Volume 24, Issue 10

Die untersuchten Komplexverbindungen der homogenen Hydrierungskatalysatoren IrX (CO) L 2 mit ungesättigten Verbindungen R 1 CH = CHR 2 sind thermodynamisch um so stabiler, je kleiner die Elektronendichte am Iridium und in der C = C-Doppelbindung ist.

Analog zu den Iridiumkomplexen IrX(CO)L 2 sind auch die entsprechenden Rhodiumverbindungen RhX(CO)L 2 Katalysatoren für die homogene katalytische Hydrierung von Olefinen und ungesättigten Verbindungen. Die Rhodiumkomplexe RhX(CO)L 2 bilden jedoch mit molekularem Wasserstoff keine isolierbaren Hydridkomplexe RhX (CO) L 2 H 2 .

Es wird gezeigt, daß die Anwendung der Gleichung von Svedberg, die den Zusammenhang zwischen Diffusionskoeffizient und Sedimentationskoeffizient liefert, auf eine reversibel assoziierende Substanz die Bestimmung des Gewichtsmittels des Mol.-Gew. gestattet.

Saturated ethanol vapour in an atmosphere of nitrogen was expanded in a cloud chamber. The condensation arising thereby was shown by light scattering. At the same time the temperature curve occurring after the expansion was measured by means of a resistance thermometer. Experiments with twenty different expansion ratios (from E=1,083 to E= 1,324) were carried out at room temperature. The expansions were polytropic at n = 1,24. Supersaturations were obtained at about 1,3 and 1,5 regardless of E and never attained the critical value of 2,1. Nevertheless a condensation was shown every time, although nuclei were not present. The cloud vanished shortly after its appearence, long before the initial temperature could be reached again. The formation as well as start and finish of the evaporation of this “subcritical fog” can be traced exactly in the registered temperature curves. The simultaneous light scatteringand temperature measurement make a stronger interpretation of the temperature curves recorded by STACHORSKA also possible.

The complexation reaction of magnesium and 3,5-dinitrosalicylic acid has been investigated by potentiometric method in aqueous 0.1 M KNO 3 medium. The formation constants (log K) of the complex MgA predominating in the pH range 6 — 9 have been found to be 2.30, 2.425 and 2.65 at 25, 30, and 35°C respectively. The values of overall changes in ΔF, ΔH and ΔS accompanying the reaction have also been evaluated at 30°C and found to be —3.385 kcal/mole, —13.71 kcal/mole and —34.0 cal/degree respectively.

Chemische Verschiebungen von Phosphorkernen in Verbindungen mit Phosphor der Koordinationszahl 3, 4, 5 und 6 sind tabellarisch zusammengestellt und werden z. T. diskutiert. Die Kopplungskonstanten J PH und J PF sind — soweit bekannt — angegeben.

The electronic spectra of MoO 3 S 2⊖ and WO 3 S 2⊖ are measured in aqueous solution. They are discussed and compared with electronic spectra of other thiomolybdates and -tungstates.

Methylthiophosphonsäureamidfluorid, CH 3 P (S) FNH 2 , und Äthylthiophosphonsäureamidfluorid, C 2 H 5 P(S)FNH 2 , reagieren mit Trimethylchlorsilan in Gegenwart von Triäthylamin zu den Verbindungen CH 3 P(S)FNHSi(CH 3 ) 3 und C 2 H 5 P(S)FNHSi(CH 3 ) 3 . Mit PCl 5 läßt sich Äthylthiophos-phonsäureamidfluorid zum C 2 H 5 P(S)FN = PCl 3 umsetzen. Durch partielle Ammonolyse von Phenylthiophosphonsäuredifluorid erhält man C 6 H 5 P(S) FNH 2 . Bei der Reaktion von P 3 N 3 F 5 NH 2 mit PF 3 Cl 2 entsteht P 3 N 3 F 5 N = PF 3 . Die entsprechende Umsetzung mit C 3 N 3 F 2 NH 2 ergibt C 3 N 3 F 2 N = PFCl 2 . Mit FSO 2 NH 2 reagiert PF 3 Cl., sowohl zum FSO 2 N = PF 3 als auch zum FSO 2 N = PF 2 Cl. IR-, 19 F- und 1 H-KMR-Spektren werden angegeben.

Die Darstellung von und wird beschrieben und ihre Eigenschaften werden mitgeteilt. Die Verbindungen lassen sich anhand ihrer IR- und 19 F-KMR-Spektren unterscheiden.

Potential energy constants of the G.V.F.F. type, generalised mean square amplitudes of vibration, shrinkage effect and Coriolis coupling coefficients of PClF 4 molecule are evaluated from spectroscopic data. The results are discussed in relation to the structure of the molecule.

Potentiometric studies are described for mixed ligand complex formation of copper(II) with iminodiacetic acid (IMDA) as primary ligand and certain hydroxy acids, such as salicylic acid (SA), 5-sulphosalicylic acid (SSA), tiron (3.5-pyrocatechol disulphonic acid PDS) and chromotropic salt (3,6-disulpho-1,8-dihydroxynaphthalene disodium salt CS) as secondary ligands. The pH titrations of the reaction mixtures containing copper nitrate, iminodiacetic acid and one of the secondary ligands in equimolar concentrations indicated the formation of 1:1:1 mixed ligand complex. From the nature of the titration curves it appears that in the lower buffer region 1:1 copper (II) -iminodiacetic acid complex is initially formed and the formation of mixed ligand complex takes place only after the combination with the primary ligand is complete. However, in the case of Cu (II) -IMDA-HQSA system it appears that the mixed ligand complex is not formed stepwise, but the chelation with both the ligands takes place simultaneously. The formation constants (log K) of the mixed ligand chelates of Cu (II) -IMDA-SA. Cu (II)-IMDA-SSA. Cu (II) -IMDA-Tiron and Cu (II) -IMDA-CS system have been calculated. All the titrations were carried out at room temperature (25±1°C) using 5 × 10 3 м concentration of metal and ligand ions (μ= 0.1) with the help of potassium nitrate.

The OH radical rapidly reacts with CH 3 NH 2 and C 6 H 5 NH 2 but reacts slower with CH 3 NH 3 ⊕ , respectively C 6 H 5 NH 3 ⊕ . In the reaction with methylamine. the complex is formed which loses water with τ½=26 µs. The addition of OH to the aromatic ring of aniline occurs in 20% of the reactions. The hydroxy-amino-cyclohexadienyl radical has its absorption maximum at 3500 A. It decays by elimination of water to yield the anilino radical C 6 H 5 NH (τ½= 5.7µs at pH = 7), H ⊕ and OH ⊖ ions catalyse the decay. In 80% of the reactions. · OH adds to the amino group of aniline. The subsequent loss of water or of OH ⊖ occurs rapidly (<1 µs). However, the basic form of the addition complex decays much more slowly (τ½=10 µs at pH= 13.7). The pK-value of the equilibrium is estimated to be equal to 11 — 12. The absorption spectra of C 6 H 5 NH 2 ® and the pK-value of 7.0 of C 6 H 5 NH 2 ⊕ first described by LAND and PORTER are confirmed.

The NQR spectra of chloroderivatives of benzenediazonium tetrafluoborates have been investigated at 77 K. The temperature dependence of some of the NQR frequencies was measured. The correlation between the NQR frequencies and substituent parameters is pointed out and the strong influence of the inductive effect on the NQR frequencies is discussed. The 2,4,6-trichlorobenzenediazonium tetrafluoborate crystallizes in two modifications as shown by NQR spectroscopy.

Unabhängig vom Lebensalter und Sklerosegrad enthalten menschliche Aorten gleichartig aufgebaute Chondroitinsulfat- und Heparansulfat-Peptide, wobei das Verhältnis der Chondroitinsulfat-Peptide A und C etwa konstant bleibt. Der Gehalt menschlicher Aorten an Chondroitinsulfat-Peptiden ist in Abhängigkeit vom Lebensalter und Sklerosegrad verschieden. Den höchsten Gehalt hat die Aorta bei beginnender Sklerose. Einen gleichartigen Gang in der quantitativen Verteilung findet man beim Heparansulfat-Peptid.

1. Nach Zusatz von Nucleinsäuren zu wäßrigen Toluidinblaulösungen treten neue Farbqualitäten auf. Ihre Absorptionsmaxima lagen bei 655, 585 und 555 nm. 2. Art und Umfang dieser Metachromasie sind abhängig vom Reaktionsmilieu, vom Farbstoff-Polyanionen-Konzentrationsverhältnis sowie von Molekülgröße und Nativität der einzelnen Nucleinsäurepräparate. 3. In wäßrigen Proteinlösungen gelöste hochmolekulare DNS-Präparate verhalten sich gegenüber DNS-Lösungen ohne Proteinzusatz wie Präparate höherer Nativität. 4. Änderungen der metachromotropen Eigenschaften von DNS-Protein-Lösungen sind qualitativ und quantitativ als empfindlicher Nachweis für denaturierende Einflüsse (Hitze, ionisierende Strahlen, UV-Licht, Ultraschall, Tris- (β-chloräthyl) -amin oder DNase I) verwertbar.

A considerable number of saponins and aglycones of the triterpene type has been tested for hemolytic activity. From the results it is deduced, that the optimum hemolytic activity depends on the following structural arrangements. Aglycones require a polar grouping in ring A and a moderate polar grouping in ring D or E. Compounds containing a 16α-OH or 16-keto group together with a 3/β-OH group had the highest hemolytic potential of the substances tested. The distance of 10,5 A between 3/β-OH and 16α·ΟΗ appears to be of special significance. Acylation of either group results in a remarkable loss of activity. With saponins, which bear a sugar chain on 3/β-OH, the distance between the strong and the weak polar grouping is less critical. The composition of the sugar chain has a certain influence on the hemolytic power. A polar grouping in ring D and/or E, such as a sugar chain or a number of OH-groups, results in considerable inactivation of the substance.

A new method is described for separating cystine peptides from other peptides after hydrolysis of native bovine insulin by the specific protease thermolysin using paper shields instead of column chromatography. The application of this method to sequence determination of other species insulins is possible. In contrast to the proteolytic fraction (α-protease) from Crotalus atrox venom, thermolysin rapidly hydrolyzes all susceptible peptide bonds in native insulin in high yields. Therefore, the amounts of substrate required to sequence determination are low compared with the known methods involving the denaturation and chemical splitting of polypeptides before proteolysis, such as the mercaptolysis of insulin, carboxymethylation of the A- and B-chain and column chromatography of the reaction products. The yields of the isolated chains are too low for further enzymatic digestion and analysis if the substrate is available only in minimal quantities. Instead of thermolysin, it is in principle possible to use any other bacterial protease, e. g. subtilisin, but the products of hydrolysis of insulin are easily soluble in water so that the fractionation in soluble and insoluble peptides before isolation is not possible. Thus, thermolysin is a valuable tool in sequence analysis of cystine-containing polypeptides.

An estimation of the dose relationship of intestinal iron absorption in man is only reasonable if a reliable method for the measurement of iron absorption is used, and the amount of available storage iron, which influences iron absorption considerably, is considered. Intestinal 59 Fe 2⊕ -absorption was therefore quantitated by measuring the whole body retention of absorbed 59 Fe within a 4 π-large volume radioactivity detector with liquid organic scintillator. The diagnostic 10 μΜοl (⧋ 0.558 mg) 59 Fe 2⊕ -absorption test was used for discriminating between persons with normal 59 Fe-absorption due to normal iron stores and persons with very much increased 59 Fe-absorption caused by depleted iron stores. Within a dose range from 0.56 to 50 mg 59 Fe 2 ® the bilogarithmic plotting of the estimated 59 Fe 2⊕ -absorption (in mg) against the iron dose resulted in a straight line, which can be described in males and females with normal iron stores by the equations R mg = 0.206 · D 0.676 and R mg = 0.250-D 0.668 respectively. In males and females with depleted iron stores the dose relationship can be characterized by the absorption equations R mg =0.594·D 0.684 and R mg =0.731·D 0.650 respectively. The whole body 59 Fe turnover rate in man (= iron requirement) and the dose relationship of intestinal 59 Fe-absorption are a suitable experimental basis for the oral iron prophylaxis and therapy.

The incorporation of thymidine-2- 14 C-monophosphate (TMP) after UV and X-ray irradiation in two diploid Saccharomyces strains with different radiation sensitivities of colony-forming ability was measured to determine the rate of DNA synthesis. The sensitive strain was homozygous for a gene causing UV and X-ray sensitivity (r 8 1 r 8 1 ) whereas the resistant strain was homozygous for the corresponding wild type alleles (++). The TMP-incorporation was measured for a period of three hours either immediately after irradiation or after an intervall of 3 or 6 hrs. in nutrient medium without radioactive TMP. The dose effect curves obtained were generally biphasic with a steep slope at low doses and with a shallow slope at high doses. The values obtained for the r 8 1 r 8 1 -strain were significantly lower than those of the + + -strain. The difference in the rate of DNA-synthesis increased with increasing interval between the time of irradiation and the time of application of TMP.

Es wird die Wirkung des Orotaldehydoxims, des Orotaldehydthiosemicarbazons, des Orotaldehydsemicarbazons und des Orotaldehydphenylhydrazons als potentielle Antimetabolite der Orotsäure auf das Wachstum von Neurospora crassa untersucht. Die höchste wachstumshemmende Wirkung zeigt das Orotaldehydthiosemicarbazon. Der wuchshemmende Effekt der untersuchten Orotaldehyd-Derivate wird durch Orotsäure enthemmt.

Macrophages have been cultured as uniform cell populations. These cells incorporate uridine but not thymidine into their nucleic acids during the culture period. Sheep erythrocytes in the presence of macrophage cytophilic antibodies were agglutinated to rosettes and phagocytized. Cytophilic antibodies did not have to be species specific; phagocytosis was not complement-dependant. During phagocytosis, incorporation of H 3 -uridine into the RNA was increased. Sucrose gradient analysis showed that the increase in uridine incorporation was mainly due to increased m-RNA synthesis.

In Präparaten von Mäuse-Leukämie-Viren (MLV) läßt sich ein Hämagglutinin nachweisen, wenn man sie mit Neuraminidase und Phospholipase C bebrütet. Die entsprechende, mit Hammel-Erythro-cyten reagierende Komponente besitzt die Sedimentationseigenschaften und die Schwimmdichte der MLV-Partikeln. Ihre hämagglutinierende Wirksamkeit wird durch typspezifisches, nicht aber durch typfremdes Antiserum inhibiert. Aus diesem Verhalten wird geschlossen, daß das nachgewiesene Hämagglutinin einen virusspezifischen Bestandteil der MLV-Partikeln repräsentiert, der wahrscheinlich mit einem typspezifischen Antigen gekoppelt ist. In den unbehandelten Viruspartikeln scheint das Hämagglutinin durch Glykoproteide und Phospholipoide, die wahrscheinlich von der Membran der Wirtszelle herstammen, in seiner Funktion behindert zu werden.

In all analysed tissues of Acheta domestica two DNA fractions are present. The amount of the heavier satellite fraction is very small, but considerably increased in the ovaries of young females, which possess an extrachromosomal DNA body in the oocyte nucleus. Evidence is presented that the heavier fraction is at least partly identical with the DNA body.