Phenylalanine

Phenylalanine
	Skeletal formula of L-phenylalanine
	L-Phenylalanine at physiological pH
Ball-and-stick model	Space-filling model
Names
Pronunciation	US: /ˌfɛnəlˈæləniːn/ ⓘ; UK: /ˌfiːnaɪl-/
	IUPAC name Phenylalanine
	Systematic IUPAC name (S)-2-Amino-3-phenylpropanoic acid
Identifiers
CAS Number	L: 63-91-2 ; D/L: 150-30-1 ; D: 673-06-3 ;
3D model (JSmol)	L: Interactive image; D: Interactive image; L Zwitterion: Interactive image; D Zwitterion: Interactive image;
ChEBI	L: CHEBI:17295 ; D/L: CHEBI:28044; D: CHEBI:16998 ;
ChEMBL	L: ChEMBL301523 ;
ChemSpider	L: 5910 ; D/L: 969 ; D: 64639 ;
DrugBank	L: DB00120 ;
ECHA InfoCard	100.000.517
IUPHAR/BPS	L: 3313;
KEGG	L: D00021 ;
PubChem CID	L: 6140; D/L: 994; D: 71567;
UNII	L: 47E5O17Y3R ; D/L: 8P946UF12S ; D: 032K16VRCU ;
CompTox Dashboard (EPA)	L: DTXSID4040763 ;
	InChI InChI=1S/C9H11NO2/c10-8(9(11)12)6-7-4-2-1-3-5-7/h1-5,8H,6,10H2,(H,11,12)/t8-/m0/s1 Key: COLNVLDHVKWLRT-QMMMGPOBSA-N ; L: Key: COLNVLDHVKWLRT-QMMMGPOBBC; D/L: Key: COLNVLDHVKWLRT-UHFFFAOYSA-N; D: Key: COLNVLDHVKWLRT-MRVPVSSYSA-N;
	SMILES L: c1ccc(cc1)C[C@@H](C(=O)O)N; D: c1ccc(cc1)C[C@H](C(=O)O)N; L Zwitterion: [NH3+][C@@H](CC1=CC=CC=C1)C([O-])=O; D Zwitterion: [NH3+][C@H](CC1=CC=CC=C1)C([O-])=O;
Properties
Chemical formula	C9H11NO2
Molar mass	165.192 g·mol−1
Solubility in water	9.97 g/L at 0 °C ; 14.11 g/L at 25 °C ; 21.87 g/L at 50 °C ; 37.08 g/L at 75 °C ; 68.9 g/L at 100 °C
Acidity (pKa)	1.83 (carboxyl), 9.13 (amino)
Hazards
NFPA 704 (fire diamond)	2 1 0
Supplementary data page
	Phenylalanine (data page)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Phenylalanine (symbol Phe or F) is an essential α-amino acid with the formula C
₉H
₁₁NO
₂. It can be viewed as a benzyl group substituted for the methyl group of alanine, or a phenyl group in place of a terminal hydrogen of alanine. This essential amino acid is classified as neutral, and nonpolar because of the inert and hydrophobic nature of the benzyl side chain. The L-isomer is used to biochemically form proteins coded for by DNA. Phenylalanine is a precursor for tyrosine, the monoamine neurotransmitters dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline), and the biological pigment melanin. It is encoded by the messenger RNA codons UUU and UUC.

Phenylalanine is found naturally in the milk of mammals. It is used in the manufacture of food and drink products and sold as a nutritional supplement as it is a direct precursor to the neuromodulator phenethylamine. As an essential amino acid, phenylalanine is not synthesized de novo in humans and other animals, who must ingest phenylalanine or phenylalanine-containing proteins.

The one-letter symbol F was assigned to phenylalanine for its phonetic similarity.