The story

Arthur Harden and William Young found a heat-stable cofactor in yeast juice in 1906 that fermentation could not run without. Hans von Euler-Chelpin worked out its structure and shared the 1929 Nobel Prize for it, and Otto Warburg showed in the 1930s that it carries hydrogen in energy reactions. The modern story began when Leonard Guarente in Boston and Shin-ichiro Imai, a Japanese biologist, showed in 2000 that the sirtuins need NAD+ to work. Imai's group then showed that the enzyme NAMPT, which recycles NAD+, falls with age and drives metabolic decline. Australian work by Ross Grant tracked how NAD+ given into a vein is taken up and turned over in the human body.