The Common Old Name: Dextrose
While currently known as glucose, the most common historical name for this sugar is dextrose. This term remains in use today in various fields, including commercial, medical, and scientific applications. The origin of the name "dextrose" comes from a specific chemical characteristic: glucose solutions are dextrorotatory, meaning they rotate plane-polarized light to the right. The term itself is derived from the Latin word dexter, which translates to "right". The more precise term glucose became prevalent in general chemical literature, but dextrose continues to be used, often referring specifically to the D-isomer of glucose, which is the form found in nature.
Other Historical Monikers for Glucose
Before and alongside the use of dextrose, glucose was also known by other names based on its sources. One such name was "grape sugar," reflecting its presence in grapes and other sweet fruits. German chemist Johann Tobias Lowitz's isolation of glucose from grapes in 1792 further contributed to this informal name. Another common name is "blood sugar," which highlights glucose's essential role as the primary sugar in the bloodstream. The current name, "glucose," was coined by French chemist Jean-Baptiste Dumas in 1838. It comes from the Greek word gleukos, meaning "sweet wine" or "must". The suffix "-ose" is the standard chemical designation for sugars.
A Timeline of Glucose Discovery and Naming
- 1747: Andreas Marggraf isolates a sweet substance from raisins.
- 1792: Johann Tobias Lowitz isolates the same substance from grapes.
- 1838: Jean-Baptiste Dumas proposes the name "glucose".
- Mid-19th Century: The term "dextrose" is introduced, based on the molecule's ability to rotate polarized light to the right.
- 1891-1894: Hermann Emil Fischer determines the stereochemical structure of glucose.
Why the Names Changed: A Scientific Evolution
The shift in nomenclature from descriptive terms like dextrose to the systematic name glucose reflects the progress in organic chemistry. Scientists began to understand the three-dimensional structures of molecules, moving beyond classifications based solely on physical properties like optical rotation. The development of systems like the D/L notation provided a more precise way to describe the absolute configuration of sugars. While the name glucose became the standard, dextrose remained relevant, particularly when referring to the naturally occurring D-glucose isomer.
Comparison of Common Simple Sugars
| Feature | Glucose (Dextrose) | Fructose (Levulose) | Galactose |
|---|---|---|---|
| Other Names | Dextrose, Grape Sugar, Corn Sugar, Blood Sugar | Levulose, Fruit Sugar | Brain Sugar (component) |
| Primary Source | Fruits, honey, breakdown of starch and glycogen | Fruits, honey, sugar beets, sugar cane | Milk sugar (lactose), dairy products |
| Optical Rotation | Dextrorotatory | Levorotatory | Dextrorotatory (variable) |
| Classification | Monosaccharide, Aldohexose | Monosaccharide, Ketohexose | Monosaccharide, Aldohexose |
The Modern Relevance of the Name "Dextrose"
The term dextrose is still actively used today, especially in medicine and the food industry. In clinical settings, glucose solutions given intravenously are commonly referred to as dextrose solutions because D-glucose is the body's primary energy source. The food industry produces dextrose from starch hydrolysis and uses it as a sweetener, filler, and in fermentation. Dextrose remains a relevant term for this crucial sugar.
Conclusion
The old name for glucose, dextrose, highlights the history of scientific understanding of this vital sugar. While the systematic name glucose is now standard, dextrose persists in various applications, particularly in medical and food contexts. The evolution of its names reflects the progress in chemistry from descriptive properties to a detailed understanding of molecular structure. For additional information on glucose metabolism, a useful resource can be found at the {Link: ScienceDirect topic page https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/glucose}.
