Phenylalanine was found in the seedlings of Lupinus Zuteus by Schulze and Barbieri in 1879 - before it was discovered among the products of hydrolysis of proteins. Almost a century later, a Japanese company started production of Phenylalanine by fermentation.

Chemical Structure of L-Phenylalanine

Structure of Phenylalanine

Identifiers and properties of Phenylalanine

IUPAC Name: (2S)-2-Amino-3-phenylpropanoic acid
Symbol: Three-letter code - Phe. One-letter code - F
Molecular Weight (Molar Mass): 165.18914 g/mol
Molecular Formula (Structural Formula): C9H11NO2
Canonical SMILES: C1=CC=C(C=C1)CC(C(=O)O)N
Isomeric SMILES: C1=CC=C(C=C1)C[C@@H](C(=O)O)N
CAS Number: 63-91-2
MDL Number: MFCD00064227
Melting point: 270-275 °C
RNA codons: TTC, TTT
Solubility in water: 27 g/L (20 °C); pKa - 1,83; pKb - 9,13
Rf value in n-butanol/acetic acid/water = 12:3:5 - 0.68
2D Molfile: Get the molfile
3D PDB file: Get the PDB file
Other names: L-beta-Phenylalanine; L-2-Amino-3-phenylpropionic acid; (S)-alpha-Amino-benzenepropanoic acid; (S)-alpha-Aminohydrocinnamic acid; (S)-alpha-Amino-beta-phenylpropionic acid; Phenyl-alpha-alanine; (-)-beta-Phenylalanine; beta-Phenyl-alpha-alanine; beta-Phenyl-L-alanine; 3-Phenyl-L-alanine; L-beta-Phenylalanine; (S)-Phenylalanine; 3-Phenylalanine

What are the functions of the Phenylalanine?

Phenylalanine is a precursor of Tyrosine, combined with which it leads to the formation of adrenaline. In turn, adrenaline is converted into a brain chemical utilized to produce noradrenaline responsible for promoting mental alertness and memory, and also for the elevation of mood and for the suppression of appetite.

Since noradrenaline affects mood, various forms of phenylalanine have been suggested to treat such conditions as lack of energy, memory problems, depression, confusion, decreased alertness, and lack of appetite, all of which are considered to be caused by the Phenylalanine deficiency.

There is a rare metabolic disorder - phenylketonuria, which occurs in people missing an enzyme that the human body requires to utilize Phenylalanine. As a result, the disorder causes high levels of this amino acid, which in turn can lead to severe, irreversible mental retardation if is not treated before three weeks of age. In our country, all newborns are tested for this disorder during the first 2-3 days of life. People suffering from it have to eat a diet avoiding Phenylalanine.

Benefits of Phenylalanine

According to a number of researches, this amino acid can help treat chronic pain, strengthen the effect of UVA radiation for people with vitiligo, and even Parkinson's disease - there was a study on animals suggesting that Phenylalanine is able to improve walking disabilities, rigidity, speech difficulties, and depression caused by Parkinson's disease. Finally, Phenylalanine is considered to be helpful in treating depression, because this amino acid stimulates the production of brain chemicals like dopamine and norepinephrine.

Phenylalanine is an essential amino acid, also acting as a building block for proteins, indicating that, although your body requires this amino acid for health, it is unable to produce it by itself. So, you have the only way to satisfy your demand in Phenylalanine - to get it from food.

Food sources

Phenylalanine needs to be obtained through the diet, as the body cannot produce it. It's important to note that people with phenylketonuria (PKU), a rare genetic disorder, need to closely monitor their phenylalanine intake, as they cannot metabolize it properly. Phenylalanine is found in most protein-containing foods such as milk, eggs, cheese, nuts, soybeans, chicken, beef, pork, beans and fish. Here are some foods that are good sources of phenylalanine.

Meat and Poultry. Chicken breast: Approximately 1.6 grams per ounce. Turkey: About 1.7 grams per ounce. Beef: Contains around 1.5 grams per ounce.

Fish. Tuna: About 1.7 grams per ounce. Salmon: Approximately 1.8 grams per ounce.

Dairy Products. Cheese (Parmesan, Swiss, Cheddar, etc.): Phenylalanine content can vary but is generally around 0.7 to 1 gram per ounce. Milk: About 0.4 grams per cup.

Eggs. One large egg contains about 0.2 grams of phenylalanine.

Legumes. Soy Products: Tofu: Approximately 0.4 grams per ounce. Soybeans: About 0.7 grams per ounce.

Other Legumes. Lentils: Approximately 0.4 grams per ounce. Chickpeas: About 0.7 grams per ounce.

Nuts and Seeds. Almonds: Approximately 0.7 grams per ounce. Sunflower seeds: About 0.5 grams per ounce.

Grains. Whole grains such as quinoa and oats contain phenylalanine, but the amounts are relatively small.

It's essential to note that phenylalanine content can vary based on factors such as the specific type or cut of the food and cooking methods. If you have specific dietary needs or restrictions, particularly related to phenylketonuria (PKU), it's crucial to work closely with healthcare professionals and dietitians to manage your phenylalanine intake appropriately.