adenine

 

(ăd'ənĭn, –nīn, –nēn) , organic base of the purine family. Adenine combines with the sugar ribose to form adenosine, which in turn can be bonded with from one to three phosphoric acid units, yielding the three nucleotides adenosine monophosphate, adenosine diphosphate, and adenosine triphosphate. These adenine derivatives perform important functions in cellular metabolism. Adenine is one of four nitrogenous bases utilized in the synthesis of nucleic acids. A modified form of adenosine monophosphate is thought to be a secondary messenger in the propagation of many hormonal stimuli. Adenine is an integral part of the structure of many coenzymes.

Adenine
Systematic (IUPAC) name
7H-purin-6-amine
Synonyms
6-aminopurine
Identifiers
CAS number	73-24-5
EINECS	200-796-1
PubChem	190
Chemical data
Formula	C5H5N5
Molar mass	135.127
SMILES	Nc1ncnc2[nH]cnc12
Physical data
Melt. point	360 - 365 °C (-265 °F)
Complete data

Adenine is a purine with a variety of roles in biochemistry including cellular respiration, in the form of both the energy-rich adenosine triphosphate (ATP) and the cofactors nicotinamide adenine dinucleotide (NAD) and flavin adenine dinucleotide (FAD), and protein synthesis, as a chemical component of DNA and RNA.^[1]

Structure

It forms several tautomers, compounds that can be rapidly interconverted and are often considered equivalent.

Biosynthesis

The Purine metabolism involves the formation of Adenine and Guanine. Both adenine and guanine are derived from the nucleoside inosine monophosphate (IMP), which is synthesised on a pre-existing ribose through a complex pathway using atoms from the amino acids glycine, glutamine, and aspartic acid, as well as formate ions transferred from the coenzyme tetrahydrofolate.

Function

Adenine is one of the two purine nucleobases 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 in the cytoplasm for protein synthesis, adenine binds to uracil.

Adenine forms adenosine, a nucleoside, when attached to ribose, and deoxyadenosine when attached to deoxyribose. It forms adenosine triphosphate (ATP), a nucleotide, when three phosphate groups are added to adenosine. Adenosine triphosphate is used in cellular metabolism as one of the basic methods of transferring chemical energy between chemical reactions.

History

In older literature, adenine was sometimes called Vitamin B4.^[2] It is no longer considered a true vitamin nor part of the Vitamin B complex. However, two B vitamins, niacin and riboflavin, bind with adenine to form the essential cofactors nicotinamide adenine dinucleotide (NAD) and flavin adenine dinucleotide (FAD) respectively.

Some think that, at the origin of life on Earth, the first adenine was formed by the polymerization of five hydrogen cyanide (HCN) molecules. However, this has been criticized by some chemists.^[3]

External links

• Computational Chemistry Wiki

References

Major families of biochemicals
Peptides | Amino acids | Nucleic acids | Carbohydrates | Lipids | Terpenes | Carotenoids | Tetrapyrroles | Enzyme cofactors | Steroids | Flavonoids | Alkaloids | Polyketides | Glycosides
Analogues of nucleic acids:	Types of Nucleic Acids	Analogues of nucleic acids:
Nucleobases:	Purine (Adenine, Guanine) | Pyrimidine (Uracil, Thymine, Cytosine)
Nucleosides:	Adenosine/Deoxyadenosine | Guanosine/Deoxyguanosine | Uridine | Thymidine | Cytidine/Deoxycytidine
Nucleotides:	monophosphates (AMP, UMP, GMP, CMP) | diphosphates (ADP, UDP, GDP, CDP) | triphosphates (ATP, UTP, GTP, CTP) | cyclic (cAMP, cGMP, cADPR)
Deoxynucleotides:	monophosphates (dAMP, TMP, dGMP, dCMP) | diphosphates (dADP, TDP, dGDP, dCDP) | triphosphates (dATP, TTP, dGTP, dCTP)
Ribonucleic acids:	RNA | mRNA | piRNA | tRNA | rRNA | ncRNA | gRNA | shRNA | siRNA | snRNA | miRNA | snoRNA
Deoxyribonucleic acids:	DNA | mtDNA | cDNA | plasmid | Cosmid | BAC | YAC | HAC
Analogues of nucleic acids:	GNA | PNA | TNA | Morpholino | LNA

Vitamins (A11)
fat soluble	Retinol (A) | Ergocalciferol and Cholecalciferol (D) | Tocopherol (E) | Naphthoquinone (K)
water soluble	B vitamins (Thiamine (B1), Riboflavin (B2), Niacin (B3), Pantothenic acid (B5), Pyridoxine (B6), Biotin (B7), Folic acid (B9), Cyanocobalamin (B12)) | Choline | Ascorbic acid (C)

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