WO1993021252A1 - Synthetic melanin - Google Patents
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- WO1993021252A1 WO1993021252A1 PCT/US1993/003430 US9303430W WO9321252A1 WO 1993021252 A1 WO1993021252 A1 WO 1993021252A1 US 9303430 W US9303430 W US 9303430W WO 9321252 A1 WO9321252 A1 WO 9321252A1
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- Prior art keywords
- melanin
- soluble
- dhica
- dopachrome
- dihydroxyindole
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- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12G—WINE; PREPARATION THEREOF; ALCOHOLIC BEVERAGES; PREPARATION OF ALCOHOLIC BEVERAGES NOT PROVIDED FOR IN SUBCLASSES C12C OR C12H
- C12G3/00—Preparation of other alcoholic beverages
- C12G3/04—Preparation of other alcoholic beverages by mixing, e.g. for preparation of liqueurs
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- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
- A23L5/00—Preparation or treatment of foods or foodstuffs, in general; Food or foodstuffs obtained thereby; Materials therefor
- A23L5/40—Colouring or decolouring of foods
- A23L5/42—Addition of dyes or pigments, e.g. in combination with optical brighteners
- A23L5/43—Addition of dyes or pigments, e.g. in combination with optical brighteners using naturally occurring organic dyes or pigments, their artificial duplicates or their derivatives
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- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
- A23L5/00—Preparation or treatment of foods or foodstuffs, in general; Food or foodstuffs obtained thereby; Materials therefor
- A23L5/40—Colouring or decolouring of foods
- A23L5/42—Addition of dyes or pigments, e.g. in combination with optical brighteners
- A23L5/47—Addition of dyes or pigments, e.g. in combination with optical brighteners using synthetic organic dyes or pigments not covered by groups A23L5/43 - A23L5/46
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K31/00—Medicinal preparations containing organic active ingredients
- A61K31/74—Synthetic polymeric materials
- A61K31/785—Polymers containing nitrogen
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K8/00—Cosmetics or similar toiletry preparations
- A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
- A61K8/72—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
- A61Q17/00—Barrier preparations; Preparations brought into direct contact with the skin for affording protection against external influences, e.g. sunlight, X-rays or other harmful rays, corrosive materials, bacteria or insect stings
- A61Q17/04—Topical preparations for affording protection against sunlight or other radiation; Topical sun tanning preparations
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
- A61Q19/00—Preparations for care of the skin
- A61Q19/02—Preparations for care of the skin for chemically bleaching or whitening the skin
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
- A61Q19/00—Preparations for care of the skin
- A61Q19/04—Preparations for care of the skin for chemically tanning the skin
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09B—ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. PIGMENTS; MORDANTS; LAKES
- C09B69/00—Dyes not provided for by a single group of this subclass
- C09B69/10—Polymeric dyes; Reaction products of dyes with monomers or with macromolecular compounds
- C09B69/104—Polymeric dyes; Reaction products of dyes with monomers or with macromolecular compounds containing an indole dye, including melanine derivates
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- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12C—BEER; PREPARATION OF BEER BY FERMENTATION; PREPARATION OF MALT FOR MAKING BEER; PREPARATION OF HOPS FOR MAKING BEER
- C12C5/00—Other raw materials for the preparation of beer
- C12C5/02—Additives for beer
- C12C5/04—Colouring additives
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- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
- C12P17/00—Preparation of heterocyclic carbon compounds with only O, N, S, Se or Te as ring hetero atoms
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
- C12P17/00—Preparation of heterocyclic carbon compounds with only O, N, S, Se or Te as ring hetero atoms
- C12P17/10—Nitrogen as only ring hetero atom
Definitions
- the present invention concerns the synthesis of soluble forms of melanin and their composition, and methods of using such compositions to provide a natural-appearing tan to mammalian skin and hair and to provide a sun-screen, to treat hypopigmentation, to tint glass and plastic, to provide color to foods and beverages, and to protect industrial materials against ultraviolet damage.
- melanins are heteropolymers consisting of L-dopa and its enzymatic derivatives. They are ubiquitous in living organisms and are produced throughout the zoological and botanical phyla. In mammalian skin, melanins are produced through enzymatic processes in specialized cells known as "melanocytes". Melanins are the pigments of mammalian skin and hair.
- Mammalian melanins are highly insoluble and can be dissolved (solubiiized) only through non-physiological treatments such as boiling in strong alkali, or through the use of strong oxidants such as hydrogen peroxide.
- Tyrosinase a key enzyme in the melanin biosynthetic pathway, can catalyze the formation of melanin in a test tube using L-tyrosine, L-dopa or 5,6-dihydroxy ⁇ ndoIe as substrates; however, the product is an insoluble precipitate as described above.
- melanin may be a polymer of 5,6- dihydroxyindole and 5,6-dihydroxyindole-2-carboxyIic add. Ito, however, does not teach or suggest combining these chemicals to form melanin.
- Herl ⁇ hy (US Patent Number 4,515,773) disdoses a skin tanning composition containing a melanin precursor and a tyrosinase enzyme in a cosmetic base. He does not, however, teach or claim the application of melanins, either natural or synthetic to the skin.
- Gaskin (US Patent Number 4,806,344) discloses a sun protectant composition comprising "melanin” as one of the ingredients: Gaskin further discloses that the melanin is "synthesized from tyrosinase and DOPA". She does not teach or suggest that such melanin is synthesized non-enzymatically or that it is comprised of precursors which confer either negative or positive charges on the polymer, rendering it soluble in aqueous solutions.
- melanins It would be of commercial value to have synthetic varieties of melanin with different solubility, molecular size, and color characteristics. That is, it would be useful to be able to produce various melanins of predictable colors and physicochemical charaderistics through specific changes in the synthetic reaction conditions. For example, it would be of value to produce a melanin that, at neutral pH, is soluble in aqueous solvents such as those used in skin creams and lotions, while at acid pH, is soluble in organic solvents such as those used in oil-based paints. Such melanins could impart a natural-appearing tan to mammalian skin and hair. Such melanins would also be effective as sun-screens, since melanins are the chemicals in the skin which absorb ultraviolet radiation and thus provide protection from its harmful effects, such as premature skin aging and the occurrence of skin cancers.
- melanins would be effective in treating post-inflammatory hypopigmentation due to eczema, acne, trauma, burns and psoriasis. Also, as a cover-up for vitiligo and other disorders of hypopigmentation, soluble melanins would be quite effective.
- melanins absorb light throughout the ultraviolet and visible spectra, they would also be effective as glass or plastic tinting agents for eye glasses, contact lenses, car windows, house windows, office buildings, etc. Since melanins exhibit brown, red-brown, and golden-brown colors, they would be effective food and beverage colorants for such things as beer, tea, coffee, potato chips, and the like.
- One such process involves reaction of dopachrome with at least one enzyme, now known as dopachrome tautomerase, derived from biological cells or tissues which contain a pigmentary system.
- dopachrome tautomerase derived from biological cells or tissues which contain a pigmentary system.
- 5,6-dihydroxyindole, indole-5,6-quinone and/or melanochrome are also present.
- compositions and methods for modifying the spedral charaderistics of such melanins It is another object of the present invention to provide compositions and methods for modifying the solubility charaderistics of such melanins so that they can be dissolved readily in either organic or aqueous solvents.
- Still another object is to provide soluble melanins with an array of possible colors.
- the present invention relates to a melanin that is soluble in aqueous solution, e.g., water or an aqueous buffered solution, at a pH of at least 5 to 9, preferably 6.5 to 7.5, at a temperature of 0° to 100°C.
- aqueous solution e.g., water or an aqueous buffered solution
- the present invention also relates to a melanin that is soluble in organic solutions, e.g., butanol or butoxyethanoL
- the soluble melanin is further charaderized by being capable of being filtered through at least a 0.45 micron size filter.
- the solubility of the melanin in aqueous solutions around neutral pH is in large part due to the abundance of carboxyl and/or amino-groups, whereas the solubility of the melanin in organic solutions is in large part due to the protonation of said carboxyl-groups at acid pH, and/or the de-protonation of amino-groups at basic pH.
- the present invention also concerns a method of producing synthetic melanin comprising combining in a reaction mixture dopachrome and dopachrome tautomerase and a phenethylamine of the formula
- X and Y each independently is OH or NH 2 ,
- R is H or COOH
- R 1 , R 2 and R 3 each independently is H, NO 2 , CHO, CN, OR 4 , halogen,
- R 4 , R 5 , R 6 , R 7 , and R 8 each independently is H or alkyl, preferably lower alkyl of 1 to 4 of 1 to 4 carbon atoms.
- a preferred phenethylanine is 3-amino-tyrosine which imparts a red golden cast to the resulting melanin.
- a 5,6-dihydroxyindole and/or 3-amino-tyrosine may be added to the dopachrome and the enzyme dopachrome tautomerase, or dopachrome may be allowed to spontaneously form 5,6-dihydroxyindole before adding the enzyme.
- the reaction mixture may comprise a 5,6-dihydroxyindole-2-carboxylic acid alone, or in a mixture with 5,6-dihydroxyindole and/or 3-amino-tyrosine, or the reaction mixture may comprise a 5,6-dihydroxyindole in combination with 3-amino-tyrosine, in which cases enzymes are not necessary and the reactions occur in the presence of oxygen.
- the color of the soluble melanin can be varied between black, brown, red and yellow by altering the contents of the readion mixtures, for example by adding sulfhydryl containing compounds, or various metals such as, but not limited to, Cu 2+ , Ni 2+ , and Co 2+ or by altering the pH of the reaction mixtures.
- the basis for the solubility of the melanin in aqueous solutions is in a large part due to the high degree of carboxyl groups present in the molecule, said carboxyl groups being incorporated as part of the 5,6-dihydroxyindole-2-carboxyIic add precursor.
- carboxyl groups being incorporated as part of the 5,6-dihydroxyindole-2-carboxyIic add precursor.
- 3-amino-tyrosine or similar compounds are incorporated into the melanin
- the basis for the solubility of the melanin is also due to the high degree of amino groups present in the molecule, said amino groups being incorporated as part of the 3-amino-tyros ⁇ ne precursor.
- Compounds similar to 5,6-dihydroxy ⁇ ndole-2-carboxyiic acid or 3-am ⁇ no-tyrosine could substitute in providing said carboxyl- or amino groups and could therefore also act as precursors to soluble melanin.
- the melanins of the invention remain in aqueous solution, at- neutral pH (e.g., pH of 5 to 9, preferably 6.5 to 7.5), for long periods of time, e.g., indefinitely, at room temperatures of 0°C to 100°C, e.g., room temperature.
- the melanins according to the invention are further charaderized by remaining soluble upon freezing/thawing.
- the inventive melanins are also characterized by being capable of being filtered through at least a 0.45 micron size filter.
- the melanins according to the invention can be precipitated below pH4.
- the melanins cannot be dialyzed through a semi-permeable membrane which allows the passage of molecules having less than a molecular weight of approximately 10,000. Therefore the melanins according to the invention are of molecular weights greater than 10,000; however, this is not an essential charaderistic for their usefulness.
- the melanins can be lyophilized to a dry powder form and then reconstituted to soluble form with distilled water or suitable aqueous solvents, e.g., sodium phosphate 0.1M or sodium chloride 0.1M. Following precipitation at acid pH, they can also be reconstituted in organic solvents such as butanol or 2-butoxyethanoI.
- the melanins according to the invention can be prepared non-enzymatically (synthetically) or enzymatically.
- the enzymatic preparation according to the Invention comprises combining in a reaction mixture a substrate, i.e., dopachrome and dopachrome tautomerase (E.C.5.3.2.3) which catalyzes the isomeric tautomerization of dopachrome to 5,6-dihydroxyindoIe-2-carboxyl ⁇ c add (DHICA).
- the readion mixture comprises as a substrate DHICA alone or a mixture of DHICA, 5,6-dihydroxyindole, and/or 3-amino-tyrosine.
- Suitable analogs of DHICA i.e., similar structures containing carboxyl- or amino- groups, may be substituted in the reaction.
- similar structures containing other electrically charged moieties, such as phosphate groups may be substituted In the reaction.
- An example of such a structure is 3 '- and/or 4' - phosphoryl phenylalanine (dopa phosphate).
- the enzymatic or nonenzymatic readion mixtures may still further comprise as a substrate indole-5,6-quinone and/or melanochrome.
- Metal ions and sulfhydryl-contain ⁇ ng compounds may be included.
- the individual components of the substrate be it one component, i.e., dopachrome, as in the enzymatic preparation, or more than one component as in the nonenzymatic preparation, preferably will be in an amount of .01 to 5.0 millimolar, but not necessarily limited to this concentration range.
- the combining of substrate and enzymes, or precursors without enzymes in the reaction mixtures is preferably conduded at a temperature of 15°C to 90°C.
- oxygen e.g., air or pure oxygen
- dopa quinone ieuco dopachrome, dopachrome, DHICA, 5,6-dihydroxyindole, indole-5,6-quinone, and melanochrome are all derivatives of dopa.
- Dopa itself is a derivative of tyrosine, so the above compounds are also derivatives of tyrosine.
- dopachrome can give rise to 5,6-dihydroxyindole in a spontaneous non-enzymatic reaction, or it can give rise to DHICA in an enzymatically-catalyzed readion. Dopachrome can also give rise to DHICA in a metal-catalyzed reaction (not shown).
- the enzyme which catalyzes dopachrome to DHICA is named dopachrome tautomerase-
- the enzyme may also be a part of a complex comprising tyrosinase, dopachrome tautomerase, glycoprotein 75, MSH receptor, lysosome-associated membrane protein-1 and other unknown proteins.
- MSH receptor Seth J. Orlow, Sara Hotchkiss, and John M. Pawelek, "Internal Binding Sites for MSH: Analyses in Wild Type and Variant Cloudman Melanoma Cells:. J. Cellular Physiology. 142:129
- the melanins according to the present invention can be admixed with a physiologically acceptable carrier to form a composition, which has the uses previously noted.
- Physiologically acceptable carriers useful in the pradice of the invention are known in the art and non-limiting examples of such carriers include, for controlled release ⁇ microcapsules comprising carboxymethylene copolymers; for transdermal release ⁇ acrylam ⁇ des; and for topical application ⁇ cosmetic bases.
- composition according to this embodiment comprises at lease one additive seleded from the group consisting of solvents, fragrances, sunscreening agents, preservatives and chelating agents.
- Cosmetic bases useful in the practice of the invention are well known and include lotions, creams, ointments, lipstick, blush, cover-up, foundations and dusting powders. Examples thereof may be found in, e.g., U.S. Pat. Nos. 4,228,151; 4,282,206 and 2,949,403.
- inventive compositions are used as tinting agents for glass and plastic or as industrial produd protecting agents, e.g., for protedion against UV degradation
- inventive composition will be incorporated into the glass or plastic or industrial produd.
- the inventive compositions are easily incorporated in the glass or plastic or industrial produd.
- the carriers, diluents, or the like would not have to be physiologically acceptable.
- Other conventional agents for such uses could also be formulated therewith.
- Solvents for use in accordance with the invention include, for example, ethanol, isopropyl alcohol, benzyl alcohol, oil, for example, ground nut oil, distilled and/or deionized water, physiological saline solution and the like.
- the specific solvent chosen will depend on the method of application. It may also be desirable to add a preservative to the inventive compositions if they are to be used for topical applications.
- the preferred mode of administration of the inventive compositions is topical administration.
- the melanins of the present invention may be combined with substances that stimulate the pigmentary system under conditions of low levels of UV light.
- Preservatives are well known and may be exemplified by methylparaben, "DOWACIL 2000" and propylparaben.
- bases, acids or buffers may be added thereto in accordance with the knowledge of the art.
- the concentration of melanins in an aerosol, cream, lotion or other composition is preferably 1.0 mg/ml to 100 mg/ml, but not restrided to this concentration range.
- Solutions have different colors depending on the concentration of "chromophore: dissolved in them. For example, a deep red solution will appear orange or pink when diluted with more solvent, but no additional chromophore.
- soluble melanin when it is dissolved at a fairly high concentration in water, e.g., 0.5 mg/ml, it appears brown-black in color. When more water is added so that the concentration of the soluble melanin is reduced to, e.g., 0.1 mg/ml, the solution appears golden in color. It is not believed that diluting the material effeds any shift in the absorbance spectrum, rather it is believed to be a visual perception.
- the 5,6-d ⁇ hydroxyindole-2-carboxylic acid, 5,6-d ⁇ hydroxyindole, and 3-amino-tyrosine may be maintained separately, for example, in microspheres, or in separate tubes or containers, until being mixed together on the skin of a mammal, e.g., human.
- the melanins can be made to adhere to the skin for several days and be resistant to water and soap simply by mixing the melanin with any commercially available preparation of dihydroxyacetone (DHA), e.g., Lancome's Conque le du Sol oil R .
- DHA dihydroxyacetone
- the DHA apparently acts as a cross-linking agent to covalently link the melanin with various fadors, e.g., proteins in the skin. It is likely that other cross-linking agents will achieve the same or better results.
- An additional advantage of treatment with DHA is that such treatment alters the spectral charaderistics of the melanin, giving it a more even absorbance throughout the UV and visible spectra, without substantially altering the color of the melanin.
- Treatment of melanins with acetic anhydride also alters the spedral charaderistics of the melanin (Figure 7).
- Figure 1 depicts a schematic representation of two pathways for the metabolism of dopachrome.
- Figure 2A-C depid graphs showing spedral analyses of DHICA (5mM) incubated with oxygenation ⁇ or various time periods in sodium phosphate buffer (0.1M, pH7.8, 20°C), compared to that of the produd of the dopachrome tautomerase readion (incubation of enzyme + dopachrome 5mM) (2D).
- Figure 3 depids graphs showing the formation of melanins by incubating DHICA alone ( ⁇ ——- ⁇ ), or DHICA + DHI (o——-o) at various pH's.
- Figure 4 depids a graph showing the effects of aeration on the spectrum of DHICA-melanin.
- Figure 5 depids a graph showing the solubility of DHICA-melanin as a function of pH.
- Figure 6 depids a graph showing chromatography of DHICA-melanin on an HPLC molecular sieve column.
- Figure 7 depids a graph showing the spedral characteristics of soluble melanin composed of a mixture of DHICA (10%) and 3-amino-tyrosine (90%).
- Figure 1 depicts a schematic representation of two pathways for the metabolism of dopachrome.
- dopachrome spontaneously converts to dihydroxyindole (DHI), losing its carboxyl group in the process, however if the enzyme dopachrome tautomerase is present, dopachrome is converted to 5,6-dihydroxyindole-2-carboxylic acid (DHICA).
- DHI dihydroxyindole
- DHICA 5,6-dihydroxyindole-2-carboxylic acid
- Figure 2A-C depicts graphs showing spedral analyses of DHICA (5mM) incubated with oxygenation for various time periods in sodium phosphate buffer (0.1 M, pH7.8, 20°C), compared to that of the produd of the dopachrome tautomerase reaction (incubation of enzyme + dopachrome 5mM) (2D).
- Fig. 2C displays a similar spedrum to that of enzymatically-synthesized melanin (Fig. 2D).
- the graphs also demonstrate that ' the melanins absorb light throughout the ultraviolet and visible spectra, thus fulfilling necessary requirements for efficacy as sunscreens and UV-protedants.
- Figure 3 depids graphs showing the formation of melanins by incubating DHICA alone ( ⁇ ——- ⁇ ), or DHICA + DHI (o——-o) at various pH's.
- the compounds were incubated at concentrations of 5mM at pH5 (sodium acetate, 0.1 M), pH6 (sodium phosphate, 0.1M), and pH7 (sodium phosphate 0.1 M) with oxygenation, and optical densities of allquots (1:50 dilution) were determined over 24 hours.
- Results for DHI alone are not shown, since this material formed a precipitate which could not be accurately quantitated by spectral analysis.
- Table 1 depicts quantitation of melanins before and after filtration through 0.22 micron filters. Results are from the same experiment shown in Figure 3 at pH7. Table 1 : Filtration of Melanins Synthesized from DHICA and/or DHI
- DHI (5mM) and DHICA (5mM) were mixed vigorously, separately or together, in 0.1M sodium phosphate pH7.0 for 24 hours at room temperature. Aliquots were filtered, samples were diluted 1:20 with H 2 O, and optical densities were determined in a spedrophotometer.
- Figure 4 depids the effects of aeration on the spedrum of DHICA-melanin.
- DHICA-melanin was synthesized by incubation of DHICA (5mM) in sodium phosphate buffer (0.1 M, pH7.8) at room temperature under partial anaerobic (de-gassed buffers, stoppered flasks) and aerobic (gassed buffers, open flasks) conditions. After 72 hours with vigorous mixing, spectral analyses were made. The ratios of aerated/anaerobic spectra are presented. The results were that synthesis of DHICA-melanin is enhanced by aeration, and that the effeds of aeration are disproportionate, being most apparent in the visible light range (above 300nm).
- Figure 5 depids the solubility of DHICA-melanin as a function of pH.
- DHICA-melanin o——-o
- the model peptide glu:tyr ⁇ ——- ⁇
- DHICA-melanin and the g!u:tyr peptides are consistent with their common expression of carboxylic acid residues.
- DHICA-melanins When DHICA-melanins are precipitated at add pH, they can readily be dissolved in organic solvents such as butanol or butoxyethanol.
- FIG. 6 depicts the chromatography of DHICA-melanin on an HPLC molecular sieve column.
- DHICA-melanin was synthesized by incubating DHICA (5mM) for 96 hours in sodium phosphate (0.1M, pH7.8) with vigorous shaking in an open flask. The material was applied to a Waters Protein PAK 300 SW column and its migration rate was compared to that of known globular proteins with molecular weights of approximately 20,000 and 70,000 daltons. Results show that under the above synthetic conditions, DHICA-melanins were formed with molecular weights ranging from 20,000-70,000 daltons.
- Table 2 depids the recovery of DHICA+DHI-melanin following dialysis and filtration.
- the melanin remained within dialysis tubing having a 12,000-14,000 dalton exclusion limit, and passed through a 0.22 micron filter. It was also determined that the melanin was stable to freezing/thawing, boiling, and that it could be quantitatively redissolved following lyophilization (not shown).
- DHICA and DHI were mixed vigorously at 20°C for 48 hours at a molar ratio of 1.2:1.0 (DHICA:DHl) and a total precursor concentration of 10mM in 0.1M sodium phosphate, pH7.4.
- DHICA:DHl a molar ratio of 1.2:1.0
- Allquots of the material were subjeded to exhaustive dialysis in standard dialysis tubing (12,000-14,000 dalton exclusion limit) and/or filtration through 0.22 ⁇ filters.
- the material which remained within the dialysis tubing and/or which passed through the filters was quantitated for optical density at 450nm and the data were normalized to the % of starting material. Results represent average + range of duplicate samples.
- Figure 7 depids the spectral charaderistics of soluble melanin composed of a mixture of DHICA (10%) and 3-amino-tyrosine (90%).
- the melanin was treated with dihydroxyacetone or acetic anhydride as noted in the graph. It can be seen that both treatments produced a more even absorbance of the melanin throughout the spedrum, specifically reducing the spectral peak exhibited by untreated melanin at approximately 340nm. Treatment of the melanin with dihydroxyacetone advantageously enhances adherence of the melanin to mammalian skin.
- the enzyme preparation for the synthesis of DHICA-containing melanins can be obtained from any biological source expressing dopachrome tautomerase adivity. Such activity has been described in a number of mammals, including humans, as well as in inseds (Pawelek, J.M. "After Dopachrome?", Pigment Cell Research 4:53-62, 1991; Sugumaran , M. "Molecular Mechanisms for Mammalian Melanogenesis-Comparison with Insed Cuticular Sclerotization” FEBS Letters 293:4-10, 1991 ; Li, J. and Nappi, A.J. "Electrochemical Identification of Dopachrome Isomerase in Drosophila Melanogaster", Biochem. Biophys. Res.
- ad ⁇ ve preparation of dopachrome tautomerase obtained, for example, from an extract of cultured mouse melanocytes, with 5mM dopachrome, in an aqueous buffer of 0.1M sodium phosphate, pH6.8, at 15-37°C.
- Orange dopachrome is tautomerized to colorless DHICA within one hour.
- DHICA-melanin forms through auto-polymerization of DHICA ( Figure 2D).
- DHICA DHICA
- DHI DHI
- 3-am ⁇ no-tyrosine 5mM
- cysteine 5mM
- hydrogen peroxide (50mM) and/or metal ions such as Cu ++ or Fe ++ (1mM) can be added to increase the rate of the reaction and thereby reduce the time involved for melanin formation.
- H 2 O 2 and/or metal ions can be added together with DHICA and/or with DHICA in various combinations with DHI, 3-amino-tyrosine, or cysteine as mentioned above.
- the melanin so produced can be passed through at least a 0.45 micron filter (Tables 1 and 2), is predpitated below pH4 ( Figure 5), is nond ⁇ alyzeable (Table 2), is of a molecular weight of greater than at least 10,000 daltons and more closely of the order of 20,000 to 70,000 daltons ( Figure 6), and is stable to freezing, thawing, and boiling.
- DHICA (10mM) is incubated in 0.2M ammonium hydroxide with aeration at 15-70°C for 72 hours.
- DHICA-melanin is formed through auto-polymerization of DHICA ( Figure 2A-C).
- Other suitable precursors and procedures for speeding up the reaction, as described in Example 2, can be employed.
- Charaderistics of the non-enzymatically synthesized melanins are identical to those of enzymatically synthesized melanins (Example 2).
- Example 4 Method for Adherence of DHICA-melanins to Human Skin and Hair
- DHICA-melanin is mixed with any commercially available preparation of dihydroxyacetone, e.g., Lancome's Conque le du Sol oil R to a final concentration of 1 to 5% (wt/vol) and applied evenly to the skin until the desired degree of darkening is achieved.
- the melanin adheres to the skin and, at suitable concentrations, masks or alters the net coloring-effeds of dihydroxyacetone known to the art. Similar procedures can be followed for adherence of melanin to hair.
- DHA (5-50mM) can be included in the synthetic readions described in Example 2 and the melanin so produced exhibits adherence to skin and hair.
- DHICA-melanin (10% wt/vol), preferably containing co-polymerized monomers of 3-amino-tyrosine, as described in Example 2, is mixed with equimolar dihydroxyacetone at room temperature, or equimolar acetic anhydride on ice for one hour.
- Example 6 Adaptation of DHICA-melanin to Solubility in Organic Solvents DHICA-melanin (10% wt/vol) is precipitated from aqueous solution by lowering the pH below 4 with acid such as HCI or acetic acid ( Figure 5). The precipitated material is dried by either air-drying, lyoph ⁇ lization, or ether extraction. The dried melanin is then dissolved in either butanol or butoxyethanol at concentrations in the range of but not limited to 0.05-5% by volume of the organic solvent.
- acid such as HCI or acetic acid
- DHICA-melanin (10% wt/vol), preferably, containing co-polymerized monomers of 3-amino-tyrosine, is mixed with, for example, Budweiser Beer, until a desired color is achieved.
- the melanin concentrations vary between, but are not limited to 0.005-1.0% by weight of the beer solution.
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP93909312A EP0638101A4 (en) | 1992-04-13 | 1993-04-12 | Synthetic melanin. |
JP5518541A JPH07509012A (en) | 1992-04-13 | 1993-04-12 | synthetic melanin |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/867,851 | 1992-04-13 | ||
US07/867,851 US5227459A (en) | 1990-05-18 | 1992-04-13 | Synthetic melanin |
Publications (1)
Publication Number | Publication Date |
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WO1993021252A1 true WO1993021252A1 (en) | 1993-10-28 |
Family
ID=25350590
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1993/003430 WO1993021252A1 (en) | 1992-04-13 | 1993-04-12 | Synthetic melanin |
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US (2) | US5227459A (en) |
EP (1) | EP0638101A4 (en) |
JP (1) | JPH07509012A (en) |
AU (1) | AU3977393A (en) |
WO (1) | WO1993021252A1 (en) |
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Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0820275A1 (en) * | 1995-02-23 | 1998-01-28 | Yale University | Cosmetic melanins |
EP0820275A4 (en) * | 1995-02-23 | 2000-03-08 | Univ Yale | Cosmetic melanins |
WO2010012751A2 (en) * | 2008-07-28 | 2010-02-04 | Omnica Gmbh | Sesame seed derived pigments |
WO2010012751A3 (en) * | 2008-07-28 | 2010-06-03 | Omnica Gmbh | Reduced sesame seed derived pigments |
US8128970B2 (en) | 2008-07-28 | 2012-03-06 | Omnica Gmbh | Sesame seed derived pigments |
WO2014110641A1 (en) * | 2013-01-21 | 2014-07-24 | Universidade Estadual Paulista "Júlio De Mesquita Filho" | A process for producing synthetic melanin and product obtained |
Also Published As
Publication number | Publication date |
---|---|
EP0638101A4 (en) | 1995-07-26 |
JPH07509012A (en) | 1995-10-05 |
AU3977393A (en) | 1993-11-18 |
EP0638101A1 (en) | 1995-02-15 |
US5227459A (en) | 1993-07-13 |
US5384116A (en) | 1995-01-24 |
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