[Behavior of ketoamine in animals]

A simple ketoamine 14C-fructosoglycine with all the fructose carbon atoms labelled was synthesized for studies of possible pathways of the ketoamines metabolism in animal body. The ketoamine bond in the fructosoglycine was not hydrolyzed during incubation with homogenates of rabbit liver, kidney, spleen and testicular tissues within 3 hrs at pH 4.8 and 7.3 as well as after hydrolysis with pancreatine (the enzymatic extract from bovine pancreas) at pH 8.4. 14C-fructosoglycine administered into rabbit circulation was mainly excreted with urine (about 70% of the label) within 8-14 days. The main part of the ketoamine was excreted as fructosoglycine and the lower amount--as glycated dipeptide; some amount of fructosoglycine was hydrolyzed liberating fructose or converted into aldimine which was hydrolyzed with formation of glucose. The ketoamine was metabolized also into non-reducing isosucrose-like glucofructoside, insensitive to acid and enzymatic hydrolysis.