Tyrosine manufacture

Directing the iodination reaction toward histidine residues in proteins, as opposed to principally tyrosine modification, is possible simply by increasing the pH of the lodobeads reaction from the manufacturer s recommended pH 7.0-8.2 (Tsomides et ai, 1991). No reducing agent is required to stop the iodination reaction as is the case with chloramine-T and other methods. 

What kind of business This depends largely on what kind of dope you plan to manufacture. Amine-type precursors go hand in hand with perfumery or dyes. Nitrating-type compounds (nitromethane, nitroethane) are also used as solvents, and rocket fuels. Indole has been used in perfumery. Tyrosine and tryptophan are nutrients added to feeds. Urea is a plant fertilizer and a feed additive. 

There are 22 different AAs in the body of the bird, 10 of which are essential AA (EAA arginine, methionine, histidine, phenylalanine, isoleucine, leucine, lysine, threonine, tryptophan and valine), i.e. cannot be manufactured by the body and must be derived from the diet. Cystine and tyrosine are semi-essential in that they can be synthesized from methionine and phenyla-... 

Hie hormone made by the thyroid which is responsible for regulating BMR is called thyroxine it is an iodine-containing amino acid derived from tyrosine. Almost the whole of the body s stock of iodine is used by the thyroid in the manufacture of thyroxine, which has the structure... 

The phenol structure is widespread in nature as vitamin E, oil of wintergreen, vanillin, the amino acid tyrosine, adrenalin, and tetrahydrocannibinaol (the hallucinogen ingredient of marijuana). Phenol compounds are used as antiseptics and disinfectants, as antioxidants, and to manufacture plastics and aspirin. 

Oxidation occurs generally on the amino acid side chains due to exposure to air, residual peroxide from excipients, or exposure to visible or ultraviolet light. In particular, methionine, cysteine, tryptophan, and tyrosine are prone to oxidation. Metal ions such as iron, zinc, copper, or tungsten from metals that are used in the manufacturing process, leached from contact materials, or present in trace amounts in excipients can catalyze oxidation as well as other degradation processes [2, 17]. 

The shikimic acid pathway is responsible for the biosynthesis of a large number of aromatic compounds, particularly in plants. Most important for many mammals is the fact that plants manufacture the aromatic amino acids Phe (phenylalanine), Tyr (tyrosine), and Trp (tryptophan). These are essential amino acids for humans—we have to have them in our diet as we cannot make them ourselves. 

However, of industrial importance is the manufacturing of (L)-3,4-dihy-droxyphenylalanine ((L)-DOPA), an agent against Parkinson s disease, using a tyrosine phenol-lyase. Ajinomoto employs a whole-cell preparation from Er-winia herbicola to obtain the target compound in a three-component reaction, starting from catechol, pyruvic acid and ammonia. The annual capacity amounts to around 250 tonnes. [64]... 

The human body is made up of molecules, as are also bacteria and other vectors of disease. We might accordingly say that all diseases are molecular diseases, involving molecules in one way or another. For example, phenylketonuria, which causes feeble-mindedness or more serious mental impairment, is an inborn error of metabolism such that the patient is not able to carry out the oxidation of phenylalanine to tyrosine. This disease is due to an abnormal gene, present in double dose either the gene is not able to manufaeture the enzyme catalysing the oxidation reaction, or it manufactures abnormal enzyme molecules, with decreased effectiveness. 

The disease phenylketonuria, discovered about forty years ago by Felling in Norway, may be considered a molecular disease. This disease involves a gene mutation such that the patient fails to manufacture molecules of an enzyme normally present in the liver, which catalyzes the oxidation of phenylalanine to tyrosine, or produces an abnormal enzyme, with greatly reduced catalytic aiitivity. The patients are homozygotes, who have inherited the... 

Phenylalanine is the precursor of the artificial sweetener aspartame and used in feed and infusion solutions, nutrition, and health. The increasing demand ftrr the low calorie artificial sweetener has been driving the phenylalanine production.Tyrosine has its potential use in the manufacture of DOPA (dihydroxyphenylalanine) for the treatment of Parkinson s disease. 

Figure 1 Structures of (A) Bisphenol A, a widely used diphenol in the manufacture of commercial polycarbonate resins (B) tyrosine dipeptide with specific chemical protecting groups Xj and alkyl substituents X9 attached to the N and C termini, respectively.

The oxidation of phenols to catechols or hydroquinones by tyrosinase enzymes has been developed for biocatalysis. For example, the ortho-hydroxylation of L-tyrosine 162 (and also substituted variants) to give l-DOPA 163 has been extensively studied due to the importance of l-DOPA in the treatment of Parkinson s disease [92, 93]. An arene hydroxy lating enzyme having a broad substrate scope is 2-hydroxybiphenyl 3-monooxygenase from Pseudomonas azelaica, which is able to oxidize many ortho-substituted phenols 68 to the corresponding catechols 127 [94], as shown in Scheme 32.19. A notable example of an industrial biocatalytic arene hydroxylation that has been employed on very large scale (lOOm fermentation) is the pora-hydroxylation of R)-2-phenoxypropionic acid 164 by whole cells of Beauveria bassiana Lu 700 to give (R)-2-(4-hydroxyphenoxy)propionic acid 165, an important intermediate in herbicide manufacture [95]. 

D-hydroxyphenylglycine, L-hydroxyproKne, L-isoleucine, L-lysine, L-ornithine, L-phenylalanine, o-phenylglycine, L-polylysine, L-proline, L-serine, L-threonine, L-tryptophan, and L-tyrosine) was investigated and successfully manufactured on an industrial scale. Glycine is produced by chemical methods because the molecule has no chiral center, and methionine is also produced by chemical methods in its racemic form because the main use of the amino acid is as feedstuff. o-Methionine is metabolized in animals by the action of D-amino acid oxidase. These amino acids were useful as sources of medicines, food additives, feed-stuffs, and starting materials for chemical synthesis. 

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