L(-)-триптофан химические свойства, назначение, производство
Химические свойства
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.
Использование
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.
Определение
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.
Методы производства
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.
Всемирная организация здравоохранения(ВОЗ)
L-tryptophan, an essential aminoacid and precursor of serotonin,
was introduced into medicine in 1963 for the treatment of depression and sleep
disorders. Its effectiveness in these conditions has, however, never been
convincingly demonstrated. It is also widely used in dietary supplements,
parenteral nutrition preparations and dietary products for children with
phenylketonuria. In 1989, reports from the USA showed an association between the
consumption of L-tryptophan containing preparations and the development of
eosiniphilia-myalgia syndrome (EMS), a condition characterized by intense
eosinophilia, severe muscle and joint pain, swelling of the arms and legs, skin
rashes and possible fever. Some of the reported cases have been fatal. Since it is
not yet clear whether L-tryptophan itself or an unidentified contaminant is the
cause of the EMS, many drug regulatory authorities have suspended the marketing
authorization of products containing tryptophan pending further investigation,
whereas others have withdrawn these products or restricted their use.
Общее описание
White powder with a flat taste. An essential amino acid; occurs in isomeric forms.
Реакции воздуха и воды
Slightly soluble in water.
Профиль реактивности
Amines are chemical bases. They neutralize acids to form salts plus water. These acid-base reactions are exothermic. The amount of heat that is evolved per mole of amine in a neutralization is largely independent of the strength of the amine as a base. Amines may be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. Flammable gaseous hydrogen is generated by amines in combination with strong reducing agents, such as hydrides.
Угроза здоровью
ACUTE/CHRONIC HAZARDS: When heated to decomposition L-Tryptophan emits toxic fumes.
Пожароопасность
Flash point data for L-Tryptophan are not available. L-Tryptophan is probably combustible.
Профиль безопасности
Moderately toxic by
intraperitoneal route. Experimental
teratogenic and reproductive effects. Human
mutation data reported. Questionable
carcinogen with experimental tumorigenic
data. When heated to decomposition it
emits toxic fumes of NOx.
Методы очистки
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.]
L(-)-триптофан препаратная продукция и сырье
сырьё
препарат