L-Leucine Property

Melting point:

>300 °C (lit.)

alpha 

15.4 º (c=4, 6N HCl)

Boiling point:

122-134 °C(Press: 2-3 Torr)

Density 

1,293 g/cm³

vapor pressure 

<1 hPa (20 °C)

refractive index 

1.4630 (estimate)

FEMA 

3297 | L-LEUCINE

Flash point:

145-148°C

storage temp. 

2-8°C

solubility 

1 M HCl: 50 mg/mL

form 

powder

pka

2.328(at 25℃)

color 

White to Off-white

Odor

at 100.00?%. odorless

PH

5.5-6.5 (20g/l, H2O, 20℃)

optical activity

[α]20/D +15.5°, c = 2 in 6 M HCl

Water Solubility 

22.4 g/L (20 C)

λmax

λ: 260 nm Amax: 0.05
λ: 280 nm Amax: 0.05

JECFA Number

1423

Sublimation 

145-148 ºC

Merck 

14,5451

BRN 

1721722

Stability:

Stability Moisture and light sensitive. Incompatible with strong oxidising agents.

LogP

0.80

CAS DataBase Reference

61-90-5(CAS DataBase Reference)

NIST Chemistry Reference

Leucine(61-90-5)

EPA Substance Registry System

L-Leucine (61-90-5)

Safety

Safety Statements 

24/25

WGK Germany 

3

RTECS 

OH2850000

TSCA 

Yes

HS Code 

29224995

Hazardous Substances Data

61-90-5(Hazardous Substances Data)

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P271Use only outdoors or in a well-ventilated area.

P280Wear protective gloves/protective clothing/eye protection/face protection.

L-Leucine Chemical Properties,Usage,Production

description

L-leucine is one of the eight essential amino acids, and belonging to the aliphatic amino acids within twenty kinds of proteins. L-leucine and L-isoleucine and L-valine are called three branched chain amino acids. L-leucineLeucine and D-leucine are enantiomers . It is a white shiny hexahedral crystal or white crystalline powder at room temperature , Odorless, slightly bitter . In the presence of hydrocarbons ,it is stable in the aqueous mineral acid. Per gram is dissolved in 40ml water and about 100ml acetic acid. Very slightly soluble in ethanol or ether, dissolved in formic acid, dilute hydrochloric acid, a solution of alkali hydroxides and a solution of carbonates.
L-leucine can promote insulin secretion, can lower blood sugar; promote sleep, reduce sensitivity to pain, migraine headaches, anxiety and ease tension, reduce symptoms of chemical reactions disorder in the body caused by alcohol , and helps control alcoholism; it has a role in the treatment of dizziness , also can promote skin wound and bone healing, so doctors usually advise patients to take leucine supplements after surgery. amino acid infusion and comprehensive amino acid preparations are often formulated to be used in the treatment or health care; also be used as food, cosmetics and feed additives and plant growth promoter.
The best food sources of leucine include brown rice, beans, meat, nuts, soy flour, and whole wheat. Excessive intake can also cause side effects, high intake can cause pellagra, vitamin A deficiency, dermatitis, diarrhea, mental disorders and other issues,which needs to be paid attention to . Diet containing too much leucine will increase the number of ammonia in the body and destroy the liver and kidney function. Therefore, patients with impaired liver or kidney function should not be excessive intake, otherwise it will exacerbate the condition.

Chemical Properties

White shiny hexahedral crystals or white crystalline powder. Slightly bitter (DL-leucine is sweet). Sublimation at 145~148 ℃. Melting point 293~295 ℃ (decomposition). It belongs to the essential amino acids,and adult men requirement is 2.2g/d (151 version). It is necessary in normal growth for infants and maintaining normal nitrogen balance for adults.
Natural products are found in the spleen, heart, etc., and are present in a variety of plant and animal tissues in the form of the proteins, free out after decomposition and corruption.

Uses

Amino acid drugs. Used as amino acid infusion and comprehensive amino acid preparations. For the diagnosis and treatment of children with idiopathic high blood sugar and glucose metabolism disorders,bile liver disease associated with reduced secretion , anemia, poisoning, muscular dystrophy, poliomyelitis, neuritis and mental illness. Diabetes, cerebral vascular sclerosis and kidney disease associated with proteinuria and hematuria is contraindicated. Gastric and duodenal ulcer patients should not be served.
The product is used as a nutritional supplement,an amino acid infusion preparation and a comprehensive amino acid preparation,a hypoglycemic agent, a plant growth promoter.The product can be used as a spice according to GB 2760-8 .

toxicity

Safe for food (FDA, §172.3202000).
LD505379mg/kg (rat, subcutaneously).

Description

Small, white, lustrous plates, or a white, crystalline powder, with a slightly bitter taste. One g dissolves in about 40 mL of water and in about 100 mL of acetic acid. It is sparingly soluble in alcohol, but is soluble in dilute hydrochloric acid and in solutions of alkali hydroxides and carbonates. ι-Leucine may be synthesized by bromination, followed by amination of isocaproic acid; via the acetamidomalonic ester; by isolation from gluten, casein, keratin; from hydantoin.

Chemical Properties

L-Leucine is odorless and has a slightly bitter taste. L-Leucine is a branched-chain, essential amino acid that stimulates muscle protein synthesis.

Chemical Properties

Leucine occurs as a white or almost off-white crystalline powder or shiny flakes.

Occurrence

Reported found as a constituent in proteins; also present in the free state in the human body

Uses

L-Leucine plays a vital role in hemoglobin formation, protein synthesis and metabolic functions. It assists the growth and repair of muscle and bone tissue. It is used in the treatment of amyotrophic lateral sclerosis - Lou Gehrig's disease. It prevents the breakdown of muscle proteins after trauma or severe stress and may be beneficial for individuals with phenylketonuria. It is also used as a food additive and flavor enhancer. Further, it is used to preserve muscle glycogen.

Uses

L-Leucine is an essential amino acid. It is also considered to be a branched chain amino acid, along with L-Isoleucine and L-Valine. It is used as a cell culture media component in the commercial biomanufacture of therapeutic recombinant proteins and monoclonal antibodies.

Uses

L-Leucine is an essential amino acid. L-Leucine acts as a nutrient signal to stimulate protein synthesis. It has also activates the mammalian target of rapamycin kinase that regulates cell growth.

Definition

ChEBI: The L-enantiomer of leucine.

Preparation

By bromination followed by amination of isocaproic acid; via the acetamidomalonic ester; by isolation from gluten, casein, keratin; from hydantoin.

Production Methods

Leucine is produced microbially by incubating an amino-acidproducing microorganism including but not exclusive to Pseudomonas, Escherichia, Bacillus, or Staphylococcus in the presence of oxygen and a hydrocarbon. The nutrient medium should contain an inhibitory amount of a growth inhibitor that is a chemically similar derivative of leucine (e.g. methylallylglycine, a-hydrozinoisocaproic acid, or b-cyclopentanealanine) to inhibit the growth of the organism except for at least one mutant that is resistant to the inhibitory effect. The resistant mutant is then isolated and grown in the presence of oxygen and the hydrocarbon in the absence of the inhibitor. The mutant cells are then harvested and a nutrient medium is formed that includes a hydrocarbon as the sole source of carbon. Finally, the harvested cells are incubated in the medium in the presence of oxygen.

Pharmaceutical Applications

Leucine is used in pharmaceutical formulations as a flavoring agent. It has been used experimentally as an antiadherent to improve the deagglomeration of disodium cromoglycate micro-particles and other compounds in inhalation preparations; and as a tablet lubricant. Leucine copolymers have been shown to successfully produce stable drug nanocrystals in water.

Biochem/physiol Actions

Leucine is a non-glucogenic, essential amino acid. It is a branched-chain amino acid that is a structural component of proteins. Leucine positively influences insulin release to eliminate toxic sugars out of the blood. The degradation of leucine leads to the formation of ketone bodies.

Safety

Leucine is an essential amino acid and is consumed as part of a normal diet. It is generally regarded as a nontoxic and nonirritant material. It is moderately toxic by the subcutaneous route.
LD50 (rat, IP): 5.379 g/kg

storage

Leucine is sensitive to light and moisture, and should be stored in an airtight container in a cool, dark, dry place.

Purification Methods

Likely impurities are isoleucine, valine, and methionine. Crystallise L-leucine from water by adding 4 volumes of EtOH. It sublimes at 180-188o/0.3mm with 99.1% recovery, and unracemised [Gross & Gradsky J Am Chem Soc 77 1678 1955]. [Greenstein & Winitz The Chemistry of the Amino Acids J. Wiley, Vol 3 p 2075-2094 1961, Kameda et al. J Pharm Soc Jpn 78 763 1958, Beilstein 4 IV 2738.]

Incompatibilities

Leucine is incompatible with strong oxidizing agents.

Regulatory Status

Included in the FDA Inactive Ingredients Database (IV infusion; oral tablets). Included in nonparenteral medicines licensed in the UK.