Abstract
An antimetabolite, THX, was isolated from fermentation broths of the thienamycin producer, Streptomyces cattleya, when the organism was grown in the presence of a fluorine-containing substrate. THX was subsequently identified as one of the four possible stereoisomers of 4-fluorothreonine. Inorganic fluoride or any one of a number of organofluorine compounds can be used as precursors of 4-fluorothreonine. In addition, 19F NMR has provided evidence that the organism synthesizes fluoroacetate under the same fermentation conditions. The in vitro antibacterial spectrum of 4-fluorothreonine is also presented.