Band 19, Heft 8

Der magnetische Suszeptibilitäts-Effekt bei der Protonenresonanz-Verschiebung wird untersucht. Die bisherigen Daten aus der Literatur sind in vielen Fällen durch Effekte anderer Art scheinbar verfälscht. Die experimentellen Ergebnisse stehen jedoch tatsächlich in Einklang mit der theoretischen Erwartung. Die Messungen an diamagnetischen und paramagnetischen Medien ergeben für den Suszeptibilitäts-Verschiebungsfaktor den Wert 2,09.

Molybdändibenzol bildet mit Trifluorphosphin unter hohem Druck kristallines, farbloses Hexakis-(trifluorphosphin) -molybdän (O): Der typische Durchdringungskomplex ist stabiler und flüchtiger als Molybdänhexacarbonyl, dem er in seinem physikalischen und chemischen Verhalten weitgehend gleicht. Bei Hochdruckumsetzungen von Trifluorphosphin mit Molybdänhexacarbonyl erhält man Gemische der Verbindungen Mo (PF 3 ) 6 - n (CO) n (n ≥ 2). Hingegen bildet Mesitylen-molybdän (O) -tricarbonyl mit Trifluorphosphin unter Druck quantitativ das ebenfalls farblose, kristalline und sehr flüchtige Tris- (trifluorphosphin) -molybdän (O) -tricarbonyl: IR-Spektren, Struktur und Bindungsverhältnisse der diamagnetischen Verbindungen werden diskutiert.

Virus-like particles found in the epidermis of carps affected with “carp-pox” are described. In the nuclei of the host-cells round to ovoid particles, surrounded by a single-layered membrane with a diameter of appr. 110 mμ are observed. In the cytoplasm the virus-like particles have a doublelayered membrane and a diameter of about 140 mμ. In both nucleus and cytoplasm, forms of the virus occur differing withs respect to their nucleoids. It is suggested, that the virus-like particles represent a virus belonging to the Herpes-group.

Der magnetische Suszeptibilitäts-Effekt bei der Protonenresonanz-Verschiebung wird untersucht. Die bisherigen Daten aus der Literatur sind in vielen Fällen durch Effekte anderer Art scheinbar verfälscht. Die experimentellen Ergebnisse stehen jedoch tatsächlich in Einklang mit der theoretischen Erwartung. Die Messungen an diamagnetischen und paramagnetischen Medien ergeben für den Suszeptibilitäts-Verschiebungsfaktor den Wert 2,09.

Most of the 32 P-labelled RNA absorbed to suspended tissue culture cells can be removed by RNase treatment. During the first 15 minutes of incubation - after which time the maximum of adsorption is reached - roughly one third of the cell bound RNA resists RNase treatment (Tab. 2). While on further incubation the total amount of cell bound RNA remains constant, some more of this RNA is converted from an RNase sensitive to an RNase resistant state (Tab. 1).

The excretion and distribution of 137 Cs in a 60 year old male given a single dose of 8,2 μC through a gastrostomy have been studied. The excretion rates and the concentrations in faeces, urine and blood are presented, as well as the distribution of 137 Cs in several of the internal organs removed after death. The biological half-life for cesium in this study is approximately 100 days.

The primary reactions of photosynthesis are fast reactions. To get detailed informations we developed three different methods. 1. sensitive flash photometry 38 , 2. periodically chemical relaxation 51, 26a , 3. manometry in flashing light groups 26b . With the method of flash photometry fast absorption changes in suspensions of chlorella and spinach chloroplasts were studied. 7 different types of absorption changes have been separated and analysed (Fig. 2). Older results 28-49 lead to a reaction scheme published in l. c. 13 . This scheme was refined (s. Fig. 3) by results published in l. c. 14-26 . In the following 6 papers these investigations are described in detail and supplement by new results. Separation of the difference-spectrum of chlorophyll-al (P 700) in 5 ways. Under “normal” conditions (exciting Hill - active chloroplasts with blue light between 380 and 480 mμ or with red light between 620 and 720 mµ) mixed changes of absorption can be observed between 400 and 800 mµ (Fig. 4, this difference-spectrum does not include the changes with τ<10 -3 sec, s. Fig. 2). Out of this overall difference-spectrum one component with changes of absorption at 430 and 703 mμ could be separated by using the following different systems: a) aged chloroplasts reactivated by addition of reduced DPIP or reduced PMS (ascorbate in excess) (Fig. 5), b) plastoquinone-extracted chloroplasts [extraction with petroleumether] (Fig. 6), c) digitonin-treated chloroplasts reactivated by addition of reduced PMS [ascorbate in excess] (Fig. 7), d) chloroplasts at -150°C with addition of reduced PMS [ascorbate in excess] (Fig. 8), e) chloroplasts under the influence of far-red background-light [728 mµ] (Fig. 9). Kinetics. During the flash the absorption at 430 and 703 mµ decreases very fast (<10 -5 sec). In the dark the back reaction takes place in ≈10 -2 sec at 20°C (s. Fig. 10). This reaction time is always observable in the presents of far redbackground light λ>700 mμ. (The detecting light at 703 mµ can act already as far red background light.) At very low itensities of far red background light the backreaction takes place however in <10 -4 sec (details s. l. c. 25a ). Identification of chlorophyll-al. The upper results (5 equal spectra under different conditions) suggest that the changes of absorption at 430 and 703 mμ are caused by one substance. This was additionally proved by comparing the magnitude and the kinetic of both changes in reactivated aged or digitonin-treated chloroplasts under different conditions. The ratio of the amplitudes and the halflifes are identical at 430 and 703 mµ at different values of pH (Fig. 11 and Fig. 12) and also at different concentrations of added reduced PMS (Fig. 13). Decreases of absorption just within the two absorption bands of chlorophyll-a indicate that very probably a chlorophyll-a (Chl-aI-430-703) is in action. From the magnitude of the changes of absorption at 703 mμ it follows, that Chl-al has a concentration of 0,1% of the bulk of chlorophyll. Oxidation of Chl-ai. The decreases of absorption indicate an oxidation of Chl-al in the light. This is proved by the fact, that in aged or digitonin-treated chloroplasts reduced PMS can be directly coupled to the light product. This is demonstrated by the strong acceleration of the back reaction with increasing concentrations of reduced PMS (Fig. 13 and Fig. 15) and by the demonstration of a first order back reaction (Fig. 14 and Fig. 15). The experimental results are theoretically explained. It is proved, that the light product Chl-aI ⨁ reacts with PMSH ⊖ [compare measuring points and theoretical curve in Fig. 12] [s. scheme (1)]. From the measurements it follows a reaction constant of 1,5·10 7 l/Mol·sec (Fig. 15) and an energy of activation of 3,8 kcal/Mol (Fig. 16) for the reaction of Chl-aI ⨁ with PMSH ⊖ . Chl-aI-oxidation as a primary act. The fact, that Chl-ai ⊕ is built up within <10 -5 sec (20°C) [Fig. 10] and that Chl-aI ⨂ could be trapped at -150°C (Fig. 8 and Fig. 17) give evidence, that this oxidation is a primary act. The electron acceptor of Chl-ai is called Ζ. Ζ ⊖ reduces via intermediary products TPN. Under the reported conditions a - e one light reaction cycle (I) of the overall electron transport system of photosynthesis has been isolated [s. scheme (1) and (2)].

The effect of far-red background-light. In chlorella or chloroplasts with added Hill - oxidants far-red actinic light between 700 and 730 mμ oxidizes Chl-a I ; in the dark Chl-a I ⊕ stays in this oxidized state. Actinic light in the range λ<700 mμ results also in an oxidation of Chl-a I , but in the dark Chl-a I ⊕ is reduced. Therefore light of λ<700 mμ is channeled into two reaction centres. One part (hν I )is channeled to Chl-a I (with the effect of oxidation of Chl-a I ), a second part (hν II ) is channeled to a second reaction centre where it provides electrons for the reduction of Chl-a I ⊕ [s. scheme (1)]. Under the influence of far-red background-light (700 -730 mμ) Chl-a I accumulates in its oxidized form. The magnitude of its oxidation depends on the intensity of the background-light. a) In soft far-red background-light practically no Chl-a I ⊕ is accumulated (s. Fig. 1 a). A supplementary red flash (<700 mμ) at t 1 with hν I and hν II -light should have the following effect: The hν I -light oxidizes Chl-a I immediately. The hν II -light provides electrons from a second reaction centre for the reduction of Chl-a I ⊕ . b) In stronger far-red background-light Chl-a I accumulates in its oxidized form (Fig. 1 b and Fig. 1 c). A supplementary red flash (<700 mμ) at t 3 or t 5 oxidizes the rest of Chl-a I immediately. Afterwards all Chl-a I ⊕ is again reduced. - Changing from soft to stronger far-red background-light a shift from negative changes of absorption of Chl-a I to positive ones is aspected (Fig. 1 a′ and 1 b′). However, in chloroplasts without any added Hill- oxidants no shift takes place (Fig. 2 top). This indicates that no accumulation of Chl-a I ⊕ has occurred. The reason is, that Chl-a I ⊕ can be reduced by a backflow of electrons from the electron acceptor Z [s. scheme (2)]. Trapping the electrons of Z ⊖ by electron acceptors (ox. S I ) prevents the backflow [s. scheme (3)] and positive changes of absorption occur (Fig. 2 bottom). By shifting the changes of absorption of Chl-a I from negative to positive values it is possible to separate the difference-spectrum of Chl-ai from the overall difference-spectrum under complete natural conditions (s. Fig. 4 and 1. c. 1 ). Electron-acceptors of Z ⊖ . All substances surnamed under ox. S I (Table I and Fig. 11) trap electrons of Z ⊖ (shift from negative to positive changes of absorption at 703 mμ). In this way it was shown, that also photosynthetic-pyridine-nucleotide-reductase (PPNR) - but not TPN alone - traps electrons from Z e . Therefore PPNR must contain a redox system [ferredoxin] [s. scheme (4)]. From the highest redox potential of ox. Si (methyl viologene) that of Z/Z ⊖ (≲ -0,44 volt) was estimated. Water as the ultimate electron-donor for Chl-a I . CMU blocks oxidation of water. If water is the the ultimate electron donor for Chl-a I , turnover of Chl-a I should vanish in the presence of CMU [s. scheme (5)]. This is true for chlorella, but not for chloroplasts without ox. Si (Fig. 5 midth). The reason is again the backflow of electrons from Z ⊖ to Chl-a I ⊕ which keeps the cycle in action. Trapping the electrons of Z ⊖ by addition of ox. Si results in the disappearence of the changes of Chl-ai (Fig. 5 bottom). In aged chloroplasts, where Chl-a I ⊕ is supplied directly by electrons of PMSH ⊖ , addition of CMU should have no influence on the changes of Chl-a I (Fig. 6). a) Redox potential. By addition of different ratios of ferro/ferricyanide the ratio of Chl-a I /Chl-a I ⊕ can be changed in the dark. This is shown by the dependence of the light induced changes at 703 mμ on the ratio of ferro/ferricyanide (Fig. 7). The oxidation of Chl-ai occurs by a single electron transfer. The redox potential of Chl-a I ⊕ /Chl-a I was determined to +0,46 ± 0,1 volt. b) The Chl-ai-reaction is stable between p ʜ = 3 and p ʜ = 11 (Fig. 8). c) The Chl-ai-reaction is stable up to 65°C (Fig. 9). d) Aging up to 7 days at 5°C has no influence upon the Chl-ai-reaction (Fig. 10). Reaction Scheme. The results are summarized in Fig. 11 and Table 2. In chlorella and fresh chloroplasts Chl-a I ⊕ is reduced by electrons originating from water with the help of hν II -light. After suppressing water-oxidation (by aging, extraction of plastoquinone, treatment with digitonin, addition of CMU) 1 Chl-a I ⊕ can be reduced by backflow of electrons from Z ⊖ or by added electron-donators as reduced PMS or reduced DPIP. The electrons of Z ⊖ can be trapped by TPN (via ferredoxin) or substances surnamed under ox. S I .

The carcinogenic hydrocarbon 3.4-benzopyrene is soluble in aqueous solutions of different proteins. The solubilities are easily determined by the fluorimetric method. The fluorescence o. the hydrocarbon in the protein solutions is not quenched by molecular oxygen. Nevertheless only in presence of air (oxygen) an irreversible decrease of the fluorescence intensity occurs under irradiation with UV-light of wavelength 366 mμ, which is considerably faster than under nitrogen or in solutions of the hydrocarbon in ethanol or aqueous caffeine. In the systems investigad, a correlation was found between the half-life period of the reaction and the SH-group activities. The participation of protein-SH-Groups in the 3.4-benzopyrene photoreaction is demonstrated by ampèrometric Ag⊕-titrations. The influence of protein denaturation and inhibiting additives on the photoreaction are investigated by the fluorimetric method. Irradiation- and oxygen-dependence of the reaction are analogous to the observations of photodynamic action and skin cancer induction by 3.4-benzopyrene. By 366 mµ irradiation of β-lactoglobuline solutions containing 3.4-benzopyrene the heatdenaturation characteristics of the protein are changed. The same changes are produced without 3.4-benzopyrene by UV-light of the wavelength 280 mµ. Treatment of the β-lactoglobuline solutions with an amount of cigarette smoke, which certainly does not contain 3.4-benzopyrene in sufficient concentration, acts in the same direction. Along with the changes in the protein properties the typical fluorescence of 3.4-benzopyrene vanishes. The hydrocarbon does not act as a catalyst in photodynamic action, but is chemically altered as well as the protein, at least in the system under investigation.

Die Verbreitung des Lignanglykosids Arctiin in der Familie der Compositae wurde untersucht. In 20 Arten konnte die Verbindung neu nachgewiesen werden. Die Verteilung dieses Pflanzenstoffes stützt die bekannte Auffassung der Systematik von einer engen Zusammengehörigkeit der Carduinae und Centaureinae.

The incorporation of tritium into carbohydrates during photosynthesis with Chlorella was investigated. The fixation of 14 C and T was compared by providing 14 CO 2 and HOT simultaneously. The intramolecular distribution of T in hexose and glyceric acid was determined by degradation. The incorporation of T during the carboxydismutase, the aldolase and triosephosphate-isomerase reaction was studied in enzyme systems. The results indicate that - in general - incorporation of T into the products of photosynthesis is due to isomerisation reactions. The influence of isotope effects at various stages of the photosynthetic cycle on the final T-content is discussed. The intramolecular T-distribution in the glucose from starch is different from that of soluble glucose derivatives. To interpret this, it is assumed that the isomerisation of fructose-6-phosphate to glucose-6-phosphate firstly is completely intramolecular in intact Chlorella and secondly shows a large discrimination for tritium-containing (at C-1) molecules. Thirdly, it is proposed that the sequence of reactions from fructose-6-phosphate to starch occurs in a multienzyme system without exchange with free sugar phosphate-pools.

Bei Ratten traten nach einer letalen Ganzkörper-Röntgenbestrahlung mit 1000 R ein starker Gewichtsverlust, eine Vergrößerung der Nebennieren und eine Corticoidvermehrung im Nebennierengewebe auf. Bei den Veränderungen im Corticoidgehalt der Nebennieren nach Bestrahlung ließen sich zwei Perioden unterscheiden. In einer ersten Periode von 48-stdg. Dauer kam es zu mehrfachen Zu- und Abnahmen in Form von Schwankungen um den Kontrollwert. In der zweiten Periode vom 3. Tage ab nahm der Corticoidgehalt der vergrößerten Nebenniere stark zu; er lag bei den männlichen Tieren am 6. Tag nach der Bestrahlung 93%, bei den weiblichen Tieren am 7. Tag nach der Bestrahlung 79% über dem Kontrollwert. Die Versuchsergebnisse zeigen, daß es bei letal röntgenbestrahlten Ratten nach 3 Tagen zu einer Steigerung der Nebennierenrinden-Aktivität kommt, die bis zum Tod der Versuchstiere anhält. Dieser Befund wird mit den Literaturangaben verglichen und diskutiert.

Actinomycin D blockiert in den Konzentrationen von 1 - 10 γ/ml im steigenden Maße und relativ spezifisch die Synthese morphogenetischer Substanzen im Zellkern von Acetabularia mediterranea. Dagegen wird die Auswirkung eines bereits im Cytoplasma vorhandenen Speichers an morphogenetischen Substanzen nur wenig beeinflußt. Aus Transplantationsversuchen zwischen den Arten A. mediterranea und crenulata (cren 0 med 1 -Transplantate) geht hervor, daß die Actinomycinhemmung die Synthese der artspezifischen, genomabhängigen morphogenetischen Substanzen betrifft. Diese Substanzen sind Überträger genetischer Informationen. Am Zellkern der Alge ruft Actinomycin D RNS-Verarmung hervor. Die sich ergebenden Beziehungen zwischen artspezifischen morphogenetischen Substanzen und Informations- (messenger) -RNS sowie die möglichen Ursachen für die kleinen cytoplasmatischen Hemmwirkungen des Actinomycins werden diskutiert.

Deskriptive und experimentelle Untersuchungen führten zur Bestätigung einer alten Hypothese R. GOLDSCHMIDTS: Die Schuppen der Querbinden des zentralen Symmetriesystems auf dem Vorderflügel von Plodia interpunctella entwickeln sich langsamer als die Untergrundschuppen der Umgebung. Die Modifikation des Schuppentyps -wird durch diese Entwicklungsverschiebung bestimmt, die ihrerseits durch den Ausbreitungsvorgang determiniert wird.