THE BIOSYNTHESIS OF THE PSEUDOMONAS ANTIBIOTIC OBAFLUORIN FROM PARA-AMINOPHENYLALANINE AND GLYCINE (GLYOXYLATE)

DL-[2,3-H-2(3)]-p-Aminophenylalanine is incorporated into obafluorin (1) with retention of C-3 deuterium and loss of deuterium from C-2. Labelled samples of p-nitrophenylacetic acid, p-aminophenylacetic acid and the N-acetylcysteamine thioester of the latter are not incorporated into obafluorin. Results of experiments with [2-C-13]-, [1-C-13]-, and [2-H-2(2)]-glycine show that glyoxylic acid is specifically the source of C-1 and C-2 of the antibiotic. A mechanism is proposed for the biosynthesis of the unit (2) in obafluorin (1).