3.18; ALS) has been extracted from etiolated barley shoots (Hordeum vulgare L.) and purified to near homogeneity. Purification was made possible by a fivestep procedure using hydrophobic interaction, gel filtration, anion-exchange and hydroxylapatite chromatography, the last two steps performed with an HPLC- and FPLC-system, respectively. A 300-fold purification was achieved representing 13% of the initial activity in the crude extract; only small amounts of pure acetolactate synthase could be isolated. Although the enzyme was found labile during the chromatographic steps, purified ALS maintained its activity for several hours and could be stored at 70 K for weeks with a 15-30% loss.

The apparent molecular weights of the enzymatically active species as determined by gel filtration were about 440 kDa and 200 kDa, respectively. We assume these species are no isozymes but different polymeric forms of a basic unit of ALS. SDS-PAGE analysis showed one polypeptide with an apparent molecular weight of 58 kDa. Preliminary enzymatic characterization of the purified enzyme confirms a marked synergism in the feedback control by branched-chain amino acids. The combination of valine plus leucine exhibited the most co-operative inhibition.
Spontaneous Formation of Giant Phospholipid Vesicles
Authors: Servuss Rolf-M.
Published: August 2018

The spontaneous formation of giant (diameter > 10 μm) vesicles from a number of phospholipids in excess aqueous solution has been studied by light-microscopy. Electrically neutral as well as charged phospholipids swell to form giant vesicles only if the lipids are in the fluid phase. This shows that electrostatic repulsion alone cannot explain the spontaneous formation of giant vesicles. The results confirm the suggestion that steric forces between extended membranes play a significant part in this process.