bluuebunny/crossref_metadata_2025 huggingface dataset:
Anlagerung von Aminoacyl-tRNS an Rattenleber-Ribosomen
Authors: Kramer Gisela , Klink Friedrich
Published: February 2015

Interaction of Phe-tRNS with Poly-U-linked ribosome subunits from rat liver was investigated at different Mg2 +⃝-concentrations with and without transfer enzymes. Using Mg2 +⃝-concentration optimal for protein synthesis Phe-tRNS binding was found only in the presence of both complementarily acting transfer enzyme fractions with peptide synthesis simultaneously occurring. At high Mg2®-concentrations Phe-tRNS was bound non-enzymatically to ribosomes.
Analyse des Vermehrungsmechanismus des Newcastle disease Virus (NDV) mit Hilfe verschiedener Inhibitoren
Authors: Schäfer Werner , Pister Liselotte , Schneider Rita
Published: February 2015

The reproduction of NDV in chick-embryo-fibroblast cultures was studied with 6-Azauridine, 8-Azaguanine, Parafluorophenylalanine (FPA) and Puromycine as inhibitors. The results suggest that no virus initiated FPA-sensitive material is needed for the uncoating of the infecting particles, and that viral parental RNA is able to induce the formation of protein (s) needed for viral RNA-synthesis (“RNA-protein“) as well as the production of viral structural antigen (s). Further antigenic material appears after the beginning of new viral RNA-synthesis. The “RNA-protein (s)“become (s) detectable between 2 and 3 hours after infection and is (are) stable in its function over several hours. According to the formation of viral antigenic material parental viral RNA can act as a messenger longer than 9 hours. The capacity for the production of hemagglutinating units appears after the viral antigen producing capacity, when viral RNA can already be synthesized. This capacity is separated from that to produce plaque forming particles by a FPA-sensitive phase. The character of the corresponding FPA-sensititve material is unknown.
Der Nucleinsäure-Stoffwechsel der Rattenmilz während der Synthese von Antikörpern gegen Brucella abortus
Authors: Kröger H. , Papanastasiu D.
Published: February 2015

1. 3H-Thymidin und 3H-Cytidin werden sehr rasch in die DNS bzw. RNS der Rattenmilz eingebaut.

2. Während der Erstimmunisierung mit Brucella abortus ist der Nucleinsäure-Stoffwechsel in der Rattenmilz gesteigert; die DNS-Synthese nimmt wesentlich mehr zu als die der RNS.

3. Die Basen-Zusammensetzung der Kern-RNS wird durch Immunisierung leicht verändert.

4. Während der Zweitimmunisierung mit Brucella abortus ist der Nucleinsäure-Stoffwechsel in der Rattenmilz ebenfalls gesteigert; die RNS-Synthese erreicht das Maximum schneller, die DNS-Synthese langsamer als bei der Erstimmunisierung.
Über die Funktion der sauren Hefephosphatase
Authors: Günther Th. , Kattner W.
Published: February 2015

Die auf der Zelloberfläche lokalisierte, dereprimierbare saure Hefephosphatase hat keinen Einfluß auf anaerobe Glykolyse und Wachstumsgeschwindigkeit. Bei Phosphatmangel kann sie der Hefezelle im Medium vorhandene Phosphatester als Phosphatquelle erschließen. Die saure Hefephosphatase ist nicht identisch mit der intrazellulär wirksamen Phosphatase.
On the Fate of Methanol and Ethanol in the Adult Larva of the Cotton Leaf Worm (Prodenia litura F.)
Authors: Zayed S. M. A. D. , Hassan A. , Fakhr I. M. I.
Published: February 2015

The metabolic fate of C14-methanol and 1-C14-ethanol in the adult larva of Prodenia litura has been investigated in vivo. Following the intersegmental injection of C14-methanol (1.2 mg/g. insect), about 70% of the radioactivity was recovered as C14O2 in the expired air, after 20 hours. Also, about one fourth of the administered dose was recovered as unchanged methanol, during the first six hours. Only a minute trace of C14-formate was found in the excreta. It is suggested that a catalase-peroxide system is involved in the oxidation of methanol. Ethanol and its metabolites were eliminated at a slower rate than methanol. After 20 hours, C14O2 - being the major C14-metabolite - accounted for 56% of the applied dose. In addition, there is at least one minor non-volatile C14-metabolite eliminated in the excreta of ethanol-treated larvae.
Micro Determination of Molybdenum (VI) with Phenylazoxine S Dye
Authors: Goyal S. S. , Tandon J. P.
Published: February 2015

Micro determination of molybdenum (VI) with 7-phenylazo-8-hydroxyquinoline-5-sulphonic acid is described. Molybdenum (VI) forms yellow, water souble complex in the pH range 2.5 — 5.5. 1:1 (M:L) stoichiometry has been established by (i) JOB’s and (ii) molar ratio methods. The colour reaction is instantaneous and the colour intensity remains unchanged for about 24 hours. The Beer's law is obeyed from 0.2 to 8.0 ppm of molybdenum per ml. The molecular extinction coefficient of the complex has been found to be E400 mµ =1.38 × 104, giving Sandell's sensitivity coefficient 0.0069 μg of molybdenum per cm2.

The values of formation constant (log K) and free energy of formation (JF°) obtained by three methods are 5.40 ± 0.3. 5.20 ± 0.15, 5.62 ± 0.03 and (-7.50 ± 0.40, —7.22 ± 0.20, —7.80 ± 0.04 K.cals) respectively. The interference due to a number of anions and cations in the determination of molybdenum (VI) has also been studied.

Azoxine S dyes having the general formula:

(where R represents substituted benzene ring)

have been found to form yellow, water soluble complexes with a number of metal ions. The dyes have been mainly used as metal ion indicators in recent years 1—5. However, a few physico-chemical studies on the complexation reactions of these dyes have also been reported 7—9.

In the present investigations, a detailed study of molybdenum (VI) complex of the 7-phenylazo-8-hydroxy-quinoline-5-sulphonic acid has been carried out and it has been shown to form 1:1 complex in the pH range 2.5 to 5.5. The reaction is quite sensitive and can be used for the micro determination of molybdenum (VI).
In vitro-Neubildung von Leber-Polyribosomen in Gegenwart von Leberzellkern-Fraktion
Authors: Aepinus K. F.
Published: February 2015

Bei der in vitro-Proteinsynthese mit pH 5-Überstand, tRNA und Cysteamin an Leber-Polyribosomen wird in Gegenwart von Leberzellkern-Fraktion eine Neusynthese von Polyribosomen beobachtet. Ein Übertritt der Orotsäure-6-14C in vivo markierten mRNS und des 3H-1-Arginin markierten Kernprotein vom Kern auf die Ribosomen bzw. Polysomen kann gezeigt werden. Polyribosomen, die vor der in vitro-Proteinsynthese 10 min bei 35 °C erwärmt werden, zeigen eine verminderte Anlagerung von mRNS und Kernprotein und eine Reduzierung der Proteinsynthese. Die Diskussion ergibt, daß eine Stabilisierung der mRNS durch Kernprotein angenommen werden kann.
Die Verteilung 51Cr-markierter Clostridien-Sporen in Tumor-tragenden Ratten
Authors: Wenzel Martin , Eissner Dagmar
Published: February 2015

Tumorgewebe wird mangelhaft mit Sauerstoff versorgt. Bei der i. v. Injektion von anaerob auskeimenden Sporen von Clostridium butyricum finden daher die Sporen nur im Tumorgewebe einen geeigneten Nährboden.

Mit Hilfe Tumor-tragender Ratten wurde daher untersucht, ob bei der i. v. Injektion von 51Crmarkierten Sporen sich eine bevorzugte Sporen- und damit Aktivitätsanreicherung im Tumorgewebe im Vergleich zum Normalgewebe feststellen läßt. Entsprechende Verteilungsstudien wurden in vivo durch Szintigraphie und nach Töten der Versuchstiere durch Aktivitätsmessung in den einzelnen Organen ausgeführt.

Die Ergebnisse zeigen eine bevorzugte Aktivitätsanreicherung im RES. Der zentrale nekrotische Bereich der Tumoren besaß eine erhöhte spezifische Aktivität gegenüber den Tumorrandgebieten.
Enzymatisch isolierte Cellulose-Fibrillen der Valonia-Zellwand
Authors: Franke Werner W. , Falk Heinz
Published: February 2015

Cellulose microfibrils from the cell wall of the green alga Valonia macrophysa were isolated by enzymatical digestion of the wall matrix and examined in the electron microscope using the negative staining technique. The smallest fibrils obtained after prolonged treatment were found to be flat ribbons with a width about 10—20 nm and a height of 3 to 4 nm. This result is discussed in relation to Frey- Wyssling's concept of an “elementary fibril“ with a cross-section of 3.5 × 3.5 nm. Some alternation of unstained areas along the fibrils was observed. This was interpreted as artificially induced rather than relating to the structure and the arrangement of the cellulose chain molecules.
Über die Bindung von 4-Hydroxy-2.3-enalen an Protein-SH-Gruppen
Authors: Schauenstein E. , Dorner F. , Sonnenbichler J.
Published: February 2015

4-Hydroxy-pentenal und 4-Hydroxy-octenal reagieren prompt mit Glutathion, wobei es zur Addition der SH-Gruppe an die Doppelbindung des Aldehyds kommt. Die Aldehyd-Gruppe bildet sodann im Sekundärschritt mit der Hydroxy-Gruppe an C4 ein zyklisches Halbacetal. Das Reaktionsprodukt liefert mit 2.4-DNP-Hydrazin das Hydrazon eines gesättigten Aldehyds und reagiert auch mit Schiff schem Reagenz positiv. Die Reaktion von Hydroxy-enalen mit Glutathion und das dabei gebildete Reaktionsprodukt dient als Modell für die Reaktion der Hydroxy-enale mit isolierten und zellständigen Proteinen.
Über den Einfluß verschiedener Glycerinkonzentrationen auf die Ausbeute in einem Eisen(II)-sulfat-Dosimeter (Fricke-Dosimeter)
Authors: Lamprecht Ingolf , Umlauf Christa , Stein Werner
Published: February 2015

The oxidation of ferrous to ferric iron is used as a measure of the effect of ionizing radiation in Fricke dosimeter solution in the presence of glycerine at various concentrations. At low glycerine concentrations the sensitivity of the system to X-rays was found to be increased by the presence of the alcohol while at higher concentrations a radiation-protection effect was observed. The increased sensitivity rose to a maximum at glycerine concentrations of 0.01 to 0.1 Mol, the size of the maximum depending on the duration of the radiation. The peak represents a sensitivity of about twice the normal ion conversion. The falling off at low concentrations is explained on the basis of a model where the presence of alcohol leads directly to increased ferric ion yield, that at high concentrations as being due to increased viscosity of the system. Other alcohols showed similar results.
Zur Kinetik der strahleninduzierten Wasserstoffabspaltung aus Thymin
Authors: Heitkamp D. , Merwitz O. , Späth H.
Published: February 2015

Im Anschluß an Messungen der Tritiumabspaltung aus γ-bestrahltem Thymin-(methyl-T) und Thymin-6-T wird ein kinetisches Modell für die während der Bestrahlung ablaufenden Reaktionen diskutiert. Die auf Grund dieses Modells berechneten Dosiseffektkurven stimmen mit den gemessenen im Dosisbereich 105— 5 · 108 rad sehr gut überein.
II. P-Tosyl Lysine and P-Tosyl Glutamic acid
Authors: Reyes Joseph , Frye Herschel
Published: February 2015

Several complexes have been prepared with selected divalent transition metal cations and either p-tosyl lysine or p-tosyl glutamic acid; both acids were the L isomer. These complexes were synthesized in dilute aqueous solution and have been studied polarographically. Eight previously unreported compounds were prepared and studied, and their dissociation constants and coordination numbers are reported in this paper. The calculated Free Energies of Formation are also reported.
Kernresonanzspektroskopische Untersuchungen an Nitrilen III
Authors: Wendisch Detlef
Published: February 2015

Es wird über die Analyse der Kernresonanzspektren einiger aliphatischer Nitrile berichtet. Solvenseffekte und Rotationsisomerie-Phänomene werden untersucht und diskutiert.
Acid Carboxypeptidases: Their Occurrence in Plants, Intracellular Distribution and Possible Function
Authors: Zuber H. , Matile Ph.
Published: February 2015

Saure Carboxypeptidase, welche Phenylalanin von CbO-Leu-Phe-OH bei pH 5,3 abspaltet, ist ein in höheren Angiospermen weit verbreitetes Enzym. Es scheint dagegen in primitiven Angiospermen (Fagus und Magnolia) sowie in Gymnospermen und Kryptogamen (Ausnahme: Equisetum) zu fehlen. Bei Zitrone ist die Aktivität saurer Carboxypeptidase von Natur und Alter der extrahierten Gewebe abhängig (Exocarp und Endocarp der Früchte, Blätter). In Zellen der Wurzelspitzen von Maiskeimlingen ist das Enzym in meristematischen Vakuolen lokalisiert. Funktionell ist die saure Carboxypeptidase als lysosomales Enzym, welches am intrazellulären Proteinabbau teilnimmt, anzusprechen.
Ein chemischer Nachweis für bösartige Geschwülste im Blutserum
Authors: Neunhoeffer Otto
Published: February 2015

Im Eiweiß bösartiger Geschwülste läßt sich ein sehr spezifisches Reduktionsvermögen gegenüber Au3® nachweisen. Dieses wurde auch im Blutserum Krebskranker gefunden. Hier ist jedoch die Menge des durch Reduktion gebildeten elementaren Goldes zu gering, um eindeutig sichtbar zu werden. Man kann jedoch zur Verstärkung auf den Goldkeimen Silber aufwachsen lassen, so daß ein eindeutig sichtbares rotviolettes Kolloid entsteht- Die Spezifität der Reaktion wurde bis jetzt an ca. 400 Fällen geprüft.
Untersuchungen über Nebenreaktionen und den sterischen Verlauf bei der Direkt-Markierung einfacher Verbindungen mit Tritium-Gas
Authors: Simon Helmut , Schmidt Klaus , Müllhofer Gerhard , Eder Walter , Medina Ramiro
Published: February 2015

Free tartaric acids, various tartrates, malic, hydroxymaleic, fumaric and aspartic acid, as well as propane diol-1.2 have been labelled by the Wilzbach method. In propane diol, hydrogen attached at C-2 is substituted by tritium three times faster than a hydrogen atom of the methyl group whereas that at C-l is substituted two times faster. Splitting of a carbon-carbon bond and fixation of tritium is eight to nine times more probable than the substitution of hydrogen by tritium. The OH group in propane diol as well as in tartaric and malic acid is more often replaced by atomic tritium than hydrogen atoms fixed at carbon. During the formation of malic acid from tartaric acid the second center of asymmetry is not attacked. The replacement of the OH group occurs in the cases of the free acid and the dimethylester to a high degree under inversion. Is the calcium or copper salt exposed retention prevails. In meso tartaric acid the carbon bound hydrogen is substituted with 12% inversion. When glycolic acid is formed from copper L-tartrate 29% inversion takes place.
a-6-Isomerie der Cyano-aquo-Corrinoide
Authors: Friedrich Wilhelm , Moskophidis Matthäus
Published: February 2015

The isomerisation of the a and b forms of several acid cyano-aquo-corrinoids (with one to four carboxyl groups or one phosphoric acid group) in aqueous medium was investigated. The reaction is accelerated by light, heat, anions (e.g. acetate ion) and carbon monoxide. For all cyano-aquo-corrinoids with carboxyl groups investigated the equilibrium a ⇄ b shifts in the direction a → b when the carboxyls dissociate; in the case of carbonic acids prepared from cobyric acid, the shift grows with the number of the carboxyls. On the contrary, the cyano-aquo-corrinoids with a phosphoric acid group (cobinamide phosphate and its three isomers) exist as a mixture of about 55 per cent a form and about 45 per cent b form in the entire pH range (2.5 to 9) investigated. It is shown that the isomerisation of the cyano-aquo-corrinoids follows the known rules of ligand exchange (and of the connected reactions, such as steric change, racemisation, and disproportionation) for cobalt (III) complexes.
Die Reaktionen des weißen Phosphors mit Dimethyldisulfid unter γ-Bestrahlung
Authors: Scheffler M. , Drawe H. , Henglein A.
Published: February 2015

Trimethylthiophosphite and red phosphorus are formed when solutions of white phosphorus in dimethyldisulfide are exposed to γ-radiation. The red phosphorus has a high content of CH3S groups. It is very reactive and can be converted into trimethylthiophosphite upon further irradiation in dimethyldisulfide suspension. Both the formation of red phosphorus from white phosphorus and the formation of trimethylthiophosphite from red phosphorus are chain processes. The radiation chemical yields are of the order of several 100 molecules/100 eV at room temperature.
Light Scattering and Viscosimetric Studies on DNA after the Photoreaction with Some Furocoumarins
Authors: Dall’Acqua F. , Terbojevich M. , Benvenuto F.
Published: February 2015

The light scattering measurements and the viscosimetric “i-assay” performed on native DNA solutions before and after irradiation at 3655 Å in the presence of furocoumarins show that the C4-cycloadditions of furocoumarins to the 5,6-double bond of the pyrimidine bases of DNA, which take place in the photoreactions, produce neither breakages of the polynucleotide chains nor relevant modifications of the macromolecule conformation.
II. Isolierung und Charakterisierung der Chloroplasten-Ribosomen von Antirrhinum majus
Authors: Ruppel Hans Georg
Published: February 2015

Methods for very efficient isolation of non-degraded chloroplasts from Antirrhinum majus are described. When studied in the analytical ultracentrifuge, isolated ribosomes of such chloroplasts show a single symmetrical 68s peak. Extraction of the ribosomal RNA from chloroplasts and chromatographic separation on methylated serum albumin yields 4 main fractions: (1) low molecular weight RNA (fraction I b) with s20 = 5.5, (2) high molecular weight RNA (fraction III) with s20 = 16-17, (3) high molecular weight RNA (fraction V) with s20 = 23, and (4) a RNA fraction (fraction VI) heterogeneous in molecular size. In addition data are presented which show a higher resolution of RNA species by polyacrylamide gel electrophoresis than by chromatographic fractionation on methylated serum albumin. The high molecular weight RNA (16 -17s) of chloroplasts differs from the corresponding “light” ribosomal RNA of the cytoplasm in its electrophoretic mobility.
Acteosid und Neoacteosid; Zuckerester aus Syringa vulgaris (L.) 1, 2
Authors: Birkofer Leonhard , Kaiser Christelmargot , Thomas Ursula
Published: February 2015

Aus den Blüten des weißen Flieders (Syringa vulgaris L.) gelang es, sechs Kaffoylglykosen zu isolieren, von denen Acteosid (1) und Neoacteosid (2) in kristalliner Form erhalten wurden. Die Strukturaufklärung von 1 und 2 erfolgte durch Permethylierung, saure und alkalische Hydrolyse sowie Heranziehung der NMR-, UV- und IR-Spektren.

1 erwies sich als (3.4-Dihydroxy-β-phenyläthyl) 0-α-L-rhamnopyranosyl (1 →· 3) -β-ᴅ- (4-O-kaffoyl) glucopyranosid und 2 als (3.4-Dihydroxy-β-phenyläthyl) O-α-L-rhamnopyranosyl (1 →· 3) -O- [β-ᴅ-glucopyranosyl (1 →· 6)] -β-ᴅ- (2-O-kaffoyl) -glucopyranosid.

Bei den übrigen vier Verbindungen konnte papierchromatographisch ermittelt werden, daß es sich bei allen um (3.4-Dihydroxy-β-phenyläthyl) -glucoside handelt, bei denen die Kaffeesäure ebenfalls esterartig an dieser Glucose sitzt. Sie unterscheiden sich durch die Art und Anzahl der anderen Zuckerkomponenten. Einer der weiteren Inhaltsstoffe des Flieders konnte als (4-Hydroxy-β-phenyläthyl) -β-D-glucopyranosid (3) identifiziert werden.
Synthese und hypoglycämische Wirkung eines insulinanalogen Cystathionin-Peptides: ein Argument gegen die Beteiligung der intrachenaren Disulfidgruppe bei der Insulinwirkung
Authors: Jošt K. , Rudinger J. , Klostermeyer H. , Zahn H.
Published: February 2015

Insulin 1 enthält ebenso wie die Hypophysenhormone vom Typ des Oxyocins und Vasopressins einen zwanziggliedrigen Disulfidring. Reduktion desselben führt beim Oxytocin praktisch zum Verlust der Aktivität 2. Beim Insulin ist eine selektive Reduktion des intrachenaren Ringes (Abb. 1) bisher nicht gelungen, doch verliert das Hormon bereits seine hypoglycämische Wirksamkeit bei statistischer Reduktion von ein Drittel seiner drei Disulfidbindungen 3.
Untersuchungen über die Abhängigkeit der Mikrowellensättigung bei der Elektronenspinresonanz strahleninduzierter freier Radikale des ᴅʟ-Valins und des ᴅʟ-Leucins von der Bestrahlungsdosis
Authors: Schnepel Gerd Henning
Published: February 2015

Many investigations with electron spin resonance spectroscopy have shown that the spin-lattice interaction of radiation induced free radicals in organic materials is too weak to allow rapid thermal relaxation. Therefore saturation effects can be produced by a microwave power not sufficiently attenuated. The saturation effect of radiation induced free radicals in d,l-valine and d,l-leucine was studied. The linear relationship between the intensity of the spectrum and the field strength was changed by large values of the microwave power in both of the amino acids. The microwave saturation is independent of the X-ray absorbed dose in the case of d,l-leucine however not in the case of d,l-valine. After higher X-ray doses the saturation effect is obtained at larger values of the microwave field strength than after lower doses. Our results may be interpreted by the fact that at room temperature two species of free radicals occur in d,l-valine. Each of them may have a different spinlattice interaction time and the numerical proportion of the two species may be a function of the X-ray absorbed dose.
Die unimolekulare thermische Spaltung von Äthylchlorid-2-d3 und Äthylchlorid-2-d1 nach einem Vierzentrenmechanismus
Authors: Völker G. W. , Heydemann H.
Published: February 2015

The unimolecular thermal decomposition of chloroethane-2-d3 and chloroethane-2-d1 was studied in a static system at two temperatures and at pressures between 0.1 and 10 mm Hg. The rate constants for the high pressure limit were obtained from these measurements and used to calculate the Arrhenius equations. The decomposition of chloroethane-2-d3 was also studied at high conversions and yielded almost exclusively (97%) DCl and CD2CH2 as shown by mass spectrometric analysis thus proving a molecular elimination mechanism via a four-centered reaction complex.
Messungen zur Manipulation der Glucose-abhängigen Tumorsäuerung in vivo
Authors: Rauen Hermann Matthias , Friedrich Michael , Norpoth Klaus
Published: February 2015

On experimental rat tumors, preferentially on DS-Carcinosarcoma, special glass electrodes were used to measure and to register development of tissue-pH after injection of glucose into the rats.

On tumor surface pH-values were lowered more quickly and increased much faster as in tumor depth. The lowest registered pH was about 5,9.

High s. c. dosages of Insulin caused a marked decrease of pH-values for nearly one hour too. In metabole effective small tumors tumor acidity could be regulated satisfactory with administered glucose and insulin between pH 7,0 and 6,0.

Determination of lactate concentration in tumor tissue, surrounding the electrode, indicated a linear correlation between pH-value und lactate concentration in the range between pH 6,0 and 7,0. Regression coefficient comes to — 40,9 ± 2,2 ×10-3 mMol/g wet weight and pH-unit.

It is emphasized that according to the varying cell supply the compact tumor shows no homogeneity on pH-rates, acidification kinetics, and sensibility against acidotic cell lesion.

Results are criticized with reference to other publications and their significance for the theory of tumor lesion by alkylating agents is discussed.
Enzymatische Glucosylierung von pflanzlichen Sterinen
Authors: Kauss H.
Published: February 2015

A particulate enzyme preparation from dark grown mung bean shoots incorporates the glucosyl unit from UDP- (14C) -glucose into lipophilic products. These were identified by thin layer chromatography as a mixture of β-sitosterylglucoside and stigmasteryl-glucoside (80%) as well as the acylated forms of these substances (20%). The reaction is almost linear with time up to 10 minutes, optimal at pH values between 6.3 and 6.6 and does not require divalent cations. The acceptor sterols were shown to be present in the particulate preparation; exogenous sterols do not seem to act as acceptors.

The same particulate enzyme preparation can also synthesize cellulose from UDPG 15 and lipid intermediates for its biosynthesis have been predicted 20. It appeared possible, therefore, that the sterylglucosides act as such intermediates. This, however, does not seem to be the case, since dilution of the UDP- (14C) -Glucose with unlabelled UDPG as well as its hydrolysis with phosphodiesterase within the course of an experiment demonstrates that the glucosyl units of the sterylglucosides show no turnover.
Beiträge zur Chemie des Hydrazins und seiner Derivate XIV
Authors: Linke K.-H. , Skupin D.
Published: February 2015

Durch Umsetzung von Selenocarbohydrazid mit Cyansäure und Thiocyansäure wurden 1-Carbamoyl-selenocarbohydrazid, NH2-CO-NH-NH-CSe-NH-NH2, und 1-Thiocarbamoyl-seleno-carbohydrazid, NH2-CS-NH-NH-CSe-NH-NH2, durch Reaktion des Sulfates von Selenocarbohydrazid mit Ammoniumthiocyanat das 1.5-Bis-thiocarbamoyl-selenocarbohydrazid, NH2-CS-NH-NH-CSe-NH-NH-CS-NH2, erstmals dargestellt. 1-Carbamoyl-selenocarbo-hydrazid und 1-Thiocarbamoyl-selenocarbohydrazid reagieren mit Aldehyden unter Hydrazonbildung. Zur weiteren Charakterisierung wurden alle Verbindungen IR-spektroskopisch und röntgenographisch untersucht, wobei gezeigt werden konnte, daß sie ganz analog den entsprechenden Thiocarbohydrazid-Derivaten aufgebaut sind.
Potentiometric Studies on Stepwise Mixed Ligand Complex Formation
Authors: Sharma G. , Tandon J. P.
Published: February 2015

Stepwise mixed ligand complex formation is observed in the systems containing metal ion, iminodiacetic acid (IMDA) as primary ligand and one of the diamines, such as ethylenediamine (en), 1,2-propanediamine (1,2-pn) and 1,3-propanediamine (1,3-pn) as secondary ligands. Potentionmetric titrations indicate the formation of ternary complexes having a 1:1:1 molar ratio of metal ion to iminodiacetic acid to the secondary ligand. Initially, metal-IMDA (1:1) complex is formed in the lower buffer region prior to the formation of the ternary complex and the addition of the secondary ligand takes place only after the combination with the primary ligand is complete. Formation constants (log KMAB) of the ternary complexes have been calculated and the probable reaction mechanism is suggested. The order of stability in terms of metal ion has been found to be Cu (II) > Ni (II) >Zn (II) >Cd (II) and in terms of secondary ligand as 1,2-pn>en>1,3-pn.
II. Mitt.: Auflösung der Chromoproteidfraktion aus Rattenleber-Ribosomen mit Hilfe der Polyacrylamidgel-Elektrophorese
Authors: Domschke Wolfram , Meyer-Bertenrath Jürgen G.
Published: February 2015

After preparation of a coloured protein component containing iron from rat liver ribosomes 1 this fraction was submitted to detailed analysis by means of polyacrylamide gel electrophoresis. Thus it may be separated into one main and two secondary bands, which do not contain RNA detectable by methylene blue staining. The ferric content of all bands can be demonstrated by staining with 2,4-dinitroso-1,3-naphthalenediol 2. These bands are to be found in the large ribosomal subunits as well as in the small one in qualitative conformity, they differ, however, in their quantitative relations to each other depending on origin. LiCl-extraction as described for the preparation of ribosomal proteins causes dissociation of the chromoproteid fraction into six bands possessing lower molecular weights each than the original bands.

The chromoproteids, localized in the large ribosomal subunits on the one hand and in the small subunits on the other hand were prepared differentiatedly by gel filtration. Results show the chromoproteid represented in the 57-S-subunit on a bigger scale than the nucleoproteid part, on the contrary, the 29-S-subunit is constructed of RNA-containing material preferably.
Normal Coordinate Analysis of Some Nitrogen-Halogen Compounds
Authors: Ramaswamy K. , Mohan N.
Published: February 2015

The approximate force fields for a group of nitrogen halogen compounds like ONF3, NF3, NF2Cl, NFCl2, NF2D and NCl3 were studied using the kinematic methods of Herranz and Torkington. It was found that the application of Torkington's method yields a reliable set of potential energy constants consistent with other molecular constants. A linear relationship between the N -F bond stretching force constants and the bond order was found to exist. It was also found that the value of the N-F bond stretching force constant is proportional to the number of fluorine atoms substituted.
Morpholines-(I)
Authors: Chatterjee Basanta G. , Abdulla Riaz F.
Published: February 2015

ω- (N-aryl-chloracetamido) -acetophenones have been cyclized with triethylamine in warm benzene solution to the corresponding 1,4-oxazines. The reaction appears to be general for any N-aryl substituent, as long as an overall electron-withdrawing substituent is present para- or meta, in the aromatic nucleus of the acetophenone moiety. The predominant tautomeric form present is shown by IR spectrography to be the “keto” tautomer in every case. The structure of one morpholine is confirmed by mass spectral fragmentation analysis.
Synthese des 19-Oxo-3-aza-A-homo-5 β-androstans
Authors: Habermehl Gerhard , Haaf Arthur
Published: February 2015

Zur Untersuchung der wesentlichen Reaktionsschritte der Synthese des Cycloneosamandions wurde als Modellsubstanz das 19-Oxo-3-aza-A-homo-5β-androstan, ausgehend vom 3β-Hydroxy-5α- chlor-6β,19-epoxy-androstan-17-on dargestellt. Die spektroskopischen Daten stehen im Einklang mit der erwarteten Struktur.
Zur Wirkung von Insulin auf die nucleare Proteinbiosynthese der Rattenleber
Authors: Buck Max Dieter , Schauder Peter , Weser Ulrich
Published: February 2015

Intraperitoneal injections of insulin into rats appeared to increase the rate of nuclear protein biosynthesis in rat liver. A one hour pulse of insulin stimulated the [14C]-DL-leucine incorporation up to 50% compared to control values. A maximum (100% increase) was passed after 3 - 5 hours and the original rate of nuclear protein biosynthesis was obtained after 10 hours. The reactivity of insulin has been shown to be progressively diminished employing decreasing insulin concentrations. If [14C] -DL- leucine was replaced by [3H] -L-lysine no rise of nuclear protein biosynthesis, attributable to insulin, could be observed.
Isolation of a Ribosome-Dependent Guanosine Triphosphatase From Yeast
Authors: Albrecht Uwe , Klink Friedrich , Richter Dietmar
Published: February 2015

A relatively heat-stable protein fraction from yeast has been isolated hydrolyzing GTP only in the presence of ribosomes. The ribosome-dependent GTPase does not catalyze peptide chain elongation by itself but is active in this process with a second protein fraction previously referred to as FII. The ribosome-dependent GTPase as well as the peptide chain elongation are inhibited by the antibiotic fusidic acid.
Gewinnung von Porphyrinen mittels Propionibacterium shermanii
Authors: Müller G. , Dieterle W. , Siebke G.
Published: February 2015

The preparation of uroporphyrin I and III by incubation of suspensions of P. shermanii in the presence of δ-amino-levulinic acid is described. The fermentation of P. shermanii in a synthetic medium yields coproporphyrin III. Furthermore the separation of uroporphyrin, hepta-, hexa-, penta- and tetracarboxylic porphyrins is described.
Observations on the Thermochromism of Triphenylchloromethane
Authors: Simoni Rosa , Toschi Maria
Published: February 2015

Es wurde die Thermochromie von Lösungen des Triphenylchlormethane in Dekalin im Temperaturbereich von 25° bis 150°C untersucht.

Polarisationmessungen zeigen keine Veränderung bis 110°C. Der Thermochromie ist die Bildung des Triphenylmethyl-Radikals, das sich in Anwesenheit von Luft zersetzt, zuzuschreiben. Die Reaktionsprodukte wurden identifiziert und das Reaktions-Schema angegeben.
Organic Compounds of Uranium (V)
Authors: Dubey S. , Misra S. N. , Kapoor R. N.
Published: February 2015

The reactions of Uranium pentaethoxide with 1,3 dicarbonyl ligands (dibenzoyl methane, ethyl 1-methyl acetoacetate, 5,5 dimethyl 1,3 cyclohexane dione (dimedone) have been studied under anhydrous conditions and the derivatives of the type U(OEt)5-x(lig)x (where x= 1, 2 or 3) have been isolated. These derivatives interchange their ethoxy groups with tertiary butoxy groups when treated with tertiary butanol. Determination of molecular weight of soluble derivatives suggest them to be monomeric in boiling benzene.
Zur Photosynthese grüner Pflanzen, III. Untersuchungen der chemischen Vorgänge beim Metzner schen Photosynthese-Modell / Photosynthesis in Green Plants III. Investigation of the Chemical Processes in Metzner’s Model for Photosynthesis
Authors: Budzikiewicz H. , Eckau H. , Inhoffen H. H.
Published: February 2015

H. METZNER described 2 a model for the photosynthesis of green plants consisting of a) the photolysis of AgCl sensitized by chlorophyll, reaction of Cl with H2O to give O2 and Cl⊖, and b) regeneration of Ag⊕ by reductive cleavage of Janus Green (1) by Ag. It is shown that under reaction conditions described the latter process is of no importance the main reaction being the well-known sequence a), and in part destruction of 1 by Cl formed in the course of a).
Einfluß von 5-Azacytidin auf Reversion und UV-Sensibilität von Escherichia coli K12-Stämmen mit unterschiedlichen UVR-Genen / Influence of 5-Azacytidine on Reversion Rate and UV-Sensitivity of Escherichia coli K12 Strains with different UVR-Genes
Authors: Grunow R. , Geissler E.
Published: February 2015

3 µg AC/ml cause an inhibition of cell division of E. coli K12 strains. This concentration is not mutagenic, because the reversion frequencies of the markers thr-, his- and arg- are not changed by AC treatment. However the reversion frequencies of thr- and arg- increased 1 to 4 orders of magnitude after UV irradiation, simultaneous treatment with AC and UV decreased these enlarged reversion rates at 1 exponent. The marker his- used in this experiments is not reverted by UV.

The UV-sensitivity of bacterial strains with different uvr-genes is studied. The results are discussed from the view point that the influence of AC caused an inhibition of protein synthesis, whereby phenotypic expression of UV induced DNA damage is delayed and the time for repair of DNA is enlarged.
Über die Bildung sequenzisomerer glimmerartiger Schichtsilicate
Authors: Lagaly G. , Weiss Armin
Published: February 2015

This paper deals with the preparation of sequence isomers of mica type layer silicates. These isomers differ in the succession of structurally identical but differently charged layers.
Zur Photosynthese grüner Pflanzen / Photosynthesis in Green Plants
Authors: Budzikiewicz H. , Eckau H.
Published: February 2015

It is shown that the rate of photosynthesis of Chlorella pyrenoidosa Chick, is partially inhibited by Diamox which has, however, no influence on the isotopic composition of the photosynthetic oxygen if H2
18O, C16O2 and HC16O3′ are used as substrates. No inhibition of the exchange between H2O and CO2 on the surface om maize leaves could be observed if the leaves were exposed to a Diamox solution.
Über die Verwendung von 86Rb als Indikator für Kalium, Untersuchungen am lichtgeförderten 42K/K- und 86Rb/Rb-Influx bei Elodea densa/ On the Application of 86Rb as a Tracer for Potassium, Measurements of the Lightdependent 42K/K- and 86Rb/Rb-Influx in Elodea densa
Authors: Jeschke Wolf Dietrich
Published: February 2015

1. The light-dependent influx of K⊕ and of Rb⊕ into isolated leaves of Elodea densa was measured by using 42K⊕ and 86Rb⊕ as tracers.

2. If 86Rb was used as a tracer for K⊕ and then the K⊕ influx was determined from the specific activity σ86Rb/K an influx vK(86Rb) was obtained which was lower than the K(42K) influx (fig. 1). The ratio of vK(42K)/vK(86Rb) = SK,Rb increased with increasing [Rb⊕]0 and decreasing [K⊕]0 (figs. 1 and 7). The depression of vK(86Rb) as compared to vK(42K) was not a consequence of the competitive inhibition of K⊕ influx by Rb⊕ (cf. fig. 1).

3. As a working hypothesis it is proposed that 86Rb⊕ functions only as a tracer of Rb⊕ and that vK(84Rb) can be calculated from the parameters of the Rb (86Rb) influx and its competitive inhibition by K⊕.

4. By using the Michaelis - Menten - Kinetics a formula was derived for vK(86Rb), the Michaelis constant KmK(86
Rb), and for VmaxK(86
Rb). From these calculations it may be predicted a) that vK(86Rb) will show a Michaelis - Menten - Kinetic only if [Rb⊕] is kept constant at all K⊕ concentrations; b) that VmaxK(86
Rb) is independent of [Rb⊕] and not necessarily equal to VmaxK(42
K); and c) that KmK(86
Rb) is greater than KmK(42
K) and dependent on [Rb⊕].

5. In order to test the calculations the mutual competitive inhibition of K⊕ - and Rb⊕ -influx (figs. 2, 3) was measured. From the Michaelis - Menten - Parameters of the Rb (86Rb) influx and the inhibition constant KiK of potassium vK(86Rb) was calculated. The predictions mentioned above were verified. The calculated depression of vK(86Rb) as compared to vK(42K) corresponded satisfactorily to the experimental values (fig. 7).

6. The isotherms of K (42K) and of Rb (86Rb) influx were measured (fig. 4). In the range of low concentrations (system 1) VmaxK(42
K) greatly exceeded VmaxRb(86
Rb), the same was true of KmK(42
K) as compared to KmRb(86
Rb). Thus in system 1 the Rb⊕ influx proceeded with much greater affinity but lower capacity than the K⊕ influx. Thus, although with regard to competitive inhibition K⊕ and Rb⊕ seem to use the same transfort site the relative similarity of vK(42K) and vK(86Rb) must be termed rather incidental though predictable.

7. At higher concentrations (system 2) the influx of K⊕ and Rb⊕ was less different with respect to Km and Vmax (fig. 7), an observation which was confirmed by competitive inhibition on almost equal terms.

8. It must be stated that the value of 86Rb⊕ as a tracer instead of 42K⊕ is limited. However, the metabolic linkages of K⊕ influx can also be detected by the use of 86Rb⊕.
Untersuchungen an Crown-Gall
Authors: Beiderbeck Rolf
Published: February 2015

Concentrations of 10 µg/ml rifampicin reduce the growth of Agrobacterium tumefaciens by more than 90%, concentrations of 100 µg/ml prevent tumor formation in Kalanchoë daigremontiana by the same bacteria.

A treatment with rifampicin does not irreversibly alter the bacteria; after removal of the drug bacterial propagation and the ability of tumor induction are restored.

0-24 h treatments of the plant wounds with rifampicin prior to infection prevent tumor formation completely.

Addition of rifampicin after infection inhibits tumor formation optimally if the drug is added only few hours after inoculation. 30 h after infection the bacteria-host-system is resistant against rifampicin.

100 μg/ml rifampicin do not influence the growth of already induced tumors.
III. Mitt.: Induktion qualitativer Veränderungen der Ferritinfraktion durch hepatotrope Carcinogene / III: Alterations of the Ribosomal Ferritin-Fraction Induced by Hepatotropic Carcinogens
Authors: Meyer-Bertenrath Jürgen G. , Domschke Wolfram
Published: February 2015

Liver ribosomes from rats pretreated with carcinogenic agents release a ferritin fraction which differs from that of normal ribosomes. This was demonstrated by disc-electrophoresis of the native protein and of the subunits produced by LiCl-urea-treatment. Moreover, the nucleoproteids into which those ribosomes dissociate during incubation with protease-free ribonuclease show a significant alteration in their electrophoretic pattern. - The Michaelis - constant of ribonuclease was found about hundredfold higher, which indicates that the superficial RNA structures are masked by the pathological ferritin to a greater extent than the RNA of normal ribosomes.
Influence of pH on the Stability of Some Aminoacyl Transfer Ribonucleic Acids and Their Elution Pattern in Chromatography on Columns of Methylated Albumin Adsorbed on Kieselguhr
Authors: Lodemann Edgar , Niedenthal Ilse , Wacker Adolf
Published: February 2015

At pH 5.3 and 4.5 the half life of valyl-, threonyl-, leucyl- and seryl-tRNA from E. coli K 12 is significantly higher than at pH 6.8. While no changes were observed in the MAK elution patterns of valyl- and threonyl-tRNA, leucyl-tRNA was eluted in two peaks at pH 6.8 and 5.3 and in one broad peak at pH 4.5. Seryl-TRNA - two peaks at pH 6.8 - was separated in three peaks at pH 5.3 and 4.5. Rechromatography of these peaks at the other pH suggests the existence of at least four species of seryl-tRNA in E. coli K 12.
Herbizide Trifluormethyl-benzimidazole
Authors: Büchel K. H.
Published: February 2015

De Darstellung zahlreicher im Benzolring substituierter 2-Trifluormethyl-benzimidazole aus den entsprechenden o-Phenylendiaminen wird beschrieben. Ein einfaches und stufensparendes Verfahren geht von o-Dinitro- oder o-Nitro-aminobenzolen aus. Diese werden mit Metallen (Sn oder Fe) in Salzsäure/Trifluoressigsäure gleichzeitig reduziert und cyclisiert. Die Trifluormethyl-substituier-ten Benzimidazole fallen dabei wegen ihrer hohen NH-Acidität aus. Eine Reihe von N-Alkyl- und N-Acyl-Derivaten wird beschrieben.
Zur Koordinations-Isomerie von Kobalt-methyl-Faktor I b und Kobalt-methyl-cobalamin
Authors: Friedrich Wilhelm , Moskophidis Matthäus
Published: February 2015

Methylierung von Faktor I b am Kobalt ergibt zwei Diastereoisomere im Mengenverhältnis von 1 : 1, die sich säulenchromatographisch mittels Sephadex-DEAE A-50-CN⊖ bei 0°C sehr gut trennen lassen. Das schneller wandernde Isomer b (Methylgruppe „oben“) hat das gleiche Absorptionsspektrum wie Kobalt-methyl-cobinamid. Das langsamer wandernde Isomer a (Methylgruppe „unten“) unterscheidet sich im Absorptionsspekrum nicht von der Kobalt-methyl-cobyrsäure a. Die Isomeren a und b lassen sich durch Licht bzw. Wärme (80-100°C) ineinander umwandeln, wobei ein spezifisches Gleichgewicht erreicht werden kann. Belichtung führt zu 30% a (neben 70% b), Erhitzung zu 11% a (neben 89% b). Die Isomerisierung verläuft mit maximaler Geschwindigkeit in Wasser, nach Sättigung mit CO. Praktisch keine Isomerisierung wird bei Belichtung in O2-Atmosphäre sowie in alkoholischen Medien beobachtet. In der Wärme in O2-Atmosphäre ist die Isomerisierung sehr langsam.
Über substituierte Pentaphenyl-cyclopentadienyl-Verbindungen und Tetracyclone VIII
Authors: Kurreck Harry , Broser Waldemar
Published: February 2015

Das aus Tetracyclon mit Lithium entstehende Metallketyl assoziiert in höherer Konzentration zu zwei ineinander umwandelbaren Dimeren-Komplexen (c und d), für die wegen der hohen Spindichte am Sauerstoff eine intermolekulare Elektronen-Spin/Spin-Kopplung zur Elektronenkonfiguration Triplett EPR-spektroskopisch nachweisbar ist. Der Zusammenhang zwischen Tetracyclon, Tetracyclon-Monoanion, den Dimeren-Komplexen und dem Tetracyclon-Dianion und der Einfluß von Phenyl- und Brom-Substitution wird diskutiert.
Heterotransplantation of Ehrlich Ascites Tumor Cells in Rats Pre-Treated with Cytostatics and Antimetabolites
Authors: Emanuilov Emanuil , Golovinsky Evgeny
Published: February 2015

Pre-reatment of rats with various doses of cytostatics and antimetabolites (cyclophosphamide, mitomycin-C, 6-mercaptopurine, 6-azauridine and 5-azaorotic acid) permits successful heterotransplantation of Ehrlich ascites tumor, as indicated by the progressive growth of the tumor cell population. Experiments with cyclophosphamide suggest a direct dose dependence of the rate of tumor growth in heterologous recipients.
Die Aminosäuresequenz des Serin und Asparaginsäure enthaltenden Mureins von Bifidobacterium bifidum Orla Jensen/ The amino acid sequence of the serin and aspartic acid containing mureins of Bifidobacterium bifidum ORLA JENSEN
Authors: Koch Dieter , Schleifer Karl Heinz , Kandler Otto
Published: February 2015

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, GlcNH2NAc, 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.
Überführung von 1-Benzylisochinolinen in Berbinium-Salze
Authors: Wiegrebe W. , Sasse D. , Reinhart H. , Faber L.
Published: February 2015

The syntheses of the dibenzoquinolizinium-salts 3, 13, 16, 20 and 25 which are of spectroscopic interest are described. Their electronic excitation spectra will be published later by Perkampus and coworkers in this journal
Synthesen mit nitrilen XXXI / Syntheses with nitriles, XXXI
Authors: Junek H. , Aigner H.
Published: February 2015

Tetracyanoethylene was added to dihydroresorcine and dimethyldihydroresorcine which yielded 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3,4,4-tricarbonitriles by cyclization. Dimethyl-dihydro-resorcine-monoimine together with tetracyanoethylene eliminated HCN and resulted in a 7,7-dimethyl-tetrahydro-quinoline derivative. The structures were proved by alkaline degradation and by IR- and NMR-spectroscopy
Das Bürzeldrüsensekret der Reiherente (Aythya fuligula)
Authors: Jacob Jürgen , Zeman Alfred
Published: February 2015

The acidic and alcoholic components of the uropygial gland wax from the tufted duck (Aythya fuligula) were investigated by a combination of GLC and mass spectrometry. Main components of the acidic part of the waxes are 2,4,6-trimethyl-nonanoic (39.0%) 2,4,6-trimethyl-octanoic (8.7%) and 2,6-dimethyl nonanoic acid (5.9%). Besides, 2,4,8-, 2,6,8-, and 2,6,10-trimethyl-substituted fatty acids occur. As minor components 2-methyl- and homologous series of 2,4-, 2,6-, 2,8-, and 2,10-dimethyl-substituted fatty acids could be detected.

Main components of the wax alcohols were n-hexadecanol and n-octadecanol. As minor components 2-, 6-, 10-, 12-, and 14-methyl-branched primary alkanols occur.

The tufted duck shows an uropygial gland wax which is typical for the 17th order of the natural system
Elektrophorese der Samenproteine von neutroneninduzierten Pisum-Mutanten in Polyacrylamid-Gel / The Electrophoresis of seed Proteins from the Neutron induced Pisum-Mutants in Polyacrylamid-Gel
Authors: Chen Robert
Published: February 2015

Seed proteins of the 50 pea mutants induced by neutron radiation were investigated electrophoretically. The proteins were isolated in two fractions: insoluble (in water) seed proteins (Fraction I) and soluble proteins (Fraction II). The protein patterns from fraction II of 11 mutants differed from that of the initial line. However, no patterns from fraction I differed from that of the initial line. It is evident, that the fasciation mutans do not have the “γ”-Band in the protein pattern
2-Anilinothiophene als Entkoppler der oxydativen Phosphorylierung in Mitochondrien / 2-Anilinothiophenes, Uncouplers of Oxidative Phosphorylation in Mitochondria
Authors: Büchel K. H. , Schäfer G.
Published: February 2015

A series of NH-acidic 2-anilino-3,5-dinitro-thiophenes (II), 2-anilino-3,4-dinitro-5-halo-thiophenes (VI), and some 3,5-dinitro-thienole-derivatives (IX, X) were synthesized. Compounds II and VI are potent uncouplers of oxidative phosphorylation in rat liver mitochondria. The most active comcounds yielded a 50% uncoupling at a concentration of 10-7 ᴍ.

With some of the 2-anilino-3,5-dinitro-5-halo-thiophenes (BDCT or DDCT), added to respiring liver mitochondria, a transitory uncoupling of energy-linked reactions could be observed which is comparable to the phosphorylating cycles produced by ADP. The mechanism of this effect is discussed