Testing many keys in one lock: an unsuccessful yet fruitful quest for the cure of beri-beri

Sutematsu Kajiura found himself in the early 20th century where the known essential nutrients only consisted of amino acids, carbohydrates, fats, minerals and water. Therefore, scientists and doctors were navigating a battlefield without comprehensive knowledge of the terrain, being completely unaware of the essential sector of vitamins. This is the world in which our story was published and Kajiura was on a mission to find the cause of the ‘national disease,’ beriberi, now known to be caused primarily by thiamine (vitamin B1) deficiency. Though Kajiura discovered neither the cause nor the cure, he made major contributions to plant seed biology by identifying and isolating the major protein in rice, oryzenin, which was later studied indepth. In addition, he was unknowingly a part of the massive movement toward the discovery of vitamins, the newest member of the essential nutrient family.