bluuebunny/crossref_metadata_2025 huggingface dataset:
Über Ba3CaU2O9 und Ba3SrU2O9 / On Ba3CaU2O9 and Ba3SrU2O9
Authors: Kemmler-Sack S. , Wall I.
Published: February 2015

The compounds Ba3CaU2O9 and Ba3SrU2O9 crystallize in an ordered cubic perovskite lattice. According to the results of the magnetic and optic investigations both compounds contain U (V) in a distorted octahedral coordination.
Darstellung von Schwermetallsulfiden durch Fällung aus organischen Lösungsmitteln. IR-Spektren von Metallsalzen der Naphthensäure / Preparation of Metal Sulphides from Organic Solvents. IR-Spectra of Metal Salts of Naphthenic Acid
Authors: Lutz Heinz Dieter , Haeuseler Hartmut
Published: February 2015

The following sulphides were precipitated with hydrogen sulphide from solutions of naphthenates in organic solvents: In2S3, CoS, NiS, CuS, ZnS, CdS, HgS, PbS, Ag2S and the thiospinels NiIn2S4, CdIn2S4 and HgIn2S4. Not precipitated are chromium (II) and chromium (III). The ir-spectra of the naphthenates are discussed.
Das Schwingungsspektrum der Trichlorcyanursäure, (ClNCO)3 / The Vibrational Spectrum of Trichloroisocyanuric Acid, (CINCO) 3
Authors: Dehnicke K. , Leimeister H.
Published: February 2015

The vitrational spectrum (IR and Raman) of trichloroisocyanuric acid, (CINCO) 3 is recorded and assigned on the basis of a planar molecule with symmetry D3h.
Umlagerungsreaktionen von Cumarinen als Folge einer intermediären Öffnung des Lactonringes / Rearrangements of Coumarins, Caused by an Intermediate Cleavage of the Lactone
Authors: Junek Hans , Frosch Franz
Published: February 2015

The condensation of 2-hydroxy-1-naphthaldehyde with ethyl cyanoacetate is investigated. Rearrangement for the obtained naphthopyranyl-ethyl-cyanoacetate (5) is reported, yielding 5,6-benzocoumarin-carbonitrile and naphthopyranyl-aminoacrylate (6). Enamine-lactone-rearrangement of 6 leads to chromene-carboxylic acid (7). By hydrolysis of the benzopyranyl-ethyl-cyanoacetate (8) and addition of cyanoaceticacid derivatives to 3-cyanocoumarin or 3-carboxyamido-coumarin resp., the benzopyrano-pyridines 12 are obtained.
Photoreactivity (365 nm) of Some Coumarins and 4′,5′-dihydro-furocoumarins with Nucleic acids
Authors: Marciani S. , Dall’Acqua F. , Guelfi L. , Vedaldi D.
Published: February 2015

The Authors have studied the capacity to photoreact with native DNA and r-RNA using six coumarins and four 4′,5′-dihydro-furo-coumarins. Six of these substances have shown a definite photoreactivity both with DNA and r-RNA, even if in a very much lower extent in respect to that of skin-photosensitizing furocoumarins.

The low capacity to photoreact with nucleic acids of these substances is discussed, also in connection with the absence of skin-photosensitizing activity.
Microdetermination of Nodososide and Related Compounds Using Ceric Sulphate as Oxidizing Agent
Authors: Rizvi S. A. I. , Sultana Tajwar
Published: February 2015

Nodososide and emodin from the flowers of Cassia nodosa and physcion-1-glucoside and physcion from the seeds of Cassia occidentalis can be determined in micro amounts by oxidation with eerie sulphate in presence of sulphuric acid. The reactions required 48, 26, 54 and 30 moles of oxidant respectively, resulting in the formation of formic and acetic acids in each case while carbon dioxide was also produced in the cases of nodososide and physcion-1-glucoside. The conditions of stoichiometric oxidation of the anthraquinones have been studied. Methylation of the hydroxyl groups has been found to retard the rate of oxidation of the anthraquinones whereas free hydroxyl groups are easily attacked by ceric ions. The ranges of errors observed are 0.2 -1.7%, 0.3 - 2.9%, 0.2 -3.5% and 0.2 - 3.5% respectively.
Synthese und Eigenschaften unsymmetrischer Diketopiperazine des Cysteins / Synthesis and Properties of Unsymmetrical Diketopiperazines of Cysteine
Authors: Rossbach, V. , Wenck H.
Published: February 2015

The synthesis of cyclo (c)-cys-ser, c-cys-asp and c-cys-try via cyclisation of the corresponding cystin-dipeptidesters and subsequent reduction of the disulfides of the diketopiperazines with mercapto-ethanole is described. The ir-spectra of the cyclo-dipeptides and their disulfides were studied with regard to interactions of the functional groups. The spectra indicate a strong hydrogen bridge between the OH-groups of c-cys-ser-disulfide and interactions between the SH and other functional groups of the above mentioned diketopiperazines. The kinetics of the reaction of cysdiketopiperazines with N-ethylmaleimide and p-nitro-phenylacetate were studied. The SH-groug of cys-diketopiperazines has a greater nucleophilic reactivity towards p-nitro-phenylacetate than was expected on the basis of the pKSH-values.
Konzentration einiger Lipide in den Chloroplasten von Zea mays und Antirrhinum majus / Concentration of Some Lipids in the Chloroplasts of Zea mays and Antirrhinum ma jus
Authors: Koenig Friederike
Published: February 2015

Stroma-containing chloroplasts from Zea mays and Antirrhinum majus were isolated in aqueous medium. The average dry weight of chloroplasts from Zea mays is 27·10-12 g, that of Antirrhinum majus 30·10-12 g. Water freed chloroplasts consist up to 49 or 45 percent respectively of lamellar system. The lipid content of the lamellar system of Zea mays is 49 percent, that of Antirrhinum majus 45 percent. A chloroplast of Zea mays contains on the average 920·106 chlorophyll molecules, 220·106 carotenoid molecules, 2000·106 molecules of galactolipids, 190·106 molecules of sulpholipid, 260·106 phosphatide molecules and 64·106 molecules of lipophilic quinones. In addition to phosphatidylglycerol also phosphatidylinositol and phosphatidylcholine were found. It is very probable that besides vitamin K1 the homologeous compound lacking one methylgroup is present in the chloroplasts. In contrast to the literature only 62 percent of the total leaf galactolipids are found in the chloroplasts.
Beiträge zur Chemie des Hydrazins und seiner Derivate, XXX / Über die Umsetzung von Hydrazin und 1.2-Dimethylhydrazin mit Dichlordisulfan / The Reaction of Hydrazine and 1,2-Dimethylhydrazine with Dichlorodisulfane
Authors: Lingmann Herbert , Linke Karl-Heinz
Published: February 2015

Hydrazine in ethereal solution is oxidized to nitrogen by means of dichlorodisulfane, while the sulfane is reduced to sulfur. Intermediates of the oxidation of hydrazine could not be observed. By reaction of 1,2-dimethylhydrazine with dichlorodisulfane tetramethyl cyclotetrasulfurdihydrazide has been obtained.
Untersuchungen über das Verhalten von Graphitelektroden in nichtwäßrigen Elektrolyten / Investigation of the Behaviour of Graphite Electrodes in Nonaqueous Electrolytes
Authors: Besenhard Jürgen , Fritz Heinz P.
Published: February 2015

The behaviour of graphite electrodes in organic electrolytes sufficiently stable to oxidation (e. g. LiClO4 in propylene carbonate) has been investigated by potentiostatic and galvanostatic measurements.

Strongly oxidising products are obtained by electrochemical oxidation of graphite in such electrolytes; this reaction shows good reversibility and charge efficiency. The results point at the existence of graphite intercalation compounds.
Über das Vorkommen von 3-(1′.1′-Dimethylallyl)-scopoletin in Gewebekulturen von Ruta graveolens / The Occurrence of 3- (1′,1′-dimethylallyl) -scopoletin in Tissue Cultures of Ruta graveolens
Authors: Von Brocke Wolfgang , Reinhard Ernst , Nicholson Graeme , König Wilfried A.
Published: February 2015

In tissue cultures of Ruta graveolens the new coumarin 3- (1′,1′-dimethylallyl) scopoletin (1) was found by combined gaschromatography-mass-spectrometry. The mass-spectra of 1, of its TMSi-derivative and of an isomer of 1 are discussed. 1 has not been observed so far in plants and tissue cultures of Rutaceae.
85. Mitteilung über Flechteninhaltsstoffe
Authors: Huneck Siegfried , Schreiber Klaus , Snatzke Günther , Fehlhaber Hans-Wolfram
Published: February 2015

From Lecidea lilienstroemii D. R. and Lecidea leucophaea (Flk.) Nyl. has been isolated the new depside miriquidic acid, the structure of which is 4-[2-hydroxy-6-(3-oxo-n-pentyl) -p-anisoyl] -6-n- pentyl-β-resorcylic acid (1).
Control of Fatty Acid and Lipid Biosynthesis in Euglena gracilis by Ammonia, Light and DCMU
Authors: Pohl P. , Wagner H.
Published: February 2015

When Euglena gracilis was grown under white (fluorescent) light in media containing high concentrations of ammonium chloride (more than 0.005%), the main lipids synthesized were monogalactosyl diglyceride, digalactosyl diglyceride, phosphatidyl glycerol, sulfolipid and the all cis △7,10-16:2, △7,10,13-16:3, △4,7,10,13-16:4, △9,12-18:2 and △9,12,15-18:3 fatty acids. At low levels of ammonium (less than 0.002%) these compounds were produced only in small amounts, while neutral lipids, phosphatidyl choline, phosphatidyl ethanolamine and the 14:0, 16:0 and 16:1 fatty acids predominated.

When Euglena gracilis was grown in white light in the presence of dichlorophenyldimethylurea (DCMU) or in the dark, fatty acid and lipid biosyntheses followed the same pattern as in white light at low levels of ammonium. Similar results were obtained when nitrate served as the only nitrogen source in the light and in the dark.

The results indicate that in Euglena gracilis there are a light independent and a light and ammonium dependent pathway of fatty acid biosynthesis. Both pathways seem to be in association with specific lipids.
Influence of UV-Light on Gene-Conversion in Neurospora
Authors: Hammerl Hans , Klingmüller Walter
Published: February 2015

1. Crosses between wild type (dark ascospores) and the asco-mutant (light ascospores) were set up and the spores collected as unordered octads. The analysis of 1317 such octads revealed 69 with abnormal segregation of the asco-marker (5.2%). If crosses were irradiated with UV at a dose equivalent to 66% conidial killing, an increase of the number of aberrant octads was found. This increase was most pronounced if the crosses were exposed to the irradiation from one day before to 2 days after plasmogamy, when up to 8.7% aberrant octads were obtained. No effect was observed from 4 days after plasmogamy until the end of the sexual cycle.

2. The relative frequency of the 8 possible types of aberrant octads was analyzed separately for experiments without and for experiments with UV-irradiation. The distribution of these frequencies was the same for unirradiated and irradiated crosses, a finding which suggests that the conversion mechanism acting spontaneously and that acting upon UV-irradiation may be identical. In both cases, there was a strong bias in favour of octads of the 2 : 6 type (giving wild spores first) as compared to such of the 6: 2 type, also the frequency of the 0 : 8 type was higher than that of the 8 : 0 type. Hence, the conversion mechanism in this cross “prefers” to act from the wildtype to the mutant allele.
Growth Regulation Specificity Exhibited by Substances Present in the Fruit Pulp of Citrullus lanatus (Thunb.) Mansf.
Authors: Bhandari M. C. , Sen D. N.
Published: February 2015

The specific effect of the extract from the fruit pulp of Citrullus lanatus was demonstrated on the seed germination and seedling growth of Citrullus lanatus, Citrullus colocynthis and Pennisetum typhoideum. The extract from C. lanatus inhibited the germination of its own seeds, but promoted that of the other two species. The promoting substance for the growth of root and shoot was found at Rf 0.66.
Schwingungsspektren von komplexen Boraten.
Authors: Frey K. , Funck E.
Published: February 2015

The aim of the investigations was the characterization of the polyborates, as far as IR-spectroscopy is concerned. The investigations covered the absorption spectra of different pentaborates, including those substituted by 10B-, 11B-, and H-D-isotopes, as well as the reflection spectra of potassium-pentaborate single crystals with polarized radiation. The concept of group frequency analysis was successfully applied to the interpretation of the pentaborate-spectra; almost all bands were attributed to vibrations of the BO3, BO4 and OH units.
Di-μ-halogeno-bis(tricarbonyleisen): Über die Bildung dimerer Halogeneisentricarbonyle bei der thermischen und photochemischen Umsetzung von Eisencarbonylen mit Halogenwasserstoff / Di-μ-halogen-bis (tricarbonyliron) : Formation of Dimeric Halogen Iron Tricarbonyls in the Thermal and Photochemical Reaction of Iron Carbonyls with Hydrogen Halides
Authors: Gustorf E. Koerner Von , Hogan J. C. , Wagner R.
Published: February 2015

The hitherto unknown dimeric halogen iron tricarbonyls [Fe(CO)3X]2 (X = Br, I) have been prepared by reacting HBr or HI with Fe2(CO)9 and by the photoreaction of Fe(CO)5 with HBr. The properties of these compounds are discussed.
The N-terminal Amino Acid Sequence of Sheep Heart Myoglobin
Authors: Vötsch Walter , Anderer F. Alfred
Published: February 2015

The N-terminal amino acid sequence of residues 1—50 of sheep heart myoglobin was determined using the automatic Edman degradation procedure. The amino acid phenyl-thiohydantoins were identified by thin layer chromatography and/or by mass spectrometry.
Autoradiographische Untersuchungen zur Proteinsynthese während der Frühentwicklung von Dermestes frischi (Coleoptera) / Autoradiographic Investigations on Protein Synthesis During Early Development of Dermestes frischi (Coleoptera)
Authors: Küthe H. W.
Published: February 2015

Injection of tritiated phenylalanine or leucine in eggs shortly after deposition shows the importance and use of free amino acids during cleavage stages. First the activity is found homogeneously distributed in the yolk system and ooplasm. In late cleavage stages the amino acids are incorporated into the periplasm of the egg. These results lead to the conclusions, that there is a continuous transfer of material out of the yolk system into cortical regions during cleavage. Secondly the first new synthetized protein fractions are located in the cortical ooplasm.
Light Scattering and Flow Dichroism Studies on DNA After the Photoreaction with Psoralen
Authors: Marciani S. , Terbojevic M. , Dall’Acqua F.
Published: February 2015

Light scattering measurements performed on DNA after irradiation in the presence of psoralen clearly show that inter strand cross linkings are present in the macromolecule. In fact after heat denaturation and successive cooling irradiated macromolecule shows a molecular weight practically unchanged while a DNA sample after the same treatment shows a molecular weight half of the intact native DNA. Also the general conformation of irradiated DNA undergoes practically to no modifications after the same heat treatment while native DNA shows itself to have been strongly modified. Moreover, on the basis of flow dichroism determinations, DNA cross-linked by psoralen after heat denaturation showed to be able to restore its ordered double helix structure, during the successive cooling.
Interactions of Concanavalin A with the Membrane of Influenza Virus Infected Cells and with Envelope Components of the Virus Particle
Authors: Rott R. , Becht H. , Klenk H.-D. , Scholtissek C.
Published: February 2015

Treatment of host cells with Concanavalin A prevents the assembly or release of fowl plague virus from chick fibroblasts and inhibits fusion of BHK cells by the paramyxovirus SV5. Metabolic events of the host cells are not greatly impaired during the early phase of infection. There is evidence that the carbohydrate moiety of the Con A receptor of fowl plague virus is associated with the viral neuraminidase.
Serum Hepatitis and the Seroprophylaxis of Measles
Authors: Waterson A. P.
Published: February 2015

The events leading to the recognition of serum hepatitis (“homologous serum jaundice”) as a disease entity are described and reasons given why seroprophylaxis against measles played an important role in this discovery. The injection of human serum as a prophylactic was practised on an increasing scale from about 1920 to about 1950, by which time it had largely been superseded by immunoglobulin (gamma globulin). Apart from the transfusion of blood and blood products the other major human to human transfer of material was vaccination against yellow fever in the years 1937 - 1940. The consequences of this large scale interchange between human subjects included the dissemination of serum hepatitis virus, and the possibility of transfer of other viruses is discussed.
Quantitative Selection of Respiratory Deficient Mutants in Yeasts by Triphenyltetrazolium Chloride
Authors: Bachofen V. , Schweyen R. J. , Wolf K. , Kaudewitz F.
Published: February 2015

Triphenyltetrazolium chloride exhibits a strong growth inhibition in respiratory competent cells but shows only minor effects in respiratory deficient mutants of Saccharomyces cerevisiae and Schizosaccharomyces pombe. Use of this dye thus allows rapid selection of rarely occurring respiratory deficient mutants, showing karyotic as well as extrakaryotic inheritance. Mutation induction by tetrazolium chloride was not observed. The results favour the hypothesis that triphenyltetrazolium chloride interferes with the terminal oxidase of the respiratory chain.
In Vitro Studium der Trägerproteine von 3H-markierten juvenilhormonwirksamen Verbindungen in der Hämolymphe von Tenebrio molitor L. Larven / In Vitro Study of the Carrier Proteins of 3H-labelled Juvenile Hormone Active Compounds in the Haemolymph of Tenebrio molitor L. Larvae
Authors: Trautmann K. Heinz
Published: February 2015

The labelling of Methyl 7,11-dichloro-3,7,11-trimethyl-2-dodecenoate and Methyl 10,11-epoxy-3,7,11-trimethyl-2-cis/trans-dodecenoate with tritium by methylation of the acids with diazomethane in the presence of carrier-free tritium water and the hydrogenation of 10,11-Epoxy-6,7-cis-2,3-trans/cis-farnesyl propynyl ether with titrium gas gave high spec. radioactivities (3.7; 0.49 and 25 Ci/mMol).

The strong binding of these hormones to the haemolymph proteins of white newly moulted and of colored larvae was demonstrated by gelfiltration with sephadex G-25.

The disc-electrophoretic identification of the carrier proteins in the haemolymph of colored larvae showed that the hormones are approximately total bound by the hormone binding factor of a lipoprotein band.

In the haemolymph of white newly moulted larvae there is a second hormone binding band beside the lipoprotein band with similar binding capacity.
Pteridine and Riboflavin Patterns During Tail Regeneration in Triturus Species and the Effects of Chloramphenicol, Isoxanthopterin and Reserpine
Authors: Kokolis Nikos , Mylonas Nikos , Ziegler Irmgard
Published: February 2015

In Triturus cristatus amputation causes the reappearance of larval tetrahydrobiopterin, thus raising the ratios tetrahydrobiopterin/isoxanthopterin and tetrahydrobiopterin/riboflavin from zero to values between 3-5. This increase first occurs in the remaining skin and in the eyes. The increase of both ratios in the regeneration bud, beginning with the 20th day after amputation, coincides with their drop in both other tissues. Chloramphenicol and isoxanthopterin both strongly inhibit the formation of a regeneration bud. They also block the increase of both ratios in the remaining skin and in the rudimental regenerate as well. Reserpine induces regenerative ability in Triturus vulgaris, which normally lacks this. It has a strong melanizing effect and, moreover, it causes an increase of both ratios in the regeneration bud and in the remaining skin.
ESR-spektroskopische Untersuchung der Deprotonierung von Dibenzolchrom(I)-Kation / ESR-Study of the Deprotonation of Bisbenzenechromium (I)-Cation
Authors: Elschenbroich Ch. , Gerson F. , Heinzer J.
Published: February 2015

Reaction of bisbenzenechromium (I)-cation with strong bases yields - in addition to diamagnetic products - a paramagnetic species for which the structure of (π-C6H6) Cr⊕ (π-C6H5
⊖) is suggested on the basis of ESR spectroscopic evidence. The ESR spectrum also indicates an intramolecular, interannular proton exchange with a frequency of the order 107 sec-1.
Grundschaltungen von flüssigen Automaten und Relaxationssystemen / Basic Circuits of Fluid Automata and Relaxation Systems
Authors: Rössler Otto E.
Published: February 2015

Homogeneous reaction systems showing automatic dropping-down behaviour have become known only recently. A synopsis of the so far devised basic circuits (i. e. prototype reaction systems) is presented. It is observed that the abstract design of these systems follows especially simple rules: They can be composed after the building-block principle from simpler flipping-systems. This is in accordance with the mathematical theory of these systems. An eventual technological significance of the presented class of chemical systems seems possible.
Photochemische Synthese von Pinocarvon-, Pulegon- und Benzalacetophenon-tricarbonyleisen. Ein Beitrag zur Frage der Bindung α, β-ungesättigter Ketone in Eisen-Komplexen / Photochemical Synthesis of Pinocarvone-, Pulegone-, and Benzalacetophenone-tricarbonyliron. A Contribution to the Nature of Bonding in Iron-Complexes of α,β-unsaturated Ketones
Authors: Koerner Von Gustorf E. , Grevels F.-W. , Krüger C. , Olbrich G. , Mark F. , Schulz D. , Wagner R.
Published: February 2015

The photochemical synthesis of the title compounds is described. It has been established by spectroscopic evidence and by the x-ray structure of pinocarvone tricarbonyliron that in all these cases bonding to the iron involves only the π-system of the α,β-unsaturated ketones and not the nonbonding electrons of the keto group. The preferential site of monodentate coordination of α,β-unsaturated carbonyl compounds to transition metals is discussed on the basis of MO-considerations which are extended to 1,2-dicarbonyl compounds.
Synthesis and Studies of some Substituted Naphthalides
Authors: Singh E. , Gupta P. C.
Published: February 2015

A number of naphthalides in which the central carbon (C*) atom is attached to different rings obtained by condensation of phenols with 3-benzoyl-2-naphthoic acid are described. The constitution of the dyes has been studied and the visible UV and IR spectra have been presented and discussed. The absorption maxima of the dyes have been found to be shifted like those of phthaleins.
Ist die Gompertzsche Absterbeordnung durch eine exaktere zu ersetzen? / Is the Gompertz’s Law of Mortality to be Replaced by a more Accurate One?
Authors: Sippel Arnulf
Published: February 2015

A novel law of mortality, discovered by the author, is compared with the Gompertz’s law with special regard to deviations (from the observed data), which turn out to be three times larger in the case of the Gompertz’s law.
Röntgenkleinwinkelstudien über die Substruktur von Helix pomatia Hämocyanin / Small-Angle X-Ray-Scattering Studies on the Substructure of Helix pomatia Hemocyanin
Authors: Pilz Ingrid , Glatter Otto , Kratky Otto
Published: February 2015

Hemocyanin of the snail helix pomatia was studied by small-angle X-ray scattering in 0.15 M phosphate buffer pH 6.

The outer portion of the scattering curve showed minima, which indicated that the hemocyanin molecule is composed of a large number of identical (or very similar) nearly spherical subunits. From the position of the minima the radius of gyration Ru of the subunit was calculated to be 1.55 nm; this corresponds a diameter of 4 nm assuming a spherical shape. The number of the subunits is discussed, too; a number of 330 can be given as lower limit, a number of 528 as upper limit (most propable value 350 — 400).

Various models were put up by arranging the subunits (diameter 4 nm) in different ways to hollow cylinders. The theoretical scattering curves of these models were compared with the experimental one and a model equivalent in scattering is suggested for the hemocyanin Helix pomatia.

In this model, which fits very well to the experimental curve, 360 subunits form a hollow cylinder. The model shows also the essential features found by electron microscopy by VAN BRUGGEN. The essential features are an arrangement of the subunits in 6 layers vertical to the cylinder axis and a 5-fold screw axis parallel to it.
Über die Umsetzung von Benzylmalonylchlorid mit verschiedenen Natriumsalzen von Carbonsäuren / The Reaction of Benzylmalonyl Chloride with Sodium Salts of Carboxylic Acids
Authors: Wittmann Helga , Rathmayr Helmut
Published: February 2015

Benzylmalonyl Chloride reacts in the presence of sodium acetate in boiling benzene to give tribenzyl-phloroglucinol-triacetate, however with sodium chloroacetate to 3,5-dibenzyl-6-phenethylpyran-2,4-dion. In both cases trimerisation of benzylketene or benzylketene carboxylic acid chloride occurs. On the other hand, benzylmalonylchloride reacts with sodium benzoate and sodium phenylacetate via a dimeric benzylketene carboxylic acid chloride under the loss of phosgene to yield cyclopentadienyl derivatives.
Studies on the Mechanism of the Photosensitized Dimerization of Pyrimidines
Authors: Kornhauser A. , Pathak M. A.
Published: February 2015

Thymine-2-14C was irradiated with UV light (>300 nm) in water solutions in the presence of different sensitizers. Pyrimidines upon irradiation with wavelengths of 300—320 nm in the presence of some ketones as sensitizers, yield cyclobutyl pyrimidine dimers. The reaction occurs through a triplet-triplet energy transfer from the sensitizer to the substrate. The energy transfer, however, does not occur through a simple physical mechanism. The ability of a donor (e. g. ketone molecule) in its excited state to form a complex with the acceptor (pyrimidine molecule) appears to be a prerequisite in this type of photodimerization reaction. A correlation of the photochemical behavior of different ketones in this reaction with the nature of their excited states has been proposed. Carbonyl compounds possessing n, π* lowest triples are active in inducing pyrimidine dimerizations. By introducing some different electron donating groups to the ketone molecules that lower its π, π* state below its n, π* level, the sensitizing ability of the molecule appears to decrease or disappears completely. Ethylacetoacetate was found to be a more effective sensitizer than acetone or acetophenone. Likewise, dihydroxyacetone was found to be a potent photosensitizer in dimerization of thymine. Urocanic acid (UCA), a major UV absorbing compound in mammalian skin, did not show any sensitizing ability to induce cyclobutyl pyrimidine dimers on irradiation in the presence of thymine, with wavelengths greater than 300 nm.
Zur Kenntnis der Dihalogen-tris-(4-dimethylamino-phenyl)-Verbindungen von Phosphor, Arsen, Antimon und Wismut / Dihalogeno-tris- (4-dimethylamino-phenyl) -Compounds of Phosphorus, Arsenic, Antimony, and Bismuth
Authors: Keck Jörn-Michael , Klar Günter
Published: February 2015

The synthesis of the dihalogeno-tris-(4-dimethylamino-phenyl)-compounds Ar2EX2 (E = P, As, Sb; X = Cl, Br, J and E = Sb, X = F; E = Bi, X = Cl) is described. A generally valid correlation between the chemical shift of the n.m.r. signal of an atom and the atomic parameters electronegativity and principal quantum number of valence electrons is deduced.
Darstellung und Eigenschaften der Tris-(4-dimethylamino-phenyl)-arsen(V)- und -antimon(V)-Kationen / Synthesis and Properties of the Tris- (4-dimethylamino-phenyl) -Arsenic (V) - and -Antimony (V) -Cations
Authors: Keck Jörn-Michael , Klar Günter
Published: February 2015

The synthesis of a new type of organometallic compounds with a group VB element and the composition Ar3E2+ (Ar = 4-dimethylamino-phenyl; E = As, Sb) in which this element has the oxidation state +5 and the coordination number 3 is reported. In accordance with the electronic and n.m.r. spectra it is assumed that the electronic structure of these intensive blue cations is similar to that of the isoelectronic cation of crystal violet.
Adsorption of Triphenyl Phosphine Oxide at the Dropping Mercury Electrode in Methanolic Solutions
Authors: Gupta S. L. , Holleck L.
Published: February 2015

Triphenyl Phosphine Oxide (TPO) which is known as a strong inhibitor of electrode processes in aqueous solutions is progressively adsorbed at the dme from methanol in the potential range -0.5 to -1.3 volts as compared with water, -0.15 to -1.6 volts (Ag/AgCl), for the concentrations studied. Adsorption activity as well as the sharpness of the desorption peak of TPO decrease in the order: water > 50% methanol > methanol and the adsorption region contracts as the solvent is changed from water to methanol. Adsorption isotherms in methanol and 50% methanol follow Langmuir's equation with adsorption coefficients equal to 1.58 x 102 l/mole and 1.62 x 104 l/mole respectively.
UV-Photolyse von 5-Joduracil, IV Reaktionen des Uracilradikals mit primären und sekundären Alkoholen in wäßriger, sauerstoffgesättigter Lösung / Photochemistry of 5-Iodouracil in Aqueous Oxygenated Solution in Presence of Primary and Secondary Alcohols
Authors: Gilbert E. , Wagner G.
Published: February 2015

UV-Photolysis (λ=254 nm) of 5-iodouracil in aqueous oxygenated solution in presence of ethanol, ethylene glycol and i-propanol was investigated at pH = 6. Isodialuric acid, uracil, H2O2 and iodine were found in all solutions. In addition to the above products in presence of ethanol, ethylene glycol and i-propanol acetaldehyde, glycolaldehyde and acetone respectively were formed. The yields of these products were determined as a function of the alcohol concentrations. The results suggest that the primary step is a homolytic splitting of the C-I-bond forming a uracil radical and an iodine atom. The uracil radical reacts with oxygen to form isodialuric acid and with alcohols to give uracil and an alkylhydroxyradical. The ratio of the rate constants between the addition of oxygen and the H-atom abstraction of the uracil radical has been determined for the following H-donors: ethanol, ethylene glycol, i-propanol and glycerine (Table 1). The reactions of the alkylhydroxyradicals with oxygen give the corresponding aldehyde or ketone respectively and H2O2. In the absence of oxygen the UV-photolysis of iodouracil in the presence of i-propanol leads to uracil, acetone and iodide. Consideration of the material balance leads to a reaction scheme which explains all the final products.
Pulsradiolytische Untersuchung zur Oxidation der Ascorbinsäure durch OH-Radikale und Halogen-Radikal-Komplexe in wäßriger Lösung / Pulse Radiolysis Studies of the Oxidation of Ascorbic Acid by OH-radicals and Halide Radical Anion Complexes in Aqueous Solution
Authors: Schöneshöfer M.
Published: February 2015

Ascorbic acid is oxidized by the OH radical and by radical anion complexes X2⁻ (X: Cl, Br, J, SCN) to yield the “ascorbic acid radical”

which finally disappears by second order. The pK of this radical was found to be about 3. It has several precursor radicals formed by the addition of OH or X to ascorbic acid. They lose H2O or HX, respectively, with different rates or are desactivated in radical-radical reactions. The precursor radicals are acids of different pK values. Since ascorbic acid exists in two tautomeric forms in aqueous solution, two precursor radicals are postulated for the reaction of OH with ascorbic acid:

They lose water or OH⁻ with different rates to form the ascorbic acid radical. The absorption spectra of these species were measured. All radicals including the ascorbic acid radical have strong absorption at 3600 A, although somewhat different extinction coefficients. The decay of the 3600 A absorption in the 100 μs and millisecond range, which in earlier work of BIELSKI et al. 3 has been attributed solely to the disappearance of the ascorbic acid radical is partly due to the loss of water of long-lived precursors and to radical-radical desactivation of precursors and the ascorbic acid radical. Earlier conclusions of BIELSKI et al. about the pK of the ascorbic acid radical and about its protonization cannot be confirmed taking into consideration the complex precursor reactions. The kinetics is strongly dependent on the dose below about 400 rad. The precursor radicals formed by the addition of X to ascorbic acid are generally shorter lived than the OH addition precursors.
Synthese und biochemische Eigenschaften von heterocyclischen Thioäthern des 2-Chlor-6-mercaptopurins / Synthesis and Biochemical Properties of Heterocyclic Thioethers of 2-Chloro-6-mercaptopurine
Authors: Niebch G. , Schneider Fr.
Published: February 2015

The synthesis of the following thioethers of 2-chloro-6-mercaptopurine is described: 2-chloro-6-[4-phenyl-imidazole-2-thio] purine; 2-chloro-6- [4-guanidopropyl-imidazole-2-thio] purine; 2-chloro-6-[4-t.butyl-thiazole-2-thio] purine; 2-chloro-6- [4-phenyl-thiazole-2-thio] purine; 2-chloro-6- [4-methylthiazole-2-thio] purine; 2-chloro-6- [4-carbethoxymethyl-thiazole-2-thio] purine; 2-chloro-6- [4-carboxamido-5-amino-thiazole-2-thio] purine; 2-chloro-6- [5-phenyl-thiadiazole (1,3,4) -2-thio] purine; 2-chloro-6- [5-t.butyl-thiadiazole (1,3,4) -2-thio] purine; 2-chloro-6- [tetrazole-5-thio] purine. The thioether bond of these compounds is cleaved by nucleophilic agents especially by mercaptanes under mild conditions. The compounds are not metabolized by ascites cells and preferentially bound to the cell surface. They are inhibitors of DNA-, RNA-, and proteinsynthesis and of proliferation of Ascites cells in a different degree; the ascites carcinoma of mice was not influenced. A possible mechanism of action of their metabolic effects is discussed.
Das Bürzeldrüsensekret der Dreizehenmöwe (Rissa tridactyla) / The Uropygial Gland Wax from the Kittiwake (Rissa tridactyla)
Authors: Jacob J. , Zeman A.
Published: February 2015

The uropygial gland fat from the kittiwake is a complex mixture of ester waxes. As acidic components mainly n-octanoic acid and 2-methyl-substituted fatty acids are found. Besides 2,6-, 2,3 and 2,10-dimethyl-substituted fatty acids could be detected.

Among the alcoholic components n-, 2-methyl-, 2,6-, 2,8-, 2,10- and 2,12-dimethyl-substituted primary alkanols were observed.

Chemotaxonomically the kittiwake should be placed between the puffin and the limicoles.
Synthese und Umsatz von Ribonukleinsäuren in suspendierten Säugetierzellen / Synthesis and Turnover of Ribonucleic Acids in Suspended Mammalian Cells
Authors: Trams Günther , Vollertsen Ingeborg , Koch Gebhard
Published: February 2015

The influence of ionizing radiation on the turnover of high molecular weight RNA in mammalian cells was studied. Growing cultures of suspended human amnion cells were labeled with 32P and irradiated with different doses of X-rays. RNA was isolated by hot phenol and the high molecular weight RNA fractionated by chromatography on methylated serum albumin celite columns. The salt gradient eluted RNA with sedimentation coefficients of 16 S or greater, which were characterized by analysis of nucleotide composition.

Irradiation with doses from 900—6000 R results in degradation of pre-labeled RNA. A quantitative determination reveals that more 32P-radioactivity leaves the high molecular weight RNA compared to labeled total material that is degraded to acid soluble products. This indicates that RNA is partly broken down to low molecular weight fragments.

Nucleotide analysis of the high molecular weight RNA fractions indicate a preferred degradation of ribosomal precursor RNA.

The experimental results give evidence that the analysis of RNA synthesis for a certain period after irradiation is complicated by interfering processes like the simultaneous degradation of RNA.
The Coordination Chemistry of Phosphoryl Compounds Containing the — N(CH3)2 Group, Part VIII
Authors: De Bolster M. W. G. , Groeneveld W. L.
Published: February 2015

A number of new solvates and adducts containing bisphenyldimethylaminophosphine oxide is reported. The solvates have the general formula M[(C6H5)2P(O)N(CH3)2]4
2+(anion-)2, in which M = Mg, Ca, Mn, Fe, Co, Ni, Cu, Zn and Cd, and the anions are ClO4
- and BF4
-. The adducts have the general formula M[(C6H5)2P(O)N(CH3)2]2Cl2, where M stands for the same series of metals.

The compounds are characterized and identified by chemical analyses and physical measurements.

Ligand-field and vibrational spectra have been investigated; values for the ligand-field parameters are reported. It is concluded that coordination takes place via the oxygen atom of the ligand.

X-ray powder patterns were used in combination with ligand-field spectra to deduce the coordination around the metal ions.

The interesting behaviour of the nickel (II) chloride adduct upon heating is discussed and it is shown that both a square pyramidal and a tetrahedral modification exists.
Nematische Systeme, V
Authors: Steinsträsser Ralf
Published: February 2015

One unsymmetricly p,p′-disubstituted trans-stilben and more than 60 new phenylbenzoates are described (Tab. 1). These compounds show partly enantiotropic, partly monotropic nematic behaviour. Some low melting substances and especially eutectic mixtures of this class of compounds are useful as room-temperature nematic, colourless liquids for electro-optical applications.
Acridin-Alkaloide aus Kalluskulturen von Ruta graveolens L. / Acridine-Alkaloids from Callus Cultures of Ruta graveolens L.
Authors: Scharlemann Wolfgang
Published: February 2015

Rutacridone, 1-hydroxy-N-methylacridone, and 1-hydroxy-3-methoxy-N-methylacridone have been isolated for the first time from callus cultures, which had been obtained from meristematic stem cells of Ruta graveolens L. The alkaloids were identified by co-chromatography with authentic compounds, by IR spectra, and by electronic spectra before and after addition of AlCl3. The use of the bathochromic shift by the AlCl3-complex in the analysis of acridine-alkaloids has been demonstrated for the first time.
Thionicotinamide-NADP, a Nucleotide Analog Interfering with Ferredoxin-NADP Reductase/Ferredoxin Interaction
Authors: Böger Peter
Published: February 2015

Diaphorase and transhydrogenase activities (system NADPH; dichlorophenolindophenol and NADPH;NAD, respectively) of ferredoxin-NADP reductase are increased by ferredoxin. Reduced thionicotinamide-NADP (TN-NADPH) only slightly inhibits these activities with no ferredoxin present in the assay, but the activity increments in the presence of ferredoxin are strongly decreased. Photosynthetic pyridine nucleotide reduction is also inhibited by the reduced analog, the extent of inhibition being approx. in the same order with all three activities. The ferredoxin stimulated activities therefore appear to be due to the same interaction between reductase and ferredoxin in all three cases.

The inhibition by TN-NADPH resembles that with Na-pyrophosphate (or NaCl), although in contrast to salt inhibition it is a.) not alleviated by higher ferredoxin concentrations, and b.) it still allows reductase/ferredoxin binding.

The binding of the reduced pyridine nucleotide analog to the reductase seems to interfere rather specifically with the stimulation which ferredoxin can exert on the enzymic activities of the reductase.
Infrared Spectrum and Vibrational Assignment of Diazocyclopentadiene-h4 and -d4
Authors: Cataliotti R. , Poletti A. , Paliani G. , Foffani A.
Published: February 2015

Infrared spectra of Diazocyclopentadiene-h4 and -d4 in the liquid and vapour phases were studied and almost all fundamental vibrations of the light molecule were assigned on the basis of vapour phase band profile and H/D isotopic shift ratio.
Phosphorus-Fluorine Chemistry, XXXI
Authors: Hewson M. J. C. , Schmutzler R.
Published: February 2015

The preparation of a series of methyl-substituted piperidyl-fluorophosphoranes is described, of general formula RR′NPF4-nPhn (where RR′N = 2-Me-piperidyl-, 3-Me-piperidyl-, or 4-Me-piperi-dyl; n = 0, 1, or 2), from the cleavage of silicon-nitrogen bonds in methyl-substituted piperidyl silanes by fluorophosphoranes. The structures of the new compounds are deduced from 19F and 31P n.m.r. data.
Über den Einfluß von Chlor-Substituenten auf die Bindungsverhältnisse im Tricarbonyl(buta-1.3-dien)eisen: Tricarbonyl(trichlor-buta-1.3-dien)eisen / The Effect of Chloro-Substituents on Tricarbonyl (buta-1,3-diene) iron Complexes: Tricarbonyl (trichloro-buta-1,3-diene) iron
Authors: Brune Hans Albert , Horlbeck Gernot , Müller Paul
Published: February 2015

Attempts to synthesize trichloro-substituted buta-1,3-diene-irontricarbonyl complexes are reported. While from trans-1,2-dichloro-3-chloro-buta-1,3-diene and trans-1,2-trans-4-trichloro-buta-1,3 -diene and triirondodekacarbonyl the correspondingly substituted tricarbonyl (buta-1,3-diene) iron complexes are obtained, 1,1-trans-4-trichloro-buta-1,3-diene under similar conditions does not form an irontricarbonyl complex.
Zur Konjugation in makrocyclisdien Bindungssystemen, XXI1
Authors: Ege G. , Vogler H.
Published: February 2015

For the corannulenes 1 to 7 the mean susceptibilities χm, exaltations A and benzene increments Δ̅ are calculated. For all the corannulenes 1 to 7 the exaltation A is > 12 [10-6 cm3 Mol-1] and consequently these hydrocarbons fulfil the criterium of aromaticity of DAUBEN, WIL-SON and LAITY 2.
Die Flavon-C-glykoside von Viola tricolor L. / The Flavone-C-glycosides of Viola tricolor L.
Authors: Wagner H. , Rosprim L. , Düll P.
Published: February 2015

For a flavone-di-glycoside from a garden variety of Viola tricolor L. the structure 5,7,4′-Trihydroxyflavone-6-C-β-ᴅ-glucopyranosyl-8-C-α-ʟ-rhamnopyranoside was elucidated using mainly perjodate oxidation, NMR- and mass-spectroscopy.

From the same plant besides the mono-C-glucosides Vitexin, Saponaretin, Orientin and Isoorientin four Apigenin-di-C-glycosides were isolated, one of them proved to be identical with Vicenine-2.
Studies on Esterases Levels in Various Tissues of Uromastix Hardwickii during Activity and Hibernation
Authors: Farzana Farida , Hasnain S. N.
Published: February 2015

Esterases, acetylcholinesterase and cholinesterase activities were determined in various tissues of Uromastix hardwickkii during hibernation and activity.

1. The protein concentration was significantly reduced during hibernation.

2. The esterase activity in all the tissues was found to be significantly reduced during hibernation.

3. Acetylcholinesterase activity was significantly increased in all the tissues.

4. There was no significant difference in the cholinesterase activity duriing the two periods.

5. The specific activities of all the enzymes were found to be significantly increased during hibernation.
Differential Effect of Ethidium Bromide and Cytosine Arabinoside on Mitochondrial and Nuclear DNA Synthesis in HeLa Cells
Authors: Kato Kenzo , Radsak Klaus D. , Koprowski Hilary
Published: February 2015

The effect of ethidium bromide (EB) on the synthesis of circular DNA of mammalian cells was studied by isopycnic centrifugation in a CsCl-EB solution. EB (0.1—0.5 μg/ml) interferes with the synthesis of newly-formed circular DNA of HeLa cell mitochondria and causes degradation of the pre-existing circular DNA, as well. Under the same conditions, nuclear DNA synthesis was not inhibited. This effect was not reversible at a concentration of 0.5 μg EB/ml or more. Cytosine arabinoside (ara-C) did not exhibit an effect similar to that of EB.
Studies of Reactions between Flavins and Quinones, Mercaptans, and Enolates
Authors: Gibian Morton J. , Elliott D. Lauriston , Kelly Charles , Borge Brad , Kupecz Kirklen
Published: February 2015

A. Equilibrium and second-order rate constants have been measured for the redox reaction between phthaloquinone and dihydroriboflavin (and its reverse) at a number of pH values. The equilibria and kinetic determinations are in agreement. No intermediates could be found in the reaction, and it is proposed that with this and other quinones electron transfer occurs within a complex of the flavin and hydroquinone (or dihydroflavin and quinone). B. A survey of the reaction between mercaptans and flavins is reported, as well as data showing that with mercaptoethanol the reaction is reversible, the disulfide and reduced flavin giving mercaptan and flavin. C. The reaction of alkylphenone enolates with isoalloxazine is described. This reaction leads t 50% isoalloxazine radical anion and an adduct of the enolate with the ketone. A possible route for this process is discussed.
Nitroalkanes as Reductive Substrates for Flavoprotein Oxidases
Authors: Porter David J. T. , Voet Judith G. , Bright Harold J.
Published: February 2015

Nitroalkanes have been found to be general reductive substrates for D-amino acid oxidase, glucose oxidase and L-amino acid oxidase. These enzymes show different specificities for the structure of the nitroalkane substrate.

The stoichiometry of the D-amino acid oxidase reaction is straightforward, consisting of the production of one mole each of aldehyde, nitrite and hydrogen peroxide for each mole of nitroalkane and oxygen consumed. The stoichiometry of the glucose oxidase reaction is more complex in that less than one mole of hydrogen peroxide and nitrite is produced and nitrate and traces of 1-dinitroalkane are formed.

The kinetics of nitroalkane oxidation show that the nitroalkane anion is much more reactive in reducing the flavin than is the neutral substrate. The pH dependence of flavin reduction strongly suggests that proton abstraction is a necessary event in catalysis. A detailed kinetic mechanism is presented for the oxidation of nitroethane by glucose.

It has been possible to trap a form of modified flavin in the reaction of D-amino acid oxidase with nitromethane from which oxidized FAD can be regenerated in aqueous solution in the presence of oxygen.
D- and L-6-Hydroxynicotine Oxidase, Enantiozymes of Arthrobacter oxidans
Authors: Decker K. , Dai V. D. , Möhler H. , Brühmüller M.
Published: February 2015

D- and ʟ-hydroxynicotine oxidase were obtained in homogeneous form and compared with regard to molecular weight, subunit structure, reaction mechanism, and specificity. The most striking differences between these enantiozymes are the type of coenzyme binding and the reactivity towards artificial two-electron acceptors.
NADH Dehydrogenases from Azotobacter Vinelandii
Authors: Dervartanian Daniel V.
Published: February 2015

NADH dehydrogenases have been isolated in a low-molecular weight form (56,500) from both low-iron and normal-iron grown cells of Azotobacter vinelandii. Unlike low-molecular weight forms of NADH dehydrogenases reported from mammalian mitchondria, the enzymes in this study have not undergone any unusual alterations in various reactivities with substrates and electron acceptors. The NADH dehydrogenases from A. vinelandii do differ in cofactor cotent, light-absorption spectra and electron paramagnetic resonance spectra but show similar catalytic-center activities with substrates and electron acceptors. The relationship of these NADH dehydrogenases to site I oxidative phosphorylation in both the bacterial and mammalian systems is discussed.
Flavodoxin from the Sulfate Reducing Bacterium Desulfovibrio vulgaris. Its Structure at 2.5 A Resolution
Authors: Watenpaugh K. D. , Sieker L. C. , Jensen L.H. , Le Gall J. , Dubourdieu M.
Published: February 2015

Crystals of oxidized Desulfovibrio vulgaris flavodoxin have been studied by X-ray diffraction techniques. The structure has been determined at 2.5 A resolution. The molecule consists of a pleated sheet core with two sections of helix on each side of the sheet. The FMN group is distinguishable: it is mostly burried but 7- and 8-Methyl groups appear to be at the surface of the protein.
Untersuchungen an Salzhydraten, III.
Authors: Manewa M. , Fritz H. P.
Published: February 2015

IR and Raman spectra of LiBF4 · n H2O and LiBF4 · n D2O (n = 1, 3) and the normal vibrations of crystal water in the temperature range from 20° to - 125°C are reported. The hydrogen bond strength is correlated with relative force constants and thermogravimetric data.
Coordination Polymers of Some Trivalent and Tetravalent Metals
Authors: Saxena U. B. , Rai A. K. , Mehrotra R. C.
Published: February 2015

The reactions of ethoxides and isopropoxides of aluminium and titanium with bis (acetoacetates) in various molar ratios have been carried out. In all the cases, the treatment in the molar ratio 1 : 0.5 and 1 : 1.0 liberated one and two moles of alcohol respectively. The isopropoxy groups could be fully replaced only in the case of aluminium, when the reactions was carried out in higher molar ratio (1 : 1.5). However, even with excess of the ligand, the replacement of the fourth molecule of alcohol in case of titanium could not be accomplished.