James F. Esancy

An approach to the design of non-mutagenic azo dyes: 1. The identification of non-mutagenic precursors and potential metabolites

Abstract This paper describes a strategy for the development of non-mutagenic dyes by identifying and elaborating some non-genotoxic precursors. The approach presented makes use of the numerous published articles which describe the results of the mutagenicity and carcinogenicity testing of azo dyes and their intermediates. A number of chemical intermediates have been evaluated in this study as potential replacements for known carcinogenic dye intermediates which have been used in the past to produce dyes possessing good physical and chemical properties. Several of the intermediates examined were found to be non-mutagenic, and were converted to azo dyes which were themselves non-mutagenic. The results of this study suggest that the development of non-carcinogenic azo dyes could be accomplished by employing an approach which would utilize non-mutagenic intermediates and also take into consideration the potential genotoxicity of the metabolites resulting from reductive cleavage of the azo linkages.

An approach to the design of nonmutagenic azo dyes: analogs of the mutagen ci direct black 17

Abstract The effect on mutagenicity caused by incorporating an alkoxy substituent into the structure of a disazo hydrophilic dye has been investigated. The results of this study indicate that while bulky alkoxy groups are useful in lowering the mutagenicity of certain analogs of CI Direct Black 17, the decrease observed is less than that noted for a series of monoazo disperse dyes. The color and fastness properties of these novel disazo dyes are also described.

Genotoxicity of azo dyes: Bases and implications

Genotoxicity is a general term employed by genetic toxicologists when referring to adverse interactions between DNA and various substances to produce a hereditable change in the cell or organism. In humans, such changes are associated with birth defects, carcinogenesis, teratogenesis, and other types of diseases. It is generally believed that interactions with DNA which cause mutations to occur constitute the early events leading to hereditable changes. Consequently, much of the experimental work in this area has been devoted to mutagenicity testing. This approach is used as a cost-effective and relatively quick way to predict the potential carcinogenicity of organic substances. Although the genotoxicity of azo dyes has been the subject of numerous publications since the carcinogenicity of benzidine towards humans was first confirmed, this subject continues to be extremely important. It is interesting to note, however, that very little of the reported work on this subject appears to be aimed at developing data useful to dyestuff chemists in the design of non-genotoxic dyes. Rather, it is evident that much of the generated data are intended for use in formulating databases that can be used by regulatory agencies in predicting the potential health risks of proposed (new) and existing commercial dyes. This chapter, while by no means presented as an exhaustive treatment of the subject, contains a summary of recent literature, along with examples of how this information has been used to design non-mutagenic azo dyes and aromatic amines, and will be presented more from the perspective of a dyestuff chemist rather than a genetic toxicologist.

Proton magnetic resonance spectra of some naphthalene derivatives

Abstract The chemical shifts of the ring protons of some monosubstituted naphthalenes were assigned from 250 MHz spectra, and the assignments were used to assist in the interpretation of the spectra of a number of naphthalene sulfonic acids which are commonly used as dyestuff intermediates. A table of parameters is presented which would assist in the identification of complex azo dyes that are derived from these naphthalene derivatives.

Anomalous behavior of aminohydroxynaphthalenesulfonic acids during diazo coupling

Abstract The effect of pH on the diazo coupling reaction of some commonly used coupling components (J-acid, Gamma acid, H-acid and S-acid) with monosubstituted diazobenzenes has been investigated. The results demonstrate that, contrary to previous reports, selective diazo coupling ortho to an amino group of an aminohydroxynaphthalenesulfonic acid does not occur in weakly acidic (pH 5–6) media. In fact, such media were found to give nearly exclusive diazo coupling ortho or para to the hydroxyl group. The desired amine coupling reactions required a pH of 3.0–3.5 and occurred only with the more reactive diazonium salts. The structures of the dyes obtained were unambiguously determined with the aid of 1H-NMR spectroscopy.