Thiamine (Vitamin B1)
Like all the water-soluble B vitamins, thiamine functions as a coenzyme, primarily in the metabolism of carbohydrates and, to a lesser extent, fats and proteins. It also helps to produce ribose, an important sugar needed by all body cells for the production of nucleic acids.
Because thiamine is not synthesized by the body's intestinal bacteria (except in cattle and other ruminants), nor is it stored in fat tissues, a daily dietary source is needed. Without such a source, both humans and most animals soon develop some form of deficiency disease. In humans, the disease is called beri-beri, a serious and disabling disease characterized by polyneuritis, an inflammation of nerves in the arms and legs. It was the search for a cure for beri-beri that led to the discovery of thiamine.
In the 1880s, most physicians were certain that beri-beri was caused by some sort of toxic bacteria. Since the disease was particularly widespread in Far Eastern countries where rice was a dietary staple, the bacteria was naturally suspected to be in rice. In 1886, a commission was sent to the Dutch East Indies (now Indonesia) to try and locate the causative organism. The commission failed, but one of its members, Christiaan Eijkman, stayed behind to continue his experiments.
Between 1890 and 1897, Eijkman began reporting that chickes fed a diet high in polished rice developed symptoms similar to those of his beri-beri patients. Even more important, Eijkman reported that adding rice hulls ot the diet quickly effected a cure. A colleague, Gerrit Grijns, found that other foods--such green peas and meat--could also prevent beri-beri. In 1901, Grijns correctly deduced that all these experiments proved that certain natural foodstuffs must contain some sort of antiberi-beri factor.
Roughly a decade later, Casimir Funk, a Polish-born biochemist, was inspired by reading the reports of Grijns and Eijkman, and began searching for the elusive antiberi-beri factor in rice hulls. He did manage to isolate an active substance and was briefly elated. Unfortunately, the substance (which later proved to be niacin) had only minimal effect on beri-beri, and Funk discarded it and want on with his research. Then, in 1926, two other biochemists, P. Jansen and W.P. Donath, working in the same laboratory in the Dutch East Indies originally used by Eijkman and Grijns, isolated a crystalline material that actually could cure polyneuritis--at least in birds. They called the substance aneurine and, in Europe, that remained its name for several years while researchers studied it.
Unfortunately, for years too little of the substance could be isolated to make identification certain. Finally, in the 1930s, scientists made important discoveries that would allow them to synthesize the substance. In 1932, the German chemist Adolf Windaus (1876-1959) was able to isolate a sulfur atom in a molecule of another substance. This was a crucial step in determining the structure of the compound. In 1934, American chemist Robert Runnels Williams (1886-1965), using highly advanced laboratory techniques, managed to isolate approximately one third of an ounce of the active crystalline material from almost a ton of rice hulls. Because the vitamin proved to contain a sulfur molecule (of the thio group) and an amine, the substance was named thiamine. Two years later, Williams and his colleagues successfully synthesized the substance.
In addition to beri-beri, thiamine deficiency can cause a disease called Wernicke-Korsakoff syndrome. This is a disorder which causes encephalopathy (inflammation in the brain) and memory dysfunction, and is found in people who are suffering from malnutrition or alcoholism. Symptoms of thiamine deficiency include problems with the gastrointestinal tract, cardiovascular system, and peripheral nervous system. In the early 1990's, such deficiencies were reported in Cuba as a result of the U.S. trade embargo. Between 1989 and 1995 the daily caloric intake for the citizens of this country went down a third, and serious problems with malnutrition, low birth weights, and vitamin deficiencies occurred as a result.
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