Zur Kenntnis des Muscarins

Summary The alkaloid muscarin was isolated from fly agaric. The analyses of crystallized salts (chloride, tetra-chloroaurate,Reinecke's salt) led to C₉H₂₀O₂N⁺ as the simplest formula. The presence of aldehyde and tri-methyl-ammonium groups, which had been assumed hitherto, could not be proved. The quaternary nature of the nitrogen atom was shown. Pharmacological tests on frog heart, rabbit gut and cats show the purely peripheral parasympathomimetic effect of the smallest doses.     

Zur Kenntnis der Vernetzungspolymerisation

Summary The intrinsic viscosity of cross-linked copolymers of styrene andm,m-divinyl-azobenzene orp-divinyl-benzene was measured for different degrees of polymerization.It has been shown that the two vinyl groups of the cross-linking agent are taken up by growing chains, each one independently of the other.The number of cross-linkages is not absolutely identical with the number of the molecules of divinyl compound, but is determined by the magnitude of the various rates of growth.     

Zur Kenntnis der Formazylverbindungen

Summary 1-benzal-2-4-diphenyltetrazene is obtained in highest yields by reaction of benzalphenylhydrazone with benzene diaziniumchloride at pH 4–8. This reaction is reversed by treatment with hydrochloric acid. In pyridine or alcohol solution the tetrazene suffers an intramolecular transposition to triphenylformazane.     

Zur Kenntnis des lamellaren Musters in ausgewachsenen und der Kristallgitterstruktur in jungen Chloroplasten

Summary (1) It is shown that in the chloroplasts ofChlamydomonas andAnthoceros thick, dense lamellae and thin, less dense lamellae alternate. (2) In the chloroplasts of many phanerogame plants with grana, thin less dense lamellae limit the parcel of thick grana-lamellae above and below. Since the differentiations 1 and 2 are present in the photographs of many publications (although not mentioned), it is suggested that this kind of lamellarmodel has often been overlooked until now. — The « Kristallgitterstruktur » has been found in a cryptogamous plant,Selaginella, in young chloroplasts, for the first time. The connection between the elementary particles of the crystal-lattice and the young lamellae has been verified again. — The possibility of formation of double lamellae by fusion of blastulae or tubuli is discussed in detail.     

Zur Kenntnis von Levorin A und Candicidin

Summary A sample of Russian provenance of the antifungal antibiotic levorin A, containing 30,000 microbiological units of activity/mg, was shown to consist of several components. Three components, designated levorin A₁, A₂ and A₃, were isolated and shown to be distinguishable by their partition coefficients in the system chloroform-methanol-borate buffer pH 8.4 (2:2:1). An enriched sample of the antifungal antibiotic candicidin, prepared from a commercial preparation of American provenance, showed a very similar pattern of distribution as levorin A did in 600 transfers. Levorin A₂, the main component of the levorin A sample, was not distinguishable within the error limits of the applied tests, from the main component of the enriched candicidin sample.

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64. Mitteilung der Reihe «Stoffwechselprodukte von Mikroorganismen». 63. Mitteilung: Experientia, im Druck (1968).     

Zur Frage des Angriffspunktes des Thiouracil

Summary The mechanism of action of thiouracil and thiourea was investigated on Xenopus tadpoles. Both substances are able to stop metamorphotic changes if administered early enough. Characteristic disturbances occur in the epithelium of the thyroid follicles after only 24 hours. The action of these substances over a period of several weeks may lead to goitre. In the pituitary anterior lobe, on the other hand, the same characteristic changes take place in the basophilic cells as after thyroidectomy. The thyroid structure of hypophysectomised tadpoles corresponds to that of untreated hypophysectomised animals. Thiourea and thiouracil do not inhibit the thyroxine effect on thyroidectomised and hypophysectomised tadpoles. These findings indicate that the point of attack of thiouracil and thiourea lies in the follicular epithelium of the thyroid, and thus supportAstwood's hypothesis.     

Zur Frage des pH-Optimums des Pepsins

Summary Natural and purified proteins were split by crystallized pepsin. The break down of substrates was followed by a turbidimetric method. pH optima were found from 1.5 to 3.8. Only unpurified egg albumin had two optima, crystallin had one in the acid range. Ovomucoid not being split by pepsin, the second peak at pH 3.79 is referred to conalbumin. While the disintegration of caseinogen becomes slow with decreasing acidity, this is not true for casein (paracasein) which is well split up to pH 3.28 (cows casein) or 3,73 (womens casein). Nevertheless, the optimum is in the range of 1.5–2.0, like most proteins. Above this limit, the following optima were found: fibrinogen 2.93, thrombin 2.78, edestin 3.08, crystallized hemoglobin 3.19, conalbumin 3.79.     

Zur Biogenese des Lignins

Summary Potato germs grown in absence of light contain a substance which doubtless can be classified as lignin. This statement, though contradictory to the findings ofP. Klason, may be proved by microscopic staining methods as well as by chemical analysis. It is concluded that photo-energy is not necessary for the formation of lignin.     

Zur Gestalt des Influenza-Virus

Summary Influenza-Virus particles are generally considered to be of spherical shape after conventional fixation in OsO₄. However, after fixation with KMnO₄, the elementary bodies of the Influenza-Virus (Type A Singapur I/57) — adsorbed on the surface of erythrocytes — exhibit hexagonal shape in ultrathin-sections.     

Zur Biosynthese des Ubichinons

Summary ¹⁴C labelled mevalonic acid is incorporated by the rat into the ubiquinone molecule. Vitamin E, however, is no precursor of ubiquinone. It is suggested that the ring component is essential for animals and that the isoprene side chain is at least partly built up by mevalonic acid.     

Zur Biosynthese des Plumierids

Summary It has been shown that the leaves ofPl. acutifolia incorporate acetate-1-¹⁴C and mevalonate-2-¹⁴C specifically for the formation of the aglycone moiety of plumieride.

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Wir danken dem Schweizerischen Nationalfonds sehr für die Unterstützung der Arbeit, Herrn Dr.J. Würsch (F. Hoffmann-La Roche & Cie., Basel) für markiertes Mevalonsäure-lakton und Herrn Prof.D. Arigoni (Zürich) für interessante Diskussionen.     

Zur Geschichte des Metermasses

Summary The history of the normal meter shows distinct steps of development. The meter itself was defined by French scientists as a national unit at the beginning of the great French Revolution and realized in 1799 by a platinum rod. A better reproduction of the unit of length was given in 1889 by a 90% Pt-10% Ir platinum bar of special cross section according to an international convention. Every substantial standard, however, has many disadvantages, besides the possibility of an entire loss by an accident. The red cadmium line was therefore used in 1893 to express the meter by the number of its wave lengths in air and a provisional resolution was adopted in 1927 on this basis. Much more suitable, however, is an orange line emitted at 63°K from the isotope⁸⁶Kr, which can be produced in a thermal diffusion column in the state of highest purity. Since 1960, the vacuum wave length of this element has served as the fundamental unit of length.     

Zur Einteilung des Ostwaldschen Farbtonkreises

Summary The foundations of the division of the colour circle according toOstwald andRichter ² are subject to contradictions. A new division is calculated, based upon a limited formulation of the principle of inner symmetry. Finally different possibilities of connecting theOswald numbers and the trichromatic coordinates are discussed.

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Natuurkundig Laboratorium der N. V. Philips¹ Gloeilampenfabrieken Eindhoven, Nederland.     

Zur Wirkung des Calciums auf die Myofibrillen-ATPase des Herzmuskels

Summary The inhibition of cardiac myofibrillar ATPase activity by EDTA can be completely reversed by Ca⁺⁺ under certain experimental conditions. This shows that there is no fundamental difference between the reaction of cardiac myofibrillar ATPase and the tension development of glycerinated cardiac fibres, as was supposed byBriggs andHannah on account of the results ofParker andBerger.     

Zur peripheren sympathikushemmenden Wirkung des Clonidins

Summary The influences of clonidine, tetracaine and procaine on the effects of electrical stimulation of the postganglionic sympathetic cardiac nerves have been compared in the isolated perfused rabbit heart. Much lower concentrations of clonidine than of tetracaine were necessary to antagonize the output of noradrenaline and the rise of frequency and contractility. Procaine even in the highest concentration tested did not inhibit the effects of nerve stimulation. In addition to its known central depression of sympathetic tone, clonidine exerts a specific inhibitory action on postganglionic sympathetic neurons.     

Zur Konstitution des Resibufogenins und Artebufogenins

Summary The structure of Resibufogenin is unambiguously shown to be 3-hydroxy-14, 15-oxido-bufadien-(20, 22)-olide on the basis of new degradation work. Artebufogenin A and Artebufogenin B are 3-hydroxy-14-15-keto-bufadien-(20, 22)-olide and 3-Hydroxy-14-14-keto-bufadien-(20, 22)-olide, respectively.     

Zur Biosynthese des Verbenalins und Aucubins

Summary Verbena officinalis specifically incorporates 2-¹⁴C labelled mevalonic acid in the formation of the aglycone moiety of verbenalin (2). In aucubin (6), isolated fromVerbascum thapsus, the incorporation rate is very low and the main part of the activity is located in the sugar moiety.     

Zur Biosynthese des Cantharidins. I

Summary In contrast to the female, the adult males ofLytta vesicatoria (Coleopt. Meloidae) produced radioactive cantharidine on injection with¹⁴C-1-acetate and¹⁴C-2-mevalonate solutions. A partial degradation of the cantharidine showed that in the acetate experiment approximately of the activity occurred at C atoms 2 + 3 whereas with mevalonate approximately of the activity was at C atoms 8 + 9 and at C atoms 10 + 11. These results show that cantharidine is not formed by a tail to tail linkage of 2 isoprene units.

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Wir danken dem Schweizerischen Nationalfonds zur Förderung der wissenschaftlichen Forschung für die Unterstützung dieser Arbeit, Herrn Dr.J. Würsch (Physikalisch-chemische Abteilung der Firma F. Hoffmann-La Roche & Co. AG, Basel) für¹⁴C-2-Mevalolacton und unserer mikroanalytischen Abteilung (LeitungH. Frohofer) für die Aktivitätsbestimmungen.