Chemical modification of DNA with muta-carcinogens. I. 3-Amino-1-methyl-5H-pyrido[4,3-b]indole and 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole: metabolic activation and structure of the DNA adducts.
3-Amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) and 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1) are potent mutagen/carcinogens isolated from pyrolyzates of tryptophan and glutamic acid, respectively, and they have been found to exist in many cooked foods. Trp-P-2 and Glu-P-1 bind to DNA covalently after metabolic activations. The compounds are oxidized to the corresponding hydroxylamines (N-OH-Trp-P-2 and N-OH-Glu-P-1) by microsomes. N-OH-Trp-P-2 and N-OH-Glu-P-1 are the proximate forms of Trp-P-2 and Glu-P-1, respectively. They are further activated by cytosol to the O-acyl derivatives, which bind covalently with DNA. The structures of the modified nucleic acid bases were identified as 3-(C8-guanyl)amino-1-methyl-5H-pyrido[4,3-b]indole (Gua-Trp-P-2) and 2-(C8-guanyl)amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Gua-Glu-P-1). These initial events caused by Trp-P-2 and Glu-P-1 were established chemically, both in vitro and in vivo.
D000818:Animals; D001711:Biotransformation; D002243:Carbolines / Q000378:metabolism* / Q000633:toxicity; D002273:Carcinogens / Q000378:metabolism*; D004247:DNA / Q000302:isolation & purification / Q000378:metabolism*; D007093:Imidazoles / Q000378:metabolism* / Q000633:toxicity; D008099:Liver / Q000378:metabolism; D009153:Mutagens / Q000378:metabolism*; D051381:Rats
D002243:Carbolines; D002273:Carcinogens; D007093:Imidazoles; D009153:Mutagens; C023785:2-amino-6-methyldipyrido(1,2-a-3',2'-d)imidazole; C019133:3-amino-1-methyl-5H-pyrido(4,3-b)indole; D004247:DNA