Phenylalanine

Phenylalanine is an aromatic, proteinogenic, alpha-amino acid that occurs naturally in its L-form as a protein component. Phenylalanine is an essential amino acid for humans. It is synthesized by plants and microorganisms via the so-called "shikimic acid-chorismic acid pathway" and is both glucoplastic and ketoplastic.

Phenyalanine is degraded in the organism by phenylalanine hydroxylase, initially via L-tyrosine, homogentisic acid and further intermediate steps to fumaric acid and acetoacetic acid. The lack of phenylalanine hydroxylase leads to the clinical picture of phenylketonuria, Fölling's disease.

Phenylalanine is slightly soluble in water and poorly soluble in ethanol. The substance is involved in the synthesis of several important hormones, messenger substances and compounds such as adrenaline, noradrenaline, dopamine, insulin and melanin.

Offered as a dietary supplement, phenylalanine is found in foods such as dried peas, soybeans, walnuts, pumpkin seeds and various types of fish and meat.

In cosmetics: Phenylalanine (INCI) is used in cosmetic formulations. The amino acid acts as an antistatic agent (reduces static charges by neutralizing the electrical charge on the surface, for example of hair) and improves combability, i.e. it reduces or prevents tangling of the hair due to changes or damage to the hair surface and thus improves combability.

1. Ammon HPT et al. (2014) Hunnius Pharmaceutical Dictionary 11th Edition Walter de Gruyter Berlin-New York S. 1386-1387