Phenylalanine

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
InChIKey Identifier: COLNVLDHVKWLRT-KMJKUPBBDK
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.

Phenylketonuria

Phenylketonuria (PKU) is a rare but serious inherited metabolic disorder. It occurs in individuals who lack the enzyme phenylalanine hydroxylase, which is necessary for converting the amino acid phenylalanine into tyrosine. Without this enzyme, phenylalanine accumulates in the blood and brain to toxic levels. This condition, if left untreated, can result in severe and irreversible intellectual disability, behavioral problems, and seizures. It is crucial to diagnose and start treatment for PKU within the first few weeks of life to prevent these adverse outcomes.

PKU is usually detected through newborn screening, which is mandatory in many countries. The test involves a simple heel prick blood sample taken from the newborn within the first few days of life. Early detection allows for prompt dietary management to keep phenylalanine levels in check.

People with PKU must adhere to a strict diet low in phenylalanine. This means avoiding high-protein foods such as meat, eggs, dairy products, nuts, and soybeans, as well as many common artificial sweeteners like aspartame, which contains phenylalanine. Instead, they rely on special medical formulas and low-protein products to meet their nutritional needs. This diet must be maintained for life to prevent neurological damage and other complications.

Managing PKU requires regular blood tests to monitor phenylalanine levels and adjust the diet as necessary. In addition to dietary restrictions, some individuals with PKU may benefit from a medication called sapropterin dihydrochloride, which can help lower phenylalanine levels in certain cases.

Ongoing research is exploring potential new treatments for PKU, including gene therapy and enzyme replacement therapy, which aim to address the underlying cause of the disorder. These advancements hold promise for improving the quality of life for individuals with PKU and potentially reducing the need for strict dietary management in the future.

Living with PKU requires careful planning and support, but with early diagnosis and proper management, individuals with PKU can lead healthy and fulfilling lives. Education and awareness about PKU are essential for ensuring early detection and treatment, as well as for providing the necessary support for those affected by this condition.

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.