bluuebunny/crossref_metadata_2025 huggingface dataset:
Coa/Coß-Isom erie der Corrinoide. Partialsynthese und Escherichia coli -Aktivität weiterer Isomerenpaare der (Co-M ethyl)-corrinoide Coa/Co/Msomerism of Corrinoids. Partial Synthesis and Escherichia coli Activity of Further Isomer Pairs o f the (Co-methyl)-Corrinoids
Authors: Moskophidis M , Maria Klotz Christa , Friedrich W , Errn H. , Moskophidis M. , Kühnau  , Klotz Christa Maria , Friedrich W.
Published: August 2018

Vitamin B 12 , Methylcorrinoids, Coα/Coβ-isomerism, E. coli Activity In 2-methyladenyl-(Coβ-methyI) -cobamide and in adenyl-(Coβ-methyl)-cobamide the nucleotide base is coordinated to the cobalt atom in neutral and weak acidic aqueous solutions (in the cor­ responding adenosylcorrinoids the nucleotide base is not coordinated). 2-Methylthioadenyl-(Coβ-methyl)-cobamide resembles, with regard to the coordination of the nucleotide base, the benz-imidazole-corrinoids.

The partial synthesis via cobalt (I) corrinoids results in a variable proportion: (Coα-methyl) iso­ mer/(Coβ-methyl) isomer, e .g . 7/93 (cobalamin) and 50/50 (p-cresylcobamide). This proportion is generally low, if in the corresponding cyanocorrinoid the nucleotide base is firmly coordinated; it is high, if the coordination in the corresponding cyanocorrinoid is weak or absent. These results are compatible with the assumption that in the cobalt (I) corrinoids the nucleotide base is to a certain extent coordinated.

In Escherichia coli 113-3 the examined (Coα-methyl)-corrinoids show a weaker bioactivity than the corresponding (Coβ-methyl) -corrinoids.
Isolation and Properties of Yeast Mutants with Highly Efficient Thymidylate Utilization
Authors: Fäth Wolfgang W. , Brendel Martin
Published: August 2018

A screening procedure is presented which allows the isolation of yeast mutants (typ tlr) with highly efficient utilization of exogenous deoxythymidine-5′-monophosphate (5′-dTMP) (>50% ). Data are given concerning the phenomenon of 5′-dTMP utilization in general: (i) The ability of S. cerevisiae to incorporate exogenous 5′-dTMP was found to already be a wild type feature of this yeast, i. e. apparently not to be due to any mutation such as typ , tup, tmp per or tum. Consequently these mutations are interpreted as amplifiers of a pre-given wild type potency. So far eight stages of 5′-dTMP utilization were detected as classified by the optimal 5′-dTMP requirement, with 5′-dTMP biosynthesis blocked, of the corresponding mutant strains isolated. All of them fit well into a mathematical series of the type “2n × 1.5” (n = 0, 1, 2, … , 11), where the product term for n = 11 represents the 5′-dTMP requirement (μg/ml) of the best 5′-dTMP utilizing wild type strain found, (ii) Amplification of the 5′-dTMP utilizing potency obviously is due to any genetically determined alteration of the yeast 5′-dTMP uptaking principle itself or of physiological processes accompanying the monophosphate’s uptake, (iii) The functioning of 5′-dTMP uptake requires acidic (≦ pH 6) conditions in the yeast cell’s outer environment, (iv) Some yeast typ and typ tlr mutants were found to exhibit a more or less pronounced sensitivity towards exogenously offered 5′dTM P. The response of a sensitive strain towards inhibitory concentrations of the nucleotide apparently is co-conditioned by the presence or absence of thymidylate biosynthesis. With 5′-dTMP biosynthesis blocked the 5′-dTMP mediated inhibition is a permanent one and finally leads to the death of a cell. With a functioning thymidylate biosynthesis, in contrast, the inhibition is only temporary, (v) Yeast typ or typ tlr strains were observed to dephosphorylate exogenous 5′-dTMP to thymidine due to a phosphatase activity which cannot be eliminated at pH 7 + 70 mм inorganic phosphate conditions in the growth medium. This 5′-dTMP cleavage obviously occurs outside the cell and does not seem to be correlated both to the monophosphate’s uptake and to the phenomenon of 5′-dTMP sensitivity. The destruction of 5′-dTMP does not disturb (5′-dTMP) DNA-specific labelling.
Photosynthetic Electron Carriers at a Heptane-Water Interface
Authors: Brody S. S. , Owens N. F.
Published: August 2018

Surface properties of monomolecular films of chlorophyll (Chi), plastocyanin (Pc), cytochrome c (Cyt) and ferridoxin (Fd) were measured at a heptane-water interface. Mixed films of Chl and the other components were examined in darkness and in light. The area/molecule, A, for Fd (from Cl. pasteurianum) is much larger at a heptane-water than Fd (from spinach) at an air-water interface. This difference in A may be the source of the Fd or the extent of denaturation at the different interfaces. There appears to be a photoreaction between Chil and Fd in the presence of ascorbate. The A for Cyt is much larger at a heptane-water than at an air-water interface. In mixed films there is a strong interaction between Chl and reduced Cyt in the dark. No such interaction is ob­served between Chi and oxidized Cyt. With mixed films of Chi and reduced Pc there is a significant, reversible, light induced change in ΔV.
Chromosomale Strukturen von Pseudomonas testosteroni. II. Aktivität der endogenen RNA-Polymerase /Chromosomal Structure of Pseudomonas testosteroni. II. Activity of the Endogenous RNA-Polymerase
Authors: Reimer Günter , Drahovsky Dusan
Published: August 2018

After careful lysis the nucleoid of Pseudomonas testosteroni can be isolated in three different forms with compact and unfolded DNA structures 1. The released nucleoids contain endogenous DNA-dependent RNA-polymerase activity using the chromosomal DNA as a template. RNA syn­ thesis is proportional to duration of RNA-polymerase reaction and amount of DNA-protein-complexes. The sensitivity towards ionic strength and rifampicin indicates that a part of RNA-polymerase activity is tightly bound to the chromosomal DNA.
β -Diketoester und deren Enoläther als Aminosäure-Antagonisten. On Amino Acid Antagonists: β-Diketoesters and Their Corresponding γ-Enolethers
Authors: Trowitzsch Wolfram , Sahm Hermann
Published: August 2018

Starting with well known β-diketoesters the corresponding y-enolethers are synthesized and described. Both classes of compounds inhibited the growth of some microorganisms. The inhibition is abolishable by addition of certain amino acids to the definite medium. A possible mechanism of inhibition is discussed and compared with the mechanism of some β,γ-unsaturated α-amino acids. The known unsaturated a-amino acids, their origin and their biological activity are summarized in two tables.
Studies on Prototropic Tautomerism in Neutral and Monoanionic Forms of Pyrimidines by Nuclear Magnetic Resonance Spectroscopy
Authors: Stolarski Ryszard , Remin Mieczyslaw , Shugar David
Published: August 2018

NMR methods have been applied to evaluation of prototropic tautomerism, N(1)H ⇌ N (3) H, in several selected pyrimidines, viz. the neutral forms of Isocytosine and 2-alkylthiopyrimidone-4, and the monoanionic forms of uracil, 5-fluorouracil and 4-thiouracil.

The predominant tautomeric species of the neutral forms could be estimated only qualitatively from 1H chemical shifts. For the monoanionic forms this procedure was not applicable, for reasons which are discussed in detail.

For the monoanionic form of uracil, 13C chemical shifts of C(5) provided a suitable criterion for quantitative estimation of the populations of the two known tautomeric species. However, the potential scope of this procedure appears somewhat limited.

By contrast, the values of the vicinal proton-proton coupling constants, J (5,6), provided both necessary and adequate criteria for quantitative evaluation of the tautomer populations for all the neutral and monoanionic forms. The results were in satisfactory agreement with those obtained by optical spectroscopic methods. In some instances the results obtained in this way may be more reliable than those derived from optical methods.

The range of applicability, and utility, of NMR methods to studies on protropic tautomerism in pyrimidines are critically assessed.
Chromophore Content of C-Phycoerythrin from Various Cyanobacteria
Authors: Muckle Günther , Rüdiger Wolf
Published: August 2018

The molar extinction coefficient for phycoerythrobilin (1a) was calculated by two independent methods. It is different from that of the cleaved chromophore, phycobiliviolin (2). By unfolding with urea or tryptic digestion, the chromophore absorption of C-phycoerythrin (PE) was determined free of any protein influence. The chromophore content of PE from various Cyanobacteria was determined with these data to be either 5 or 6, depending on the organism. This corresponds to a chromophore distribution over phycoerythrin subunits α:β of either 2:3 or 2:4. The phylogenetic significance of varying chromophore content is discussed.
A Kinetic Model for Translocators in the Chloroplast Envelope as an Element of Computersimulation of the Dark Reaction of Photosynthesis
Authors: Giersch Christoph
Published: August 2018

A kinetic model for the chloroplast translocators (mediating equal and opposite exchange fluxes between the external medium and the stroma) is derived. This model is a modification of the classical Widdas model corresponding to the exchange of an arbitrary number of compounds with no contribution to net transport. It describes the rate of transport of each compound in simple terms and with a minimum number of kinetic constants. Predictions from the model agree with experimental data as recorded in the literature.

From the experimental apparent kinetic constants VMAX and Km those in terms of the model are calculated. These constants complete the model and make it applicable to the study of metabo­lism of photosynthesis by means of computer simulation. The set of differential equations describing the operation of the phosphate translocator is solved numerically for some illustrative examples.
NOTIZEN / Langkettige Alkane und Alkohole aus den Blattwachsen verschiedener Coffea-Arten / Long Chain Alkanes and Alcohols from the Leaf Waxes of Different Coffea Species
Authors: Stocker Hans , Wanner Hans
Published: August 2018

A gaschromatographic study has been made of the alkane-and alcoholic fractions from the leaf waxes of some Coffea species. The n-alkanes have the odd-carbon-numbered, the primary alcohols the even-carbon-numbered members pre­ dominating. The major homologues of the alkane fractions are C29 and C31 and of the alcoholic fractions C30 and C32 . The sub-divisions Erythrocoffea and Pachycoffea could be distinguished by the alkane patterns. Im Rahmen einer chemotaxonomischen Studie der Gattung Coffea wurden die Alkan-und Alkohol­ fraktionen der Blattwachse untersucht.
Pisatin as a Major Phytoalexin in Laihyrus
Authors: Robeson David J. , Harborne Jeffrey B.
Published: August 2018

The pterocarpan pisatin has been identified as a major phytoalexin in fifteen species of Lathyrus. Thus, the genus is closer in its phytoalexin response to Pisum than to Vicia, which is known to produce furanoacetylenes on fungal in­ vasion.
Properties of an Adenosine Cyclic Phosphates Degrading Enzyme in Nicotiana tabacum L. var. Xanthi
Authors: Brennicke Axel , Frey Hans Dieter
Published: August 2018

This work describes an enzyme which degrades adenosine 3′:5′-cyclic phosphate (3′ :5′-cyclic-AMP) and adenosine 2′:3′-cyclic phosphate (2′:3′-cyclic-AMP). The reaction pro­ ducts are 3′-AMP and 5′-AMP in case of 3′:5′-cyclic-AMP, 2′-AMP and 3′-AMP when 2′:3′-cyclic-AMP is given as substrate. Inorganic phosphate acts as a strong inhibitor, whereas theophyllin does not act up to a concentration of 10-3 m . Probably the adenosine cyclic phosphates degrading enzyme has no function in a ‘second messenger’ system with 3′:5′-cyclic-AMP.
Structure of Cerebrosides I. Phrenosine at 23 °C and 66 °C
Authors: Fernandez-Bermudez S. , Loboda-Čačković J. , Čačković H. , Hosemann R.
Published: August 2018

Small angle and wide angle powder diffraction diagrams (SAXS and WAXS) have been ob­tained from samples of dry phrenosine cerebrosides prepared from beef brain. Two kinds of lamellae bundles exist within the powder at 23 °C. The first (structure I) with 15% of the molecules having a long period P of 65 Å and a paracrystalline g-value (Hosemann and Bagchi [1962]) of 4.2% consists of orthorhombic subcells similar to CnH2n + 2 (n ≧ 26) buth with larger lateral dimensions. It has an angle of 60° between the chain direction and the lamellae surface which is parallel to the (201) netplanes of the paraffin-like subcells. The second (structure II) constitutes 22% of these lamellae and 63% with a period of 49 Å and triclinic subcells similar to C20H42 . The angle between the chain direction and lamellae surface is here 45°. The SAXS reflections of structure II are analysed with a bimodal statistic which proves that the 65 Åand 49 Å lamellae are mixed statistically. At 66 °C only a structure III exists with a 52 Å long periodicity. Here all orthorhombic lamellae are built in but now their (301) netplanes are parallel to the lamellae surface. They obviously stabilize the structure instead of the (201)-netplanes which stabilize at 23 °C. A Fourier-analysis of the first 4 SAXS reflections of the relatively undistorted structures II and III projected to the normal of the lamellae surface shows a series of 21 Å wide step functions with a periodicity of 51 or 52 Å. This proves directly a head to head and teil to tail structure. The 21 Å wide heads are attributed to two galactose rings with their amide linkages and oxygens of the fatty acids and sphingosines. Knowing their size (9 Å) one unequivocally can phase the other 6 SAXS reflections which give rise to a gap of some Å’s thick between them. The gap is deeper for structure II because here lamellae of two different thicknesses are mixed. Two further small gaps in the center of the bilayers indicate the ends of the double chain molecules. From the line widths of WAXS it is evident that small paracrystallites (mPC’s) exist with 40 to 100 Å lateral dimensions. From SAXS line widths one concludes that bundles of 4 to 7 bilayers build up macroparacrystallites (MPC’s), where each bilayer consists of 10 to 25 mPC’s. Obviously the galactose rings on the surface of the bilayers produce much larger paracrystalline distortions than the methyl-end-groups in paraffins but much smaller ones than the backfolds in mats of polyethylene single crystals. Consequently 4 to 7 lamellae can be found in each MPC. The galactose rings are the cause of larger lateral distances between the paraffin-like chains and generate distortions cor­responding to a g-value of ~2.6% in the mPC’s. This is explained by the high degree of con­formational variety that the chains adopt which is larger than in synthetic polyethylene. This would further explain why all our attempts to obtain better crystallinity failed.
Notizen: Weak and Strong Phase Shifting in the Activity Rhythm of Leucophaea maderae (Blaberidae)after Light Pulses of High Intensity
Authors: Wiedenmann Gottfried
Published: August 2018

In the running activity of the cockroach Leucophaea maderae a strong phase response curve is found when using high intensity light pulses (80 000 lx and about 12 hours duration). The phase response curve has an unsymmetric shape: delays are larger than advances. The phase jump lies about 2 hours after subjective midnight.
Biochemie der Metallocene, II Organ-Verteilung und Thymus-Anreicherung von [103Ru]Cinnamoyl-ruthenocen / Biochemistry of Metallocenes, II. Organ-Distribution and Thymus Affinity of Cinnamoyl-[103Ru] Ruthenocene
Authors: Wenzel M. , Herken R. , Klose W.
Published: August 2018

Metallocenes, labelled with 103Ru, are potential radiopharmaceuticals for use in nuclear medicine diagnosis. Ruthenocene derivatives with oxopropene side-chains were administered to mice and rats to study their biochemical properties. Excretion rates and organ distributions of 103RuCl3 and Cinnamoyl-[103Ru] ruthenocene were very different. While 103RuCl3 was relatively evenly distributed in the body, the metallocene derivative was concentrated in liver, lungs and spleen after intravenous (i.v.) injection. After i.p. injection however a high thymus affinity was observed and autoradiography proved that the site of 103Ru accumulation was in thymocytes. The thymus affinity can be diminished by corticoid pretreatment and raised by inhibition of phagocytosis (BeSO4). The mechanism of accumulation in the thymus and a possible clinical application are discussed.
Gamma-Radiolysis of Aqueous Solution of Histidine
Authors: Hrnčiř Štĕpán , Kopoldová Jiřina
Published: August 2018

The dependence of Gi( - M) values of histidine on the concentration of irradiated 10-4 -10-1 ᴍ solutions, pH and the presence of O2, N2O and sec-butyl alcohol was investigated. In oxygen-free medium the maximum radiation sensitivity of histidine was found at pH 5 - 8; in oxygenated solutions it was shifted to the 6 - 11 pH range. The formation of radiation products was also studied. The course of radiation decomposition of histidine depends on the presence of oxygen and on the pH of irradiated solution.
Nonenzymatic Transformation of Riboflavin into 5,6-Dimethylbenzimidazole
Authors: Renz Paul , Wurm Rainer , Hörig Joachim
Published: August 2018

Riboflavin, the biosynthetic precursor of the 5,6-dimethylbenzimidazole moiety of vitamin B12, is transformed non-enzymatically into 5,6-dimethylbenzimidazole in small yield on treatment with 1 ɴ or 5 ɴ NaOH at 100 °C. Besides 5,6-dimethylbenzimidazole 1,2-diamino-4,5-dimethylbenzene, 1.2- dihydro-6,7-dimethyl-2-keto-1-ᴅ-ribityl-3-quinoxaline carboxylic acid and N-1-ᴅ-ribitylamino-2- amino-4,5-dimethylbenzene can be detected. When [1′-14C] riboflavin is used the 5,6-dimethyl­benzimidazole contains about 75 per cent of the specific radioactivity of riboflavin. N-1-ᴅ-ribityl- amino-2-amino-4,5-dimethylbenzene is transformed into 5,6-dimethylbenzimidazole more efficiently than riboflavin. Oxygen enhances the yield of 5,6-dimethylbenzimidazole and 1,2-diamino-4,5-di- methylbenzene from riboflavin as well as from N-1-ᴅ-ribitylamino-2-amino-4,5-dimethylbenzene. 1.2- diamino-4,5-dimethylbenzene reacts together with formaldehyde but not with formate to form 5,6-dimethylbenzimidazole under alkaline conditions at 100 °C.

It is therefore suggested that the nonenzymatic reaction of riboflavin proceeds via N-1-ᴅ-ribityl- amino-2-amino-4,5-dimethylbenzene and 1,2-diamino-4,5-dimethylbenzene, and that the latter reacts with formaldehyde preferably formed by oxidative degradation of C-1′ of the ribityl side chain to form 5,6-dimethylbenzimidazole via its unstable imidazoline derivative. The possible relevance of these results for the enzymatic process is discussed.
Sucrose Gradient Analysis: Computer Simulation and Measurement of the Parameters Involved in the Sedimentation of DNA Molecules
Authors: Macchiato M. F. , Grossi G. F. , Gialanella G. C. , Cascino A.
Published: August 2018

The Montecarlo method is used to computer simulate a random distribution of molecular lengths generated by inducing T4 DNA fragmentation through the decay of 32P atoms introduced in the molecule.

Taking into account the experimental conditions we find that the value of α for alkali sucrose gradients is 0.46 + 0.02 and does not depend on the running time. Our findings also prove that the computer simulation can be utilized to analyze sedimentation profiles of DNA molecules fragmented in vivo.
On Domain Structure and Local Curvature in Lipid Bilayers and Biological Membranes
Authors: Gebhardt C. , Gruler H. , Sackmann E.
Published: August 2018

The lateral lipid organization and the local surface curvature in small and giant bilayer vesicles of binary lipid mixtures were investigated. Mixtures of the following lipids are studied: Cholesterin, di-alcyl-lecithins, dioleyl-lecithin and di-alcyl-phosphatidic acid. The latter is considered as being representative of charged natural lipids (e.g. phosphatidyl serine or cardiolipin).

Three different experimental methods are compared: 1) The excimerfluorescence method, 2) the spin label technique and 3) the freeze fracture electron microscopy. The latter two methods yield information on the size of lipid precipitations. The surface curvature may be studied by electron microscopy. The essential experimental results are: (1) Mixtures of smectic phases of different symmetry undergo lateral phase separation. (2) The phase separation leads to a domain-like lateral lipid organization. (3) The domain structure is often accompanied by a variation in local curvature. (4) In membranes containing a charged lipid component, the domain structure may also be triggered by external charges (such as surface proteins). (5) two types of domains are observed: Circular domains (diameters of the order of several 100 Å) occur in mixtures of non-tilted fluid and rigid phases. Elongated domains (width ∼ 100 Å) are observed in mixtures of tilted and nontilted phases. This domain pattern is characteristic for mixtures of lecithins and cholesterols.

The domain structure is explained by combining the theory of spinodal decomposition of alloys with the essential result of the orientational elastic model of membranes. The domain size calculated from this model agrees well with the experimental result. The periodic ripple structure observed between the pre-and the main transition is explained by generalizing the concept of spinodal decomposition to include the separation of phases which are only distinguishable (e. g. by the tilt angle). The width of the domains in equilibrium is explained in terms of the spontaneous curvature of the decoupled monolayer of a bilayer. Good agreement with the experimental result is obtained. The ripple phase is only a special case of the surface induced domain structures in ordinary liquid crystals. The defect structure of the ripple phase has been analysed in terms of its symmetry. A symmetry rule is established which leads to a model of lipid orientation.

Below the pretransition no periodic domain pattern is observed under normal conditions. But upon cooling a bilayer very rapidly a defect structure reminiscent of a screw dislocation is ob­ served. This is expected for coupled biaxial monolayers.
Studies on the Helical Structure of β-ᴅ-1,3 Xylan
Authors: Haleem M. Abdul , Parker K. D.
Published: August 2018

The structure of β-ᴅ-1,3 xylan has been studied in detail. Atomic coordinates in the unit cell are determined. A method for calculating structure factors for the triple helical structure of β-ᴅ-1,3 xylan which is suitable for com puter and which avoids Bessel function is described. The structure is further refined by least square method. The R-value and Φ-value are minimized at 0.41 and 4.417.
Composition of the Ventral Gland-Pad Sebum from the Mongolian Gerbil, Meriones unguiculatus
Authors: Jacob Jürgen , Green Uwe
Published: August 2018

The chemical composition of the gland-pad sebum of gerbils of both sexes is analysed using gas-liquid chromatographical and mass spectroscopical techniques and compared with the lipids from distal skin areas. Cholesterol esters, with (ω-1)-methyl-substituted fatty acids as acidic constituents, were shown to occur in the gland-pad sebum of both sexes in high concentrations, whereas cholesta-3,5-diene could be detected in the males only.
Acid/Base-Induced Exchange of Adenine Nucleotides on Chloroplast Coupling Factor (CF1)
Authors: Huchzermeyer Bernhard , Strotmann Heinrich
Published: August 2018

Exchange of CF1-bound adenine nucleotides was shown to take place when isolated broken chloroplasts were subjected to an acid/base treatment. This process was measured in forward (in­ corporation of 14C-labeled nucleotides) as well as back exchange reactions (release of bound labeled nucleotides). In the presence of unlabeled ADP and Pi a high precentage of labeled ATP was found to be released into the medium.

Exchange is highly specific for exogenous ADP and ATP. Acid/base-induced adenylate exchange and acid/base-induced phosphorylation were measured in dependence of several external factors. The substrate constant for ADP in exchange was 1.6 μм, whereas an apparent Km of 5 μм was determined for ADP in the phosphorylation process.

Acid/base-induced exchange of adenine nucleotides and acid/base-induced phosphorylation depend in a similar way on the pH values of the acid and base stages.

Acid/base-induced ATP formation was sensitive to prolonged treatment in the acid stage whereas exchange was not. Mg2+ was strictly required in phosphorylation but less important in exchange. The phosphorylation ability decreased within seconds after acid/base transition; however, the ability of [14C]ADP incorporation persisted for minutes. The formation of ATP depended on an acid/base transition, whereas some adenylate exchange was also induced by an acid treatment alone.

The results suggest that appropriate pH values at the inner and outer side of the thylakoid membrane rather than energy from a pH gradient is sufficient for adenylate exchange to take place on membrane-bound CF1.
Isolation of the Major Glycoprotein (gp70) of Simian Sarcoma Virus (SSV-1/SSAV-1) in Preparative Quantities
Authors: Thiel H.-J. , Bergholz C. , Beug H. , Deinhardt F. , Schwarz H. , Schäfer W.
Published: August 2018

The major glycoprotein (gp70) of simian sarcoma virus is present in “soluble” form in the medium of virus-producing suspension cultures. It could be isolated from the supernatant of such cultures in substantial amounts by an immuno-adsorbent technique. Some of its gel-electrophoretic and serological properties are described.
Verteilung von Zink, Kupfer und Cadmium in verschiedenen Organen von Plötzen (Rutilus rutilus L .) aus Neckar und Elsenz / Distribution of Zinc, Copper, and Cadmium in Various Organs of Roaches ( Rutilus rutilus L.) from the Neckar and Elsenz Rivers
Authors: Müller German , Prosi F.
Published: August 2018

Zinc, copper and cadmium concentrations in various organs of 30 roadies (Rutilus rutilus L.) from the Neckar and Elsenz Rivers were investigated. The contents of all three metals are elevated in all fishes; however, only Cd in older fishes was found to exceed the tolerance limit for human health in a section of the Neckar River, which until 1973 was heavily contaminated with Cd from industrial wastes. The higher degree of Zn-pollution in the Elsenz River is also clearly expressed in the Zncontents of the Elsenz fishes. The following order of sequence of metal concentrations (independant of the collection area and the degree of contamination) could be observed: Zn and C d: muscle < liver <C kidney Cu : muscle < kidney < liver Our findings demonstrate the importance of fishes as indicator organism for heavy metal contamination. They also clearly implicate that for ecological rather than for human toxicological investigations the organ in which a specific metal tends to preferentially accumulate (p. ex. Zn and Cu in the kidney; Cu in the liver; Pb in the skeleton; Hg in lipids) is the best indicator of that metal. As a consequence specific fish organs should be increasingly used to determine the extent of heavy metal contamination in aquatic systems.
Flavonoid and Isoflavonoid Compounds from Leaves of Sainfoin (Onobrychis vicii folia )
Authors: Ingham John L.
Published: August 2018

The 5-deoxyisoflavones, afrormosin and formononetin have been isolated from healthy leaves of Onobrychis viciifolia. In addition to these compounds, several other flavonoid (iso-liquiritigenin; liquiritigenin; garbanzol) and isoflavonoid (medicarpin; vestitol) derivatives including the new iso-flavanone, vestitone (7,2′-dihydroxy-4′-methoxyisoflavanone), are present in leaves inoculated with the fungus Helmintho-sporium carbonum.
Eine Untersuchung der in vivo Oxidation des Capsidiols mit Hilfe der 13C-NMR Spektroskopie / A 13C-NMR Study of the Biological Oxidation of Capsidiol
Authors: Stothers J. B. , Stoessl A. , Ward E. W. B.
Published: August 2018

The mechanism of the biological hydroxylation of the isopropenyl side-chain of the sesquiterpene capsidiol, to give 13-hydroxycapsidiol, has been investigated with 13C-NMR techniques, using capsidiol biogenetically enriched with 13C from [1,2-13C2] acetate. The results indicate that neither an allylic rearrangement nor the formation of an epoxide intervene in the process.
Über den Duftstoff zweier Rißpilzarten (Agaricales, Basidiomycetes)/On the Odorous Substance of Two Inocybe Species (Agaricales, Basidiomycetes)
Authors: Schmitt Johannes A.
Published: August 2018

The Odorous Substance of the two Inocybe species I. corydalina Quel, and I. pyriodora (Pers. ex Fr.) Quel. (Agarics) had been isolated and identified by analysis and spectroscopy as methyl- cinnamate, thus providing the first demonstration of this compound in higher fungi living on soil.
Identification of Juvenile Hormone 3 as the Only JH Homolog in All Developmental Stages of the Honey Bee
Authors: Hagenguth Hartwig , Rembold Heinz
Published: August 2018

Total extracts from worker larvae, pupae, and adults of the honey bee were analyzed for their juvenile hormone contents. Using the 10-(heptafluorobutyrate)-11-methoxy derivative, the hormone was isolated in yields of 20 - 50% in nanogram quantities as calculated from isotope dilution and from gas chromatography with electron capture detection. The procedure is sensitive enough to isolate the juvenile hormone out of 1-4 grams insect material for qualitative and quanti­tative analysis. Only juvenile hormone 3 (methyl 10.11-epoxy-2-trans, 6-trans-farnesoate) could be detected as the predominant hormone homolog of all the three developmental stages. Juvenile hormone 1 (methyl 3.11-dimethyl-10.11-as-epoxy-7-ethyl-2-trans, 6-trans-tridecadienoate) could, if at all, only be identified in trace amounts, and juvenile hormone 2 was completely absent in all stages. This first systematic analysis of a hymenopteran insect shows a modulation of JH3 titre between zero and 2 ng per gram body weight during imaginal development and a rather constant JH3 titre near 10 ng per gram in the adult.
Excitation Energy Transfer among Chlorophyll a Molecules in Polystyrene: Concentration Dependence of Quantum Yield, Polarization and Lifetime of Fluorescence
Authors: Wong D. , Govindjee  , Merkelo H. , Vacek K.
Published: August 2018

Electronic excitation energy transfer was studied for chlorophyll a in a solid solution of poly­styrene by measuring the concentration quenching of quantum yield, polarization, and lifetime of fluorescence. The concentration quenching of the experimental fluorescence quantum yield is adequately described by Kelly and Porter’s empirical formula (Proc. Roy. Soc., Lond. A 315, 149, 1970), and of polarization of fluorescence by the Jablonski theory (Acta Phys. Pol., 14, 295, 1955). With increasing concentration of chlorophyll a, the fluorescence peak at 672 nm (mainly monomer) is red-shifted, the intensity of the emission peak at ∼730 nm (mainly aggregate) relative to that at the shorter wavelength is increased. The R̅0 values, calculated by using total concentrations, for the emission at 672 nm and 730 nm are 73 ± 2 Å and 45 ±1 Å, respectively. This may suggest that the chlorophyll monomers have a greater efficiency of energy transfer than the aggregates, which fluoresce at ∼ 730 nm.
Spectroscopic Studies on Vapour Phase Tautomerism of Natural Bases Found in Nucleic Acids
Authors: Nowak Maciej J. , Szczepaniak Krystyna , Barski Andrzej , Shugar David
Published: August 2018

Infrared absorption spectra, in the vapour phase, have been recorded in the regions of NH, OH and carbonyl stretching frequencies, for a series of 1-substituted uracils and 9-substituted adenine and hypoxanthine, formal analogues of the natural nucleosides of uracil, adenine and hypoxanthine found in DNA and/or RNA. A number of related analogues was also examined, including the N-methyl derivatives of the known mutagen and chemotherapeutic agent, 5-fluorouracil.

The infrared absorption spectra provide unequivocal evidence for the existence of 1-substituted uracils as the 2,4-diketo tautomer, of 9-substituted hypoxanthine as the 6-keto tautomer, and of 9-substituted adenine as the 6-amino tautomer. These are the known predominant tautomeric forms in solution, so that the gas phase results are in sharp contrast with those for other nitrogen heterocycles, where the tautomeric equilibrium constants may differ by several orders of magnitude in going from solution to the vapour phase. The significance of these results is evaluated in relation to the types of heterocyclic bases found in natural nucleic acids, and to concepts of spontaneous and induced mutations in terms of mis-pairing.

The ultraviolet absorption spectra of the various compounds have also been examined in the gas phase, but proved of relatively limited use in studies on tautomeric equilibria under these conditions.

Heats of vaporization have been determined for most of the compounds examined. In particular the heat of vaporization for 1,3-dimethyluracil, which is incapable of association by hydrogen bonding in the condensed phase, is much lower than for uracil and 1 (3) -methyluracils which can associate by hydrogen bonding.
Proteinsynthese mit Zellextrakten von Micrococcus radiodurans/ Protein Synthesis with Cell Extracts of Micrococcus radiodurans
Authors: Widmann Annette , Süssmuth Roland
Published: August 2018

Pure active ribosomes of cells of Micrococcus radiodurans could be obtained when cultivated in trypton, glucose and nutrient broth by adding natrium citrate. The optimal conditions for a cell-free protein synthesis were investigated at the (polyuridylic acid) dependent polyphenylalanine synthesis. When exchanging ribosomes and S100-fractions with the corresponding fractions of E. coli, we found that the enzyme fractions of M. radiodurans extremely inhibit the ribosomal activity. The incorporation rates in the cell-free system of M. radiodurans yield, at com parable conditions, in relation to E. coli under 10%.
Physiological Characterization of Cyanophora paradoxa, a Flagellate Containing Cyanelles in Endosymbiosis
Authors: Bothe Hermann , Floener Liliane
Published: August 2018

Culture conditions are described under which Cyanophora paradoxa grows with a generation time of less than two days. The organism is an obligate photoautotrophic flagellate unable to degrade exogenous carbohydrates via respiration. It does not synthesize nitrogenase but can form a hydrogenase with similar properties as in blue-green algae. The photosynthetic O2-evolution pro­ceeds with essentially the same rate as in green or blue-green algae. Besides CO2, p-benzochinon, nitrate and nitrite also stimulate the photosynthetic O2-evolution. Nitrite reduction is strictly light- dependent where the stoicheiometry between nitrite-disappearance and photosynthetic O2-evolution is 1:1.5. It is concluded that the cyanelles supply the eucaryotic host both with carbon and nitrogen compounds.
Isopycnic Equilibrium of Mouse Liver [131I]Albumin Digesting Particles in Sucrose Gradients
Authors: Bertini Francisco , Otta M. Eduardo , Conzalez Mercedes
Published: August 2018

The isopycnic equilibrium of [131J] albumin digesting particles from mouse liver homogenates occurs, in a sucrose gradient, at a density 1.25, and it does not change with time after albumin injection (5 to 300 minutes).
Derivate des Benzo[1.3] dioxols, 421 Über Amino-benzo[1.3]dioxole / Derivatives of 1.3-Benzodioxoles, 42 Am ino-1,3-benzodioxoles
Authors: Daliacker Franz , Erkens Leonardus , Kim In-O
Published: August 2018

We describe the preparation of the amino-1,3-benzodioxoles 1b-10b. They were prepared by reduction of 5-nitro-(1a), 6-nitro-5-methoxy-(3a), 6-nitro-5-methoxy-(4a) , and 5-nitro-4,7-dimethoxy-1,3-benzodioxole (7a) with hydrogen and palladium as catalyst.Further the amides of 1,3-benzodioxole- 4-(2a) , 4-methoxy-1,3-benzodioxole-5- (5a), 4-methoxy-1,3-benzodioxole-7- (6a), 4,5-dimethoxy- 1,3-benzodioxole-6-(8a), 4,5-dimethoxy-1,3-benzodioxole-7-(9a), and 5,6-dimethoxy-1,3-benzodioxole-4-carboxylic acid (10a) were subjected to Hofmann’s reaction.

The pKBH +-values of the amino-1,3-benzodioxoles 1b-10b and of 2,3-dimethoxyaniline were measured.

5-Amino-1,3-benzodioxole (1b) was found to be the strongest, and 4-amino-5,6-dimethoxy-1,3- benzodioxole (10b) the slightest base.
Determination of Thallium in Brain Tissue by Stable Isotope Dilution and Field Desorption Mass Spectrometry
Authors: Schulten H.-R. , Lehmann W . D. , Ziskoven R.
Published: August 2018

The utility of field desorption mass spectrometry for quantitative metal cation analysis in forensic sciences is demonstrated by the determination of a lethal thallium level in the brain tissue of an experimental animal. Stable isotope dilution and accumulation of the electrically recorded field desorption ion currents with a multi-channel analyzer allowed a direct estimation of thallium in homogenized tissue samples without further pretreatment. Experiments with standard solutions revealed the limit of detection for thallium to be about 10pg of the metal cation.
A Rapid Procedure for the Purification of Ferredoxin from Spinach Using Polyethyleneimine
Authors: Thauer R. , Schirrmacher H. , Schymanski W. , Schönheit P.
Published: August 2018

A rapid procedure for the purification of ferredoxin from spinach is described, which is based on the finding that ferredoxins can be precipitated with polyethyleneimines from acetone containing solutions. The ferredoxin was obtained in high yields (25-35 mg/kg spinach) and high purity (A420/A275= O.47) within less than 8 hours.
Ätherisches Öl in Radix Chamomillae (Matricaria chamomilla L .) / Essential Oil of Radix Chamomillae
Authors: Reichling Jürgen , Becker Hans
Published: August 2018

The essential oil of chamomil roots has been investigated. Three sesquiterpenoids could be isolated and characterized by their retention time in reference to authentic substances and by their mass spectre. These are α-farnesene, β-farnesene and bisabololoxid A. Other sesquiterpenoids and polyentype substances are present and will be identified later.
Vanadium Catalysis in the Nonenzymatic Transamination of δ-Aminolevulinic Acid
Authors: Meisch Hans-Ulrich , Hoffmann Heinz , Reinle Wolfgang
Published: August 2018

By nonenzymatic model reactions, the influence of vanadium (VO2+, VO3
−) and other metal ions (Al3+, Fe2+, Fe3+, Zn2+, Ni2+, Cr3+) on the transamination of 4,5-dioxovaleric acid (DOVA) with ʟ-alanine (Ala) to δ -aminolevulinic acid (δ-ALA) and pyruvic acid (PA) with pyridoxal phosphate (PLP) is investigated. The examinations of the partial reactions show that VO2+, VO3
− and Fe2+ effectively enhance both conversions, while Ni2+ only promotes the conversion of DOVA to δ -ALA with pyridoxamine phosphate (PMP). Besides Cr3+ , which inhibits the transaminations, all other metals tried slightly enhance both reactions. The coupled transamination DOVA/Ala to δ-ALA/PA with PLP as a catalyst is performed at 40 °C , the extent of the reaction being judged by the amount of δ-ALA formed. Among all metal ions tested, VO2+ and VO3
− were found to be the most effective ones. Fe2+, Al3+ and Fe3+ also slightly enhance the reaction, but all other metals do not influence or inhibit the transamination. In presence of VO2+ or VO3
− ions, the optimum pH of the reaction shifts from pH 4 to pH 7.4. The positive influence of vanadium on δ-ALA transamination is discussed in connection with known structures of analogous Schiff base complexes with metal ions.
Evidence for Distinct Amino Acid Transport Systems in Cultured Tobacco Cells
Authors: Berlin Jochen , Mutert Ulrich
Published: August 2018

It is shown by competition experiments that tobacco cell lines have distinct transport systems for ʟ-amino acids. For all tested amino acids the Lineweaver-Burk plots were diphasic indicating the presence of more than one carrier for any one amino acid. Moreover distinct transport systems for neutral, acidic and basic amino acids were kinetically characterized. Based on competition experiments neutral amino acids were absorbed by all transport systems. Aspartic acid entered the cells via its own carrier and via the basic carrier while arginine was taken up only by the basic carrier. Neutral amino acids such as ʟ-leucine or ʟ-phenylalanine were taken up faster than acidic or basic amino acids.
Die krebserzeugende Wirkung polycyclischer aromatischer Kohlenwasserstoffe / The Carcinogenic Effect of Polycyclic Aromatic Hydrocarbons
Authors: Contag Bodo
Published: August 2018

The two most important theories on the mode of action of carcinogenic hydrocarbons are juxtaposed by a new theory. This theory refers to ideas which have been discussed for a rather long time in silicose research and describes a mechanism whose principle will possibly be important for the specific effect of some pharmaceutica.
Peroxidatic Degradation of Flavanones
Authors: Patzlaff Martin , Barz Wolfgang
Published: August 2018

Peroxidases were shown to be responsible for the degradation of flavanones as occuring after application of these substrates to plant cell suspension cultures. - Comparative studies with various flavanones and horseradish peroxidase showed that only 4′-hydroxyflavanones will be catabolized peroxidatically. - Intensive analyses of naringenin (5,7,4′-trihydroxyflavanone) degradation by horseradish peroxidase revealed that very complex reactions with many catabolites are involved. Main degradative pathways comprise a) hydroxilation in the 3′-position, b) elimina­tion of ring B leading to chromones, c) cleavage reactions of the heterocylic ring resulting in phenolic catabolites from ring A and most important d) oxidative destruction of ring A leading to C6 - C3-, C6 - C2- and C6-C1- units from ring B. - The data are compared with the results of feeding experiments and are discussed with regard to their physiological significance.
Zufallspaarung mit teilweiser Selbstung unter verschiedenen Modellen von häufigkeitsabhängiger Selektion /Mixed Random Mating and Selfing with Different Models of Frequency-Dependent Selection
Authors: Hühn M.
Published: August 2018

Given a large population with mixed random mating and selfing (one locus-two alleles) different models of frequency-dependent selection were discussed - including a simple biometrical model for considering and analysing the competitive effects between neighbouring individuals in plant populations. For each model there were studied: changes in gene frequencies, population genetic equilibria, times until reaching these equilibria etc. - in dependence of the different parameters used: composition of the initial population, probability of selfing, selection-coefficients, competition-parameters.

Apart from only few differing results it follows from the studies performed in these investigations, that the different composition of the initial population is of no particular importance as well for the gene frequencies p̂ at equilibrium as for the time t̂ until reaching these equilibria. This result is especially right for p̂.

Different probabilities of selfing and different degrees of dominance in the selection coefficients are indeed of some influence on the existence and location of the population genetic equilibria, but here too we find an disproportionately stronger dependence with the time t̂ until reaching the equilibrium than with the gene frequency p̂ at equilibrium . The special importance of overdominance for the maintenance of genetic polymorphisms, which is well known in the case of non­ frequency-dependent selection (see: model 1 of the present studies) turn out to be of some other meaning in the models of frequency-dependent selection, which were analysed in the present paper: Depart from only few special situations (model 2 ; complete self-fertilization in models 5 and 6 ; extremely high probabilities of selfing in model 7) nontrivial equilibria are reached for all degrees of dominance. Therefore, the special importance of overdominance mentioned above, not proves right in the case of frequency-dependent selection.

The investigations of the present paper have shown, that existence and location of the non­ trivial population genetic equilibria are determined not so much by degree of dominance and probability of selfing, but the equilibria are mainly determined by the model of the investigation used in the concerning studies.

In the case of frequency-dependent selection, therefore, the explicit form of the fitness values as functions of the frequencies plays the decisive role in maintaining genetic polymorphisms.
The Variation of the Electrochromic Difference Spectrum at Various Stages of the Chloroplast Development
Authors: Renger G. , Difiore D. , Luuring B. , Gräber P.
Published: August 2018

The flash-induced difference spectrum in the range of 450 - 550 nm of protochloroplasts isolated from pea-leaves greened under intermittent illumination (2 min light, 98 min dark) was measured and compared with that of fully developed chloroplasts from pea leaves. Because of the sensitivity of the decay o fthe absorption changes to the ionophore valinomycin they were shown to mainly be due to an electrochromic bandshift of the membrane pigments (chlorophylls-a, -b and carotenoids). The differences in the shape and the amplitude between both spectra are consistently explained within the framework of a recent hypothesis supposed by Sewe and Reich (Z. Naturforsch. 33 c, 161 - 171 (1978)) by the lack of chlorophyll-b in the protochloroplasts. It is concluded, that the transformation of the protochloroplasts into chloroplasts which is accompanied by the incorporation of the light harvesting complex and the formation of grana stacks does not seriously change the orientation of the field indicating pigments within the membrane with respect of the polarity of the light induced vectorial electron transport.
Isolation of Anatomical Brain Mutants of Drosophila by Histological Means
Authors: Heisenberg M. , Böhl K.
Published: August 2018

Due to its small size Drosophila melanogaster can conveniently be used in screening experiments for anatomical brain mutants. A simple method has been designed which allows to process up to 20 identifiable flies as a single preparation in a standard histology routine. Anatomical brain mutants are very frequent. Over 60 mutants were obtained from the inspection of about 3000 brains. So far genetic variations of brain structure fall into 4 classes: (1) “low fidelity” mutants in which brains are less precisely built; (2) “brain shape” mutants with globally or partially reduced brains; (3) “architectonic” mutants which show constructional defects mainly in the repetitive structures of the brain and (4) “vacuolar” mutants with globular “holes” in certain areas of the brain. These mutant classes obviously reflect different aspects of brain development like cell pro­liferation (2), “wiring” (3) and cell death (4). Some of the mutants may prove to be useful in anatomical, physiological or genetic brain research.
Phototaktische Reaktion von Asplanchna priodonta bei monochromatischem Reizlicht/Phototactic Reactions of Asplanchna priodonta to Monochromatic Light
Authors: Hertel Horst
Published: August 2018

1. The spectral sensitivity curve of the positive phototactic reaction of the rotifer Asplanchna priodon ta has a triple peak. The maxima lie at 363 nm, 453 nm and 552 nm.

2. In the shortest wavelength tested and in the area of 453 to 594 nm was the precision of the phototactic orientation found to be high. In between lies a minimum at 395 nm, above 594 nm occurs a rapid decrease in phototactic orientation.

3. No wavelength specific differences in the way of orientation were found when using dif­ ferent monochromatic test light stimuli. This leads the same mixture of photopigments.
Notizen: Methylmercury-Induced Sedimentation Heterogeneity of T7 Bacteriophage DNA
Authors: Gruenwedel Dieter W. , Brown Susan E.
Published: August 2018

Single-stranded and methylmercurated T7 DNA is composed of two species as evidenced from the sedimentation pattern displayed during band-sedimentation in self-generating density gradients as well as during equilibrium-sedimentation in Cs2SO4 density gradients. Under the given experimental conditions, viz., at pH 9.18 and in presence of 0.1 mᴍ CH3HgOH, the two species band in Cs2SO4 with a density difference of 0.008 g/ml. The ratio of the sedimenta tion coefficients of the two species is sW
°, 20 (fast)/sW
°, 20 (slow) = 1.63 at pH 9.18 and in presence of 1.6 mM CH3HgOH. Both native and denatured T7 DNA behave as monodisperse systems in the absence of CH3HgOH.