bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanism of the Oxidation of Methyl n-Propyl Ketone by Manganese (III) Sulphate
Authors: Banerji K. K. , Nath P. , Bakore G. V.
Published: February 2015

The oxidation of methyl n-propyl ketone by Mn (III) sulphate in aqueous acetic acid is first order with respect to the ketone and Mn (III). The rate independent of acidity and solvent composition. Added Mn (II) does not alter the rate. The activation parameters for the oxidation and enolisation reactions were evaluated. The oxidation is faster than the enolisation under similar conditions. A mechanism involving an attack on the keto-form by Mn (III) sulphate complex is proposed.
On the Role of Plastoquinone in Photosynthesis
Authors: Böhme H. , Reimer S. , Trebst A.
Published: February 2015

Dibromothymoquinone and its hydroquinone are inhibitors of non cyclic electron flow from water to NADP, anthraquinone or methylviologen. The inhibition is competetively reversed by plastoquinone. It appears that dibromothymoquinone is an antagonist of plastoquinone and that it prevents the enzymic (by the next endogenous carrier of the chloroplast electron transport chain) but not the chemical (by ferricyanide) reoxidation of reduced plastoquinone. This follows from the result that the photoreduction of ferricyanide and DCPIP * is not inhibited by dibromothymoquinone in sonicated chloroplasts and is inhibited in intact chloroplasts to only 60% or 80% respectively. It is concluded that dibromothymoquinone does not inhibit photoreductions by photosystem II.

According to their response to dibromothymoquinone, cyclic photophosphorylations can be subdivided in those requiring plastoquinone and those which do not. Menadione catalyzed cyclic photophosphorylation is inhibited by dibromothymoquinone, whereas the PMS catalyzed system is not. The DAD cyclic system is only partly inhibited by dibromothymoquinone. The PMS catalyzed cyclic photophosphorylation in the presence of dibromothymoquinone is antimycin sensitive, which suggests that the PMS system can switch from a plastoquinone dependent system to a plastoquinone independent, but cytochrome b dependent system, which is now antimycin sensitive. Ferredoxin catalyzed cyclic photophosphorylation is inhibited by dibromothymoquinone as well as by antimycin. The data indicate that non cyclic electron flow through both photosystems is obligatory dependent on plastoquinone, whereas cyclic systems do not necessarily include plastoquinone. The relevance of the results to the possibility of different coupling sites in cyclic and non cyclic electron flow systems is discussed.
Optical Measurements of the Rapid pH-Change in the Visual Process during the Metarhodopsin I-II Reaction
Authors: Emrich H. M.
Published: February 2015

Absorption changes indicating the metarhodopsin I -II reaction and rapid pH-changes are measured as a function of pH in isolated bovine rod outer segments (ROS), using a rapid registrating flash photometer. An alkalization of the ROS-containing solution is observed which runs parallel to the metarhodopsin I -II reaction. In this process dissociable groups with pK-values at pH 6.3 and 10.5 are involved.
Evidence of the Participation of Deoxycholate in Cancer Immunity
Authors: Vlček B. , Reif A. , Seidlová B.
Published: February 2015

The hypothesis of cancerostatic activity of deoxycholic acid, recently outlined, is supported by correlation of natural cancer resistance with the level of deoxycholic acid in animals and humans. Analyses of sera indicate lower levels of unconjugated deoxycholic acid in cancer patients, the mean values of other bile acids being normal. Application of this theory to statistics of cancer incidence reveals possibilities of new aspects.
Über eine in-vivo-Methode zur Herstellung radioaktiv markierter Phosphatide mit Sojabohnen / A Method for Preparing Radioactive Labeled Phosphatides Using Soybeans in-Vivo
Authors: Hölzl J. , Wagner H.
Published: February 2015

Germinating soybeans, when incubated for 20-30 hours under an illumination at 25°-30° temp, with labeled 32P-phosphate, 14C-acetate, 14C-glycerol and 14C-choline, radioactivity ranging from 2 to 14% is incorporated into the main phosphatides lecithin (PC), phosphatidylethanolamine (PE) and monophosphoinositide (MPI). The incorporation of 32P-phosphate in these phosphatides depending on light and temperature, increases to its maximum (3.7 mCi/1 g soybeans) almost running linear and continues further even in the absence of any further germination due to intensive exposure to radiation.

14C-acetate is incorporated almost exclusively into fatty acids of the phospholipids during germination as a result of which highest specific radioactivity was seen in the stearic acid followed by oleic acid and palmitic acid. Linol- and linolenic acid under these experimental conditions are weakly or not labeled, 14C-choline is incorporated only in PC. As the PC after 14C-(methyl) -methionine-incubation does not exhibit any significant labeling, one can exclude the pathway of PC-biosynthesis through PE-methylation. The utilization of 14C-glycerol proves that the incorporation of all the compounds under consideration here is effected not by a mere exchange but by a de novo synthesis. This procedure of labeling is suitable for preparing 3H-, 14C- and 32P-PC, -PE, -MPI and phosphatidic acid (PA).
Beeinflussung der osmotischen Hämolyse durch Benzimidazol-Lost-Derivate bei der Maus
Authors: Augsten K. , Güttner J.
Published: February 2015

By means of a new parameter “t” characterizing the time course of osmotic haemolysis registered spectrophotometrically it has been described more comprehensively the membrane stabilizing effect of biological active substances. Extent and time course of osmotic haemolysis can be varied after the influence of any stabilizing drugs in different patterns. Both substances, IMET 3393 (γ-[1-methyl-5-bis- (β-chloraethyl) -amino-benzimidazol- (2)] -butyric acid · HCl) and IMET 3164 (β- [1-phenyl-5-bis- (β-chloraethyl) -amino-benzimidazolyl- (2)] -DL-alanine), respectively, i.p. applicated have increased the osmotic resistance and have delayed also the haemolysis of red blood cells in mice. The method was proved in vitro by chlorpromazine. This agent, however, has alterated only the resistance of erythrocytes but the parameter “t” was not influenced.
Bis(trimethylsilyl)-diimin: Zur Reduktion mit Lithium / Bis (trrmethylsilyl) -diazene: Reduction with Lithium
Authors: Wiberg Nils , Joo Wan-Chul
Published: February 2015

Bis (trimethylsilyl) -diazene (BSD) is reduced by lithium at low temperatures to LiBSD3 (solvent: diethyl ether), LiBSD (solvent: tetrahydrofurane) or Li2BSD (solvent: diethyl ester/few tetrahydrofurane). Unlike the stable Li2BSD the compounds LiBSD3 and LiBSD decompose thermally at —15 respectively —78°. At this, LiBSD reacts to nitrogene and lithium-bis (trimethylsilyl) -amide, the latter of which forms an adduct with LiBSD, relatively stable at —45°.
IR-spektroskopische und kristallstrukturelle Untersuchungen an 2.4-Pentandionato-Lithium-(Li-acac)-Einkristallen / IR-Spectroscopic and X-Ray Structural Investigation of 2,4-Pentandionato-Lithium (Li-acac) Single Crystals
Authors: Funck E. , Jungermann A. , Kaiser J. , Schröder F. A.
Published: February 2015

Single crystals of Li-acetylacetonate (Li-acac) were characterised by microscopical, IR-reflection and X-ray diffraction measurements.

The space group was found to be C cca (orthorhombic). From the IR-spectra (polarised radiation) and the properties of the space group the probable arrangements of the molecular species in the crystal are deduced.
Preparation and Thermal Decomposition of Tetra-n-Propylammonium-Hexafluoroplatinate(IV)
Authors: Siegel Jay , Perros Theodore , Krauss Hans-Ludwig
Published: February 2015

The hexafluoroplatinate of the organic amine was prepared via the Lanthanium salt and decomposed at 159°/10-4 torr, yielding PtF4, propene and tri-propylammoniumhydrogenfluoride. Fluorinated organic products were formed in traces only.
The Hydrolysis of Sodium Polyphosphates
Authors: Anghileri Leopoldo J. , Miller Esther S.
Published: February 2015

The hydrolysis of 32P-sodium polyphosphates (linear and cross-linked) in aqueous solution has been studied. The radiometric determinations indicate that the ortho-phosphate formation is a slow reaction, and that the amount formed by the linear variety is higher than that produced by the cross-linked form. There is a significant formation of metaphosphates during the hydrolysis of the cross-linked polyphosphate which is missing or at least reduced to a much lesser extent in the case of the linear polyphosphate.
Zur Bedeutung der Glucose für die Vermehrung von Yoshida-Ascitestumorzellen in der Suspensionskultur / The Significance of Glucose for the Growth of Yoshida Ascites Tumor Cells in Suspension Cultures
Authors: Averdunk R. , Liss E.
Published: February 2015

The growth of Yoshida ascites tumor cells in suspension culture is dependent on the presence of glucose but not dependent on energy production by aerobic glycolysis.
Einfache Darstellungsmethode des Zwischenprodukts 2.3-Dihydroxy-6.7-dimethylnaphtalin / Synthesis of 6′,7′-Dimethyl-naphto- (2′,3′) -imidazole-4,5. A Convenient Method for the Preparation of the Intermediate 2,3-Dihydroxy-6,7-dimethyl-naphtalene
Authors: Renz Paul
Published: February 2015

2-Hydroxy-6,7-dimethyl-naphtalene is sulfonated to 2-Hydroxy-6,7-dimethyl-naphtalene 3-sulfonic acid at 100°. On fusion of this sulfonic acid with potassium hydroxide 2,3-Dihydroxy-6,7-dimethylnaphtalene is obtained. The structure of this compound was proved by nuclear magnetic resonance spectroscopy. The latter compound is a good starting material for the synthesis of 6′,7′-Dimethylnaphto- (2′,3′) -imidazole-4,5 the base of a new vitamin B12-analogue, which was biosynthetically prepared recently.
Nitril als intraanulare Gruppe / Steric Interactions of Inner Atoms in Cyclic Compounds, 18 The Nitrile Group as an Intraanular Substituent
Authors: Vögtle Fritz , Zuber Michael , Neumann Peter
Published: February 2015

Cyclophane, Konformationsanalyse, Nitril-Gruppe, Protonenresonanz, Sterische Wechselwirkungen

The bridged aromatic compounds 1-3 with internally projecting nitrile groups have been prepared. The cyclophanes 1 and 3 are conformationally rigid due to steric hindrance of the inner cyano groups; 2 shows partial conf ormational mobility.
Ein systemtheoretisches Modell zur Biogenese / A System Theoretic Model of Biogenesis
Authors: Rössler Otto E.
Published: February 2015

Three types of abstract chemical reaction systems are described: 1. The generalized catalytical system, 2. the generalized autocatalytical system, 3. a spontaneously evolving chemical system. The significance of the second and third system for a very early phase of pre-biological evolution is discussed.
Die Racemisierungs-Geschwindigkeit Schiffscher Basen von Aminosäure-estern / The Racemization of the Esters of N- (p-Nitrobenzylidene) -α-amino Acids
Authors: Siemion I. Z. , Wilschowitz L.
Published: February 2015

The racemization rate of N- [p-nitrobenzylidene] -α-amino acid esters was found to be even thousand-fold smaller than that of the azlactones of N-acyl-α-amino acids. t-Butyl esters of N-[p- nitrobenzylidene]-α-amino acids are much more stable to racemization as the correspondent methyl esters.
1.2-Dimethyl-3.4-diisopropyl-cyclobutadien-eisentricarbonyl und Trimethyl-isopropyl-cyclobutadien-eisentricarbonyl / 1,2-Dimethyl-3,4-diisopropyl-cyclobutadiene-irontricarbonyl and Trimethylisopropyl-cyclobutadiene-irontricarbonyl
Authors: Brune Hans Albert , Wolff Hans Peter , Hüther Hans
Published: February 2015

Thermal cyclization of 2,9-dimethyl-deca-3,7-diyne yields 3,4-bismethylene-1,2-diisopropyl-cyclobut-1-ene. This forms by addition of two molecules of hydrogen chloride at -78° several - with respect to the positions of the four alkyl substituents - isomeric trans-3,4-dichloro-dimethyl-diisopropyl-cyclobut-1-enes. From reaction of this mixture of isomers with diiron-enneacarbonyl 1,2-dimethyl-3,4-diisopropyl-cyclobutadiene-irontricarbonyl is obtained in a 21% yield. Trimethyl-isopropyl-cyclobutadiene-irontricarbonyl has been prepared by an analogous route from 8-methyl-nona- 2,6-diyne.

Chemical properties and spectroscopic data of these complexes are discussed with respect to structure and bonding.
Zellvermehrung und energieabhängige Stoffwechselleistungen von Ehrlich-Ascites-Zellen unter aeroben und anaeroben Bedingungen / Cell Division and Energy Dependent Metabolic Power of Ehrlich-Ascites-Tumor Cells Under Aerobic and Anaerobic Conditions
Authors: Krause H. P. , Probst H. , Schneider Fr.
Published: February 2015

Interrelations between energy metabolism and cell division were studied with permanent in vitro cultured Ehrlich-ascites-tumor-cells during the second passage in vitro. The following parameters were estimated under aerobic and anaerobic conditions and in the presence of dinitrophenol:

DNA- and RNA-synthesis measured by the incorporation of 14C-thymidine and 14C-uridine; rate of glycolysis measured by lactate production; permeation of 14C-2-aminoisobutyric acid; ATP level of the cells; cell division and number of dead cells.

The following results were obtained: Cell division and thymidine incorporation are obligate oxygen dependent processes. It was not possible to decide, whether respiration alone can maintain cell propagation. Respiration alone and glycolysis alone cannot maintain a normal level of ATP. Only an intact respiration can maintain the penetration of 2-aminoiso-butyric acid. Glycolysis alone and respiration alone can supply the energy for the incorporation of uridine. The incorporation of uridine is also influenced by oxygen dependent reactions not related to energy production. The number of dead cells does not rise significantly under anaerobic conditions.
Über den Einfluß von 4-Hydroxypentenal auf Atmung und SH-Gehalt der gesunden Rattenleber und des durch Diäthylnitrosamin induzierten Hepatoms / Influence of 4-Hydroxypental on Oxygen Uptake and the SH Content of the Normal Rat Liver and the Hepatoma Induced by Diäthylnitrosamine
Authors: Schauenstein E. , Rindler R. , Schindler R. , Taufer M. , Ruhenstroth-Bauer G.
Published: February 2015

The changes in the content of protein-bound SH (PSH) and nonprotein SH (NPSH) were determined during the development of DEN-rat hepatoma. The observed increase of NPSH is understood as a general phenomenon of chemically induced carcinogenesis. The SH-content of the soluble cell proteins (PSH) was significantly higher in the established tumor than in the normal liver. Furthermore, NPSH and PSH were determined after incubation of liver slices in 4-hydroxypentenal (ΗΡΕ). The NPSH of the normal liver as well as of the established hepatoma decreased by 50 percent. The PSH were much more resistant against ΗΡΕ decreasing only in the earlier stages of tumor development by 14%/g wet weight. No significant decrease in PSH/mg protein was observed. Similarly, the influence of ΗΡΕ on oxygen uptake of the normal liver and the hepatoma was determined: with normal liver no influence was observed, whereas a significant inhibition of 10% occurred only in the established tumor. These weak cytotoxic effects of ΗΡΕ on the DEN-hepatoma is related to the low malignancy of this tumor.
Molekulargewicht, Größe und Gestalt von Proteinen der Thylakoidmembran / Molecular Weight, Size and Shape of Thylakoid-Membrane Proteins
Authors: Menke Wilhelm , Ruppel Hans-Georg
Published: February 2015

Chloroplasten, Membranproteine, Molekulargewicht, Konformation

The lamellar system of chloroplasts, dissolved in concentrated formic acid, may be freed from lipids by dialysis or gel filtration. The structural protein on both sides of the isoelectric region is water-soluble. The molecular weight was determined to be 470 000 at pH 3.0 - 3.4. Electron micrographs reveal disc-like particles of variable diameter but constant thickness. Particles of 100 Å diameter and 50 Å thickness are mainly observed. The limiting viscosity number [η] = 12 (ml/g) demonstrated that the particles are also anisodiametric in solution. It follows from changes in circular dichroism and infrared absorption that the conformation of the polypeptides is altered by the formic acid treatment. The structural protein can be separated into polypeptides in buffers containing dodecylsulphate, yielding a major component of molecular weight 25 000. From these experiments it may be concluded that one protein layer is contained in the thylakoid membrane which is composed of supra-molecular structural elements.
Weitere Beobachtungen zur Reaktion von Corrinoiden mit Kohlenmonoxid und Chlorkohlensäureestern / Further Experiments about the Reaction of Some Corrinoids with Carbon Monoxide and with Esters of Chloroformic Acid
Authors: Friedrich Wilhelm , Moskophidis Matthäus
Published: February 2015

The results of new experiments indicate that, in alcoholic solution, CO reacts with CoIII- and not with CoII-corrinoids; corrinoids with the lactam ring at ring B (dehydro cobalamin and dehydro cobinamide) react similar like the native substances; the products of the reaction are cobaltalkoxycarbonyl-corrinoids, which can also be synthesized by means of esters of chloroformic acid. In water, diaquo-dehydro-cobinamide can be reduced by CO to the CoII-form; this indicates that in water CoIII-corrinoids, but not CoII-corrinoids, principally react with CO, since dehydro-corrinoids are not self-reducing.
RNA Gehalt und Antigeneigenschaften von Polioviren vor und nach Hitzeinaktivierung / RNA Content and Antigenicity of Polioviruses before and after Inactivation by Heating
Authors: Mietens C. , Koschel K.
Published: February 2015

The question of a possible relationship between the RNA content of poliovirus and its reactivity as N- or H-antigen was examined with double-labeled virus preparations (32P-RNA, 14C-Protein). The following results were obtained: 1. Complete virus particles containing RNA may be N- or H-reactive. 2. Heat inactivation of poliovirus causes dissociation of capsid and RNA. 3. Under certain experimental conditions of thermal inactivation, the N/H conversion preceeds RNase sensitivity of viral RNA.

The results lead to the conclusion that during thermal inactivation N/H conversion is independent of the presence of RNA in the particles and that it preceeds the dissociation of viral RNA and viral capsid.
Die Kristallstruktur von Di-μ-hydroxo-bis[aquotriamminkobalt(III)]-nitrat-2-Hydrat / The Crystal Structure of Di-μ-hydroxo-bis[aquotriamminecobalt (III)] - nitrate-2-hydrate
Authors: Wieghardt Karl
Published: February 2015

The crystal structure of Di-µ-hydroxy-bis [aquo-triamminecobalt (III)] nitrate-2-hydrate has been determined by x-ray diffraction using counter techniques. The compound crystallizes in the monoclinic space group C2h
5-P21/n with a=9.444 (2), b=9.684 (3), c=10.736 (3) Å, β=90.1 (2)°, Z= 2. A total of 1765 independent reflections was used in solving the structure, which was refined to a conventional R1-factor of 0.047. It was not possible to distinguish by x-ray methods between the oxygen and nitrogen atoms of the NH3- and H2O molecules in the complex cation, because of their similarity in point of electrostatical and spatial behaviour.
Der Redoxmechanismus des Systems Folsäure—Dihydrofolsäure— Tetrahydrofolsäure II / The Redox Mechanism of the System Folic Acid — Dihydrofolic Acid—Tetrahydrofolic Acid II
Authors: Kretzschmar Klaus , Jaenicke Walther
Published: February 2015

The electrochemical behaviour of folic acid, 7,8-dihydrofolic acid, and tetrahydrofolic acid was studied with polarographic, coulometric and spectroscopic methods in the pH range between 1,8 and 11,9.

From the experiments a mechanism is derived which contains the formation of radicals and dimers, and the proton catalyzed reductive and non reductive cleavage of the side chain.
Massenspektrometrische Untersuchungen an α,α’-Bis-acetylen-ketonen / Mass Spectrometric Investigations with α,α’-Bis-acetylenic ketones
Authors: Müller Eugen , Segnitz Adolph , Zeller Klaus-Peter
Published: February 2015

In the ion source of a mass spectrometer α,α’-bis-acetylenic ketones rearrange by elimination of carbon monoxide giving diyne-ion radicals.
Biosynthesis of 5,6-Dimethylbenzimidazole Precursor-Function of 6,7-Dimethyl-8-ribityllumazine
Authors: Kühnle Hans F. , Renz Paul
Published: February 2015

6,7-Dimethyl-14C-8-ribityllumazine was added to cell homogenates of Propionibacterium shermanii, previously grown anaerobically in the presence of cobaltous sulfate. This homogenates were shaken under aerobic conditions for 48 hours in order to produce vitamin B12 from the corrinoids formed during the anaerobic growth phase. The vitamin B12 was isolated and its 5,6-dimethylbenzimidazole moiety split off by acid hydrolysis. It was shown that the radioactive label of 6,7-dimethyl-14C-8-ribityllumazine was exclusively localized in the 5,6-dimethylbenzimidazole moiety of the vitamin B12 molecule. The specific radioactivity of the 5,6-dimethylbenzimidazole isolated was 18 per cent of the specific radioactivity of the 6,7-dimethyl-14C-8-ribityllumazine added.

The radioactive 5,6-dimethylbenzimidazole was further degraded in order to determine the radioactivity in the different carbon atoms. It was found that 45 percent of the total radioactivity was localized in the two methyl carbons (C-10+C-11) and 47 percent in carbon atoms 4 + 7 indicating that 5,6-dimethylbenzimidazole had been formed from two molecules of 6,7-dimethyl-8-ribityllumazine.
Aromatic Esters from the Liverwort, Isotachis japonica
Authors: Matsuo Akihiko , Nakayama Mitsuru , Hayashi Shûichi
Published: February 2015

The oily portion of n-hexane and methanol extracts of the liverwort, Isotachis japonica Steph., was investigated, and three aromatic esters, benzyl benzoate, benzyl cinnamate and β-phenylethyl cinnamate, were identified as major components. It was established that terpene compounds, which were main constituents in essential oils of other liverworts, were not contained in this liverwort in noticeable proportion.
Stimulierung von Kulturen embryonaler Rattenzellen durch eine Proteinfraktion aus fötalem Kälberserum / Stimulation of Embryonic Rat Cells in Culture by a Protein Fraction Isolated from Fetal Calf Serum
Authors: Hülser Dieter F. , Frank Werner
Published: February 2015

Normal embryonic rat cells incubated in serum-free medium accumulate in G1-phase of the cell cycle. On addition of a growth-stimulating protein isolated from fetal calf serum they are triggered to proceed through the cycle, and they resume DNA-synthesis 15 to 20 hours later. In this paper it is demonstrated that the surface membrane potential difference (PD) decreases immediately after changing serum-free medium against culture medium containing either calf serum or the isolated serum protein; the original PD is restored 2 to 3 hours later. Serumprotein without growthstimulating activity does not affect the PD.

A permanent rat cell line which grows independently of serum also has been tested. The PD of these cells is not significantly influenced by calf serum.
Biochemische Untersuchungen an experimentell chronisch epileptischen Tieren / Biochemical Investigations of Experimental Chronic Epileptic Animals
Authors: Riedel Eberhard , Wamsiedler Eugen
Published: February 2015

In the brain-metabolism of experimental chronic epileptic cats (modificated Kopeloffmethod of intracerebrale alumina-gel injection) some alterations were observed in the lesioned cortical hemisphere. An increase of tissue-respiration in vitro (gray-matter of the cerebral cortex), increase of the activities of alkaline (E.C. 3.1.3.1) and acid phosphomonoesterases (E.C. 3.1.3.2) and a decrease of K-Na-stimulated, Ouabain-inhibited adenosintriphosphatase (E.C. 3.6.1.3) were determined. Postconvulsive (one to six hours after seizures) these changes were found to be more extensive than one or more days after discharge. They couldn’t be found in brain tissues of cats only with mechanical lesions without injection of aluminagel2 which didn’t have convulsions. Because the good reproducibility the communicated method for experimental chronic epilepsy is proposed for pharmacological investigations.
On the Reaction between Chlorophyll-a, and its Primary Electron Donors in Photosynthesis
Authors: Haehnel W. , Döring G. , Witt H. T.
Published: February 2015

Electrons produced by Chl-aII in a short flash are finally transfered to Chl-ai after having passed several intermediates. The reaction between Chl-aI and its primary electron donators PD (probably Cyt-f and PC) has been studied by means of high time resolution flash photometry in isolated spinach chloroplasts with the following results:

1. When PD are in the oxidized state, the reduction of Chl-aI
⊕ takes place with the rate limiting reaction time of the electron transport chain (≈ 20 ms).

2. When PD are in the reduced state, the reduction of Chl-aI
⊕ takes place with the reaction times between the PD and Chl-ai. We found two half life times: one of about 200 μs and one of about 10 μs.

The reduced state of PD is realized when weak monitoring light or hvII-preillumination is used.

The two reaction times of ≈ 200 μs and of ≈ 10 µs are interpreted to represent the electron transfers between Cyt-f and Chl-aI and between PC and Chl-aI resp.

Equilibrium constants of the electron transfer from PD to Chl-aI and the arrangement of the intermediates in the electron transport chain are discussed.
On the Regulation of Enzyme Levels (phenylalanine ammonia-lyase) in Different Organs of a Plant (Sinapis alba L.)
Authors: Dittes L. , Rissland I. , Mohr H.
Published: February 2015

The time courses of formation of the enzyme phenylalanine ammonia-lyase (PAL; EC 4.3.1.5) mediated by far-red light (i. e. by phytochrome, Pfr) in cotyledons and hypocotyl of the mustard seedling (Sinapis alba L.) are described. While PAL activity in the cotyledons can scarcely be detected in the dark-grown seedling, the enzyme can be synthesized in the hypocotyl even in the dark. However, the degree of induction by far-red light is much greater in the cotyledons than in the hypocotyl. In the cotyledons the enzyme is not stable. The enzyme level eventually returns to nearly zero even under continuous far-red light. The time course of the level of PAL in the cotyledons (Fig. 1) can be explained by the following 3 factors (Fig. 2): 1. Induction of PAL synthesis by Pfr, whereby Pfr is continuously required; 2. Inactivation (degradation) of PAL by an inactivating principle; 3. Repression of PAL synthesis. The time course of the level of PAL in the hypocotyl is completely different (Fig. 1). An explanation of the hypocotyl data is presented which is based on the assumption that PAL synthesis in the dark and PAL synthesis mediated by phytochrome are independent phenomena which occur in different tissues of the hypocotyl. It appears that the occurrence of dark synthesis of a stable enzyme in the hypocotyl explains the seemingly dramatic difference between the cotyledons and the hypocotyl with respect to PAL.
Furan and Thiophene Analogs of Phenanthrene A Theoretical Study of the Absorption Spectra of Benzodifurans, Benzodithiophenes and Thienobenzofurans
Authors: Klasinc L. , Knop J. V.
Published: February 2015

The LCAO -MO -SCF -CI method was applied to benzo(1,2-b : 4,3-b′) -difuran and -dithiophene, benzo (2,1-b : 3,4-b′) -difuran and -dithiophene, benzo (1,2-b : 3,4-b′) -difuran and -dithiophene, thieno (2,3-e) benzofuran, thieno (3,2-e) benzofuran, thieno (3,2-g) benzofuran, thieno (2,3-g) benzofuran, benzofuran, benzothiophene and phenanthrene. The calculated π-electron transitions and their oscillator strengths are in good agreement with known absorption spectra. The resemblance of these spectra to the absorption spectra of phenanthrene and phenanthrolines is discussed.
Studies on the Biosynthesis of Some Furocoumarins Present in Ruta graveolens
Authors: Caporale G. , Dall’Acqua F. , Capozzi A. , Marciani S. , Crocco R.
Published: February 2015

The biosynthesis of some furocoumarins present in Ruta graveolens has been studied administering labeled psoralen, xanthotoxin, rutaretin, marmesin and 7-hydroxycoumarin-derivatives.

The results obtained indicate that the biosynthetic pathway involves not only psoralen, but also xanthotoxin and bergapten, by means of methoxylation or demethoxylation reactions.

Moreover results achieved from administering rutaretin demonstrate that this substance is a new very effective natural precursor for xanthotoxin; in a parallel way marmesin is incorporated into psoralen. The reported results indicate that also at the stage of natural 4′,5′-dihydrofurocoumarins intermediates an interconversion can occur.

Finally the essential role of umbelliferone in the biosynthesis of furocoumarins has been confirmed.
Zellturgor und selektiver Ionentransport bei Chaetomorpha linum / Cell Turgor Pressure and Selective Ion Transport of Chaetomorpha linum
Authors: Steudle E. , Zimmermann U.
Published: February 2015

The littoral alga Chaetomorpha linum is especially able to maintain a constant turgor pressure in the cell by regulating the internal osmotic pressure, if the salt content of the sea water changes. Experiments in artificial isotonic sea water with a constant sodium concentration, but variable potassium concentrations (from 1 to 50 mMol/1) prove, that the decrease or increase of the potassium concentration in the medium (CK
a) is an essential cause for this regulation of the turgor pressure besides the change of the osmotic pressure of the medium, which was thought to be the predominant cause till now. In the examined concentration range the ratio CK
a to CK
1 (potassium concentration in the cell) depends linear on CK
a in the steady state. At low values of CK
a (< 10 mMol/1) the decrease in CK
1 is compensated by a reversible sodium uptake only in part, and this leads to partly high changes in the cell turgor pressure, although the osmotic pressure of the medium remains constant. The results are discussed on the basis of carrier models.
Über Bürzeldrüsensekrete von Finkenvögeln
Authors: Jacob Jürgen , Zeman Alfred
Published: February 2015

The uropygial gland fats of the greenfinch, bullfinch and the linnet are mixtures of ester waxes, composed of 3-methyl-substituted fatty acids and normal and 3-methyl-substituted alkanols. In addition there are found traces of 2-methyl-substituted fatty acids and alkanols. As to the waxes there are close relations between the 9th and 6th family of the 4th suborder within the 32nd order of the natural system.

The simultaneously investigated depot fat of the bullfinch shows no relation to the uropygial gland fat.
The Nephelauxetic Effect — Calculation and Accuracy of the Interelectronic Repulsion Parameters
Authors: König E.
Published: February 2015

Expressions are reviewed which may be used to determine 10 Dq and B from the spin-allowed bands in the optical spectra of d3 and d7 electron systems within octahedral and tetrahedral sym metry. Application to low-temperature single crystal spectra demonstrates that (i) the semi-empirical ligand field theory reproduces transition energies with sufficient accuracy; (ii) differences in the values of 10 Dq and B observed with different fitting methods may be attributed to the inaccuracy of experimental data; (iii) there are generally valid values of B35 and β35 for each complex ion.
Auswertung nmr-spektroskopischer Messungen der Mischassoziation von Nucleosid-Derivaten bei vergleichbaren Konzentrationsverhältnissen / Evaluation of NMR-spectroscopical Results about Co-association of Nucleoside Derivatives in Comparable Concentrations
Authors: Breuer H. , Perkampus H.-H.
Published: February 2015

In this paper we described a method how to calculate from NMR the association - caused by Η-bonds - of two components. These components may be present in equal concentration and may be partially self-associated.

The may act as Η-donors and acceptors. The method is demonstrated using some nucleoside derivatives as examples.
Strahlenchemie von Alkoholen XVII
Authors: Sonntag C. v.
Published: February 2015

In the 185 nm photolysis of liquid O2-free isopropanol the following products (quantum yields) are formed: hydrogen (0.75), acetone (0.72), pinacol (0.036), methane (0.046), acetaldehyde (0.04), propane (0.02β), ane (0.0023) and carbon monoxide (0.0015). A detailed reaction scheme is proposed. The major primary processes are the formation of H-atoms by homolytic scission of the O —H-bond (61 — 69%), elimination of molecular hydrogen (21%) and molecular methane (5%). Φ(Η2) is strongly decreased by adding water which does not absorb an appreciable portion of the 185 nm light in the mixtures down to 1 mole/l isopropanol (Φ(Η2) =0.21). In contrast to the strong effect of water there is no effect on Φ(Η2) by diluting isopropanol with n-hexane. From experiments with isopropanol-OD and 2-deutero-isopropanol it is tentatively concluded that H-atoms stemming from the O—H-group of the alcohol are to about 65% the precursors of the hydrogen in these mixtures.
Untersuchungen über den Kaliumtransport bei Escherichia coli B / Potassium Transport in Escherichia coli B
Authors: Pilwat G. , Zimmermann U.
Published: February 2015

The stationary intracellular potassium concentration in E. coli B 525 has been studied as a function of the extracellular potassium and sodium concentrations.

The ratio of extracellular to intracellular potassium concentration is shown to be a linear function of the extracellular potassium concentration if the extracellular sodium concentration is low (20 mmoles/l). In the case of high sodium concentration (100 mmoles/l) the ratio is independent of the extracellular potassium concentration if the potassium concentration is below 1,2 mmoles/l.

In order to describe the distribution of potassium uniformly over the whole range of the extracellular potassium and sodium concentrations a carrier system with two sites has to be supposed.
Infrarot-Photochemie mit Lasern? / Infrared Photochemistry with Lasers?
Authors: Kompa Karl L.
Published: February 2015

The possibility of controlled chemical reactions by resonance laser activation of molecular vibrational modes is considered. This produces a selective heating of one or more vibrational degrees of freedom and a correspondingly rapid increase in the reaction rates. The competition between chemical processes and relaxation by energy transfer to other degrees of freedom is discussed. The verification of this new reaction principle requires lasers with realistic parameters. A few experimental results are reviewed.
On the Impossibility of an OH-Radical Model for Photosynthetic Water Oxidation / Über die Unmöglichkeit eines OH-Radikalmodells für die photosynthetische Wasseroxidation
Authors: Vierke Gerhard
Published: February 2015

If it is assumed that the oscillating O2 flash yield sequence of algae and chloroplasts predominantly reflects an inherent property of the O2 evolving system of the photosynthetic apparatus it is shown that the OH-radical model (O2 production by recombination of four OH radicals) is contradictory to the experimental results because it predicts an aperiodic O2 flash yield sequence.

Several experimental facts already known strongly indicate that the OH-radical model is not consistent with the kinetic model for O2 evolution of KOK et al. either.
Identification of Flavonoids and Cinnamic Acid Derivatives from Spinach Chloroplast Preparations
Authors: Oettmeier Walter , Heupel Adelheid
Published: February 2015

By immunochemical methods we had presented evidence for a primary acceptor complex for photosystem I of photosynthetic electron transport. During purification of this complex, obtained as a water soluble fraction from ether treated lyophilized chloroplasts, two low molecular fractions are also obtained, which may or may not have relation to the primary acceptor. The purification and identification of these low molecular fractions is reported. One, absorbing at 275 and 335 nm, consists of several flavonoid glycosides. The aglycon of the main component is tentatively identified as a 3-methyl-6,7-methylenedioxy-quercetagetin. The chromophore of the other low molecular fraction, absorbing at 312 nm, contains two cinnamic acid derivatives, which on alkaline hydrolysis yield p-coumaric acid. The relation of the two low molecular fractions to other fractions of various activity isolated from chloroplasts is discussed.
Effect of Poly I : C-induced Interferon on Herpes Virus Hominis Infection in Vitro and in Vivo
Authors: Munk Klaus , Frick Thomas
Published: February 2015

In this study the effect of poly I : C-induced interferon on Herpesvirus hominis (HVH) infection in vitro and in vivo was investigated.

The in vitro results revealed a significant effect of interferon on infections of HVH strains of different origin in mouse embryonic cells.

The in vivo experiments performed in the HVH-mouse system indicate that the effective induction of interferon in an aminal increases its resistance to subsequent infection with HVH.
Vorübergehende pH-Änderungen im umgebenden Medium intakter grüner Zellen bei Beleuchtungswechsel
Authors: Brinckmann Enno , Lüttge Ulrich
Published: February 2015

When light is switched on or off the pH of the medium of green cells of a large number of various plant species investigated (Elodea, Zea mays, Amaranthus caudatus, Oenothera hookeri x albicans, Mnium undulatum, Scenedesmus obliquus) increases or decreases respectively. This effect is linked with the non-cyclic photosynthetic electron flow: 1. the effect is independent of the gross ion content of the external medium, 2. green plant cells deficient in photosystem II do not show the effect, 3. addition of 2 · 10-6 M DCMU to the medium has a similar effect as switching off the light. The pH-effect is inhibited by FCCP, it is abolished in N2, but a normal effect is observed in CO2-free air. The transient changes of H⊕-net flux upon change of illumination are discussed in relation to both the proton pump of the thylakoid membranes of chloroplasts and to CO2 fixation after the uptake of HCO3
⊖ from the external solution coupled with the release of OH⊖ ions. The results are also compared to other signals of similar kinetics observed in experiments with intact plant cells, especially with light-triggered transients of membrane potential and ATP-level.
Die Kristallstruktur von (CH3NH3)4InCl7 / The Crystal Structure of (CH3NH3)4InCl7
Authors: Schlimper Hans-Ulrich , Ziegler Manfred L.
Published: February 2015

The crystal structure of (CH3NH3) 4InCl7 has been determined by x-ray diffraction. The compound crystallises in the monoclinic space group C2h
4 — P2/c with α=16.113 (3), b= 7.466 (5), c=20.300 (8) Å, β=127.9 (4)°, Z=4. A total of 834 independent reflections was used in solving the structure, which was refined to a conventional RI-factor of 0.076. The salt consists of InCl6
3⊖-respectively Cl⊖-anions and (CH3NH3)⊕-cations.
Massenspektrometrische und Emissionsspektroskopische Untersuchungen an Bernstein zur Herkunftsbestimmung
Authors: Eichhoff H. J. , Mischer G.
Published: February 2015

Amber samples of different provenance have been investigated by electron impact and fieldionisation mass-spectrometry. Whereas electron-impact mass-spectra are not specific enough, fieldionisation spectra enable one to identify amber from Baltic-, Sicilian-, Canadian- and Libanese areas.

Fe, Na, B, Ca, Mn, Al, Ti, Cu, Cr, V and Si could be determined by emission spectroscopy. Baltic amber shows a smaller trace-element content than all other samples investigated. Canadian amber shows a higher manganese content.
Darstellung neuer Phosphazene und ihre Reaktionen / Preparation of new Phosphazenes and their Reactions
Authors: Roesky Herbert W. , Kloker Wolfgang
Published: February 2015

The preparations of the following compounds are described: O = PF2N = PCl2N = PCl3, O = PF2N = PCl2N = PCl2N (CH3) 2, O = PF2N=PCl2N = PCl2N (C2H5) 2, O = PF2N = PCl2N (CH3) 2, O = PF2N = PCl2N (C2H5)2, O = PF2N = PCl2N (CH3) Si (CH3)3, O = PF2N = PCl2NCS, O = PFClN = PCl2N (CH3)2, O = PFClN = PCl2N (C2H5)2, O = PFClN = PCl [N (C2H5)2]2 and O =P (C6H5) FN = PCl3. They were characterized by 1H-, 19F- and 31P-nmr spectroscopy. Analytical, ir and mass spectral data are reported. The properties of these substances are compared with the corresponding thiophosphorylderivatives.
UV-Photolyse von 5-Joduracil / UV Photolysis of 5-Iodouracil
Authors: Gilbert E. , Wagner G. , Schulte-Frohlinde D.
Published: February 2015

UV Photosylis (254 nm) of 5-iodouracil in aqueous, oxygenated solution in presence of KI, FeSO4, KBr and K2SO4 was investigated over a pH-range of 1—6. Uracil, isodialuric acid, and isobarbituric acid were identified as photoproducts.

At a constant pH-value (pH=1) at high KI-concentrations (10-1 mole/1) the main product is uracil. With decreasing KI-concentrations the yield of uracil decreases and isobarbituric acid appears as a photoproduct. On further decreasing KI-concentrations (< 10-2 mole/1) the yield of isobarbituric acid decreases and the formation of isodialuric acid commences.

UV Photolysis of iodouracil at constant KI-concentrations (10—1 mole/1) and increasing pH (pH = 1—6) yields similar results with one exception. At higher pH-values on account of isodialuric acid at least four further compounds are formed. The yield of these products increases with increasing pH value. Addition of KBr and K2SO4 has no effect on the product distribution.

The possible mechanisms for the formation of the reaction products are discussed.
Komplexbildungskonstanten und thermodynamische Daten der Reaktion von 2.3-Diphosphoglycerat mit Erdalkalimetallionen / Equilibrium Constants and Thermodynamic Data of the Reaction of 2,3-Diphosphoglycerate with Earthalkaline Metal Ions
Authors: Dietsch Peter , Siegmund Peter
Published: February 2015

The formation constants of the complexes of Mg2+, Ca2+, and Sr2+ with 2,3-diphosphoglycerate have been determined with pH-methods according to Schwarzenbach. The enthalpies of these reactions were obtained by microcalorimetric measurements. They are positive as well as the entropies showing that the complex formation is only caused by an increasing entropy. A comparison is made with the corresponding values obtained by ANDEREGG 1 for the tripolyphosphate.
[2+3] Cycloaddition Reactions of Azido Metal Complexes and Crystal Structure of the Cycloadduct of (Ρh3Ρ)2Pd(Ν3)2 with Benzonitrile
Authors: Kreutzer P. , Weis Ch. , Boehme H. , Kemmerich T. , Beck W. , Spencer C. , Mason R.
Published: February 2015

Cycloaddition reactions of (R3P) 2M(N3)2 (M = Pd, Pt) with organic nitriles, thiocyanates, isothiocyanates, dimethylacetylenedicarboxylate and carbon disulphide are described; an X-ray analysis of the crystal structure of bis (5-phenyltetrazolato) -bis (triphenylphosphine) palladium (II) is summarised and related to isomerism of the complex in solution.
Untersuchungen der kernmagnetischen Resonanz von Phosphorverbindungen, XXIX
Authors: Heckmann Gernot , Fluck Ekkehard
Published: February 2015

The n.m.r. signal of white phosphorus in some substituted benzenes and halogen-free solvents was measured. In both types of solvents the chemical shifts were caused mainly by van der Waals interactions. An average anisotropy term of +2.4 ppm was obtained for phosphorus dissolved in benzene derivatives. A possible use for the large solvent effects of white phosphorus is given.
Lokalisierung des Monogalaktosyldiglycerids in Thylakoidmembranen mit serologischen Methoden / Serological Localisation of Monogalactosyl Diglyceride in Thylakoid Membranes
Authors: Radunz Alfons
Published: February 2015

Immunoglobulins to monogalactosyl diglyceride have been found in antisera to different chloroplast preparations. A specific antiserum to this lipid has been obtained by injection of monogalactosyl diglyceride which was adsorbed onto methylated bovine serum albumin. Inhibition tests with mono- and oligosaccharides, as well as with mono- and digalactosyl glycerol, showed that the immunoglobulin was directed to the β-galactosyl-(1 → 1) -glycerol configuration. Digalactosyl diglyceride and sulphoquinovosyl diglyceride did not react with the antiserum. The immunoglobulin is of the Ig M-type.

The antiserum to monogalactosyl diglyceride agglutinates stroma-freed chloroplasts. Fragments of the thylakoid membrane, obtained by ultrasonication and fractioning centrifugation, thylakoids and thylakoid stacks are all precipitated. In a preparation of stroma-containing chloroplasts agglutination takes place but after rupture of the chloroplast membrane and loss of the stroma. The ultrasonicated lamellar system binds a larger amount of the monogalactosyl diglyceride immunoglobulins than does stroma-freed chloroplasts. It is concluded from these experiments that some of the chloroplasts monogalactosyl diglyceride is located at the surface of the thylakoids.
Experimente zur intramolekularen Energieleitung in BU-DNA des Phagen PBSH aus Bacillus subtilis nach Bestrahlung mit langwelligem UV / Experiments Concerning the Intramolecular Energy Transfer in BU-DNA of the Phage PBSH from B. subtilis after Long-wave UV-irradiation
Authors: Mönkehaus F. , Köhnlein W.
Published: February 2015

The production of BU-phages with a relative high amount of hybrid DNA is described. Transforming experiments with the irradiated phage BU-DNA and the investigation of the photodecomposition of the single strands of hybrid DNA demonstrate clearly intramolecular energy transfer. From the breakage rates of the single strands of hybrid DNA a calculation for the relative amount of intramolecular energy transfer in hybrid BU-phage DNA is given.
Die Untersuchung der Isopolysäurebildung des Molybdats mit Hilfe dilatometrischer Titrationen / Formation of Isopolymolybdates Indicated by Dilatometric Titrations
Authors: Wiese Günther , Böse Doris
Published: February 2015

The change of the volume associated with the acidification of sodium-molybdate-solutions was continuously controlled by dilatometric titrations. Various isopolymolybdates have been identified.
Contributions to the Chemistry of Molybdenum and Tungsten, IX
Authors: Schröder F. A. , Hartman P.
Published: February 2015

By using the Periodic Bond Chain Vector method a newly prepared combination of forms of highly stoichiometric WO3 is discussed. Through the consideration of the features of the structure it can be explained, why the observed faces are built. From characteristics of the structure an improved understanding of the origin of so called shear structures of the ReO3 type family could be derived.
Über die Bildung des Ferrol-Systems bei der Reaktion von 3-Methyl-3-chlor-4-methylen-cyclobuten-(1) mit Dieisenenneacarbonyl / The Formation of the Ferrol-System in the Reaction of 3-Methyl-3-chloro-4-methylene-cyclobut-1-ene with Diironenneacarbonyl
Authors: Wolff Hans Peter , Müller Paul , Brune Hans Albert
Published: February 2015

The compound obtained by the reaction of 3-methyl-3-chloro-4-methylene-cyclobut-1-ene is identified as the irontricarbonyl-π-complex of the 2,3-dimethylferrol system.
Molecular Luminescence Studies of Flavins, II.
Authors: Song Pill-Soon , Moore Thomas A. , Kurtin William E.
Published: February 2015

The effects of experimental geometry on the theoretical polarizations of the S1 ← S0 and S2 ← S0 bands of π→π* type in riboflavin have been examined. Polarizations of these two bands are characterized by an angle between them in the range of 20—28° and are relatively insensitive to the input geometry. Thus the predicted polarizations are generally in agreement with fluorescence polarization spectrum of riboflavin at 77°K. Alloxazine forms a strong complex with KI, and the fluorescence and phosphorescence from the charge transfer states have been characterized by means of luminescence and photoselection measurements. Riboflavin did not form a strong complex with KI, but it forms aggregates (dimer) more readily than alloxazine. The excited states of flavins can be populated by the weak dipole-dipole coupling mechanism of energy transfer from 1La states of indoles to the S2 state of flavins. The measured critical distances estimated from the fluorescence depolarization experiments range from 31 Å for indole to 40 A for indole-2-carboxylic acid in glycerol-methanol mixture (9:1) at 263°K.