125I-beta-iodo-D-alanine-synthesis, biodistribution and antimicrobial activity.

Methyl N-carbobenzoxy-beta-iodo-D-alaninate (1) served as an intermediate to synthesize methyl beta-iodo-D-alaninate (2) and beta-iodo-D-alanine (3). The 125I-labeled compound 1 was synthesized by the melt method and used to synthesize 125I-labeled compounds 2 and 3. Compound 3 was shown to be substrate for D-amino acid oxidase. It was also shown that compounds 2 and 3 were rapidly eliminated from normal mammalian tissues and that compound 3 inhibited the Escherichia coli growth in a dose-dependent manner at 100-500 microgram/ml while compound 2 showed no effect at 500 microgram/ml level. Therefore, it was suggested that compound 3 may serve as an abscess localizing agent.