The structure and absolute stereochemistry of zincophorin (antibiotic M144255): a monobasic carboxylic acid ionophore having a remarkable specificity for divalent cations.

phores with ruminant growth promoting properties, we have previously reportcd the structure of antibiotic M1396032), the行rst tetronic acidcontainillg polyether. We now wish to describe antibiotic M144255, a monocarboxylic acid type ionophore from a strain of Streptomyces griseus. It has a high affinity fbr divalent cations especially zinc, for which reason it was given the trivial name, zincophorin. The molecular structure and absolute stereochemistry(Fig.1)were determined by X-ray analysis on the mixed zincInagnesium salt(see below)1). Although zinco.