Luis Leloir, 81, the Argentine who won the 1970 Nobel Prize for chemistry. Leloir, who despite his advanced age had continued to work, won the Nobel Prize for his discovery of the nucleotides-sugars and their role in the biosynthesis of carbohydrates. Manuel Sadosky, Argentina's secretary of Science and Technology, expressed his regrets for Leloir's death, saying that Leloir had played an important role in forming a large school of dedicated scientists. Leloir was the honorary president of the National Council for Scientific and Technological Investigations and he had headed several research foundations. Wednesday in Buenos Aires.