After graduating he wished to study natural sciences, but his father compelled him to work in the family business until determining that his son was unsuitable.

Here the ground had been broken by von Baeyer, but Fischer greatly advanced the field of knowledge of the purines.

In 1881 and 1882 he published papers which established the formulae of uric acid, xanthine, caffeine (achieving the first synthesis), theobromine and some other compounds of this group.

[9] He showed how to deduce the formulae of the 16 stereoisomeric glucoses, and prepared several stereoisomerides, helping to confirm the Le Bel–Van 't Hoff rule of the asymmetric carbon atom.

[8] In the field of enzymology, Fischer is known for his proposal of "the lock and key" model as a mechanism of substrate binding.

[10] Fischer was also instrumental in the discovery of barbiturates, a class of sedative drugs used for insomnia, epilepsy, anxiety, and anesthesia.

By the introduction of new methods, he succeeded in breaking down the complex albumins into amino acids and other nitrogenous compounds, the constitutions of most of which were known, and by bringing about the recombination of these units, he prepared synthetic peptides which approximated to the natural products.

His researches made from 1899 to 1906 were published in 1907 with the title Untersuchungen über Aminosauren, Polypeptides und Proteine.

The younger two died during their military service in World War I, but the oldest, Hermann, became an organic chemist.

[1] He was awarded the 1902 Nobel Prize in chemistry "in recognition of the extraordinary services he has rendered by his work on sugar and purine syntheses.