Buy Tryptophan (amino) Cas 73-22-3

Tryptophan (symbol Trp or W)^[3] is an α-amino acid that is used in the biosynthesis of proteins. Tryptophan contains an α-amino group, an α-carboxylic acid group, and a side chain indole, making it a polar molecule with a non-polar aromatic beta carbon substituent. Tryptophan is also a precursor to the neurotransmitter serotonin, the hormone melatonin, and vitamin B₃ (niacin).^[4] It is encoded by the codon UGG.

Like other amino acids, tryptophan is a zwitterion at physiological pH where the amino group is protonated (–NH⁺
₃; pK_a = 9.39) and the carboxylic acid is deprotonated ( –COO⁻; pK_a = 2.38).^[5]

Humans and many animals cannot synthesize tryptophan: they need to obtain it through their diet, making it an essential amino acid.

Tryptophan is named after the digestive enzymes trypsin, which were used in its first isolation from casein proteins.^[6] It was assigned the one-letter symbol W based on the double ring being visually suggestive to the bulky letter.^[7]

Amino acids, including tryptophan, are used as building blocks in protein biosynthesis, and proteins are required to sustain life. Tryptophan is among the less common amino acids found in proteins, but it plays important structural or functional roles whenever it occurs. For instance, tryptophan and tyrosine residues play special roles in “anchoring” membrane proteins within the cell membrane. Tryptophan, along with other aromatic amino acids, is also important in glycan-protein interactions. In addition, tryptophan functions as a biochemical precursor for the following compounds:

• Serotonin (a neurotransmitter), synthesized by tryptophan hydroxylase.^[8][9]
• Melatonin (a neurohormone) is in turn synthesized from serotonin, via N-acetyltransferase and 5-hydroxyindole-O-methyltransferase enzymes.^[10]
• Kynurenine, to which tryptophan is mainly (more than 95%) metabolized. Two enzymes, namely indoleamine 2,3-dioxygenase (IDO) in the immune system and the brain, and tryptophan 2,3-dioxygenase (TDO) in the liver, are responsible for the synthesis of kynurenine from tryptophan. The kynurenine pathway of tryptophan catabolism is altered in several diseases, including psychiatric disorders such as schizophrenia,^[11] major depressive disorder,^[11] and bipolar disorder.^[11][12]
• Niacin, also known as vitamin B₃, is synthesized from tryptophan via kynurenine and quinolinic acids.^[13]
• Auxins (a class of phytohormones) are synthesized from tryptophan.^[14]