Volume 25, Issue 11

The nuclear magnetic resonance spectra ( 31 P, 19 F) of a variety of compounds containing phosphorus-fluorine bonds have been studied, in continuation of earlier investigations on the same type of compounds. The previously observed relationship between coordination number of phosphorus and δ P was generally confirmed, i. e. δ P becomes more positive as the coordination number around phosphorus increases. No meaningful substitution rules, either for chemical shifts or for P-F coupling constants, could be established. The data obtained are discussed qualitatively in relation to the electronegativity of the substituents and to the coordination number of phosphorus. Data on the preparation and characterization of numerous phosphorus-fluorine compounds are also included.

Aryl-, Benzyl- und Alkyl-Schwefelverbindungen wurden bei tiefer Temperatur photolysiert und die dabei erhaltenen Reaktionsprodukte mit Hilfe von UV-Absorptions- und ESR-Messungen sowie gaschromatographisch identifiziert. Die Existenz freier, zum Teil stabiler Thiylradikale konnte nachgewiesen werden.

The introduction of magnesium atoms into Li 3 N lattice yields 13 NMR signals for 7 Li which is the greatest number of lines ever measured in a wide line NMR spectrum for I= 3/2. The comparison with theoretical first order quadrupole spectra allowed the observation of an additional satellite system and the quantitative calculation of the changes of the asymmetry parameters. It was found, that all changes in the Li 3 N spectrum on introduction of magnesium atoms occur in the range of the lithium satellite lines, which belong to weaker bound lithium atoms outside those lattice planes containing the nitrogen atoms.

Die Konzentrations-Abhängigkeit der 31 P-Kernresonanzlinien des Phosphortribromids und des weißen Phosphors im System P 4 -PBr 3 ist beschrieben. Die Verschiebung der Resonanz von PBr 3 mit zunehmender P 4 -Konzentration nach höherem Magnetfeld wird durch die Existenz eines P 4 · PBr 3 -Komplexes erklärt. Aus diesen chemischen Verschiebungen, bei denen die Dispersionswechselwirkung zwischen P 4 und PBr 3 berücksichtigt wurde, ergab sich bei einer Temperatur von (30,0±0,5) °C eine Assoziationskonstante von K g =(0,031 ± 0,002) kg/Mol bzw. in Molenbrucheinheiten von K m =0,25±0,02. Für die chemische Verschiebung der Resonanz des PBr 3 im Komplex relativ zu reinem Phosphortribromid findet man (42 ± 2) ppm.

Reactions of titanium isopropoxide with bifunctional tridentate Schiff bases, such as salicylidene-o-aminophenol, acetylacetone-o-aminophenol and benzoylacetone-o-aminophenol and bifunctional tetradentate Schiff bases, such as bis-acetylacetone ethylenediimine, bis-benzoylacetone ethylenediimine, bis-salicylaldehyde ethylenediamine and glyoxal-o-aminohpenol have been investigated in different stoichiometrc ratios. The resulting products Ti (OPr i ) 2 (SB), Ti (SB) 2 , Ti (OPr i ) 2 (S′B′), Ti (OPr i ) 2 (S″B″) and Ti (OPr i ) (S″B″) (S″B″H) (where SBH 2 = bifunctional tridentate Schiff base, S′B′H 2 = bis-acetylacetone or bis-benzoylacetone ethylenediimine and S″B″H 2 = bis-salicylaldehyde ethylenediamine or glyoxal-o-aminophenol) have been isolated in almost quantitative yields. The molecular weights of the products soluble in benzene have been determined ebullioscopically and plausible structure indicated. The thermogravimetric analysis of the salicylidine-o-aminophenol derivatives has also been carried out.

The behaviour of molecules and particles of 2 - 400 nm radius in gel chromatography was investigated using sephadex, agarose, and pearl shaped cellulose gel of different porosity. Correlations between elution volumes and particle sizes are given in Fig. 1. We found that particles from ca. 400 nm diameter upwards were more or less irreversibly adsorbed depending on the particle size. So only 15% of rat liver mitochondria and 5% of E. coli bacteria could be eluted from the loose cellulose Cu3. It is assumed that this adsorption is due to the absence of Brownian motion of large particles, which therefore are more or less subject to the gravity and to adsorption forces of the gel.

Several trifluoroacetylated aromatic, aliphatic, monocyclic and bicyclic terpenols have been investigated by combined gas chromatography-mass spectrometry. The fragmentation patterns of these compounds are discussed.

The title compound has been synthesised by Dieckmann cyclisation of 2-ethoxycarbonylethyl 1-ethoxycarbonyl-2-propylmethylamine, followed by reduction and dehydration.

Kondensation des Quecksilbersalzes von 4-Methyl-5-acetyl-imidazol ** mit 1-Chlor-2.3.5-O-tribenzoyl-ribofuranose liefert das geschützte Ribosid 3. Zur Strukturaufklärung der Verbindung wurde 4-Methyl-5-acetyl-1-(β-D-0-2′.3′.5′-triacetyl-ribofuranosyl)-imidazol mit Methyljodid in das 3.4-Dimethyl-5-acetyl-1-(β-D-O-2′.3′.5′-triacetyl-ribofuranosyl)-imidazoliumjodid überführt und der Zuckerrest hydrolytisch gespalten. Das entstandene Imidazol-Derivat ist identisch mit 1.5-Dimethyl-4-acetyl-imidazol. 4-Methyl-5-acetyl-1- (β-D-ribofuranosyl) -imidazol wurde mit Aceton in das Isopropyliden-Derivat 4 überführt. Die Phosphorylierung zum Nucleosid-5′-phosphat (5) führten wir mit β-Cyanäthyl-phosphat durch. Durch Kondensation mit Nicotinamid-mononucleotid erhielten wir das Coenzymanaloge Nicotinamid-4-methyl-5-acetyl-imidazol-dinucleotid (6). Die Verbindung liegt im oxydierten Zustand in gefaltener Form vor. Das Fluoreszenz-Anregungsspektrum der Dihydroverbindung zeigt keine Energieübertragung vom nichtfunktionellen 4-Methyl-5-acetyl-imidazol-Teil auf den Dihydronicotinamid-Ring. Das Coenzymanaloge weist eine größere Michaelis- Konstante im Test mit Lactat-Dehydrogenase aus Schweineherz *** auf als das natürliche Nicotinamid-adenindinucleotid ***. Die maximale Umsatzzahl ist trotz der schwächeren Bindung vergrößert. Das unterschiedliche Verhalten des Coenzymanalogen 6 gegenüber NAD läßt, neben der π-Bindung des nichtfunktionellen Teils, eine polare Gruppe im aktiven Zentrum des Enzyms vermuten, die die Ausrichtung des Coenzyms im Coenzym-Enzym-Komplex bewirkt. Dihydronicotinamid-4-methyl-5-acetyl-imidazol-dinucleotid bildet einen fluoreszierenden Komplex mit der Lactat-Dehydrogenase, der dem des NADH-LDH-Komplexes sehr ähnlich ist.

The incorporation of pyruvate-[2- 14 C] into the sugars of aldgamycin E in normal fermentations and in resting cell cultures of S. lavendulae was compared. The extent of incorporation of radioactivity into the hydroxyethyl branch of D-aldgarose (3,1′-O-carbo-4,6-dideoxy-3-C-[1′-hydroxyethyl]-D-ribo-hexose) was about the same in both cases (44 - 45% of the radioactivity in aldgarose). With D-glucose-[U- 14 C] as a precursor the radioactivity was evenly distributed in the hexose chain of aldgarose and D-mycinose (6-deoxy-2,3-O-methyl-D-allose), whereas the incorporation into the hydroxyethyl branch [C-(1′)-C-(2′)] of aldgarose was negligible. Radioactivity from L-ethionine-[ethyl- 14 C] was not incorporated to a significant extent into C-(1′)-C-(2′) of aldgarose. Experiments with bicarbonate-[ 14 C] indicate that the cyclic carbonate of aldgarose originates from a carboxylation reaction. The results of experiments with oxythiamine, pyrithiamine, bisulfite, and fluoropyruvate did not allow any conclusion on the possible participation of hydroxyethylthiamine-pyrophosphate in the biosynthesis of aldgarose.

Purified, dry DNA and dry nucleoprotein were irradiated with 60 Co-γ-rays under a nitrogen or oxygen atmosphere. The DNA was isolated from the irradiated nucleoprotein. In the DNA the following radiation induced changes were investigated: Double strand breaks, single strand breaks and crosslinks between the DNA molecules. An oxygen effect (OER > 1) was found for all of these events except for crosslinks in irradiated DNA. In the nucleoprotein, the oxygen effect is more marked than in pure DNA.

The photoreaction which takes place between benz [a] pyrene and DNA by irradiation at 365 nm leads to a covalent combination. To ascertain the reactive sites of DNA, a sample of the macromolecule has been precipitated after irradiation in the presence of benz [a] pyrene and hydrolized; among the products of hydrolysis four different fluorescent substances have been isolated, one of which was identical with the photoadduct benz [a] pyrene-thymine, already prepared by irradiation of the two substances at 365 nm. This photoadduct has been obtained in an amount corresponding to a molecular ratio 1 : 7000 in respect to the nucleotides (P atoms) present in the sample of DNA.

The interactions between human haptoglobin, Hp II (genetic types 2 - 1 and 2-2), and bovine hemoglobin, Hb, were investigated taking inhibition of complex formation and complex dissociation in various solvent media as criteria. As shown by relative peroxidase activity and gel chromatography, complex dissociation occurs at high concentrations of guanidine HCl, urea, sodium chloride, dioxane, and formaldehyde, while in case of sodium dodecylsulfate a low molar ratio (SDS/Hb -Hp<5) is sufficient to split the complex. In general the formation of the complex stabilizes the structure of its constituents. Excluding solvent conditions which lead to denaturation (as measured by optical rotation), ionpairs and H-bonds seem to prevail in the stabilization of the complex, while hydrophobic interactions should be of minor importance. Chemical modification of histidine and tyrosine with diazonium-1-H-tetrazole and N-acetylimidazole, respectively, prove histidyl-groups in Hb and tyrosylgroups in Hp to participate in the Hb-Hp contact, thus confirming earlier results.

Rats were hepatectomised and subsequently diethylnitrosamine was applied orally (2 mg DENA/kg/d). Compared with a non-treated control group the mean survival time was lowered from 225 to 158 days. In a second experiment repeated hepatectomies were performed. All these rats were killed after 40 weeks and after a total DENA dose of 351 mg/kg. By histological examination of the livers a higher rate of hepatomas was found in the hepatectomised group. Thus the proliferating processes during liver regeneration seem to favour the hepatocarcinogenesis under DENA treatment.

The temporal pattern of control by phytochrome of the enzyme lipoxygenase (EC 1.13.1.13) in the mustard seedling (Sinapis alba L.) is described. The biosynthetic system which produces lipoxygenase does not respond to phytochrome (Pf r ) up to 33.25 h after sowing (25°C). By this time the control by Pf r comes suddenly and fully into play. At 48 h after sowing the system escapes from the control by Pf r . Neither the beginning nor the end of the period of control is influenced by phytochrome. Interpretation of the data requires a double action control mechanism. It is argued that such a mechanism is necessarily a characteristic of development in multicellular organism.

Die an wildfarbigen Hauskaninchen zu verschiedenen Zeitpunkten im ersten Lebensjahr vorgenommenen Messungen des Haarmusters haben erwiesen, daß die Ausbildung des adulten Felles nicht von der Anzahl der neu gebildeten Haargenerationen abhängt, sondern ausschließlich vom Alter des Tieres. Das lokale Induzieren von Haargenerationen außerhalb der natürlichen Mauser brachte keine vorzeitige Ausbildung der einzelnen Haarabschnitte und der Gesamtlänge der Haare mit sich. Die Entwicklung des Haarfarbmusters verlief relativ kontinuierlich und erreichte im letzten Drittel des ersten Lebensjahres ihren Abschluß. Der Einfluß des Bindenbreitengens W bzw. w wurde bei den Mittelwerten der betreffenden Haarabschnitte, nämlich der Binde und k 1 (= Binde + Spitze), in induzierten wie in natürlichen Haargenerationen deutlich. Der Zuwachs der Spitzen erfolgte unabhängig davon, ebenso das Längenwachstum der Gesamthaare, wobei die Haare erst nach einem Jahr voll ausgewachsen waren.

Cell walls of Bifidobacterium bifidum var. pennsylvanicus were isolated. The polysaccharide consisted of glucose, galactose and rhamnose. Teichoic acid was not present. The murein (peptidoglycan) contained MurNAc, GlcNH 2 NAc, ᴅ-Glu, Ala. ʟ-Ser, ᴅ-Asp and L-Orn in a ratio of about 1 : 1 : 1 : 2 : 1 : 1 : 1. In one batch a high amount of ʟ-glutamic acid was found. It was not a constituent of the murein since it remained in the lysozyme insensitive residue. The amino acid sequence of the murein was determined by analyzing the oligopeptides arising during partial acid hydrolysis. It was shown that the peptide subunits attached to the muramic acid are the same as in many other mureins: ʟ-Ala-ᴅ-Glu-ʟ-Orn-D-Ala. The interpeptide bridge consisted of β-ᴅ-aspartyl-ʟ-serine. Since about 35% of aspartic acid and 6% of ornithine are N-terminal in the cell wall, it was assumed that only 60% of the peptide subunits are cross-linked. 4 other strains of B. bifidum proved to contain the same type of murein. While all other strains of other species of Bifidobacterium investigated contained other types of murein, it seems likely that the Orn-Ser-Asp type of the murein is typical of B. bifidum.