Grisorixin is an ionophorous antibiotic of the nigericin group isolated from cultures of a strain of Streptomyces griseus. It shows activity against Gram-positive bacteria and fungi but is also very toxic. The isolation and purification procedures are reported. Its structure and physico-chemical properties are also described.
Grisorixin, a polycyclic polyether antibiotic of the nigericin group, showed ionophorous properties. The conformations of crystallized grisorixin and its metallic salts are very similar and are compared in this paper. The physico-chemical properties of the salts are described. The chemical oxidation of grisorixin methyl ester allowed us to isolate several oxidation products whose structures are described.
A new antibiotic designated as victomycin which belongs to the phleomycinbleomycin group antibiotics was isolated from a sporangia-forming actinomycete. From taxonomic studies, the producing strain was classified as Streptosporangium violaceochromogenes nov., sp. KAWAMOTO et NARA 1974. Fermentative production of antibiotic complex XK 49 is described.
A new antibiotic, victomycin, is active against a variety of Gram-positive and Gram-negative bacteria, and also has in vivo activity against solid Sarcoma 180 and EHRLICH ascites carcinoma. It belongs to the phleomycin-bleomycin group of antibiotics and has been differentiated from all known phleomycins and bleomycins by its physicochemical properties and thin-layer chromatograms.
A new metabolite was isolated from the culture filtrate of a deacetylcephalosporin C-producing mutant, derived from Cephalosporium acremonium ATCC 14553, by means of adsorption on activated carbon, column chromatography on DEAE-Sephadex A-25 and gel filtration through a Sephadex G-10 column. The compound was identified as D-5-amino-5-carboxyvaleramido-(5-formyl-4-carboxy-2H, 3H, 6H-tetra hydro-1, 3-thiazinyl) glycine by spectral analyses, elucidation of hydrolysis products of the compound, and comparison of characteristics of the compound with those of a synthetic authentic compound.
EM49 is a family of similar peptide antibiotics, each an octapeptide acylated with a &-hydroxy fatty acid. This paper describes the determination of the structure of the fatty acyl residue, the selective removal of this residue from the peptide portion of the molecule, and the sequential analysis of the peptide by the EDMAN method. The structure of EM49, 1, is derived by this degradation.
Lankacidin C, a component of lankacidin-group (T-2636) antibiotics, was esterified to lankacidin C 8-butyrate in the presence of methyl butyrate by culture broth and by cell-free extract of Bacillus megaterium IFO 12108. In addition, methyl isobutyrate, methyl valerate and methyl isovalerate served as acyl donors for the esterification, and lankacidin C 8-isobutyrate, lankacidin C 8-valerate and lankacidin C 8-isovalerate were formed respectively. Lankacidin C 8, 14-dibutyrate was hydrolyzed to lankacidin C 14-butyrate by the same organism.