Glucose-Amine Sequestrants (1961)
U.S. Patent No. 2,996,449, granted on August 15, 1961, to John E. Hodge and Ben F. Moy, introduces a class of compounds derived from the reaction of sugar (glucose) and ammonia. These compounds are highly effective sequestering agents—chemicals that “trap” or “chelate” metal ions to prevent them from interfering with industrial processes or causing water hardness.
This research was conducted at the Northern Regional Research Laboratory in Peoria, Illinois, under the U.S. Department of Agriculture.
The Problem: Water Hardness and Metal Interference
Metal ions like calcium (Ca^2+) and magnesium (Mg^2+) cause water hardness, leading to scale buildup in pipes and reduced soap efficiency. Other metals like copper (Cu^2+) and iron (Fe^3+) can catalyze unwanted reactions in food and industrial systems.
While agents like EDTA and sodium gluconate were already in use, this patent sought to find more efficient, sugar-based alternatives that could be produced through a specific chemical transformation called the Amadori rearrangement.
Key Discovery: The Amadori Rearrangement
The patent focuses on the transition from glucosylamines (aldose structure) to 1-amino-1-deoxy-fructoses (ketose structure). This shift significantly enhances the ability of the molecule to bind to metals.
The inventors developed a way to produce a specific, highly potent molecule: imino-bis(1-deoxy-D-fructose). This molecule is a “secondary amine,” meaning it has two sugar chains attached to a single nitrogen atom, doubling its potential “claws” for grabbing metal ions.
Improved Manufacturing Process
Previously, reacting glucose with ammonia mostly produced mono-glucosylamine. Hodge and Moy discovered that by:
- Adding an inert drying agent (like anhydrous calcium sulfate) to absorb water.
- Conducting the reaction at atmospheric pressure.
- Carefully controlling the temperature (starting below 40 C and finishing at 60-70 C).
…they could force the equilibrium to favor the more useful di-D-glucosylamine, which they then converted into the powerful fructose sequestrant.
Performance Data: How it Compares
The patent provides quantitative data showing that these sugar-ammonia derivatives often outperform industry standards in alkaline solutions.
| Sequestrant | Copper (Cu) Chelation (pH 11) | Zinc (Zn) Chelation (pH 11) |
| Imino-bis(1-deoxyfructose) | 106 grams | 45 grams |
| EDTA (Common Standard) | 35 grams | 34 grams |
| Sodium Gluconate | 63 grams | 29 grams |
Values represent grams of metal chelated per mole of sugar derivative.
Applications
The “Glucose-Amine Sequestrants” described in this patent were designed for:
- Water Softening: Trapping calcium and magnesium to prevent “soap scum” and pipe scaling.
- Industrial Cleaning: Removing metallic stains and scale.
- Agriculture/Medicine: Maintaining polyvalent metal ions (like zinc or iron) in a soluble form that can be used by plants or animals.
The Mechanism of Chelation
The molecules function like chemical “claws.” The nitrogen atom and the multiple hydroxyl (-OH) groups on the sugar chains wrap around a metal ion, forming a stable, water-soluble complex that prevents the metal from reacting with anything else.
