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Binding of heterocyclic amines by yeast cells and their fractions
Author(s) -
Zhang Xue Bin,
Demuyakor Bawa,
Asahara Naomi,
Ohta Yoshiyuki
Publication year - 1991
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740570209
Subject(s) - yeast , saccharomyces cerevisiae , chemistry , indole test , biochemistry , quinoline , tryptophan , cell wall , isatin , stereochemistry , amino acid , organic chemistry
The binding of mutagenic pyrolysis products to cells of 50 yeast strains and their cell fractions was investigated. Cells of all yeast strains effectively bound 3‐amino‐1,4‐dimethyl‐5H‐pyrido[4,3‐b]indole (Trp‐P‐1) and 3‐amino‐1‐methyl‐5H‐pyrido[4,3‐b]indole (Trp‐P‐2). Cell walls (CW), and cell wall glucan and mannan (5 mg in each case) showed the highest binding of Trp‐P‐1 (50 μg ml −1 ); glucan adsorbed virtually all of the Trp‐P‐1. Cytoplasm also showed some binding but was much less effective. Glucans also bound well with 2‐amino‐3‐methylimidazo[4,5‐f]quinoline (IQ) and 2‐amino‐3,8‐dimethylimidazo 4,5‐quinoxaline (MeIQX) much more than CW, but 2‐amino‐5‐phenylpyridine (Phe‐P‐1) and 2‐amino‐3,4‐dimethylimidazo[4,5‐f]quinoline (MelQ) were not effectively bound. The quantity of IQ, MeIQ, Phe‐P‐1 and MeIQX bound was dependent on the strain of yeast. The mutagenic pyrolysis products bound to cells were effectively extracted by aqueous methanol, ammonia (50 g litre −1 ) and alcohol, but not by water. The binding was pH dependent and inhibited by metal salts. When yeast cells were heated to 100° for 15 min, the binding of Trp‐P‐1 decreased by about 30% but Saccharomyces cerevisiae 50 heated to 100° did not differ much from untreated cells in its binding ability.