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 build ...

. 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 non-essential amino acids such as cysteine and taurine, versatile compounds such as SAM-e, and the important antioxidant glutathione, methionine play ...

salvage pathway A salvage pathway is a pathway in which a biological product is produced from intermediates in the degradative pathway of its own or a similar substance. The term often refers to nucleotide salvage in particular, in which nucleotides (purine and py ...

that is universal to aerobic life.

Formation

The pervasive cofactor

S-adenosyl methionine ''S''-Adenosyl methionine (SAM), also known under the commercial names of SAMe, SAM-e, or AdoMet, is a common cosubstrate involved in methyl group transfers, transsulfuration, and aminopropylation. Although these anabolic reactions occur thro ...

(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 Substitution (chemistry), substituents attached to sulfur. These organosulfur compounds have t ...

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

History

In 1912, an

adenine Adenine (, ) (nucleoside#List of nucleosides and corresponding nucleobases, symbol A or Ade) is a purine nucleotide base that is found in DNA, RNA, and Adenosine triphosphate, ATP. Usually a white crystalline subtance. The shape of adenine is ...

nucleoside Nucleosides are glycosylamines that can be thought of as nucleotides without a phosphate group. A nucleoside consists simply of a nucleobase (also termed a nitrogenous base) and a five-carbon sugar (ribose or 2'-deoxyribose) whereas a nucleotid ...

was isolated by Hunter ''et al.'' from

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom (biology), kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are est ...

that were grown without

phosphorus Phosphorus is a chemical element; it has Chemical symbol, symbol P and atomic number 15. All elemental forms of phosphorus are highly Reactivity (chemistry), reactive and are therefore never found in nature. They can nevertheless be prepared ar ...

sulfur Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...

. 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'' (bandicoo ...

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

s for

lactation Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process naturally occurs with all sexually mature female mammals, although it may predate mammals. The process ...

. 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 Vitamins are Organic compound, organic molecules (or a set of closely related molecules called vitamer, vitamers) that are essential to an organism in small quantities for proper metabolism, metabolic function. Nutrient#Essential nutrients, ...

today. Hecht found in 1937 that the body temperature of

rabbit Rabbits are small mammals in the family Leporidae (which also includes the hares), which is in the order Lagomorpha (which also includes pikas). They are familiar throughout the world as a small herbivore, a prey animal, a domesticated ...

cat The cat (''Felis catus''), also referred to as the domestic cat or house cat, is a small domesticated carnivorous mammal. It is the only domesticated species of the family Felidae. Advances in archaeology and genetics have shown that the ...

s and

guinea pig The guinea pig or domestic guinea pig (''Cavia porcellus''), also known as the cavy or domestic cavy ( ), is a species of rodent belonging to the genus ''Cavia'', family Caviidae. Animal fancy, Breeders tend to use the name "cavy" for the ani ...

s 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 The guinea pig or domestic guinea pig (''Cavia porcellus''), also known as the cavy or domestic cavy ( ), is a species of rodent belonging to the genus ''Cavia'', family Caviidae. Breeders tend to use the name "cavy" for the animal, but "gui ...

in 1941.

Formation

History

References

Further reading