A Case-Study Component of
A Case-Study General Chemistry Curriculum
Supported by the National Science Foundation
Prof. Sam Stradling
Sweet It Is!"
Have you ever seen TVs The Honeymooners or The Jackie Gleason Show from the 1950s? When Ralph Cramden said "How sweet it is!", he celebrated a victory in his ongoing battle with the vagaries of everyday life.
|In 1965, James
Schlatter, of the G. D. Searle pharmaceutical
company, inadvertently tasted an
experimental compound that he had synthesized in
an attempt to discover a better gastric hormone
inhibitor, an ulcer drug. This serendipitous event (for,
as we all know, we are instructed to limit exposure to
chemicals with unknown properties) led to the
development, approval, marketing, and acceptance of the
most widely used "artificial" sweetener in the
world: aspartame, more commonly known by
its trademark name, NutraSweet.
Indeed, how sweet it is!
This ChemCases case study introduces organic chemistry through the artificial sweetener NutraSweet. With this dipeptide as a model, we will learn about bonding, structure, stereochemistry, and the methods for synthesizing a small but specific molecule. We will follow the product through regulation and into commerce and deal with issues surrounding this marvelous sweetener and the consumer problems with which it has, nevertheless, presented us.
Reference to the Concept Map suggests a mosaic of topics interrelated to NutraSweet and to each other. Although you can visually scan the individual topics of the mosaic and see their connectedness, this written narrative introduces one topic at a time, reinforcing those connections. As you read through each section, you should return to the Concept Map from time to time to refresh the connections.
Most general chemistry texts could act as a backdrop for the information presented here. This ChemCase study refers specifically, however, to the subject matter as presented in Chemistry: Molecules, Matter, and Change (3rd edition), by Peter Atkins and Loretta Jones.
The Concept Map shows the four major sections used to present information and a case for your review. The first section discusses the fundamental chemistry of the NutraSweet molecule. As important as "organic" molecules are to the world of chemistry and biology, we ignore them in many introductory chemistry courses. Courses subsequently built upon the general theories of introductory chemistry, such as organic chemistry, biochemistry, and molecular biology, are typically the vehicles that deliver the details of these important materials. Consequently, we will devote some effort to introducing those aspects of organic chemistry relevant to NutraSweet.
Once the structural aspects of NutraSweet and their relationship to physiological activity have been introduced, we will discuss the challenges of chemical synthesis, as well as some aspects of physical properties and solution chemistry.
The introduction of a synthetic chemical to the marketplace, especially one that enters as a foodstuff, justifiably requires the successful clearance of several hurdles, especially those of efficacy and safety. NutraSweet has successfully emerged from the rigorous review process, though it remains a product of considerable controversy. Patent protection has long served the entrepreneurial needs of modern society by allowing those whose commitment of time and expense in developing products to profit by that effort. Perhaps at no time in the past have the issues associated with intellectual and material property rights been more in the news. The third and fourth sections of this ChemCase explore these last two issues.
fundamentals of organic chemistry and biochemistry are
important in this case:
the past 125 years, three major artificial sweeteners
have been discovered by a scientist accidentally tasting
understand the structure of these materials and we can
see that there are few things that they have in common
other than the fact that they are water-soluble, organic
|NutraSweet consists of two amino acids linked together. We can apply the rules of stereochemistry to determine that four separate isomers of the diamino acid are possible. And if we are to manufacture NutraSweet, we must find a process that makes only the correct isomer.||Your
new product is sweet, but not as sweet as
saccharin. If used in foods, it will degrade
after a long time and no longer provide sweetness.
You can't use it in baking.
And certain people with a condition called phenylketonurea cannot use the product.
How are you going to market this sweetener? Is it wise to do so? What should the consumer know before using NutraSweet?
|Sections in this ChemCase||Or move on to|
1999 Kennesaw State University.
Principal Investigator Laurence Peterson; Project Director Matthew Hermes.
Author of this module Sam Stradling.