L-Phenylalanine Property

Melting point:

270-275 °C (dec.)(lit.)

alpha 

-34.1 º (c=2, water, dry basis)

Boiling point:

293.03°C (rough estimate)

Density 

1.29

vapor pressure 

<1 Pa (25 °C)

FEMA 

3585 | L-PHENYLALANINE

refractive index 

-34 ° (C=2, H2O)

storage temp. 

Store below +30°C.

solubility 

H₂O: 0.1 M at 20 °C, clear, colorless

form 

powder

pka

2.2(at 25℃)

color 

White to off-white

PH

5.0-7.0 (25℃, 0.1M in H2O)

Odor

at 100.00 %. odorless

Odor Type

odorless

optical activity

[α]25/D -34.2°, c = 2 in H2O (dried basis)

Water Solubility 

1-5 g/100 mL at 25 ºC

Merck 

14,7271

JECFA Number

1428

BRN 

1910408

Stability:

Stable. Incompatible with strong oxidizing agents.

InChIKey

COLNVLDHVKWLRT-QMMMGPOBSA-N

LogP

0.24

CAS DataBase Reference

63-91-2(CAS DataBase Reference)

NIST Chemistry Reference

L-Phenylalanine(63-91-2)

EPA Substance Registry System

L-Phenylalanine (63-91-2)

Safety

Hazard Codes 

C

Risk Statements 

36/37/38-34

Safety Statements 

22-24/25-37/39-45-36/37/39-27-26

WGK Germany 

3

RTECS 

AY7535000

F 

10

TSCA 

Yes

HS Code 

29224995

Hazardous Substances Data

63-91-2(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

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

L-Phenylalanine Chemical Properties,Usage,Production

Description

Phenylalanie is an essential amino acid and it is the precursor of the amino acid tyrosine. The body cannot make phenylalanie but it needs phenylalanie to produce proteins. Thus, human needs to obtain phenylalanie from food. 3 forms of phenylalanie are found in the nature: D-phenylalanine, L-phenylalanine, and DL-phenylalanine. Among these three forms, L-phenylalanine is the natural form found in most foods that containing proteins, including beef, poultry, pork, fish, milk, yogurt, eggs, cheeses, soy products, and certain nuts and seeds. The form of phenylalanine determines its application. It is suggested that L-phenylalanine can strengthen the effect of UVA radiation for people with vitiligo, in which L-phenylalanine may lead to darkening or repigmentation of the white patches, particularly on the face. The neurotransmitters L-phenylalanine affects help reduce hunger, improve memory, lessen the symptoms of ADHD and Parkinson's disease, and ease chronic pain, according to the UMMC research. Thus, L-phenylalanine is used in the manufacture of food and drink products and sold as a nutritional supplement for its reputed analgesic and antidepressant effects. L-phenylalanine is also suggested as an intermediate for anti-cancer drugs. A few small studies showed promise using L-Phenylalanine to manage alcohol withdrawal and ease PMS symptoms. It is also used in artificial sweeteners such as aspartame.

References

[1] http://www.umm.edu/health/medical/altmed/supplement/phenylalanine
[2] Xueqin Song , Philip L. Lorenzi , Christopher P. Landowski , Balvinder S. Vig , John M. Hilfinger , Gordon L. Amidon (2005) Amino Acid Ester Prodrugs of the Anticancer Agent Gemcitabine:? Synthesis, Bioconversion, Metabolic Bioevasion, and hPEPT1-Mediated Transport, 2, 157-167.

Chemical Properties

L-Phenylalanine has no odor and a slight bitter taste. It melts with decomposition at about 283°C. The pH of a 1 in 100 solution is between 5.4 and 6.0. FEMA notes this chemical is used in cocoa substitute only.

Chemical Properties

White crystalline powder

Occurrence

Reported found in white bread, macaroni, egg noodles, corn flakes, corn grits, oatmeal, wheat bran, wheat flakes, shredded wheat, barley, brown rice, rye flour, whole grain wheat flour, buttermilk, blue cheese, cheddar cheese, cottage cheese, cream cheese, parmesan cheese, bacon, cured ham, frankfurters, pork sausage, canned red kidney beans, canned sweet corn, canned peas, canned lima beans, canned potatoes, canned asparagus, canned snap beans, canned beets, beef, lamb, fresh ham, veal round, beef liver, chicken, chicken liver, turkey and other natural sources.

Uses

L-Phenylalanine is an essential amino acid. L-Phenylalanine is biologically converted into L-tyrosine, another one of the DNA-encoded amino acids, which in turn is converted to L-DOPA and further conv erted into dopamine, norepinephrine, and epinephrine. L-Phenylalanine is produced for medical, feed, and nutritional applications such as in the preparation of Aspartame.

Uses

phenylalanine is a conditioning agent with greater application in hair care than in skin care preparations. It is also used in suntan products.

Uses

L-phenylalanine is an amino acid used as a skin-conditioning agent. It has greater use in hair care than in skin care products.

Definition

ChEBI: The L-enantiomer of phenylalanine.

Preparation

From PTS-negative Escherichia coli bioengineered strains.

Production Methods

In previous large-scale production processes for L-phenylalanine two enzymatic methods were applied: 1. Resolution of N-acetyl-D,L-phenylalanine by carrier-fixed microbial acylase: This process provided pharmaceutical-grade L-phenylalanine, but suffered from the disadvantage that the D-enantiomer had to be racemized and recycled. 2. Stereoselective and enantioselective addition of ammonia to trans-cinnamic acid, catalyzed by L-phenylalanine ammonia lyase (PAL, EC 4.3.1.5): PAL-containing Rhodotorula rubra was used in an industrial process to supply L-phenylalanine for the first production campaign of the sweetener aspartame. When continuously operated in an immobilized whole cell reactor, the bioconversion reached concentration up to 50 g/L Lphenylalanine at a conversion of about 83%. Other processes started from phenylpyruvate with L-aspartic acid as amine donor using immobilized cells of Escherichia coli or from a-acetamidocinnamic acid and immobilized cells of a Corynebacterium equi strain. In both cases L-phenylalanine concentrations up to 30 g/L and more (molar yields as high as at least 98 %) were reached.
However, fermentation processes based on glucose-consuming L-phenylalanine overproducing ;mutants of E. coli and coryneform strains turned out to be more economical. L-Phenylalanine is formed in ten enzymatic steps starting from erythrose-4-phosphate and phosphoenolpyruvate. A suitable profile of the specific glucose feed rate prevents acetate formation and leads to improved L-phenylalanine production with a final concentration up to 46 g/L and a corresponding yield of 18 %.
L-Phenylalanine is recovered from the fermentation broth either by two-step crystallization or by an ionexchange resin process. The preferred cell separation technique is ultrafiltration; and the filtrates may be treated with activated carbon for further purification. Instead of ion-exchange resins nonpolar, highly porous synthetic adsorbents are recommended to remove impurities. An alternative process in which a cell separator is integrated in the fermentation part, thus allowing cell recycling, was suggested for L-phenylalanine production and may lead to prospective developments.

Synthesis Reference(s)

Canadian Journal of Chemistry, 29, p. 427, 1951 DOI: 10.1139/v51-051
The Journal of Organic Chemistry, 30, p. 3414, 1965 DOI: 10.1021/jo01021a035
Tetrahedron Letters, 26, p. 2449, 1985 DOI: 10.1016/S0040-4039(00)94850-0

General Description

Odorless white crystalline powder. Slightly bitter taste. pH (1% aqueous solution) 5.4 to 6.

Air & Water Reactions

Water soluble. Aqueous solutions are weak acids.

Reactivity Profile

L-Phenylalanine may be light sensitive. Act as weak acids in solution.

Health Hazard

ACUTE/CHRONIC HAZARDS: When heated to decomposition L-Phenylalanine emits toxic fumes of nitrogen oxides.

Fire Hazard

Flash point data for L-Phenylalanine are not available; however, L-Phenylalanine is probably combustible.

Biochem/physiol Actions

L-Phenylalanine is an essential amino acid. It is significantly involved in the synthesis of neurotransmitters such as dopamine, epinephrine, norepinephrine, l-DOPA (Dihydroxyphenylalanine), melanin and thyroxine. L-Phenylalanine metabolism also results in phenylethylamine, that brings about effect of a stimulant in the brain and enhances mood.

Safety Profile

Mildly toxic by intraperitoneal route. An experimental teratogen. Experimental reproductive effects. Human mutation data reported. When heated to decomposition it emits toxic fumes of NOx.

Purification Methods

Likely impurities are leucine, valine, methionine and tyrosine. Crystallise L-phenylalanine from water by adding 4volumes of EtOH. Dry it in vacuo over P2O5. Also crystallise it from saturated refluxing aqueous solutions at neutral pH, or 1:1 (v/v) EtOH/water solution, or conc HCl. It sublimes at 176-184o/0.3mm with 98.7% recovery and unracemised [Gross & Gradsky J Am Chem Soc 77 1678 1955]. [Greenstein & Winitz The Chemistry of the Amino Acids J. Wiley, Vol 3 pp 2156-2175 1961, Beilstein 14 IV 1552.]