Eine Titrationsmethode zur Bestimmung des Phytins

Ohne Zusammenfassung     

Pinensins: The First Antifungal Lantibiotics

Lantibiotics (lanthionine‐containing antibiotics) from Gram‐positive bacteria typically exhibit activity against Gram‐positive bacteria. The activity and structure of pinensin A ( 1 ) and B ( 2 ), lantibiotics isolated from a native Gram‐negative producer Chitinophaga pinensis are described. Surprisingly, the pinensins were found to be highly active against many filamentous fungi and yeasts but show only weak antibacterial activity. To the best of our knowledge, lantibiotic fungicides have not been described before. An in‐depth bioinformatic analysis of the biosynthetic gene cluster established the ribosomal origin of these compounds and identified candidate genes encoding all of the enzymes required for post‐translational modification. Additional encoded functions enabled us to build up a hypothesis for the biosynthesis, export, sensing, and import of this intriguing lantibiotic.     

A Ca2+‐, Mg2+‐, and Zn2+‐Based Dendritic Contractile Nanodevice with Two pH‐Dependent Motional Functions

A contractile dendritic motional device is reported where metal ions with biological importance—Ca²⁺ (the main regulatory and signaling species of the natural muscles), Mg²⁺, and Zn²⁺—initiate two kinds of motional functions. The first motional function is the metal‐ion‐induced contraction of a linear strand into a Z‐shaped dinuclear complex, and the second one is the change of the height of Z‐shaped complexes via transmetalation. By means of the pH‐dependent counterligand tren, the two motional features of the machine can depend on alternate additions of acid and base. An optical response is associated with the conversion of the linear form (which is yellow) into the metalated Z‐shaped one (which is red).     

From holes to sponge at irradiated Ge surfaces with increasing ion energy—an effect of defect kinetics?

We show that hole patterns and sponge-like layers at irradiated Ge surfaces originate from the same driving force, namely the kinetics of ion beam induced defects in the amorphous Ge surface layer. Ge hole patterns reported earlier for irradiation with low energy (5 keV) Ga⁺ ions were reproduced for low energy Bi⁺ but also for Ge⁺ self-irradiation, which proves that the dominating driving force for morphology evolution cannot originate from the implanted impurities. At higher ion energies the well-known formation of sponge-like Ge surface layers after heavy ion irradiation was found for Bi⁺ irradiation and Ge⁺ self-irradiation, also. The transition from smooth surfaces via hole patterns to sponge-like morphologies with increasing ion energies was studied in detail. A model based on the kinetics of ion beam induced defects was developed and implemented in 3D kinetic Monte Carlo simulations, which reproduce the transition from hole patterns to sponge-like layers with increasing ion energy.     

Subrecursive hierarchies on Scott domains

Summary We study a notion ofpartial primitive recursion (p.p.r.) including the concept ofparallelism in the context of partial continuous functions of type level one in the sense of [Krei], [Sco82], [Ers]. A variety of subrecursive hierarchies with respect top.p.r. is introduced and it turns out that they all coincide.     

Cohaerins C-F, four azaphilones from the xylariaceous fungus Annulohypoxylon cohaerens

Four azaphilones named cohaerins C-F, along with 4,5,4′,5′-tetrahydroxy-1,1′-binaphthyl were isolated from the methanolic extract of the stromata of Annulohypoxylon cohaerens (Ascomycetes, Xylariaceae). Cohaerins C-E constitute typical azaphilones, bearing a γ-lactone ring, while cohaerin F has an unprecedented carbon skeleton, lacking the lactone ring of the azaphilones and with an aliphatic side chain being attached directly to the azaphilone backbone by a C-C bond. Their structures were determined by 2D NMR, IR, UV, and CD spectroscopy. They showed moderate inhibitory activity of nitric oxide production in RAW cells, and strong and nonselective antimicrobial effects.