Title:  Melanins with improved ability to inhibit HIV replication

United States Patent:  6,300,057

Assignee:  Large Scale Biology Corporation (Vacaville, CA)

Filed:  February 6, 1997

Novel enzymatically produced melanins are described that are useful in the treatment of HIV infection. The novel remanins are optionally modified to contain chemical moieties such as halogens, sulfates, or sulfonyl groups. Additionally, the novel enzymatically synthesized melanins may be modified, or further modified, by chemical oxidation.

SUMMARY OF THE INVENTION

To achieve this end, a first aspect of the present invention relates to a novel method for arresting HIV replication as a therapy for persons exposed to the HIV virus or testing HIV-positive, and for AIDS patients by administering an effective dose of melanin derived from the controlled enzymatic action of tyrosinase in conjunction with specific substrates or mixtures of substrates.

A second aspect of the invention relates to methods for the chemical polysulfation of enzymatically or non-enzymatically produced melanin to increase antiviral activity, as well as the sulfated or polysulfated melanin products of such methods.

A third aspect of the invention relates to methods for the chemical polyhalogenation of melanin with fluorine, chlorine, bromine and/or iodine to increase antiviral activity, as well as the halogenated melanin products of such methods.

A fourth aspect of the invention relates to the therapeutic use of melanins that have been modified by any combination of polysulfation, polysulfonation, and/or polyhalogenation.

A fifth aspect of the invention relates to melanins produced by enzymatic synthesis using defined substrates, and modified forms thereof, that have been purified by precipitation by reducing the pH of a melanin containing solution below about 7.0, and preferably below about pH 3.0, with a preferred pH of about 1.5.

A sixth aspect of the invention relates to melanin produced by enzymatic synthesis wherein said melanin is oxidized by hydrogen peroxide or another suitable chemical oxidizer.

A seventh aspect of the invention relates to melanin produced by enzymatic synthesis wherein said melanin is further purified by passage through a suitable molecular sieve to obtain melanin having a molecular size greater than or equal to about 10,000 daltons.

An eighth aspect of the invention relates to melanin produced by either chemical or enzymatic synthesis wherein said melanin is further modified to have chemical subgroups selected from the group consisting of sulfonyl, sulfate and halogen chemical groups, or any mixture thereof.

Claim 1 of 30 Claims

What is claimed is:

1. A method for treating HIV infection, comprising administrating a therapeutically effective dose of melanin wherein said melanin is synthesized by chemical or enzymatic methods and contains at least one anionic group selected from the group consisting of sulfates and sulfonyls.

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