Volume 25, Issue 4

The absorption spectra of 2′ hydroxy 1-methyl 2-stilbazolium iodide, 3′ hydroxy 1-methyl 2-stilbazolium iodide, 3′:4′ dihydroxy 1-methyl 2-stilbazolium iodide and 4′ hydroxy 3′ methoxy 1-methyl 2-stilbazolium iodide in different solvents have been studied in the region 200 mμ -1100 mμ. Three bands have been observed in their solutions in different solvents. Based on the available evidences the bands have been assigned to different intramolecular transitions.

The activation free energies of the hindered internal rotation around the C-N bond for N,N-dimethylcinnamamide, N,N-dimethylcrotonamide, and N,N-dimethylsorbinamide obtained by the NMR line-shape method are 16.5, 14.9, and 16.2 kcal/mole, respectively. The relation between these values and the structure of the compounds is discussed.

Previously developed harmonic force fields for cyclopropene and cyclopropane were used to calculate some spectroscopic quantities of interest in refined structure studies: (a) mean amplitudes of vibration and (b) perpendicular amplitude correction coefficients for cylopropene, cyclopropene-1,2-d 2 , cyclopropene-3,3-d 2 , cyclopropene-d 4 , cyclopropane and cyclopropane-d 6 . Also reported are the (c) atomic vibration mean-square amplitudes for the light and heavy (completely deuterated) compounds.

Hydrodynamic shearing forces appearing during nucleoprotein gel-filtration on Sephadex G-25 cause a disruption of the macromolecular structure in nucleoproleins. The effect of these shearing forces can be observed both in electron micrographs and by electro­phoretic analysis. The decrease of the molecular weight and also the changes in the electronegative charge,mole­cular weight ratio cause an increase of the electrophoretic mobility of the gel-filtered highly poly­merized DNA and of the RNA complexed to it compared with the not gel-filtered nucleoprotein.

25-Desoxyecdysteron und Ecdysteron werden im Fettkörper von Larven der Schmeißfliege Calliphora erythrocephala umgewandelt in Glykoside. Aus enzymatischen und chemischen Untersuchungen schließen wir, daß 3β- (α-Glucopyranosido) -Derivate der Hormone gebildet werden. Bereits 30 Min. nach Injektion von 3 Calliphora-Einheiten/Larve sind 85% des Hormons in das Glykosid umgewandelt. Im Erfolgsorgan Epidermis findet weder eine Glykosid-Synthese statt noch wird das Glykosid in stärkerem Ausmaß von der Epidermis aufgenommen. Die Glykosidbildung erfolgt durch eine Uridindiphosphalglucose: Ecdysteron-Transglucosylasc.

It was shown by the polarographic data of the complexes between antracycline antibiotics and DNA that in contrast to their biological inactive aglycones and other antracyclinones, a cooperative interaction of the intercalating chromophore as well as the sugar residue of the anthracycline molecules, is generally responsible for the complex formation with DNA. The high complex binding constants of the antracyclines daunomycin, nogalamycin, galirubin A and galirubin B measured in dimethylsulfoxid-buffer solution are in the same order of magnitude as those of actinomycins. On the other hand, only a weak binding ability of the aglycones daunomycinon, ε-pyrromycinon and aklavinon, as well as of other investigated anthracyclinones and model hydroxyanthraquinones, could be observed. No significant influence of the number and positions of the chromophore hydroxyls could be noticed. The results suggest that the first outerphase addition of the sugar residues to the backbone of the helix gives the necessary space of time for the slower intercalation process of the planar chromophore. In the case of denatured DNA, the antibiotic-DNA-complex has a lowered stability. The important role of the sugar residue for the binding mechanism strongly suggests that modifications of the nature and position of the basic sugar residue should be most valuable for the synthesis of new effective anthracyclines.

The addition of linolenic acid to chloroplasts and sub-chloroplast particles has pronounced effect on light induced absorption changes. At a concentration of 10 -4 M linolenic acid or [LINO] /[CHL] ≈ 2 (on a mole to mole basis) spectral changes associated with System II are diminished to 50 percent. In this same range there is also a small increase in the spectral change ascribed to System I; this increase may reflect the action of linolenic acid in uncoupling phosphorylation. While at [LINO] / [CHL] ≈ 4, light induced absorption changes of System II are completely blocked, there seems to be no inhibition of System I. The effects of linolenic acid on the 515 nm spectral change are interpreted as an increase in the permeability of the thylakoid membrane.

1. Fluorescence changes of umbelliferone have been used as indicator for pH changes in the outer phase of the functional membrane of photosynthesis. In combination with the repetitive pulse technique it is possible to measure the pH change which is produced during one turn-over of the molecular machinery (Δ pH ≈ 10 −4 ). The analysis of this primary pH changes gives insight in the primary ionic events in general. 2. The rise of the primary pH formation takes place in 20-30 ms. The decay is at 20°C of first order with k ≈ 0.7 s −1 or τ ½ ≈ 1 s. 3. The rise of the pH formation corresponds to the decay of the electrical field across the membrane (pHout 7, pH in 7, isotonic solution). 4. The amplitude of the primary pH change indicates the ratio of the field driven K ⊕ and H ⊕ efflux across the membrane **. This has been proved by membrane active substances which are specific for K ⊕ and H ⊕ permeabilities respectively. 5. The ratio of the field driven K ⊕ and H ⊕ efflux depends on the pH in . At pH in 7 (pH out 7) the field drives 100% K ⊕ . With decreasing pH in the efflux shifts from K ⊕ to H ⊕ (at pH in 5, pH out 7 50% K ⊕ and 50% H ⊕ ). 6. The field driven K ⊕ efflux causes the formation of the pH changes. The field driven H ⊕ efflux causes no pH changes. 7. The K ⊕ channel and the H ⊕ channel and its regulation by pH in lead to an extended concept of the coupling of the primary events in photosynthesis. This is discussed in chapter II and fig. 4.

With the aid of a repetitive laser giant pulse photometer the rise times of two primary events in photosynthesis have been measured: a) The oxidation of chlorophyll-a I takes place in times shorter than 20 ns. b) The formation of metastable carotenoids is faster than 25 ns.

Bei Mus musculus und Aethomys namaquensis findet man ein Haarmuster, das demjenigen der Kaninchen einigermaßen gleicht: in beiden Fällen bilden die schwarzen Spitzen und die farblosen bis rötlich-gelben Binden zusammen einen Abschnitt konstanter Größe κ 1 . Der Wert κ 1 zeigt wie bei den Kaninchen prozentual und absolut die geringste Abweichung der Einzelwerte vom jeweiligen Mittelwert. Daher kann man folgern, daß der Abschnitt κ 1 den genetisch fixierten Abschluß für das Binden-Spitzen-Muster wildfarbiger Haare darstellt. Die durchschnittliche Aufteilung von κ 1 in Spitze und Binde bei verschiedenen Arten (bei Hausmäusen und Namaratten 1 : 3, bei Kaninchen 1 : 1 oder 3 : 1) basiert auf Allelen, über die noch nichts bekannt ist. Dagegen wird die Unterteilung des Einzelhaares in Spitze und Binde durch andere, nicht genetisch festgelegte Faktoren gesteuert, über die am Beispiel von Kaninchen an anderer Stelle berichtet werden soll. Zwischen Spitze, Binde und κ 1 bestehen Korrelationen, die bei Aethomys und Mus musculus annähernd identisch sind: Binden- und κ 1 -Werte sind stark positiv korreliert, Spitzen- und Bindenwerte sind schwach negativ korreliert und die Spitzen sind bei beiden Rassen sehr kurz mit einem recht einheitlichen Mittelwert von 0,5 mm. Die Mittelwerte für die Binden- und κ 1 -Werte streuen bei beiden Rassen ohne größere Sprünge jeweils um einen einheitlichen Mittelwert, so daß die Frage offen bleiben mußte, ob die Tiere dem genetischen Typ W/W oder w/w zuzuordnen sind. (Beide genetische Typen wurden für Kaninchen nachgewiesen.) Der Anteil der schwarzen Rückenhaare war bei Aethomys namaquensis stark negativ korreliert mit der Bindenbreite, d. h. je schmaler die Binden eines Felles sind, desto mehr schwarze Haare treten auf. Bei wildfarbigen Hausmäusen hat der Rücken eine einheitliche grau-braune Farbe. Die Fellfarben der Aethomys zeigen dagegen Schattierungen von grau-braun bis stark rötlich. Eine photometrische Untersuchung ergab, daß bei etwa gleichem Farbton des Pigments die Unterschiede in der Helligkeit auf Unterschieden am sichtbaren Schwarzanteil aller Haare beruhen (aus Spitzenlänge und Anzahl der einfarbig schwarzen Haare zusammengesetzt). Für die Unterschiede in der Sättigung ist wichtig, daß man die Binde in ihrer vollen Länge im Fell sehen kann, ihr Endstück also nicht wie bei Kaninchen durch andere schwarze Spitzen verdeckt wird. Je länger die Binde bzw. κ 1 , desto größer fällt der Wert für Intensität oder Sättigung aus. Daraus folgt, daß der Farbeindruck der verschiedenen Aethomys-Felle auf der Ausdehnung der Binde bzw. der Länge des Haarabschnittes κ 1 beruht. Die Farbrassen der Namaratten, die im allgemeinen am Waterberg ein dunkleres Fell zeigen als in der Wüste Namib, können aufgrund der Kreuzungsversuche und der kontinuierlichen Mittelwerte für die Bindenbreiten als Modifikationen eines Allels gedeutet werden.

35 S-Sodium sulphate was orally applied to the larvae of Araschnia levana-prorsa. After eclosion a characteristic pattern of radioactivity could be observed on the wings of the imagines. The pigment change of Araschnia levana-prorsa caused a modification of the radioactivity pattern in the wings, which was proved by means of a radioautographic method. The red scale areas emitted the strongest radiation, whereas the radiation of the dark and the light areas was considerably weaker. The possibility of introducing 35 S into the dark and light pigment matrices, as well as the direct introduction of 35 S into the molecule of the red pigment Ommatin D, is dealt with.

Young leaves of Kalanchoe daigremontiana are hurt with a “hedgehog” (a holder with 30 needles) to produce wounds of equal size in great numbers and definite intervals. Infection of these leaves with suspensions of Agrobacterium tumefaciens, strain B6, results in first small tumors as soon as 7 days after infection. A quantitative evaluation of the experiments is possible 14 days after infection. The number of induced tumors increases linearly with the logarithm of the concentration of the bacteria. The diameter of tumors (21-d-old), too, depends on the concentration of the bacteria. - The tumors mass a product of the relative success of infection I (number of tumors per number of wounds, and the average tumor diameter gives a third measure of the bacteria concentration. An application of this hedgehog-test is given: If the infecting bacteria are treated with lysozyme and EDTA the success of the infection decreases with increasing time of treatment. This decrease is reduced by the presence of 11% sucrose.

Using immunological techniques we tried to determine the localization and orientation of the sulpholipid of diloroplasts in thylakoids. During immunization of rabbits with lamellar systems of chloroplasts of Antirrhinum majus antisera were obtained which precipitated sulpholipid emulsions. Antibodies against the sulpholipid were not detected until a second series of intravenous injections. By immunizing purified sulpholipid of Fucus serratus, adsorbed to methylated bovine serum albumin, sulpholipid antisera were acquired. These antisera and the antisera against lamellar systems of Antirrhinum majus reacted with preparations of sulpholipid from widely different plant species. The sulpholipid antisera did not react with emulsions of the mono- or digalactosyl-diacyl glycerol, of lecithin or the anionic phosphatide phosphatidyl glycerol. Lamellar systems isolated without osmotic shock on a sucrose gradient were not agglutinated by sulpholipid antisera directly, but an indirect agglutination could be achieved in a Coombs-test or in a mixed antigen agglutination after Uhlenbruck. Broken chloroplasts, however, were agglutinated directly by sulpholipid antisera, as well lamellar systems which had been disrupted in a French-press or by ultrasonic treatment. From agglutination and agglutination inhibition experiments with lamellar systems prepared by different methods it is concluded that the determinant groups of the sulpholipid are accessible for antibodies in the lamellar system of chloroplasts. But probably the sulpholipid molecules are located inside the thylakoids.