Diaminobenzoic acid derivatives as dye precursors

Details Diaminobenzoic acid derivatives as dye precursors Diaminobenzoic acid derivatives as dye precursors

1999-03-18

2001-05-15

Liott, Caroline D. (Department: 1751)

Bleaching and dyeing; fluid treatment and chemical modification

Using enzymes, dye process, composition, or product of dyeing

C008S416000

Reexamination Certificate

active

06231621

ABSTRACT:

FIELD OF THE INVENTION
The present invention concerns the use of aminobenzoic acid (DABA) as a substitute for e.g. o-phenylendiamine (OPD) in analyses based on peroxidases as well as a dyeing substrate (i.e. a dye precursor) in dyeing compositions, and as an substrate for dyeing natural and synthetic fibres including textiles, thread and yarns. The invention also relates to a composition adapted for dyeing keratinous fibres, e.g. hair, wool, fur and hides, and a method for dyeing such keratinous fibres.
BACKGROUND OF THE INVENTION
Immuno-chemical Assays
Several different substrates are known in the part to be used for enzyme systems in connection with peroxidase-based immuno-chemical assays, for example ELISA. These substrates are often toxic, mutagenic or carcinogenic.
ELISA (Enzyme Linked Immuno Sorbent Assay) is a method used to assess the amount of antibody in serum. The main principle is that in a much diluted solution many antigens will become bound to the surface of plastic. Thus, if a much diluted solution of antigens is incubated for a time in plastic trays it is possible to wash the cavities in a buffer solution and still retain the film of antigens on the surface of the plastic. If it is required to determine the amount of antibodies in, for instance, serum then the trays with their deposits of antigens are incubated with the serum, The antibodies attach themselves to the antigens and, after thorough washing the trays are again incubated this time with a marker, for example anti-immune globulin serum to which there is attached a suitable enzyme by covalent bonding. In this particular case peroxidase is used.
The peroxidase-marker complex will attach itself to those locations where there is already a deposit of antibodies. After thorough washing to remove all un-combined material the enzyme activity is measured, normally by the use of a suitable colour indicator. Enzyme activity may be determined by the addition of a cromogenetic substrate (i.e. colour producing compound) and hydrogen peroxide. The enzyme catalyses the reduction of the substrate to a coloured compound and the resultant degree of absorbency provides a measure of the enzyme activity. If the serum contains no antibodies there will be no enzyme activity, on the other hand if there is much antibody present there will be very considerable enzyme activity. A standard curve can be drawn showing enzyme activity as a function of the concentration of antibodies. This may be used to estimate the content of antibodies in unknown serum samples by interpolation.
Many of the peroxidase substrates are aromatic amines and include diaminobenziden (DAB), 3,3′-diamino benzid tetra hydrochloride, 3,3′,5,5′-tetra methyl benzidin (TMD). Another peroxidase substrate, which does not belong to the group of aromatic amines, is 2,2-azino-di (3-ethyl-benzo thiazolin-6-sulphonic acid) (AEBTS), this has been used as a standard for the establishment of the activity of peroxidase preparations. According to Voogd, Van der Stel and Jacobs (1980) this material is also a mutagent.
o-phenylendiamine (OPD) is another peroxidase substrate which is widely used in hospital and development laboratories. OPD is known to be both mutagenic and carcinogenic.
The staff of laboratories in which analyses involving the use of toxic, mutagenic or carcinogenic materials are carried out are exposed to a significant degree of risk of coming into direct contact with these materials. In order to provide a safe working environment considerable efforts are now made to substitute these dangerous materials with less dangerous ones.
Hair Dyeing Composition
In addition to being used as a substrate in immuno-chemical assays OPD is used to dye hair. In this connection too it is desirable to substitute a dangerous material with one less dangerous so that the user is not exposed to danger by coming into contact with it. To protect the hands against the dangerous material it is normal for gloves to be used while the hair dye is being applied. Gloves cannot, of course, protect the scalp of the person to whom the dye is applied.
In general hair dyeing compositions on the market today can be divided into three main groups:
temporary hair dyes,
semi-permanent hair dyes, and
permanent oxidative hair dyes.
The temporary hair dyes are only intended to change the natural hair colour for a short period of time and usually functions by depositing dyes on the surface of the hair. Such hair dyes are easy to remove with normal shampooing.
When using semi-permanent hair dyes the colour of the dyed hair can survive for five or more shampooings. This is achieved by using dyes having a high affinity for hair keratin and which is able penetrate into the interior of the hair shaft.
Permanent hair dyes are very durable to sunlight, shampooing and other hair treatments and need only to be refreshed once a month as new hair grows out. with these dyeing systems the dyes are created directly in and on the hair. Small aromatic colourless dye precursors (e.g. p-phenylene-diamine, o-aminophenol, o-phenylendiamine (OPD)) penetrate deep into the hair where said dye precursors are oxidised by an oxidising agent into coloured polymeric compounds. These coloured compounds are larger than the dye precursors and can not be washed out of the hair.
By including compounds referred to as modifiers (or couplers) in the hair dyeing composition a number of hair colour tints can be obtained. Cathecol and Resorcinol are examples of such modifiers.
Some of the today most widely used dye precursors such as OPD are known to be both mutagenic and carcinogenic.
Further, traditionally H
2
O
2
is used as the oxidizing agent (colour builder), but also as a bleaching agent. Dyeing compositions comprising H
2
O
2
are often referred to as “lightening dyes” due to this lightening effect of H
2
O
2
.
The use of H
2
O
2
in dyeing compositions have some disadvantages as H
2
O
2
damages the hair. Further, oxidative dyeing often demands high pH (normally around pH 9-10), which also inflicts damage on the hair and on the skin. Consequently, if using dye compositions comprising H
2
O
2
it is not recommendable to dye the hair often.
To overcome the disadvantages of using H
2
O
2
it has been suggested to use oxidation enzymes to replace H
2
O
2
.
U.S. Pat. No. 3,251,742 (Revlon) describes a method for dyeing human hair by dye formation in situ (i.e. on the hair). An oxidation enzyme is used for the colour formation reactions at a substantially neutral pH (7-8.5). Laccases, tyrosinases, polyphenolases and catacolases are mentioned as suitable oxidation enzymes. The hair colour pigment is formed by controlled oxidation of various quinone-forming compounds and mono or poly aromatic amines having the amino groups on the aromatic rings to form natural appearing pigments. Specifically mentioned dye precursors are 2-amino-4-nitrophenol, p-phenylene diamine, m-phenylene diamine, o-phenylene diamine, 2-amino-1,4-naphthoquenone, m-aminophenol, p-aminophenol, o-aminophenol, 2-amino resorcinol, 1,2,4-benzene triamine, nitro-p-phenylene diamine, 2-amino-5-diethyl amino toluene.
EP patent no. 504.005 (Perma S. A.) concerns dyeing compositions for keratinous fibres, in particular hair, which do not require the presence of H
2
O
2
(hydrogen peroxide). The composition comprises an enzyme capable of catalysing the formation of the polymeric dyes and also dye precursors, such as bases and couplers, in a buffer solution wherein the pH of said composition is between 6.5 and 8 and said enzyme has an optimal activity in the pH range between 6.5 and 8
. Rhizoctonia praticola laccase
and
Rhus vernicifera laccase
are exemplified as the oxidation enzyme to oxidize the dye precursor(s). The following dye precursors are specifically mentioned: p-phenylene diamine, o-aminophenol, p-methylaminophenol, p-aminophenol, p-toluylenediamine and N-phenyl-p-phenylene diamine.
The aim of the present invention is to use the present findings to make available a substrate which to all intents and purposes is non-toxic, non-mutagenic and/or non-

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