Determination of the structure of the peptide moiety of the antibiotic albomycin

Zusammenfassung Der Peptidteil des Antibioticums Albomycin wurde aufgeklärt durch Überführung der -Hydroxy-ornithinreste in Glutaminsäurereste und anschliessende saure Partialhydrolyse, wobei sechs Peptide resultierten, deren Kombination eine eindeutige Strukturformel lieferten.     

Genetische und biochemische Untersuchungen über die Bedeutung der Amino- und Nucleinsäuren im Ursachengefüge von Neoplasmen (Tumoren und Gallen). Ein Dauermodifikationsbzw. Prädeterminationsphänomen

Summary If certain hybrids ofPlatypoecilus maculatus andXiphophorus helleri (viviparous platyfish and swordtails) are cultivated in diluted sea-water (0.25 or 0.5% salt concentration), the amount of free amino acids increases and the growth of macromelanophores, which normally only form certain black spots at the dorsal fin, is accelerated. Therefore melanomas arise. After changing salt water for fresh water, growth of macromelanophores remains accelerated. The same effect is seen in progenies which have been in an oocytic or embryonic state, when their mother was cultivated for some weeks in diluted sea-water (Figures 1 and 2). A similar effect has been observed in plant galls produced byPhylloxera (Viteus vitifolii) in the genusVitis. When the parasite, which injects amino acids into the tissue of the host in order to produce galls, is removed, gall formation goes on slowly for some days. It is shown that a few hours after injection of amino acids—before formation of neoplasms begins—the concentration of ribonucleic acids is increased. RNS-(and therefore protein-)biosynthesis in neoplasms may be dependent on concentration of free amino acids. A simple concept for the formation of neoplasms in hybrids of platyfish and galls ofPhylloxera is discussed.

---

---

Den Herren Prof. Dr.G. de Lattin (Zoologisches Institut der Universität des Saarlandes) und Prof. Dr.B. Husfeld (Forschungsinstitut für Rebenzüchtung Geilweilerhof/Pfalz) sind wir für die Förderung dieser Arbeit zu grösstem Dank verpflichtet. Herrn Prof. Dr.C. Kosswig (Zoologisches Institut der Universität Hamburg) verdanken wir viele Anregungen und die freundliche Überlassung von ingezüchteten Stämmen für unsere Fischkreuzungen. — Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

On the mechanism of spore germination inB. subtilis. Permeability and germination by pyruvate

Riassunto È stata studiata la permeabilità delle spore bacteriche al piruvato. Il piruvato penetra nelle spore soltanto a pH basso, quando la molecola del chetoacido ed i gruppi polari della superficie delle spore sono largamente indissociati. Le modificazioni della superficie, che si verificano nel corso della esposizione a pH acido, non hanno alcuna importanza nel fenomeno. Questi risultati sono messi in relazione con il fatto che il piruvato induce germinazione delle spore soltanto a pH basso e contribuiscono all'ipotesi che un agente germinante, per essere attivo, deve penetrare nella spora ed attivare i sistemi enzimatici quiescenti.     

Influence of the caudate nucleus on hippocampal afterdischarges in the rabbit

Résumé La stimulation du noyau caudé augmente et prolonge la postdécharge hippocampale chez le lapin.     

Influence of diglycyl-glycine on the radiation sensitivity of catalase

Zusammenfassung Die Veränderung der Strahlenempfindlichkeit von Katalase durch Diglycyl-glycin wurde spektralphotometrisch untersucht. Die Bestrahlungsdosen variierten zwischen 0–2,7 × 10⁶ r. Der Schutzeffekt lässt sich durch einen Radikal-abfangenden Mechanismus erklären. Strahlenbiologische Folgerungen werden diskutiert.     

Determination of mass spectra of non-volatile substances

Zusammenfassung Ein einfaches Glas-Einlass-System wird beschrieben, das die direkte Einführung von organischen Substanzen in die Ionisationskammer eines Massenspek trometers gestattet. Es ist somit möglich Massenspektren von Substanzen zu bestimmen die man bisher nicht aufnehmen konnte. Beispiele werden angeführt.

---

---

This paper represents part XXII in the seriesMass Spectrometry in Structural and Stereochemical Problems. For preceding article, seeE. Lund, H. Budzikiewicz, J. M. Wilson, andC. Djerassi, J. Amer. Chem. Soc., in press.     

The curvature argument

Dasgupta (2015) has recently put forward a novel argument, which he calls the ‘curvature argument’, that aims to show that Galilean spacetime is not an ideal setting for our classical theory of motion. This paper examines the curvature argument and argues that it is not sound. The discussion yields a remark about the conditions under which a ‘symmetry argument’ demonstrates that a particular spacetime is a non-ideal setting for our theory of motion.     

Gauss's first argument for least squares

Communicated by C. Truesdell     

Urushiol components as mediators in DNA strand scission

Summary Poison oak urushiol, a mixture of 3-alk(en)ylcatechol derivatives was found to mediate DNA strand scission in the presence of oxygen and with copper(II) chloride as a catalyst. The reactionis believed to occur via activated reduced oxygen produced during oxidation of the catechol into itso-quinone derivative.