X-14885A, a novel divalent cation ionophore produced by a Streptomyces culture: discovery, fermentation, biological as well as ionophore properties and taxonomy of the producing culture.

X-14885A, a novel divalent cation ionophore produced by a Streptomyces culture: discovery, fermentation, biological as well as ionophore properties and taxonomy of the producing culture. X-14547A, a new ionophorous antibiotic produced by Streptomyces antibioticus NRRL 8167. Discovery, fermentation, biological properties and taxonomy of the producing culture. Novel poryether antibiotics X-14667A and X-14667B from Streptomyces cinnamonensis subsp. urethanofaciens Discovery, fermentation, biological as well as ionophore properties and taxonomy of the producing culture. Structure of antibiotic X-14547A, a carboxylic acid ionophore produced by Streptomyces antibioticus, NRRL 8167 Microbial transformation of A23187, a divalent cation ionophore antibiotic FR-900148, a new antibiotic. I. Taxonomy, fermentation, isolation and characterization. Isolation and characterization of three novel polyether antibiotics and three novel actinomycins as cometabolites of the same Streptomyces sp. X-14873, ATCC 31679. The structure and absolute stereochemistry of zincophorin (antibiotic M144255): A monobasic carboxylic acid ionophore having a remarkable specificity for divalent cations. Microbial products. IV. X-14847, a new aminoglycoside from Micromonospora echinospora. A NEW ANTIBIOTIC X-5108 OF STREPTOMYCES ORIGIN