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US5227459A Expired / Lapsed US ⏱️ 0.0 years remaining

Synthetic melanin

Assignee: Yale University
•
Filing: 1992-04-13
•
Granted: 1993-07-13
•
Expires: 2012-04-13
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Abstract

Abstract A melanin that is soluble in an aqueous solution at a pH between 5 and 9 at a temperature of 0° to 100° C. Advantageously, the melanin is capable of being filtered through at least a 0.45 micron size filter, and has a molecular weight of greater than 10,000 kilodaltons. The melanin is useful for providing a naturally-appearing tan to mammalian skin and hair. Such melanin can be produced by combining dopachrome and an appropriate enzyme, or by incubating 5,6-dihydroxyindole-2-carboxylic acid alone or with 5,6-dihydroxyindole, or with 3-amino-tyrosine. The melanin is also useful for providing a sun-screen to mammalian skin and hair, to treat post-inflammatory hypo- and hyperpigmentation, to tint glass and plastic, to protect industrial materials against ultraviolet damage, and as a coloring agent in foodstuffs such as coffee, tea, soda, whiskey and liquors.

Inventors

  • 👤 John Pawelek
  • 👤 Michael P. Osber
  • 👤 Seth J. Orlow

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 07:36
CPC Classifications
C; C12; C12G; C12G3/00; C12G3/04; A; A23; A23L; A23L5/00; A23L5/40; A23L5/42; A23L5/43; A23L5/47; A61; A61K; A61K31/00; A61K31/74; A61K31/785; A61K8/00; A61K8/18; A61K8/72; A61Q; A61Q17/00; A61Q17/04; A61Q19/00; A61Q19/02; A61Q19/04; C09; C09B; C09B69/00; C09B69/10; C09B69/104; C12C; C12C5/00; C12C5/02; C12C5/04; C12P; C12P17/00; C12P17/10

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 31 words
In the production of a soluble melanin by polymerizing a dihydroxyindole-carboxylic acid in an aqueous reaction medium, the improvement which comprises effecting the polymerization in the presence of a 3-amino-tyrosine compound.
Claim 2
Dependent Claim 31 words
In the production of a soluble melanin by polymerizing a dihydroxyindole-carboxylic acid in an aqueous reaction medium, the improvement which comprises effecting the polymerization in the presence of a 3-amino-tyrosine compound.
Claim 3
Dependent Claim 24 words
The method according to claim 1, wherein the dihydroxyindole-carboxylic acid is 5,6-dihydroxyindole-2-carboxylic acid and the polymerization is effected in an aqueous buffer with aeration.
Claim 4
Dependent Claim 13 words
A method according to claim 1, wherein the reaction mixture further comprises 5,6-dihydroxyindole.
Claim 5
Dependent Claim 13 words
A method according to claim 1, wherein the reaction mixture further comprises dihydroxyacetone.
Claim 6
Dependent Claim 14 words
The method according to claim 1, wherein the reaction mixture further contains acetic anhydride.
Claim 7
Dependent Claim 16 words
The method according to claim 1, wherein the polymerization is effected in the presence of oxygen.
Claim 8
Dependent Claim 34 words
The method according to claim 1, wherein the polymerization is effected in the presence of at least one of a sulfhydryl-containing compound and a metal ion, thereby changing the color of the resulting melanin.
Claim 9
Dependent Claim 9 words
The product produced by the process of claim 1.
Claim 10
Dependent Claim 9 words
The product produced by the process of claim 3.
Claim 11
Dependent Claim 9 words
The product produced by the process of claim 4.
Claim 12
Dependent Claim 9 words
The product produced by the process of claim 5.
Claim 13
Dependent Claim 9 words
The product produced by the process of claim 7.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-07-12 1997-01-11 1997-07-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-07-12 2001-01-11 2001-07-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-07-12 2005-01-11 2005-07-13 $7700.00 Window Closed / Lapsed

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