5′-Methylthioadenosine is S-methyl derivative of the

adenosine Adenosine ( symbol A) is an organic compound that occurs widely in nature in the form of diverse derivatives. The molecule consists of an adenine attached to a ribose via a β-N9-glycosidic bond. Adenosine is one of the four nucleoside building ...

. It is an intermediate in the methylthioadenosine (MTA) cycle, also known as the

methionine Methionine (symbol Met or M) () is an essential amino acid in humans. As the precursor of other amino acids such as cysteine and taurine, versatile compounds such as SAM-e, and the important antioxidant glutathione, methionine plays a critical ro ...

salvage pathway that is universal to aerobic life.

Formation

The pervasive cofactor S-adenosyl methionine (SAM) is the precursor to 5′-methylthioadenosine. The

sulfonium In organic chemistry, a sulfonium ion, also known as sulphonium ion or sulfanium ion, is a positively-charged ion (a " cation") featuring three organic substituents attached to sulfur. These organosulfur compounds have the formula . Together wi ...

group in

SAM Sam, SAM or variants may refer to: Places * Sam, Benin * Sam, Boulkiemdé, Burkina Faso * Sam, Bourzanga, Burkina Faso * Sam, Kongoussi, Burkina Faso * Sam, Iran * Sam, Teton County, Idaho, United States, a populated place People and fictional ...

can cleave in three ways, one involves loss of CH₂CH₂CH(NH₃⁺)CO₂⁻, generating the title compound.

History

In 1912, an adenine nucleoside was isolated by Hunter ''et al.'' from yeast that were grown without phosphorus or

sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula ...

. Later in 1925, that substance was shown by Levene and Sobotkal to be adenylthiomethylpentose. In 1936, Nakahara ''et al.'' did experiments on

rat Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include ''Neotoma'' ( pack rats), ''Bandicota'' (bandicoot ...

s that suggested that vitamin L₂ deficiency inhibits the ability of female

s for lactation. In 1942, they identified vitamin L₂ to be adenylthiomethylpentose. Later studies by Folley ''et al'' (1942) refuted Nakahara's claims and demonstrated that L2 is not necessary for lactation and thus L₂ is not considered a vitamin today. Hecht found in 1937 that the body temperature of

rabbit Rabbits, also known as bunnies or bunny rabbits, are small mammals in the family Leporidae (which also contains the hares) of the order Lagomorpha (which also contains the pikas). ''Oryctolagus cuniculus'' includes the European rabbit speci ...

s, 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.

Formation

History

References

Further reading