# 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.

- **Patent:** US 3492131
- **Original title:** Peptide sweetening agents
- **Owner:** GD Searle LLC
- **Granted:** 1970
- **Status:** Public domain (expired)
- **Times cited:** 228
- **Field:** biotech, pharmaceutical

## What it does

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 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.

## 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.

## Real-world examples

1. Diet Coke
2. Equal sweetener packets
3. Sugar-free chewing gum
4. Diet Pepsi

## Why it matters

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.

## 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.

**Full plain-English explainer:** https://patentbrief.org/patent/us/3492131/aspartame-sweetener

**Original patent:** https://patents.google.com/patent/US3492131

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_Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._


## Related patents

Semantically similar inventions in the PatentBrief corpus:

- [How Constantin Fahlberg Discovered Saccharin](https://patentbrief.org/patent/us/319082/saccharin-artificial-sweetener-fahlberg) — The 1885 patent for the chemical process to create saccharin, the first artificial sweetener, discovered by accident in a coal tar laboratory.
- [How to Build Smaller, Synthetic Antibody-Like Molecules for Medicine](https://patentbrief.org/patent/us/5455030/immunotheraphy-using-single-chain-polypeptide-binding-molecules) — This patent describes a way to create small, single-chain proteins that mimic the binding power of full-sized antibodies to deliver medicine more effectively.
- [The Discovery of Lovastatin for Lowering Cholesterol](https://patentbrief.org/patent/us/4231938/statin-cholesterol-lovastatin) — A 1979 patent by Merck describing the isolation of a fermentation product from Aspergillus fungi that effectively lowers cholesterol levels in the blood.
- [The Chemical Discovery Behind the First Oral Contraceptive Pill](https://patentbrief.org/patent/us/2744122/birth-control-pill-norethindrone) — A 1952 patent for a synthetic hormone that became the active ingredient in the first effective oral contraceptive pill.
- [Using Specific Steroid Molecules to Block Salt Retention in the Body](https://patentbrief.org/patent/us/4081538/aldosterone-antagonists) — A 1976 medical patent describing the use of 11-beta,18-oxidopregnane compounds to help the body excrete sodium by blocking the salt-retaining effects of the hormone aldosterone.