N-(1-Deoxy-D-fructos-1-yl)-L-amino acids isolated from hog liver are endogenous lead decorporation substances with low toxicity and cell membrane crossing ability. To simulate the effect of the natural N-(1-deoxy-D-fructos-1-yl)-L-amino acids on lead decorporation, a ser ies of the epimerically pure N-(1-deoxy-D-fructos-1-yl)-L-amino acids (6a-eβ) were synthesized, and their usefulness as antagonists of lead intoxication was investigated. The results suggest that after treatment with 6a-eβ the liver, kidney, bone, and brain, lead levels of mice were significantly reduced in comparison with the control group. Except for bone and brain lead levels of the mice after chelating treatment with 6dβ, all of the other tissue lead levels of mice after chelating treatment with 6a-eβ are significantly lower than those of mice after treatment with DL-penicillamine (p<0.05). All fecal lead levels of mice after treatment with 6a-eβ are significantly higher than those of mice after treatment with 0.9% saline (controls) and DLpenicillamine (p<0.05-0.01). The effects of all chelating agents on urinary excretion of lead in mice are clearly superior to the control (p<0.05-0.01). The results of the present studies on repeated lead exposure indicated that at tested levels of i.p. injections, the fructose-amino acids were effective antagonists of lead poisoning under the experimental conditions. After treatment with the chelators, the concentration of essential metals in mice did not exhibit change as compared to the control. The effects of the compounds on cadmium decorporation were also investigated, and similar results were observed.