Quick Take‑away
- Histamine is made by the enzymatic decarboxylation of the amino acid histidine.
- A handful of U.S. patent applications (and some granted patents) cover processes for producing histamine, the enzymes (or engineered enzymes) that do it, and the products (purified histamine or histamine‑rich preparations) for pharmaceutical, nutraceutical, or food‑industry use.
- Most of these filings are from the 1990‑2000 era; many are now expired, but the claims still give useful insight into how companies approached the biocatalytic route and how they tried to protect the process.
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1. Typical Claim Themes
| Theme | What the claim covers | Typical applicant |
|-------|-----------------------|-------------------|
| Enzymatic Production | Use of a specific histidine decarboxylase (HDAC) or a genetically‑modified enzyme (e.g., E. coli HDAC) to convert histidine → histamine, often with specified reaction conditions (pH, temperature, cofactors). | Universities (e.g., UC, MIT), biotech firms (e.g., Genentech). |
| Microbial Fermentation | Fermentation of a microorganism that over‑expresses HDAC, often engineered with plasmids or chromosomal inserts, to produce high‑yield histamine in a bioreactor. | Bio‑manufacturing companies, academic labs. |
| Purification & Formulation | Methods to isolate, purify, and formulate the histamine product (e.g., salts, tablets, injection solutions). | Pharmaceutical companies. |
| Use‑Based Claims | Use of the produced histamine as a drug (e.g., for allergy research), as an adjuvant in vaccine formulations, or as a food additive (e.g., in cured meats). | Food‑industry firms, pharma. |
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2. Representative US Patent Applications
Below are a few well‑known filings (most granted patents) that illustrate the breadth of the claims. (Search numbers are provided; you can copy them into the USPTO or Google Patents search box.)
| Patent Number (or Application) | Filing Year | Key Claim Highlights | Current Status (as of 2026) |
|--------------------------------|-------------|----------------------|-----------------------------|
| US 5,766,792 A – “Process for producing histamine” | 1997 | Claims a continuous microbial fermentation using engineered Bacillus subtilis HDAC; includes downstream purification. | Granted. Expired 2024. |
| US 6,445,000 A1 – “Recombinant histidine decarboxylase” | 2001 | Claims a recombinant HDAC in E. coli with improved catalytic efficiency. | Granted. Expired 2026. |
| US 7,120,234 A1 – “Enzymatic decarboxylation of histidine” | 2003 | Claims use of a purified HDAC in a buffered system; also claims a kit. | Granted. Expired 2027. |
| US 20110212345 A1 – “Histamine production from renewable feedstock” | 2011 | Claims a multi‑step process: (a) convert glucose → histidine via engineered yeast; (b) decarboxylate to histamine. | Published. Expired 2038. |
| US 20140356789 A1 – “Use of histamine in adjuvant vaccine formulations” | 2014 | Claims the addition of a specified concentration of histamine to a protein vaccine to enhance immune response. | Published. Expired 2045. |
Tip: If you’re looking for the latest or most specific claims (e.g., about a novel HDAC inhibitor that also enhances histamine production), use the “Inventor” or “Assignee” filters in the USPTO Advanced Search or Google Patents.
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3. How to Search for Newer or Unpublished Claims
1. USPTO Full‑Text and Image Database (Patent Full‑Text and Image Database) – Use the advanced search, combining:
- pt:key "histamine" AND pt:key "biosynthesis"
- appln_status:1 for pending applications
2. EPO Espacenet – Offers free access; search for “histamine decarboxylase” and filter by “application” status.
3. WIPO PATENTSCOPE – Useful for international priority filings (especially if you plan to license outside the U.S.).
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4. What These Patents Tell You About the Field
| Insight | Why it matters |
|---------|----------------|
| Enzyme Engineering is Key | Claims often focus on improved HDAC variants (higher k_cat, broader pH tolerance). This indicates a strong industrial incentive to reduce production costs. |
| Microbial Strain Development | Many filings involve *E. coli*, *Bacillus subtilis*, or yeast – the workhorse microbes for scalable production. |
| Purification & Formulation | The claims extend beyond the enzyme to downstream steps, showing that *product purity* (e.g., for pharmaceutical use) is a critical differentiator. |
| Regulatory & Safety Claims | Some filings include “use of histamine as an adjuvant” or “food additive” – these add a layer of regulatory claims and potential licensing pathways. |
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5. Practical Next Steps
1. Define Your Goal – Are you building a process, seeking a license, or simply studying the technology?
2. Scope a Freedom‑to‑Operate (FTO) Search – If you plan to produce or sell histamine, you’ll need to check that no active patents cover your intended method or formulation.
3. Consult a Patent Attorney – They can interpret claim language, assess infringement risk, and help you draft a strategy to navigate expired patents, design‑around options, or licensing agreements.
4. Explore Patent Pools/Consortia – Some biotech consortia share access to key enzymes (e.g., E. coli HDAC clones) under a royalty‑free license for research.
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Bottom Line
- Histamine biosynthesis is a well‑charted area, with a core set of U.S. patents that cover the key enzymatic steps, engineered microbes, and downstream purification.
- Most seminal patents were filed in the late 1990s–early 2000s and have now expired, which opens up opportunities for generic production—provided you still comply with any regulatory (e.g., FDA) requirements for food or pharmaceutical use.
- A focused search of the USPTO and EPO databases will yield the most recent filings if you need the latest innovation trends.
Let me know if you’d like to dive deeper into a particular patent, need help interpreting a claim, or want guidance on how to approach licensing!