Open AccessInhibition of Aminoimidazoquinoxalinc‐type and Aminoimidazol‐4‐one‐type Mutagen Formation in Liquid Reflux Models by l ‐Tryptophan and Other Selected Indoles
Author(s) -
Jones R. Conrad,
Weisburger John H.
Publication year - 1988
Publication title -
japanese journal of cancer research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 0910-5050
DOI - 10.1111/j.1349-7006.1988.tb01580.x
Subject(s) - mutagen , tryptophan , quinoxaline , indole test , chemistry , amino acid , heterocyclic compound , ames test , stereochemistry , carcinogen , biochemistry , medicinal chemistry , organic chemistry , biology , genetics , salmonella , bacteria
The essential amino acid l ‐tryptophan ( l ‐Trp) was found to be an effective inhibitor of the development of mutagenicity (Ames test) in liquid‐reflux models known to produce identified IQ‐type mutagens, such as 2‐amino‐3,8‐dimethylimidazo[4,5‐ f ]quinoxaline (MeIQ x ) and 2‐amino‐3,7,8‐trimethylimidazo[4,5‐ f ]qninoxaline (7,8‐DiMeIQ x ), and in reflux models recently developed in our laboratory that have been found to produce novel IQ‐“like” mutagens (aminoimidazol‐4‐ones), which we have identified as 2‐amino‐1‐methyl‐5‐propylideneimidazol‐4‐one (TCP‐1), and 2‐amino‐5‐ethylidene‐1‐methylimidazol‐4‐one (TCP‐2 or ACP). Selected indoles other than l ‐Trp were also found to be effective inhibitors of mutagen formation in these same reflux models. A mechanism of inhibition of mutagen formation based on the preferential reaction of mutagen precursor aldehydes with the indole‐ring nitrogen of these inhibitors, rather than with creatinine, is indicated, and a new “concerted condensation model” for the formation of IQ‐type mutagens proposed.