Isoleucine

Chemical structure of Isoleucine Chemical structure of Isoleucine Chemical structure of L-isoleucine
Isoleucine
Systematic (IUPAC) name
(2S,3S)-2-amino-3-methylpentanoic acid
Identifiers
CAS number	73-32-5
PubChem	791
Chemical data
Formula	C6H13NO2
Molar mass	131.18 g/mol
SMILES	CC[C@H](C)[C@H](N)C(O)=O
Complete data

Isoleucine (abbreviated as Ile or I) is an α-amino acid with the chemical formula HO₂CCH(NH₂)CH(CH₃)CH₂CH₃. It is an essential amino acid, which means that humans cannot synthesize it, so it must be part of our diet. Its codons are AUU, AUC and AUA.

With a hydrocarbon side chain, isoleucine is classified as a hydrophobic amino acid. Together with threonine, isoleucine is one of two common amino acids that have a chiral side chain. Four stereoisomers of isoleucine are possible, including two possible diastereomers of L-isoleucine. However, isoleucine present in nature exists in one enantiomeric form, (2S,3S)-2-amino-3-methylpentanoic acid.

Biosynthesis

As an essential amino acid, isoleucine is not synthesized in animals, hence it must be ingested, usually as a component of proteins. In plants and microorganisms, it is synthesized via several steps, starting from pyruvic acid and alpha-ketoglutarate. Enzymes involved in this biosynthesis include:

1. Acetolactate synthase
2. Acetohydroxy acid isomeroreductase
3. Dihydroxyacid dehydratase
4. Valine aminotransferase

Isomers of isoleucine

Forms of Isoleucine
Common name:	isoleucine	D-isoleucine	L-isoleucine	DL-isoleucine	allo-D-isoleucine	allo-L-isoleucine	allo-DL-isoleucine
Synonyms:		(R)-Isoleucine	L(+)-Isoleucine	(R*,R*)-isoleucine		alloisoleucine
PubChem:	Template:PubChemCID	Template:PubChemCID	Template:PubChemCID	Template:PubChemCID
EINECS number:	Template:EINECS	Template:EINECS	Template:EINECS		Template:EINECS	Template:EINECS	Template:EINECS
CAS number:	443-79-8	319-78-8	73-32-5		1509-35-9	1509-34-8	3107-04-8

Synthesis

Isoleucine can be synthesized in a multistep procedure starting from 2-bromobutane and diethylmalonate. Synthetic isoleucine was originally reported in 1905.

External links

• Isoleucine and valine biosynthesis
• Computational Chemistry Wiki

<tr bgcolor="#ccccff"><td colspan="3" align="center">Major families of biochemicals</td></tr><tr><td colspan="3" style="text-align: center;">Peptides | Amino acids | Nucleic acids | Carbohydrates | Nucleotide sugars | Lipids | Terpenes | Carotenoids | Tetrapyrroles | Enzyme cofactors | Steroids | Flavonoids | Alkaloids | Polyketides | Glycosides</td></tr><tr bgcolor="pink"><td style="white-space: nowrap; width: 10%; color: pink;">Analogues of nucleic acids:</td><td align="center">The 20 Common Amino Acids ("dp" = data page)</td><td style="white-space: nowrap; width: 10%; color: pink;">Analogues of nucleic acids:</td></tr> ca:Isoleucina