bluuebunny/crossref_metadata_2025_split huggingface dataset:
Val-Geninthiocin: Structure Elucidation and MSn Fragmentation of Thiopeptide Antibiotics Produced by Streptomyces sp. RSF18
Authors: Sajid Imran , Shaaban Khaled A. , Frauendorf Holm , Hasnain Shahida , Laatscha Hartmut 
Published: August 2018

Abstract
Val-Geninthiocin (2), a new member of thiopeptide antibiotics, was isolated from the mycelium of Streptomyces sp. RSF18, along with the closely related geninthiocin (1) and the macrolide, chalcomycin. By intensive NMR and MS studies, Val-geninthiocin (2) was identified as desoxygeninthiocin, a thiopeptide, containing several oxazole and thiazole units and a number of unusual amino acids. Compound 2 shows potent activity against Gram-positive bacteria and minor antifungal activity, while it is not effective against Gram-negative bacteria or microalgae. Here we describe the fermentation, isolation and structure elucidation as well as the biological activity of 2.
A Sensitive Method for Identification of DNA Dependent DNA Polymerases in Acrylamide Gels after Seperation by Micro Disc Electrophoresis
Authors: Zöllner E. Jürgen , Müller Werner E.G. , Zahn Rudolf K. 
Published: August 2018

Abstract
DNA polymerase, disc electrophoresis, template affinity Two sensitive methods are described for detection of DNA dependent DNA polymerase activities in polyacrylamide gels after their fractionation by micro-disc electrophoresis.
One technique is based on the increase in fluorescence of the ethidium bromide complex with template polydeoxyribonucleotides brought about by the action of the polymerases. The sensitivity of the previously described technique has been enhanced. Another method, 14 fold as sensitive, uses radioactive precursors in the enzyme assay after electrophoretic separation; washing, slicing and counting allows to evaluate incorporation into acid insoluble polymer, requiring 3* 10" 2 units corresponding to approx. 0.02 /μg of E. coli DNA polymerase I preparation. Differing activities of polymerase species and differing template preferences may be investigated with these techniques.
DNA Turnover in Growing Yeast after X-Irradiation
Authors: Eckstein Hans 
Published: August 2018

Abstract
Growing yeast cells incorporate radioactivity from labeled nucleotides, deoxynucleotides, deoxyadenosine, and deoxycytidine into acid-insoluble material. Most of these compounds are in­ corporated predominantly into RNA, only dTMP and dTTP serve as effective and selective DNA precursors.
When yeast is prelabeled with dTMP, “specific” radioactivity of DNA decreases in the growing cells due to DNA augmentation. In X-irradiated yeast, “specific” radioactivity of DNA again decreases remarkably, though DNA augmentation of the growing giant cells in delayed. Simultaneously, radioactivity is rendered acid-soluble. Vice versa, X-irradiated unlabeled yeast incorporates radioactivity from labeled precursors into DNA, even if the DNA content of the cells does not increase.
When growing yeast cells are treated with cycloheximide, protein synthesis and DNA augmen­ tation are inhibited completely with 5·10-6 ᴍ cycloheximide. The decrease of “specific” radioactivity of DNA in X-irradiated cells, however, proves independent on an intact protein synthesis, even with 1·10-4 ᴍ cycloheximide.
The data provide clear evidence on DNA turnover in growing yeast after X-irradiation.
The Influence of Hydrogen Donors on Breakage of Parental DNA Strands and on Biological Activity of Transforming BrU-DNA of B. subtilis after 302/313 nm Radiation
Authors: Köhnlein Wolfgang 
Published: August 2018

Abstract
Long wavelength UV irradiation (302/313 nm) of hybrid and bifilarly labeled BrU-DNA of B. subtilis results in a degradation of the molecular weight of BrU and of parental thymine con­ taining DNA strands. Hydrogen donors present during UV irradiation are able to prevent these “primary” and “secondary” strand breaks. The protection factors are especially large for secondary breaks in parental normal DNA. Through the action of protective agents the biological activity could not be restored. The generation of these primary and secondary strand breaks due to BrU incorporation and the action of hydrogen donors discussed.
Studies on the Melting of DNA
Authors: Das Gokul Chandra 
Published: August 2018

Abstract
The thermal denaturation of the native DNA in solvents of varying salt concentrations was studied by viscometric and spectrophotometric methods. It was observed that within the molarity range of 0.02 ᴍ to 0.3 ᴍ, the melting temperatures obtained by the two independent methods agreed well, but that at lower ionic strength the agreement was not satisfactory. Both the visco­metric and the spectrophotometric measurements showed an increase of the melting temperature with increasing counterion concentration and a levelling off effect in the neighbourhood of 0.3 ᴍ.
Viscometric Studies on the Stability of DNA-Proflavine Complex-II
Authors: Das G. C. , Das N. N. 
Published: August 2018

Abstract
The binding of proflavine to native DNA increased its stability against thermal denaturation as measured by viscometric method. Up to a moderate ionic strength of 0.058 ᴍ, the melting temperature of the complex increased almost linearly with the increase of dye concentrations and a saturation was reached when one proflavine molecule was added per four to five DNA-Phosphates (D/P≅0.2). The extent of stabilization (ΔTm) produced by dye binding decreased gradually with the increase of ionic strength and no stabilization effect was observed at an ionic strength of about 0.3 ᴍ. The maximum melting temperature attained by Proflavine binding was almost independent of the ionic strength of the medium. The same maximum value was reached as obtained simply by increasing the sodium ion concentration.
Zur Chemotaxonomie der Corviden, II. Die Bürzelsekrete von Eichelhäher (Garrulus glandariusJ, Elster (Pica pica), Alpendohle (Pyrrhocorax graculus) und Kolkrabe ( Corvus corax) / Chemotaxonomy of Corvidae, II. The Uropygial Gland Secretion from the Jay (Garrulus glandarius), Magpie (Pica pica), Alpine Chough (Pyrrhocorax graculus), and Raven (Corvus corax)
Authors: Poltz Jens , Jacob Jürgen 
Published: August 2018

The uropygial gland fats from four species of the family Corvidae are found to be mainly mono­ ester waxes, which consist of mono-, di-, and trimethyl substituted fatty acids and n- and methyl-branched alcohols. The positions of all methyl brandlings are even-numbered, the 2-position is preferred.
About 2 - 40% of the secretions consist of triester waxes: Alkyl-hydroxy-malonic acids esterified with n-fatty acids and n-alcohols. Waxes of this type are very common in the uropygial gland fats of birds and therefore, in opposite to the monoester waxes, they are not usable for a chemotaxo­ nomy of birds.
Acid-Soluble Deoxynucleotides and DNA Synthesis in Growing Yeast after X-Irradiation, II. Synthesis of Deoxynucleoside Tri- and Monophosphates in Synchronized and Asynchronously Growing Cells
Authors: Eckstein Hans , Ahnefeld Sybille , Albietz-Loges Karin 
Published: August 2018

The behaviour of acid-soluble DNA precursors in synchronized and asynchronously growing yeast after X-irradiation is investigated by labeling techniques with 32Pi and by enzymic estimation. In prelabeled synchronized growing cells, radioactivity associated with deoxynucleoside triphosphates increases to maximum values shortly before each DNA replication, followed by a drastic decrease during S-phase. Radioactivity associated with monophosphates fluctuates, too, but with an opposite rhythm. These fluctuations apparently reflect quantitative changes of the DNA precursor pool during a cell cycle, as judged from the following findings: 1. Acid-soluble phosphorus is augmented stepwise. 2. "Specific" radioactivity from acid-soluble phosphorus compounds decreases steadily, indicating a continuous dilution of the labeled phosphorus pool with "cold" phosphorus. 3. Radioactivity associated with ribonucleotides fluctuates, too, but with a divergent rhythm.
In X-irradiated synchronice growing yeast, the fluctuations of the deoxynucleotide-associated 32P are disturbed only little. Maximum values appear nearly at the same time as in the control, they decrease to minor values even if DNA augmentation is delayed. This decrease is less drastic, however, than that during DNA replication in unirradiated yeast, yielding a slightly increased aver­ age label per generation time. At the same sime a rapid augmentation of monophosphate label is observed.
A pronounced increase of deoxynucleotide-32P is seen with X-irradiated asynchronously growing yeast, pointing to distinct radiosensitivities of the DNA/DNA precursor system in different cell stages. Neither 32P-fluctuations nor 32P-accumulation during DNA delay can be explained by cor­ responding observations with acid-soluble phosphorus or with ribonucleotide pools. Studies on 32P-incorporation also exclude radiation effects on cellular phosphorus uptake. Enzymic estimations of the deoxynucleoside triphosphate pools from asynchronously growing yeast rather exhibit a considerable increase of these substances during the radiation-induced delay of DNA augmentation. This accumulation of DNA precursors probably is caused by undisturbed synthesis, but reduced incorporation into DNA. The possible role of DNA repair in this system is discussed.
Die Röntgenstrukturanalyse von 2-(m-Brombenzyl-4.7.8.9- tetra-O-acetyl-N-acetyl-α -ᴅ-neuraminsäure * / X-Ray-Structure-Analysis of 2-(m-Br-benzyl) -4,7,8,9-tetra-O-acetyl-N-acetyl- α-ᴅ-neuraminic Acid
Authors: Wawra H 
Published: August 2018

Abstract
The structure of 2-(m-Br-benzyl) -4,7,8,9-tetra-O-acetyl-N-acetyl-α-ᴅ-neuramine acid was solved by heavy-atom methods using three-dimensional X-ray data. Known biochemical properties of the molecule allow to determine the absolute configuration.
Trägergebundenes Analog des Actinomycins C1 (D) und Affinitäts­ chromatographie von Nucleinsäuren / Resin Linked Analogue of Actinomyein C1(D) and Affinity Chromatography of Nucleic Acids
Authors: Seela Frank 
Published: August 2018

Abstract
A biospecific adsorbent for the separation of different nucleic acids was prepared by covalent attachment of a chromophore analog of actinomycin C1 (D) to Sepharose 4 B. The immobilized chromophor-derivative was obtained by condensation of 2-nitro-3-hydroxy-4-methylbenzoic acid with N6-(6-aminohexyl)-Sepharose 4 B, reduction of the nitro group and oxidative coupling with 2-amino-3-hydroxy-4-methylbenzoyl-β-(N,N-diethylamino) -ethylamide. Since the chromophore of actinomycin has a high affinity to DNA. DNA/RNA-mixtures were separated by retardation of DNA on this resin
Solubilisierung, Anreicherung und Separierung zweier 17β-HSDAktivitäten nach Phospholipase-Behandlung / Microsome-Associated 17β-Hydroxysteroid Dehydrogenases of Human Placenta, I Solubilization, Enrichment and Separation of Two 17β-HSD-Activities after Phospholipase-Treatment
Authors: Pollow Kunhard , Runge Wilfried , Pollow Barbara 
Published: August 2018

Abstract
Treatment of human placenta microsomes with phospholipase A or D inhibits the 17β-hydroxysteroid dehydrogenase [17β-HSD] activity, parallel with the hydrolysis of membrane phospholipids.
The 17β-HSD activity of phospholipase treated microsomes is reactivated by synthetic phospholipids. The distribution of 17β-HSD activity in subfractions of original microsomes and of phospholipase treated microsomes obtained by zonal centrifugation was studied.
Solubilization of the microsomal 17β-HSD was achieved by phospholipase A treatment. Two 17β-HSD were solubilized from human placenta microsomes by phospholipase A treatment and were further purified by ammonium sulphate precipitation, gel filtration on BioGel A-0.5 m, DEAESephadex chromatography and by isoelectric focusing. The enzymes were purified 25.8 and 17.4 times. The isoelectric points and molecular weights of the two 17β-HSD were determined.
Both enzymes are of a 17β-HSD type. One of the 17β-HSD, however, was sensitive to estradiol- 17β, the other to testosterone. The question of whether the two enzymes constitute a monomer and a dimer of the same 17β-HSD or are completely different enzymes, is discussed.
Kinetische Untersuchungen und Charakterisierung der solubilisierten Oestradiol-bzw. Testosteron-"sensitiven" 17 β-HSD-Aktivitäten / Microsome-Associated 17β-Hydroxysteroid Dehydrogenases of Human Placenta, II Kinetic Studies and Characterization of the Solubilized Estradioland Testosterone-“Sensitive” 17β-HSD-Activities
Authors: Pollow Kunhard , Runge Wilfried , Pollow Barbara 
Published: August 2018

Abstract
Detailed enzyme kinetic parameters of the reactions catalyzed by the two 17β-hydroxysteroid dehydrogenases (17β-HSD), which were solubilized from the microsomes of human placenta by treatment with phospholipase A, followed by enrichment and separation were determined.
Both enzymes are strictly substrate specific. The most active substrate of one of the 17β-HSD (fraction A) is estradiol-17β, the other 17β-HSD (fraction B) is sensitive to testosterone. Both NAD and NADP can serve as hydrogen transferring coenzymes, the latter giving about one-third of the initial rate of the former. With respect to the influence of temperature, different buffers and pH values, Michaelis constants [Km] with estradiol-17β and testosterone as substrates, the solubilized and separated microsomal 17β-HSD behave like those isolated from the cytoplasmic fraction.
The two 17β-HSD, after solubilization from the microsomal fraction of human placenta, enrichment and separation from each other, show only a little activity for the transfer of hydrogen between C17 of estradiol-17β and C17 of androstenedione. On the other hand, intact microsomes and an integrated system prepared by recombination of the 17β-enzymes by preincubation in phosphate buffer are able to catalyse very actively the transfer of hydrogen between estradiol-17β and androstenedione.
The effect of temperature and time on the recombination of the two enriched and separated microsomal enzyme activities and the determination of the pH-optimum of the hydrogen transfer reaction are described. Finally it is proposed that the hydrogen transfer between steroid hormones represents an aspect of the true reaction mechanism of steroid hormones: Steroid hormones function as hydrogen transferring coenzymes by forming part of a chain of hydrogen carriers.
Einfluß von Cytoplasma-und Serumfaktoren auf den [3H]Thymidintriphosphat-Einbau isolierter Leberzellkerne / Effect of Cytoplasmic and Serum Factors on the Uptake of [3H]Thymidinetriphosphate (TTP) by Isolated Nuclei of Liver Cells
Authors: Volm M. , Merz G. 
Published: August 2018

Abstract
The actions of cytoplasm (ultracentrifuged supernatant 105 000 x g) and of serum on the DNA synthesis (uptake of [3H]TTP) by isolated nuclei of liver cells were studied. Cytoplasm from liver cells obtained at various intervals after partial hepatectomy revealed a variable effect only with isolated nuclei of liver cells from partially hepatectomized rats. Cytoplasm obtained from liver cells eight hours after p artial hepatectomy failed to show the usual inhibitory effect. Presum ably the inhibitory substances norm ally present in cytoplasm are inactivated within a certain time after partial hepatectomy.
Serum of partially hepatectomized anim als enhanced the uptake of [3H]TTP by nuclei of normal liver cells and those from partially hepatectom ized animals. The stim ulating effect was present only in the serum obtained between four and twelve hours after partial hepatectomy. It remains unclear whether the effects described are growth factors specific for the liver.
Synthesis of Further Substrates of NAD(P)-Linked Dehydrogenases of High Specific Tritium Content
Authors: Alizade Miguel , Simon Helmut , Bressler Rubin , Brendel Klaus 
Published: August 2018

Abstract
Stereospecific, Hydrogen Labeled The preparation of (R) and (S) [2-3H] lactate as well as (S) [2-3H] glutam ate via the coupled exchange reaction catalyzed by NAD linked dehydrogenases and NADH : lipoam ide oxidoreductase (diaphorase) is described. The specific radioactivity of the hydrogen ions of the 3HOH /H2O can be obtained in the substrates (100% exchange) if equilibrium isotope effects are disregarded. By the exchange procedure substrates w ith higher specific radioactivity are obtained from positionally [3H] labeled racem ic m ixtures prepared by chemical reductions with [3H] labeled hydrides. The tritium content of one of the enantiom eres is “washed out” into water. As examples are presented the preparation of (R) [2-3H] (S) [2-H] malate as well as the corresponding carnitine, glutam ate and (R) and (S) lactate.
Charakterisierung von RNA aus synchron wachsender Bäcker-Hefe ( Saccharomyces cerevisiae) bei Trennung mit der Methylalbumin-Kieselgur(MAK)-Säule / Characterisation of RNA from Synchronously Growing Yeast Cells (Saccharomyces cerevisiae) as Separated by Columns of Methylated Albumin on Kieselgur (MAK)
Authors: Braun R. 
Published: August 2018

Abstract
Total RNA, extracted from synchronously growing yeast cells by the method of Georgiev-Mantieva, was separated by columns of methylated albumin on Kieselgur (MAK). By comparison with definited RNA’s in discelectrophorese and after pulse labelling with [3H] methionine the following fractions are identified: t-RNA, 5.8S RNA, m-RNA, 18S and 25S r-RNA and their precursors 20S, 27S and 35S. High molecular fractions of RNA between 40S and 70S were also found
Inhibition of Excision Repair without Influence upon UV-Sensitivity and UV-Mutability in Escherichia coli B/r Hcr+
Authors: Balgavý Pavel , Turek Robert 
Published: August 2018

Abstract
Pre-irradiation starvation of exponentially growing Escherichia coli B/r Hcr+ thy-trp- strain for thymine and tryptophan causes inhibition of pyrimidine dimer excision from ultraviolet damaged cells DNA. This inhibition of excision repair has not resulted in increasing ultraviolet sensitivity nor in increasing frequency of ultraviolet induced tryptophan revertants. The possible mechanisms of the non-excision repair in the prestarved cells, which is at least as accurate and effective as the whole dark repair in exponentially growing cells, are discussed.
Chemical Constituents of the Essential Oils of Aroliaceae and Lauraceae Families
Authors: Hayashi Nanao , Yokochyô Kôki , Komae Hisashi 
Published: August 2018

Abstract
In the course of the chemosystematic study of Aroliaceae and Lauraceae families, the leaf oils of some plants were investigated. The leaf oils were obtained by steam distillation of the fresh leaves. The individual constituents were isolated by column chromatography followed by preparative gas chromatography, and identified by gas chromatography and by infrared spectra.
Gaschromatographisch-massenspektrometrische Analyse neutraler und saurer Oligosaccharide der Frauenmilch als Trimethylsilyläther / Gas Chromatographic Mass Spectrometric Analysis of Neutral and Acid Oligosaccharides from Human Milk as Their Trimethylsilyl Derivatives
Authors: Nicolai Hubertus von , Egge Heinz , Zilliken Fritz 
Published: August 2018

Abstract
Gas chromatography and the 20 eV mass spectra of the human milk oligosaccharides fucosido-galactose, fucosido-lactose, di-fucosido-lactose, 3'-N-acetylneuraminyl-lactose, 6'-N-acetylneuraminyl-lactose and of N-acetyllactosamine as pertrimethylsilyl (TMS) ethers are described.
The gas chromatographic separation of the L-fucose containing oligosaccharides was performed on Silicone SE 30. The sialic acid containing sugars were separated on DEXSIL 300.
The correlations between oligosaccharide structures and mass spectrometric fragmentation pat­ terns are discussed.
Molecular Size of the Diapause Hormone of the Silkworm Bombyx mori
Authors: Kubota Ichiro , Isobe Minoru , Goto Toshio , Hasegawa Kinsaku 
Published: August 2018

Abstract
The diapause hormone (D H) responsible for arrested development of the silkworm Bombix mori consists of two active principles of peptide (A and B) . Since both hormones form aggregates in aqueous phases, the molecular weights were determined by gel permeation chromatography of Merckogel OR 6000 using methanol-dichloromethane mixture as the developing agent. Gramicidins and modified peptides soluble in the organic solvents were used as the standard markers for the molecular weight measurements of the hormones. The molecular weights of DH -A and -B are estimated to be 3300 ± 400 and 2000 ± 200, respectively.
6.7-Dihydroxycumarin (Aesculetin) als Substrat der Catechol-O-Methyltransferase / 6,7-Dihydroxycoumarin (Aesculetin) as a Substrate for Catediol-O-methyltransferase
Authors: Müller-Enoch D. , Seidl E. , Thomas H. 
Published: August 2018

6,7-Dihydroxycoumarin (Aesculetin) was found to be a substrate of rat liver Catechol-O-methylfransferase (COMT) (EC 2.1.1.6).
Incubation of this substrate with S-Adenosyl-ʟ-[methyl-14C] methionine and/or S-Adenosyl- methionin-hydrogensulfate in the presence of COMT yields the highly fluorescent compounds 7-hydroxy-6-methoxycoumarin (Scopoletin) and 6-hydroxy-7-methoxycoumarin (Isoscopoletin) in the ration of about 2:1. The O-methylated products obtained from Aesculetin were identified after separation by thin layer chromatographpy mainly by the reversed isotope dilution technique.
The fluorescence of the isolated methylethers was proportional to concentration within the range from 10-5 - 10-7M. A reciprocal plot of activity versus substrate concentration gives a Km of 1 × 10-6 M.
Notizen: Hohe 3-Indolylessigsäure- und Phenylessigsäure- Konzentrationen in den Pygidialdrüsen von Wasserkäfern (Dytiscidae)/ High 3-Indoleacetic Acid- and Phenylacetic Acid- Concentrations in the Pygidial Glands of Water Beetles (Dytiscidae)
Authors: Dettner Konrad , Schwinger Gerhard 
Published: August 2018

Abstract
In pygidial-glands of water beetles (Dytiscidae) 3-indoleacetic acid and phenylacetic acid have been identified by mass-spectroscopical methods and estimated by UV-spectrometry.
Erster Nachweis von freien Cilien im Mitteldarm von Arthropoden / Discovery of Cilia in the Mid-Gut of Arthopoda
Authors: Rieder Norbert , Schlecht Friedrich 
Published: August 2018

Abstract
Cells bearing two cilia are found in the mid-gut of the Phyllopod Leptestheria dahalacensis. These cells seem to be sensory cells. They may be in contact with the muscle cells of the mid-gut.
Untersuchungen zur Biogenese der Cardenolide in Convallaria majalis L.: Umwandlungen auf der Geninstufe / Cardenolide Biogenesis in Convallaria majalis L.
Authors: Kopp Brigitte , Löffelhardt Wolfgang , Kubelka Wolfgang 
Published: August 2018

Abstract
[19-3H ] Strophanthidol, fed to leaves of whole plants of Convallaria majalis L., was translocated to the rhizomes and roots. Oxidation to [19-3H] strophanthidin took place in the leaves only. No labelled glycosides of strophanthidol and strophanthidin were found; thus, the aglycones are not precursors of the respective glycosides. It is assumed that the first glycosidation occurs at the C-21 level.
Dependence of Cellular Surface Area on Growth Density of 3T3 and SV40-3T3 Cells
Authors: Seher J.-P. , Adam G. 
Published: August 2018

Abstract
The cell surface areas of 3T3 and SV40-3T3 cells both for suspended and for flat cells growing on the culture substrate have been determined in dependence on growth density. The surface areas of flat 3T3 and SV40-3T3 cells turn out to be independent of growth density over a wide range. For 3T3 cells the surface area of flat cells com pares well with that determined by Collard and Temmink for suspended 3T3 cells taking the surface area of their coverlayer of microvilli into account. This indicates that upon suspension of flat 3T3 cells the surplus surface area is disposed of in the form of microvilli. For SV40-3T3 cells we obtained a surface area of flat cells which differs by a factor of about two from that of suspended cells as determined by Collard and Temmink including the surface area of microvilli.
Microscopical diameters and electrical (“Coulter”) volumina of suspended 3T3 and SV40-3T3 cells depend only little on cell density in the range investigated.