Magnesium(I) Halide versus Magnesium Metal: Differences in Reaction Energy and Reactivity Monitored in Reduction Processes of P-Cl Bonds
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
Authors: Arras, Janet; Kruczynski, Tomasz; Bresien, Jonas; Schulz, Axel; Schnoeckel, Hansgeorg
Magnesium(I) halides ((MgX)-X-I; X=Cl, Br, I), as high temperature molecules, are trapped and finally stored at -80 degrees C in toluene/donor solutions. These solutions provide insights into the fundamental mechanism of reduction reactions using activated magnesium metal as a prototype for every base metal. The most important example of such a reaction is the preparation of Grignard reagents (RMgX). The details of this highly complex mechanism especially of intermediates between Mg metal and Mg-II (RMgX) remain unknown until today. The same is true for the reaction of bulk magnesium with Group 15 halide compounds that give biradicaloid species. We investigate the reduction of P-Cl bonds with solutions of [(MgBr)-Br-I((NBu3)-Bu-n)](2) (1). The phosphanes [ClP(mu-NTer)](2) (2) and (Me3Si)(2)N-PCl2 (3), were chosen as they had successfully been reduced by Mg metal before. Furthermore, reactions of both 1 and Mg metal are compared with an Mg-I chelate complex (LMg)-Mg-1-MgL1 containing a strong Mg-Mg sigma-bond.
Bifidobacterium canis sp. nov., a novel member of the Bifidobacterium pseudolongum phylogenetic group isolated from faeces of a dog (Canis lupus f. familiaris)
INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY
Authors: Neuzil-Bunesova, Vera; Lugli, Gabriele Andrea; Modrackova, Nikol; Makovska, Marie; Mrazek, Jakub; Mekadim, Chahrazed; Musilova, Sarka; Svobodova, Ivona; Spanek, Roman; Ventura, Marco; Killer, Jiri
A fructose-6-phosphate phosphoketolase-positive strain (GSD1FS(T)) was isolated from a faecal sample of a 3 weeks old German Shepherd dog. The closest related taxa to isolate GSD1FS(T) based on results from the EZBioCloud database were Bifidobacterium animalis subsp. animalis ATCC 25527(T), Bifidobacterium animalis subsp. lactis DSM 10140(T) and Bifidobacterium anseris LMG 30189(T), belonging to the Bifidobacterium pseudolongum phylogenetic group. The resulting 16S rRNA gene identities (compared length of 1454 nucleotides) towards these taxa were 97.30, 97.23 and 97.09%, respectively. The pairwise similarities of strain GSD1FS(T) using argS, atpA, fusA, hsp60, pyrG, rpsC, thrS and xfp gene fragments to all valid representatives of the B. pseudolongum phylogenetic group were in the concatenated range of 83.08-88.34%. Phylogenomic analysis based on whole-genome methods such as average nucleotide identity revealed that bifidobacterial strain GSD1FS(T) exhibits close phylogenetic relatedness (88.17%) to Bifidobacetrium cuniculi LMG 10738(T). Genotypic characteristics and phylogenetic analyses based on nine molecular markers, as well as genomic and comparative phenotypic analyses, clearly proved that the evaluated strain should be considered as representing a novel species within the B. pseudolongum phylogenetic group named as Bifidobacterium canis sp. nov. (GSD1FS(T)=DSM 105923(T)=LMG 30345(T)=CCM 8806(T)).