Adenylthiomethylpentose is a sulfur-containing nucleoside that was formerly known as vitamin L2. In 1912, an adenine nucleoside was isolated by Hunter et al. from yeast that were grown without phosphorus or sulfur. Later that substance was shown by Levene and Sobotkal to be adenylthiomethylpentose. Hecht found in 1937 that the body temperature of rabbits, cats and guinea pigs were lowered by 1 to 2 degrees after he gave them adenylthiomethylpentose at a dose of 0.2 g/kg. Kühn et al. replicated this in guinea pigs in 1941.