You can freely build on The Discovery of Aspartame as a Sugar Substitute
This patent expired in 1987. Every claim — 1 independent, 0 dependent — is now unenforceable. Anyone can use, reproduce, manufacture, sell, or offer for sale this technology without a license.
Original assignee
GD Searle LLC
Patent granted
1970
Expired
1987
Forward citations
228
What this patent covers
The patent claims a group of chemical compounds, specifically aspartylphenylalanine methyl ester and its related derivatives, which function as high-intensity sweeteners. These compounds are peptides, which are short chains of amino acids. By adding these substances to edible materials alongside a non-toxic carrier, the composition provides a sweet taste. The patent specifies that these compounds can exist in various stereochemical configurations, such as L-L or DL-L, to achieve the desired sweetening effect.
What is now free to use
All 1 claims of US 3492131 are in the public domain. Specifically:
Claim 1: A COMPOSITION FOR THE SWEETENING OF EDIBLE MATERIALS WHICH COMPRISES A COMPOUND SELECTED FROM THE GROUP — 1 specific element
The 0 dependent claims add narrowing limitations and are also free.
What is NOT covered
Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.
Does not cover naturally occurring sugars like sucrose, glucose, or fructose.
Does not cover non-peptide sweeteners such as saccharin or sucralose.
Does not cover the specific manufacturing process for synthesizing these peptides, only the composition itself.
Who is building on this today
The patent was originally assigned to G.D. Searle & Co., which was later acquired by Monsanto. Today, the intellectual property landscape for aspartame has evolved as the original patents have expired, allowing generic manufacturers worldwide to produce it as a commodity food additive.
Products built on expired version of this technology
Diet Coke
Equal sweetener packets
Sugar-free chewing gum
Diet Pepsi
How to cite this patent in your documentation
GD Searle LLC. US Patent 3492131. Peptide sweetening agents. Granted 1970, expired 1987. Now in the public domain.
Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.
PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.