Volume 26, Issue 1

The 220 MHz 1 H-NMR-Spectrum of a spirocompound was analysed in terms of an ABCDX Spinsystem. 4 J POCH , 3 J HH , δ H and δ p were obtained and used to determine the geometry of the molecule. The spirocompound seems to have a rigid double-chair-conformation of C 2 -symmetry.

Die intermetallischen Phasen Ca 2 LiSi 3 und Ca 2 LiGe 3 wurden dargestellt und ihre Struktur aufgeklärt. Die Verbindungen sind isotyp. Das Silicium- bzw. Germaniumteilgitter besteht aus ebenen, cis-trans-gewinkelten Ketten. Zusammenhänge mit den Kettenverbänden in den Erdalkalimonosiliciden und -germaniden werden diskutiert.

In addition to the procedure of partial oxidation of lead sulfide layers in order to increase their photoconductivity it was found that reduction may have a similar effect. When used as additives to the conventional thiourea-plumbite solution, the compounds aminoiminomethanesulfinic acid (1), rongalite or sodium dithionite, which all may form sulfoxylate in aqueous solution, enhance the photoconductivity of the deposited layers. Addition of H 2 O 2 or PbO 2 has a similar, less pronounced effect, which may also be ascribed to the intermediate oxidation of thiourea to 1.

A number of new niobium (V) - Schiff base complexes of the type Nb (SB) x (OPr i ) 5 - 2x and Nb(SB) 2 (SBH) (where SB 2⊖ and SBH ⊖ are anions of the Schiff bases and x =1 or 2) have been synthesised by the interaction of niobium pentaisopropoxide with the Schiff bases in different stoichiometric ratios. The molecular weight determinations and IR studies of a few derivatives have also been carried out. Scanty references are available in the literature regarding the Schiff base complexes of niobium (V) and tantalum (V) 1, 2 and such derivatives have been prepared from the corresponding metal chlorides and the Schiff bases. In a series of papers published earlier 3, 4 , a more convenient method, for the synthesis of such derivatives, by the interaction of metal alkoxides with the Schiff bases in anhydrous benzene medium, has been reported. The present paper describes the synthesis of several new niobium (V) derivatives with the Schiff bases derived from the condensation of salicylaldehyde or o-hydroxyacetophenone with n-hydroxyalkylamines.

At delivery commercial 59 Fe-preparations contain up to 1% contamination by 60 Co, 65 Zn, 54 Mn, 46 Sc, 134 Cs, etc., so that the physical half-life of such preparations is not constant and starts to increase permanently after about 100 days. Anion exchange chromatography was used to prepare 59 Fe with a radiochemical purity of ≧ 99.999999% as demonstrated by analytical anion exchange chromatography, paper- and thin-layer chromatography, and γ-spectroscopy. The physical half-life of radiochemically pure 59 Fe was found to be constant over 500 days with 44.52 ± 0.016 days (λ= 0.015568 ± 0.0000056 [d -1 ]). The whole-body retention of radiochemically pure 59 Fe was measured in man over one year with a 4 π-geometry whole-body radioactivity detector and utilized for the estimation of the effective half-life of 59 Fe. The correct physical half-life of radiochemically pure 59 Fe was used for the calculation of the biological half-life. Normal male subjects showed an effective half-life of 43.6 ± 0.34 days and a biological half-life of 2136 ± 807 days. This means a whole-body- 59 Fe-turnover rate of 0.032 ± 0.012%/d equivalent to 1.25 ± 0.46 mg Fe/d (for a whole-body iron pool of 3850 mg in a 70 kg man). Menstruating females were observed to have effective half-lives of 43.1 ± 0.22 days and therefore biological half-lives of 1389 ± 224 days. Their whole-body- 59 Fe-turnover rate is higher (than in males) with 0.050 ± 0.008%/d. For an optimal whole-body iron pool of 3300 mg (in 60 kg female) this would mean an iron loss of 1.65 ± 0.26 mg/d. Non-menstruating females were quite similar to males. They showed effective and biological 59 Fe-half-lives of 43.5 ± 0.48 and 1833 ± 857 days, respectively. Their whole-body- 59 Fe-turnover rate was calculated to be 0.038 ± 0.018%/d or 1.25 ± 0.59 mg Fe/d (60 kg female with 3300 mg Fe-pool). These experimental data are the first direct and reliable proof for the magnitude of daily iron loss and iron requirements in man.

It was found that bis- [p- (3-methyl-butyloxy) -phenyl] -thiourea, (applied in the therapy under the name of Thiocarlidum * as a tuberculo- and leprostatic) has two modifications in the solid state. By the aid of thermoanalitical, spectroscopical and X-ray studies it was shown, that the phase transformation arises as a result of the change in the conformtion of the molecule.

The analysis of relationships between structure and retention time in gas liquid chromatography of pentoses and hexoses leads to the formulation of following rule: the per-O-trimethylsilyl derivatives of aldoses stereoisomers with conformational stability, identical ring form and the same number of substituted OH groups are longer retained on polar columns when the equatorial substituents are more numerous and are located nearer to the anomeric carbon.

The composition of binary and ternary eutectics of homologous, nematic p,p′-disubstituted benzylideneanilines, the specifically staggered arrangement of molecules in crystals of anisaldazine-. ρ,ρ'-azodiphenetole and p-azoxyanisole, and NMR-investigations in p,p′-di-n-hexyloxyazoxybenzene lead to the suggestion that, under certain circumstances, nematic liquid crystals can enter into a short range order consisting not of individual molecules but of molecular strands of different lengths, each built up of three individual molecular chains having probably a head-to-tail sequence and turned by 180° with respect to each other. We designate such a liquid crystalline state of order as a nematic secondary structure.

The oxidation of methyl n-propyl ketone by Mn (III) sulphate in aq. acetic acid is first order with respect to the ketone and Mn (III). The rate is independent of acidity and solvent composition. The activation parameters for oxidation and enolisation were evaluated. Oxidation is faster than enolisation under similar conditions. A mechanism involving an attack on the keto-form by Mn (III) is proposed.

In the course of investigation on chemical constituents of methanol extract from the liverwort, Bazzania pompeana (Lac.) Mitt., a secondary alcohol, nonacosan-10-ol, and a benzenoid sesquiterpene hydrocarbon, cuparene, were isolated in addition to two new sesquiterpenoids, bazzanene and bazzanenol, which have been reported 2.

The uropygial (preen) gland fat of the fulmar (fulmarus glacialis) was shown to be a complex mixture of ester waxes. Acidic components were homologous series of 3-, 4- and 6-monomethylsubstituted, and 2,6-, as well as 3,7-dimethyl-substituted fatty acids. Besides, 2-methyl, 2,4-, 4,6-, and 4,8-dimethyl-substituted fatty acids could be detected. The alcoholic components belonged to homologous series of n-alkanols, and 2-, 4-, and 6-methyl-substituted primary alkanols. Furthermore, 14-methyl-hexadecanol could be identified.

Oestradiol fungiert als spezifischer Wasserstoffdonator bei der Hydrierung von 17-ständigen Oxo-Gruppen zu Hydroxy-Gruppen von Δ 4 -C 19 -Steroiden (s. frühere Untersuchungen) 1–5 . Die vorliegende Arbeit zielt darauf ab, aus den Ergebnissen von Leber-Schnittversuchen durch quantitative Analyse der oxydativ wie auch reduktiv entstandenen Metabolite die wechselseitigen reduktivoxydativen Beziehungen zwischen Oestrogenen und Androgenen zu charakterisieren. Die durch die Leberzelle hydroxylierten Metabolite werden in summa durch Messung der Bildung „hochpolarer“ Metabolite festgestellt, während die reduktiv veränderten Metabolite in möglichst breitem Spektrum identifiziert werden.

The pH-dependence of the second order rate constants of the reaction of papain with bromoacetamide in the pH-range 5,5-8,5 is described by a curve with a turning point corresponding to a pK 7,3 ± 0,1 at 25°. This is the pK of a catalytically essential imidazole residue. The activation parameters of the reaction of papain with bromoacetamide were determined. The second order rate constants at pH 7 for the reaction is 200 times greater than for the reaction of bromoacetamide with simple SH-compounds.

Antibodies were prepared against ferredoxin isolated from spinach. These antibodies and those against TPN-ferredoxin-reductase, carboxydismutase and coupling factor were used to clarify the localization of these proteins in the thylakoid membrane. Chloroplast preparations obtained by different methods show not the same immunological reactions. Only lamellar systems suspended in the leaf homogenate are agglutinated by anti-ferredoxin. Washed lamellar systems show an agglutination with anti-ferredoxin only if ferredoxin is added. In certain preparations of lamellar systems the presence of ferredoxin inhibit the reaction of anti-TPN-ferredoxin-reductase with the lamellar system. Lamellar systems freed of coupling factor by EDTA treatment are agglutinated by anti-TPN-ferredoxin-reductase. Addition of coupling factor to the EDTA treated lamellar systems inhibit the agglutination but not the adsorption of TPN-ferredoxin-reductase antibodies. By the assumption that the inhibition of the agglutination by the TPN-ferredoxin-reductase antibodies is caused by sterical hindrance, these results indicate, that ferredoxin, coupling factor and TPN-ferredoxin-reductase are localized close to each other in the thylakoid membrane. Lamellar systems suspended in leaf homogenate are agglutinated by anti-TPN-ferredoxin-reductase. That means, that to a certain extend the molecular structure of the thylakoid membrane changes with the kind of preparations employed.

During photosynthesis a metastable state is formed by superfluous excitation energy. Only carotenoids are responsible for the metastable state. Especially no chlorophyll-a is involved in this state. This result was obtained by using the repetitive ultra-short-flash technique in combination with the high frequency modulated measuring light technique.

The two autonomously manifesting mutations, eyeless (el) and white eyes (wh), of Habrobracon juglandis were compared phenotypically with the wild-type. Eyeless reduces the compound eyes in size. The penetrance is 100%, while expressivity ranges from point-shaped ommochrome crumbs over individual facets to a small eye with abundant facets. There is no correlation between the sizes of left and right eyes. The head capsule is more deformed when the eye is smaller. The homozygote ♀♀ of wild-type have smaller eyes than the hemizygote ♂♂. This gene dose effect is still stronger in el. wh causes white eye colour which remains throughout lifetime. With regard to the amount of eye pigment the three stocks can be arranged in the following sequence: wild type >el>wh. The concentrations of ommochrome precursors, however, do not agree with this sequence. The amount of 3-hydroxykynurenine in el is the same as in wild-type; although in pupal stage the peak in the former appears earlier. The kynurenine concentration in el increases at the time of pupation and induces the beginning of pigmentation earlier than in wild-type; further this process is terminated in el earlier. In wh and in wild-type the amount of kynurenine is also the same. However, there is much less 3-hydroxykynurenine in wh than in wild-type. This is presumably due to a lower kynurenine hydroxylase activity. During the entire postembryonal development there is more xanthurenic and kynurenic acid in wh; in pupal stage, even, there is a second peak. Pupae and adults of wh have a higher kynurenine and presumably also a higher 3-hydroxykynurenine transaminase activity than wild-type. The influence of the mutation wh on the differential rates of hydroxylation and transamination is discussed in relation to the results obtained with mutants of the white locus in Drosophila.