The Discovery of Aspartame as a Sugar Substitute
This 1966 patent identifies specific chemical compounds, known as aspartylphenylalanine esters, that provide intense sweetness for food and drinks without using sugar.
Original patent title: “Peptide sweetening agents”
This 1966 patent identifies specific chemical compounds, known as aspartylphenylalanine esters, that provide intense sweetness for food and drinks without using sugar. Granted to GD Searle LLC in 1970 with 2 claims and 228 forward citations, and it is now in the public domain.
Key facts
Coverage
What does this patent actually cover?
The patent claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more → 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.
The gap
What does this patent NOT cover?
- 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.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
The inventorinventorThe person who actually conceived the invention. Listed on the patent regardless of who owns it.Read more → discovered that by combining two specific amino acids—aspartic acid and phenylalanine—in a methyl ester form, he could create a compound hundreds of times sweeter than table sugar.
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Diet Coke
Equal sweetener packets
Sugar-free chewing gum
Diet Pepsi
Why it matters
The bigger picture
This patent introduced aspartame to the world, which became one of the most widely used artificial sweeteners in history. It enabled the creation of the diet soda industry and provided a critical alternative for diabetics who need to manage blood glucose levels.
Filed
April 18, 1966
Granted
January 27, 1970
Market context
Who's building on this
Companies in this space
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.
Market impact
This patent effectively launched the global market for high-intensity, low-calorie sweeteners. It triggered decades of research into food chemistry and remains a cornerstone of the multi-billion dollar sugar-substitute industry.
Claim 1 — Plain English
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.
The clever bit
The inventor discovered that by combining two specific amino acids—aspartic acid and phenylalanine—in a methyl ester form, he could create a compound hundreds of times sweeter than table sugar.
What it does not cover
- 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.
Patent Journey
From filing to expiry
PatentBrief Score
Impact Score
Moderate
Citation count
40/40
Highly cited
Claim breadth
1/20
Narrow claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$66K – $211K
Midpoint $132K · expired or expiring · industry ×2.2
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
The original legal language
Original claims
2 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Schlatter, J. M. (1970). The Discovery of Aspartame as a Sugar Substitute (U.S. Patent No. 3,492,131). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/3492131/aspartame-sweetener
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does The Discovery of Aspartame as a Sugar Substitute cover?
This 1966 patent identifies specific chemical compounds, known as aspartylphenylalanine esters, that provide intense sweetness for food and drinks without using sugar.
Who owns patent US 3492131?
GD Searle LLC owns this patent, granted in 1970.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 3492131 cited by?
This patent has been cited by 228 later patents that build on its ideas.
What problem does this patent solve?
This patent introduced aspartame to the world, which became one of the most widely used artificial sweeteners in history. It enabled the creation of the diet soda industry and provided a critical alternative for diabetics who need to manage blood glucose levels.
What does this patent NOT cover?
Does not cover naturally occurring sugars like sucrose, glucose, or fructose.
Patent monitoring