Sequential enzymatic synthesis and separation of 13N-L-glutamic acid and 13N-L-alanine

The sequential enzymatic synthesis and separation of 13N-L-glutamic acid and 13N-L-alanine are described. Basically, that involves the synthesis of 13N-L-glutamic acid by one enzyme, the transamination of the labeled glutamic acid to form 13N-L-alanine by a second enzyme, and the separation of the two amino acids by rapid column chromatography. The 13N-L-alanine was evaluated in animals by imaging and tissue distribution studies and showed good potential as a pancreatic imaging agent