bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neuere Ergebnisse zur Struktur-Aktivitäts-Beziehung/ Some New Results Concerning Structure-Activity Relationships of Herbicides
Authors: Draber Wilfried 
Published: August 2018

Abstract
Relative activities and sensitivities towards twelve 1,2,4-triazinones were determined by conventional dilution techniques. The pI50-values of photosynthesis inhibition were found in a very narrow range (6.4 -6.6) whereas their physical properties differed widely (RM , log PO/W * log PSE , log (1/c) W). The question was whether the physical parameters showed any correlation with the relative activities and relative sensitivities which differed very widely (up to 50 fold). It was found that only the water solubility (log (1/c) W) showed some correlation with activity and no correlation could be detected between the chemical structures and the activities or sensitivities.
Carotenoid Biosynthesis — a Target for Herbicide Activity
Authors: Britton George 
Published: August 2018

Abstract
Carotenoids are chloroplast constituents. In vivo different carotenoids may be present at different sites within the chloroplast, and may have different functions. Especially important is a role in protecting the chloroplast and hence the plant from chlorophyll-sensitized photooxidation. If carotenoid biosynthesis can be blocked by herbicides, such protection will no longer be afforded, and rapid death of the plant is likely. In this article current knowledge of carotenoid biosynthesis is reviewed. The main characteristics of each stage in the biosynthesis are outlined and the suit­ability of these reactions as possible herbicide targets is assessed. Two experimental approaches to the study of the effects of herbicides on carotenoid biosynthesis are suggested.
Studies about the Mechanism of Herbicidal Interaction with Photosystem II in Isolated Chloroplasts
Authors: Renger Gernot 
Published: August 2018

Abstract
Based on the functional organization scheme of system-II-electron transport and its modification by different procedures a proteinaceous component enwrapping the redox components (plastoquinone molecules) of the acceptor side (thereby acting as regulatory element) is inferred to be the unique target for herbicidal interaction with system II. This proteinaceous component, which is attacked by trypsin, provides the receptor sites for the herbicides. Studies of the release kinetics in trypsinated chloroplasts of the inhibition of oxygen evolution with K3 [Fe (CN)6] as electron acceptor indicates, that there exists a binding area with different specific subreceptor sites rather than a unique binding site for the various types of inhibitors. Furthermore, trypsination of the proteinaceous component enhances the efficiency of the plastoquinone pool to act as a non-photochemical quencher for excitation energy.
Mechanism of Paraquat Action: Inhibition of the Herbicidal Effect by a Copper Chelate with Superoxide Dismutating Activity
Authors: Youngman Richard J. , Dodge Alan D. 
Published: August 2018

Abstract
The treatment of flax cotyledons (Linum usitatissimum) with paraquat was shown to decrease the levels of chlorophyll and carotenoid pigments. The fatty acid content of chloroplast fragments isolated from treated tissue was determined and shown to be greatly decreased by paraquat treat­ment. The superoxide radical was demonstrated to play an important role in the phytotoxic action of paraquat by the use of a copper chelate of D-penicillamine, which has a high superoxide dismutating activity. The action of paraquat was inhibited by this compound. The role of superoxide is discussed with reference to the generation of more toxic species, such as singlet oxygen.
Influence of Bleaching Herbicides on Chlorophyll and Carotenoids
Authors: Kunert Karl-Josef , Böger Peter 
Published: August 2018

Abstract
Over 24 and 48 hour cultivation periods the influence of SAN 9789 (norflurazon), EMD-IT 5914 (difunon) and fluridone on growth, photosynthetic oxygen evolution and pigment content of the green alga Scenedesmus acutus was determined. Four effects were observed:
a) Both carotenoid and chlorophyll formation were inhibited.
b) Carotenoids were destroyed in the presence of air, but not nitrogen. The level of chlorophyll, however, did not change.
c) β- (and α-) carotene was markedly decreased in the presence of oxygen.
d) Photosynthetic oxygen evolution was decreased with the disappearance of carotenoids.
These effects, which are accompanied by reduced growth, are believed to represent primary herbicidal modes of action. The decrease of oxygen evolution is not due to a direct inhibition of photosynthetic electron transport by the herbicides applied.
Ribose Conformations of Adenosine Analogs Modified at the 2', 3' or 5' Positions
Authors: Klimke G. , Cuno I. , Lüdemann H.-D. , Mengel R. , Robins M. J. 
Published: August 2018

The solution conformation of adenosine(β)ribosides modified at the 2′, 3′ or 5′ position is derived from the analysis of the HRNMR spectra of the ribose protons. The conformational equilibria of the furanoside rings are described by the two state N ↔ S model introduced by Altona and Sundaralingam. The new compounds studied are: 2′-thiobenzoyl-2′-deoxyadenosine, 3′-thio-3′-deoxyadenosine, 2′-chloro-2′-deoxyadenosine, 3′-chloro-3′-deoxyadenosine, 2′-bromo- 2′-deoxyadenosine, 3′-bromo-3′-deoxyadenosine, 2′-O-methyladenosine, 3′-O-methyl-adenosine, 2,-deoxy-3,-O-methyladenosine, 5′-amino-5′-deoxyadenosine, 5′-acido-5′-deoxyadenosine, and 5′-chloro-5′-deoxyadenosine.
The emphasis in this work is to study systematically the influence of the different substituents upon the conformational equilibria of the sugar. It is found that any substitution at the 2′ position stabilizes the S-conformer. An even more pronounced stabilization of the A-conformer in the 3′ substituted analogs is observed. The equilibrium changes in these classes of compounds can neither be correlated quantitatively with electronegativity differences nor with sterical differences between the various substituents. Substitution at the 5′ position influences the N ↔ S equilibrium only slightly, but has significant effects upon the conformational preferences of the exocyclic 5′-CH2R3 group.
Radiation Aggregates of Insulin
Authors: Kopoldová Jiřina 
Published: August 2018

Abstract
During the irradiation of aqueous solution of insulin (pH 1.8) the decrease of original insulin molecules and the formation of radiation aggregates of insulin was studied in dependence on the concentration of irradiation solution, on the doses and conditions of irradiation (oxygenated and oxygen-free atmosphere, the presence of t-butanol, addition of [14C] amino acids). From the results obtained and results published earlier it may be assumed that in irradiated solution on insulin new covalent bonds between insulin molecules are formed at tyrosyl, phenylalanyl and cystyl radicals; these radicals are formed by the action of both direct and indirect effect (at present pH 1.8 mainly of H atoms).
A Sex Attractant for the Green Budworm Moth, Hedya nubiferana
Authors: Frerot Brigitte , Priesner Ernst , Gallois Martine 
Published: August 2018

Abstract
The two major components of the female pheromone blend of Hedya nubiferana have been identified as (E, E)-8,10-dodecadienyl acetate and (Z)-8-dodecenyl acetate. Each compound acts on a specialist receptor type in olfactory hair sensilla of the male antenna. In field screening tests, combinations of the two compounds and dodecanyl acetate were highly attractive to H. nubiferana males. The (Z, E)-8,10 isomer attracted males of Hedya ochroleucana.
A Radioactive 1,4-Benzoquinone as Inhibitor of the DBMIB-Type in Photosynthetic Electron Transport
Authors: Oettmeier Walter 
Published: August 2018

Abstract
An 125iodine labelled 1,4-benzoquinone, an analogue of DBMIB, was studied for its interaction with the photosynthetic system of chloroplasts. It is not covalently bound to the thylakoid mem­brane. Instead, chloroplasts slowly decompose it under release of 125iodine and formation of a quinone of only small inhibitory potency, i. e. photosynthetic activity is restored after a few minutes. The inhibition in photosynthetic electron transport caused by the 125iodine labelled 1,4-benzoquinone can also be neutralized by bovine serum albumin to which it binds covalently.
Structural Differences in the Tracheal Tapetum of Diurnal Butterflies
Authors: Ribi Willi A. 
Published: August 2018

Abstract
The three-dimensional structure of the tracheal tapetum lucidum, its reflection properties and the resulting eye glow hue were studied in members of the diurnal butterfly families Pieridae, Nymphalidae, Satyridae and Lycaenidae. Two main groups of tapeta can be distinguished by structural and physiological differences. Whereas in pierids the main tracheal trunk at the bottom of the rhabdom bifurcates into two side branches before bifurcating again more distally, the tracheal trunk in the members of the family Nymphalidae, Satyridae and Lycaenidae investigated first divides into four side brandies. A second bifurcation shortly after the first results in eight subbranches which are regularly arranged between adjoining receptor cells. The broad banded reflection colour from incidently illuminated tapetal structures (at the level of the first bifurcation) varies between and within families but does not change significantly within the same eye. Whereas in nymphalids, satyrids and lycaenids the eye glow hue corresponds with the colour of the tapetal reflection, in pierids it is dominated by the coloured receptor screening pigment.
Transcription and Release of RNA in Isolated Nuclei from Parsley Cells
Authors: Großmann Klaus , Seitz Ursula , Seitz Hanns Ulrich 
Published: August 2018

Abstract
An in vitro transcription system using nuclei from freely suspended callus cells of Petroselinum crispum is described. The use of a filtration technique allowed the measurement of transcription and release of RNA simultaneously over very short time intervals. The transcription showed a biphasic time course, with an early maximum at 2 and a later one at 20 minutes. The early maximum was ascribed to the activity of polymerase II (α-amanitin sensitive), the later to that of polymerase I. While the transcriptional process was independent of the temperature used for incubation up to 26 °C and even increased with temperatures above that, the release of RNA transcribed was inhibited by temperatures above 36 °C.
The Influence of Spermine, Spermidine and Various Sera on T-Lymphocyte and Granulocyte Colony Growth in vitro
Authors: Rainer H. , Maschler Reinhard 
Published: August 2018

Abstract
Using T-lymphocyte (T-LC) and granulocyte colony (GC) assays with truly proliferating cells, the dose-response relationships of spermine and spermidine, of fetal calf (FCS), calf (CS), horse (HS) and human AB serum (A B S), and of the polyamines in the presence of selected does of the sera were analyzed. In contrast to earlier observations using [3H] thymidine uptake measure­ ments it was found that the polyamines as well as the sera themselves inhibit T-LC and GC growth in the presence of autologous HS and ABS, respectively. The polyamines also inhibit in the presence of additional HS and ABS, yet most effectively with added FCS and CS. Thus the previously reported species-specificity of the serum-dependent polyamine inhibition has here been shown to be more quantitative than qualitative. These studies stress the significance of assays utilizing truly dividing cells and broad dose-response relationships in order to assess specific biological effects in vitro.
Messungen der Spin-Gitter-Relaxationszeit T1 an Nucleosiden / Spin-Lattice-Relaxationtime T1 Measurements of Nucleosides
Authors: Sterk H. , Kopp H. , Esterbauer H. 
Published: August 2018

Abstract
Nucleosides and nucleotides have been investigated by means of the spin-lattice-relaxationtim T1 , the measurements carried out in CDCl3 on the nucleosides adenosine (A), uridine (U) and inosine (I) indicate that the strength of H-bonding is highest in the basepair (A)-(U). The systems (A)-(A), (U)-(U) , (I)-(A) ana (I)-(U) however, show only a low tendency to associate. Plotting the spin-lattice-relaxationtime, of the nucleotide protons in fragments (mol weight below 40,000) originated from DNA or RNA, against increasing temperature gives a curve with a sigmoide shape and a Tm value of 80 °C. The average of the activation energy for the H-bonding is 18.02 KJ/mol. The investigations clearly show that the spin-lattice-relaxationtime measurements open first of all a new method for research on H-bonding, secondly it is even in the case of nucleosides and oligonucleotides, where most of the common methods fail, a way to get information about H-bonding effects.
A Viscosity Model of Polyacrylamide Gel Electrophoresis
Authors: Bode Hans-Joachim 
Published: August 2018

In current theories of polyacrylamide gel electrophoresis, the idea prevails that molecular siev­ing relies on different accessibility of volume fractions and of cross-sectional area fractions (denot­ed “pores”) to different-sized ions due to the effect of “geometric exclusion”. This correlates with the assumption that all elements of a polyacrylamide network occupy fixed and unchangeable po­sitions thus forcing colliding macro-ions to diffuse laterally in order to find an “accessible pore” and to resume motion in direction of the electrical field. However, the alternative conception would be equally well justified, i. e. the assumption that polyacrylamide chains represent smooth obstacles cleared aside under the electrokinetic pressure of a macro-ion. This explanation would even be preferable with respect to the molecular sieving effects occuring in solutions of “liquid polyacrylamide”. Yet no theory exists as to describe such effects in quantitative terms.
In the present article, a parameter is defined and discussed, which can be estimated by experi­ment, and which seems to be apt to characterize local resistivity of polymer structures against dis­location and deformation: the “fractional specific resistance”. Definition of this parameter is bas­ed on the model of a “viscosity-emulsion” composed of two interpenetrating liquid compartments which are characterized by different levels of hydrodynamic friction and the spatial dimensions of which are inferred from Ogston’s theory. This concept of “localized viscosity” may also serve as a link between theories of molecular sieving and of “macroscopic viscosity” of flexible polymers. The data of Morris, formerly taken as verifications of the “rigid-pore” concept, are now interpret­ed in terms of four factors responsible for sizediscrimination: collision frequency, duration of sin­gle contacts, size-dependent frictional force, and the extent of cooperation among fibres, due to crosslinking and to simultanous contacts of several fibres to a single macro-ion. Some functions rel­evant for problems of molecular weight determination by gel electrophoresis are discussed in rela­tion to the suggested model.
Purification and Characterization of a 3,17 β-Hydroxysteroid Dehydrogenase from Streptomyces hydrogenans
Authors: Duchmann Helmut , Träger Lothar 
Published: August 2018

3,17 β-Hydroxysteroid dehydrogenase has been enriched and purified from cytosol of Streptomyces hydrogenans. After ammonium sulfate precipitation and filtration on Sephadex G-100 the enzyme was finally purified by preparative gel electrophoresis and DEAE-Sephadex A-50 chro­matography. Polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate gave a single band of mobility corresponding to molecular weight of 70 200 ± 2 500. 3 β-. 17 β- as well as 20 β-hydroxy steroids were dehydrogenated by the enzyme in the presence of NAD+. The dehydrogenation proceeded faster than the reduction of the corresponding ketosteroids in the presence of NADH. The enzyme does not accent NADP+ or NADPH as co-substrates. The apparent Km values were calculated to be 11 μᴍ for 5 α-dihydrotestosterone, 20 μᴍ for testosterone ana 68 μᴍ for epiandrosterone in the NAD+-driven reaction, 1.8 x 10-4 m for NADH+ and 1.9 x 10-4 ᴍ for NADH. The catalytic activity was influenced by the ratio of NAD+/ATP. The inhibition by ATP appears to be of a competitive type with respect to NAD+ (Ki 1.15 x 10-3 ᴍ).
After sucrose gradient centrifugation in a preparative ultracentrifuge the enzyme sediments with 4.1 ± 0.1 S as estimated in comparison to other proteins of known sedimentation coefficient. The isoelectric point was determined to be 3.9 with the LKB preparative isoelectric focusing col­umn (pH 2-11) and 4.1 with the analytical flat bed polyacrylamide isofocusing (pH 3 - 5). The number of SH groups was determined to be 2 mol/mol enzyme. In the presence of 6 M urea the fig­ure inceases to 3 mol SH/mol enzyme. In the presence of an excess of p-chloromercuribenzoate the enzyme activity decreases only partially.
On the Possible Involvement of Ascorbic Acid and Copper Proteins in Leukemia. IV. ESR Investigations on the Interaction between Ascorbic Acid and Some Copper Proteins
Authors: Lohmann Wolfgang , Schreiber Jörg , Greulich Walter 
Published: August 2018

Abstract
The interaction between lyophilized samples of ascorbic acid and some copper proteins (ceruloplasmin, cytochrome-c-oxidase, ascorbate-oxidase) has been investigated by means of ESR spec­troscopy. The spectra obtained are identical to the one obtained with leukemic blood. The consequences of this for the molecular events occuring in cancer are discussed. The model proposed can explain the experimental findings reported thus far (such as change in spin concentration with the development of cancer, the presence of a high concentration of antioxidants etc.) as well as reconsile the two existing and seemingly contradictory hypothesis. Possible implications for lipid peroxidation and for the respiratory process are discussed.
A Theoretical Study of H3PO4, nor-N-Mustard, and Cyclophosphamide
Authors: Ulmer W. 
Published: August 2018

Abstract
Some physical and chemical properties of the cancerostat cyclophosphamide (generic name: ENDOXAN) and its basic constituents H3PO4 and nor-N-mustard have been calculated with the help of a modified CNDO/S-method. The spectroscopic data of the H3PO4 , which is the starting-point for a corresponding calculation of cyclophosphamide, has been studied by taking account of the 3 d electron of the phosphorus. Nor-N-mustard is a very reactive compound, characterized by the ability to split off chloride ions and to act as an alkylating agent. The binding of the nor-N-mustard to the cyclic phosphate ester (cyclophosphamide) modifies the chemical reactivity of the mustard group in an essential way, and the 3d electron of the phosphorus plays an important role with respect to the excitability of the C -Cl bonds. Cyclophosphamide must be metabolized in a suitable way to develop the same alkylating activity as the nor-N-mustard. The computation of the excited states of cyclophosphamide revealed a similar term scheme as it was found by Clar in the case of the carcinogenic polycyclic hydrocarbons.
A Spectroscopic Study on p-Hydroxyphenylpyruvic Acid. Keto-Enol Tautomerism and Stability of Its Complex with Fe+3 Ions
Authors: Cassidei L. , Dell’Atti A. , Sciacovelli O. 
Published: August 2018

Abstract

1H-, 13C -NMR , IR, UV-Vis, and MS spectra of p-hydroxyphenylpyruvic acid (pH PPA) have been recorded and fully interpreted.
pHPPA exists in solution as a mixture of interconverting forms: keto, hydrated keto and only one enol tautomer to which the Z configuration has been assigned according to the value (3.7 Hz) of the vicinal IH-C = C-13COOH coupling constant.
In organic solvents the enol isomer is far more stable whereas in aqueous solutions the keto form predominates. The tautomeric equilibrium is pH-dependent and the anion is present as keto form not only in aqueous solution but also in H2O-DMSO mixtures with a high content of DMSO.
The Z enol tautomer does form a coloured complex (λmax = 680 nm) with Fe+3 ions. The complex decomposes rapidly in all considered solvents except DMSO.
In view of a possible use of H2O-DMSO mixtures for clinical analysis purpose, the enol fraction of pHPPA and the stability of the pH PPA -FeCl3 com plex in H2O-DMSÒ mixtures have been examined. Our results suggest that a solvent com position containing at least 80 vol.% in DM SO could be an appropriate solvent for pH PPA determination by FeCl3 method.
Identification of 4 Sex Pheromone Components Isolated from Calling Females of Mamestra brassicae
Authors: Struble D. L. , Arn H. , Buser H. R. , Städler E. , Freuler J. 
Published: August 2018

Abstract
Evidence obtained by glass capillary gas chromatography coupled to an electroantennographic detector or a mass spectrometer confirmed that Z-11-hexadecenyl acetate is the major component in the pheromone gland washes of calling Mamestra brassicae female moths. Three other components were identified, tetradecanyl acetate, hexadecanyl acetate and E-11-hexadecenyl acetate; but none of these had obvious synergistic effects in attracting males in field tests. The attraction of males to Z -11-hexadecenyl acetate was inhibited by 0.1% Z -11-hexadecenol or 1% Z-9- tetradecenyl acetate.
Cell Proliferation and Metabolism of Ehrlich Ascites Tumor Cells Grown in Chemically Defined Albumin Medium for Several Passages
Authors: Teschner Regina , Postius Stefan , Löffler Monika , Schneider Friedhelm 
Published: August 2018

Abstract
Cell proliferation, cell cycle distribution, viability, uptake of α-aminoisobutytic acid, cyclo leucine and 2-deoxyglucose as well as DNA, RNA and protein synthesis of Ehrlich ascites tumor cells grown in suspension culture over three passages in serum free nutrient medium supplemented with 1-2 % bovine serum albumin (Cohn fraction V, Serva) were measured and compared to cells grown in medium supplemented with 15% horse serum. At the end of the fourth passage in vitro, that is the third passage in serum free albumin medium, the growth of the cells is reduced to about 10% of the controls, accumulation of the cells in G 2 is delayed and the number of dead cells rises to 30%. The transport rates of α-aminoisobutyric acid and of 2-deoxyglucose slowly decrease while the up­ take of cycloleucine shows a more complex behaviour in albumin medium. Incorporation of thy­ midine and leucine into the cells corresponds to the growth rate, while the incorporation of uridi­ne in normal as well as in albumin medium exhibits different pattern. The present experiments demonstrate, that it may be possible to preserve this cells in a fairly “physiological” state during two passages in albumin medium.