L-トリプトファン

化学的特性Appearance: white crystalline powder. Odorless, slightly bitter taste; Solubility: slightly soluble in water (1.14%, 25 ℃), insoluble in ethanol; soluble in dilute acid or dilute alkali. mp 289 ° C (decomposition). Isoelectric point: 5.89. [α] D + 2.8 (5 mol / L HCl), [α] D + 6.2 (0.5 mol / L NaOH). It can be colored upon long-term exposure to light. Its co-heating reaction with water will generate a small amount of indole while heating in the presence of sodium hydroxide and copper sulfate will produce a large amount of indole. It is stable upon heating together with acid in the dark, but is easily to be decomposed when heated together with other amino acids, carbohydrates and aldehydes. L-tryptophan will be completely decomposed when applying acid to break down the protein.

解説L-トリプトファン,小葉状または板状結晶(希エタノール)．分解点289 ℃．[α]D23"－32.5°(水)，[α]D20"＋2.4°(1 mol L－1 塩酸)．pK1 2.35，pK2 9.33．熱水，熱エタノールに可溶．アダムキーウィッツ反応が陽性であり，タンパク質の紫外吸収はトリプトファンとチロシンによる．生体内ではニコチン酸，昆虫の色素形成，植物ホルモンのインドール酢酸など，生理的に重要な化合物の代謝中間体になっている．森北出版「化学辞典（第2版）

用途製剤研究用。アミノ酸研究用。

使用L-tryptophan is an essential amino acid which is necessary for normal growth in infants and for nitrogen balance in adults. It acts as a natural dietary supplement and used as an antidepressant, anxiolytic and sleep aid. It is used as a precursor to niacin, indole alkaloids and serotonin. It acts as an important intrinsic fluorescent probe, which finds to estimate the nature of microenvironment of the tryptophan.

一般的な説明White powder with a flat taste. An essential amino acid; occurs in isomeric forms.

The most attractive production processes for tryptophan are based on microorganisms used as enzyme sources or as overproducers: Enzymatic production from various precursors; Fermentative production from precursors; Direct fermentative production from carbohydrates by auxotrophic and analogue resistant regulatory mutants. L-tryptophan is synthesized from indole, pyruvate, and ammonia by the enzyme tryptophanase or from indole and L-serine/D,L-serine by tryptophan synthase these process variants were not economic due to the high costs of the starting materials. The microbial conversion of biosynthetic intermediates such as indole or anthranilic acid to L-tryptophan has also been considered as alternative for production.However, the manufacturer using genetically modified strains derived fromBacillus amyloliquefaciens IAM 1521 was forced to stop Ltryptophan production. L-Tryptophan produced by this process was stigmatized because of side products found in the product causing a new severe disease termed eosinophilia-myalgia syndrome (EMS). One of the problematic impurities, "Peak E", was identified as 1,10-ethylidene- bis-(L-tryptophan), a product formed by condensation of one molecule acetaldehyde with two molecules of tryptophan.

純化方法Crystallise L-tryptophan from H2O/EtOH, wash it with anhydrous diethyl ether and dry it at room temperature in a vacuum over P2O5. It sublimes at 220-230o/0.03mm with 99% recovery and unracemised [Gross & Gradsky J Am Chem Soc 77 1678 1955]. [Cox & King Org Synth Coll Vol II 612 1943, Greenstein & Winitz The Chemistry of the Amino Acids J. Wiley, Vol 3 pp 2316-2345 1961, Beilstein 22 IV 6765.]

定義本品は、次の化学式で表されるアミノ酸である。

定義ChEBI: L-tryptophan is the L-enantiomer of tryptophan. It has a role as an antidepressant, a nutraceutical, a micronutrient, a plant metabolite, a human metabolite, a Saccharomyces cerevisiae metabolite, an Escherichia coli metabolite and a mouse metabolite. It is an erythrose 4-phosphate/phosphoenolpyruvate family amino acid, a proteinogenic amino acid, a tryptophan and a L-alpha-amino acid. It is a conjugate base of a L-tryptophanium. It is a conjugate acid of a L-tryptophanate. It is an enantiomer of a D-tryptophan. It is a tautomer of a L-tryptophan zwitterion.