Adenine (symbol A, or Ade) is a purine nucleotide base that is found in DNA, RNA, and ATP. Usually a white crystalline subtance. In respiration it also participates as part of the cofactors nicotinamide adenine dinucleotide, flavin adenine dinucleotide, and Coenzyme A.

It is also part of adenosine, adenosine monophosphate, cyclic adenosine monophosphate, adenosine diphosphate, and S-adenosylmethionine.

Structure

Adenine forms several tautomers, compounds that can be rapidly interconverted and are often considered equivalent. However, in isolated conditions, i.e. in an inert gas matrix and in the gas phase, mainly the 9H-adenine tautomer is found.

Biosynthesis

Purine metabolism involves the formation of adenine and guanine. Both adenine and guanine are derived from the nucleotide inosine monophosphate (IMP), which in turn is synthesized from a pre-existing ribose phosphate through a complex pathway using atoms from the amino acids glycine, glutamine, and aspartic acid, as well as the coenzyme tetrahydrofolate.

Patented August 20, 1968, the current recognized method of industrial-scale production of adenine involves heating formamide under 120 °C.

Function

Adenine is one of the two purine nucleobases (the other being guanine) used in forming nucleotides of the nucleic acids. In DNA, adenine binds to thymine via two hydrogen bonds to assist in stabilizing the nucleic acid structures. In RNA, which is used for protein synthesis, adenine binds to uracil.

{| class="wikitable left" style="text-align:center"

|-

| 180px|class=skin-invert-image

| 180px|class=skin-invert-image

| 180px|class=skin-invert-image

| 180px|class=skin-invert-image

|-

| A-T-Base-pair (DNA)

| A-U-Base-pair (RNA)

| A-D-Base-pair (RNA)

| A-Ψ-Base-pair (RNA)

|}

Adenine forms adenosine, a nucleoside, when attached to ribose, and deoxyadenosine when attached to deoxyribose.

Adenine can be prepared from ammonia and hydrogen cyanide (HCN) in aqueous solution, a process that has implications for the origin of life on Earth.

On August 8, 2011, a report, based on NASA studies with meteorites found on Earth, was published suggesting building blocks of DNA and RNA (adenine, guanine and related organic molecules) may have been formed extraterrestrially in outer space. In 2011, physicists reported that adenine has an "unexpectedly variable range of ionization energies along its reaction pathways" which suggested that "understanding experimental data on how adenine survives exposure to UV light is much more complicated than previously thought"; these findings have implications for spectroscopic measurements of heterocyclic compounds, according to one report.

Notes

References

  • Vitamin B4 MS Spectrum