Synthesis and evaluations of pentahydroxylhexyl-L-cysteine and its dimer as chelating agents for cadmium or lead decorporation.
N-(2,3,4,5,6-pentahydroxylhexyl)-L-cysteine (4) and N,N'-di(2,3,4,5,6-pentahydroxylhexyl)-L-cystine (5) were synthesized. As antagonists of cadmium or lead intoxication, they were found to be effective by oral administration on repeated exposure. The bioassay in vivo indicated that their cadmium-mobilizing potencies are significantly superior to those of N-acetyl-L-cysteine and their lead-mobilizing properties are equivalent to those of DL-penicillamine (DL-PA). The stability constants of the Cd-4 and Cd-5 complexes or Pb-4 and Pb-5 complexes were determined by use of pH titration. The membrane permeability of compounds 4 and 5 was evaluated by transporting across the Caco-2 cell monolayer. The effect of compounds 4 and 5 on the concentrations of essential metal ions in the renal cortex is negligible in comparison with that of the group treated with lead only. The acute toxicity of compounds 4 was tested by oral gavage and the resulting LD50 value for both mice and rats is larger than 10 g kg(-1) bw. The cytogenetic effects of compound 4 were evaluated in the Ames assay, mouse bone marrow micronucleus test, and sperms shape abnormality assay, and all of them show the negative reactions.
Wang
Chao
C
School of Pharmaceutical Sciences, Peking University, Beijing 100083, PR China.
Zhao
Ming
M
Yang
Jian
J
Li
Xingwei
X
Peng
Shiqi
S
D000818:Animals; D001854:Bone Marrow Cells / Q000187:drug effects; D018938:Caco-2 Cells; D002105:Cadmium Poisoning / Q000188:drug therapy* / Q000378:metabolism; D002614:Chelating Agents / Q000138:chemical synthesis* / Q000494:pharmacology* / Q000633:toxicity; D003545:Cysteine / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000494:pharmacology* / Q000633:toxicity; D005260:Female; D006801:Humans; D007202:Indicators and Reagents; D007274:Injections, Intraperitoneal; D007855:Lead Poisoning / Q000188:drug therapy* / Q000378:metabolism; D007928:Lethal Dose 50; D008297:Male; D051379:Mice; D015162:Micronucleus Tests; D011199:Potentiometry; D051381:Rats; D017208:Rats, Wistar; D013094:Spermatozoa / Q000187:drug effects / Q000648:ultrastructure; D014018:Tissue Distribution
D002614:Chelating Agents; D007202:Indicators and Reagents; C494204:N-(2,3,4,5,6-pentahydroxylhexyl)-L-cysteine; D003545:Cysteine