Thiamine
A thiamine deficiency in man leads to the condition known as beriberi; in animals the syndrome is referred to as polyneuritis. Reference has been made to the studies by Takaki, who demonstrated that through the proper dietary reforms the incidence of beriberi in the Japanese Navy could be practically eliminated. Also, the important discovery of Eijkman that chickens develop symptoms resembling beriberi when fed a diet of polished rice and that the symptoms disappear on adding rice polishings to the diet has been discussed in the introductory remarks of the preceding section.
The work of Funk was also mentioned. He attempted to isolate the active principle of rice polishings responsible for preventing or curing the symptoms in fowl which develop when these animals are fed diets of polished rice. It was this work that led him to propose the term "vitamine" (now vitamin) for the basic material he isolated that was effective prophylactically or curatively in very small amounts. At about this time'progress in the field was markedly aided by the studies of McCollum and co-workers. In 1915 McCollum and Davis reported that growth of young rats on purified diets was poor when dextrin constituted the carbohydrate of the ration, but if lactose was used, growth was fairly good. They also showed that heating the lactose destroyed the growth-promoting principle and that the active substance was water and alcohol soluble.
The term "water-soluble B" was employed by McCollum to differentiate the factor from his earlier designated growth factor, "fat-soluble A." Yeast was found to be an excellent source of the water-soluble B, and in 1920 Emmett and Luros reported that autoclaved yeast no longer contained the antiberiberi principle of Funk but did contain a substance that promoted growth of rats on certain synthetic diets. This was the first clear-cut demonstration of the dual nature of water-soluble B in yeast. We now know that these workers were dealing with thiamine
water-soluble Bl or antiberiberi principle of Funk), which was destroyed in the yeast by autoclaving, and riboflavin, which promoted rat growth with the rations employed and is not estroyed in yeast by the heat treatment used. In 1926 the antiberiberi vitamin (thiamine), as isolated from rice polishings by Jansen and Donath. The synthesis of thiamine was omplished in 1936 by Williams and co-workers.
A thiamine deficiency in man leads to the condition known as beriberi; in animals the syndrome is referred to as polyneuritis. Reference has been made to the studies by Takaki, who demonstrated that through the proper dietary reforms the incidence of beriberi in the Japanese Navy could be practically eliminated. Also, the important discovery of Eijkman that chickens develop symptoms resembling beriberi when fed a diet of polished rice and that the symptoms disappear on adding rice polishings to the diet has been discussed in the introductory remarks of the preceding section.
The work of Funk was also mentioned. He attempted to isolate the active principle of rice polishings responsible for preventing or curing the symptoms in fowl which develop when these animals are fed diets of polished rice. It was this work that led him to propose the term "vitamine" (now vitamin) for the basic material he isolated that was effective prophylactically or curatively in very small amounts. At about this time'progress in the field was markedly aided by the studies of McCollum and co-workers. In 1915 McCollum and Davis reported that growth of young rats on purified diets was poor when dextrin constituted the carbohydrate of the ration, but if lactose was used, growth was fairly good. They also showed that heating the lactose destroyed the growth-promoting principle and that the active substance was water and alcohol soluble.
The term "water-soluble B" was employed by McCollum to differentiate the factor from his earlier designated growth factor, "fat-soluble A." Yeast was found to be an excellent source of the water-soluble B, and in 1920 Emmett and Luros reported that autoclaved yeast no longer contained the antiberiberi principle of Funk but did contain a substance that promoted growth of rats on certain synthetic diets. This was the first clear-cut demonstration of the dual nature of water-soluble B in yeast. We now know that these workers were dealing with thiamine
water-soluble Bl or antiberiberi principle of Funk), which was destroyed in the yeast by autoclaving, and riboflavin, which promoted rat growth with the rations employed and is not estroyed in yeast by the heat treatment used. In 1926 the antiberiberi vitamin (thiamine), as isolated from rice polishings by Jansen and Donath. The synthesis of thiamine was omplished in 1936 by Williams and co-workers.
