L-CYSTINE

PRODUCT IDENTIFICATION
CAS NO. 56-89-3

L-CYSTINE

EINECS NO. 200-296-3
FORMULA [-SCH2CH(NH2)CO2H]2
MOL WT. 240.30

H.S. CODE

 2922.49 
SMILES

 

TOXICITY

SYNONYMS Cysteine disulfide; Dicysteine; Cystine (L)-;
(2S,7S)-(-)-Cystine; (2S,7S)-(-)-Cystine; 3,3'-Dithiobis(2-aminopropionic acid); alpha-Diamino-beta-dithiolactic acid; Dicysteine; Cys-SCy; Cystine; L-(-)-3,3'-Dithio bis(2-aminopropanoic acid); L-alpha-Diamino-beta-dithiolactic acid; L-Dicysteine; L-(-)-cystine;

CLASSIFICATION

  

GENERAL DESCRIPTION OF CYSTINE

Cystine is a dimer of cysteine with disulphide bridge which is important in stabilizing the structure of proteins, and in the role of antioxidant.

PHYSICAL AND CHEMICAL PROPERTIES
PHYSICAL STATE White crystalline powder
MELTING POINT 258 - 261 C
BOILING POINT

 

SPECIFIC GRAVITY  
SOLUBILITY IN WATER Slightly soluble (insoluble in ethanol, ether. Dissolves in dilute hydrochloric acid)
pH  
VAPOR DENSITY

 

AUTOIGNITION

 

NFPA RATINGS

 Health: 2; Flammability: 0; Reactivity: 0

REFRACTIVE INDEX

  
FLASH POINT

 

STABILITY

Stable under ordinary conditions

APPLICATIONS
Pharmaceuticals; Nutrition supplements, Cosmetics;
SALES SPECIFICATION

APPEARANCE

 White crystalline powder

ASSAY

 98.5 - 101.0%
Specific rotation -2.15° ~ 22.5°

SOLUTION CLARITY

Pass

pH

 5.0 - 6.5 (1.0g/100ml)

Cl

0.02% max

NH4

0.02% max

SO4

0.02% max

Fe

20ppm max
HEAVY METALS

10ppm max
As 1ppm max

OTHER AMINO ACIDS

Pass
LOSS ON DRYING

0.2% max
RESIDUE ON IGNITION

0.1% max
TRANSPORTATION
PACKING
25kgs in fiber drum
HAZARD CLASS Not regulated
UN NO.  

GENERAL PROPERTIES OF AMINO ACIDS

Amino Acid

Abbreviation

Formula (Mol WT)

pK1

pK2

pKR

pI

Hydropathy Index

3-Letters

1-Letter

-COOH

-NH3+

R group
Alanine

Ala

A

 C3H7NO2 (89.09)

2.34

9.69

-

6.00

1.8
Arginine

Arg

R

 C6H14N4O2(174.20)

2.17

9.04

12.48

10.76

-4.5
Asparagine

Asn

N

 C4H8N2O3(132.12)

2.02

8.80

-

5.41

-3.5
Aspartic Acid

Asp

D

 C4H7NO4(133.10)

1.88

9.60

3.65

2.77

-3.5
Cysteine

Cys

C

 C3H7NO2S(240.30)

1.96

10.128

8.18

5.07

2.5
Glutamic Acid

Glu

E

 C5H9NO4(147.13)

2.19

9.67

4.25

3.22

-3.5
Glutamine

Gln

Q

 C5H10N2O3(146.15)

2.17

9.13

-

5.65

-3.5
Glycine

Gly

G

 C2H5O2(75.07)

2.34

9.60

-

5.97

-0.4
Histidine

His

H

 C6H9N3O2(155.16)

1.82

9.17

6.00

7.59

-3.2
Isoleucine

Ile

I

 C6H13NO2(131.18)

2.36

9.60

-

6.02

4.5
Leucine

Leu

L

 C6H13NO2(131.18)

2.36

9.60

-

5.98

3.8
Lysine

Lys

K

 C6H14N2O2(146.19)

2.18

8.95

10.53

9.74

-3.9
Methionine

Met

M

 C5H11NO2S(149.21)

2.28

9.21

-

5.74

1.9
Phenylalanine

Phe

F

 C9H11NO2(165.19)

1.83

9.13

-

5.48

2.8
Proline

Pro

P

 C5H9NO2(115.13)

1.99

10.60

-

6.30

1.6
Serine

Ser

S

 C3H7NO3(105.19)

2.21

9.15

-

5.58

-0.8
Threonine

Thr

T

 C4H9NO3(119.12)

2.09

9.10

-

5.60

-0.7
Tryptophan

Trp

W

 C11H10N2O2(204.23)

2.83

9.39

-

5.89

-0.9
Tyrosine

Tyr

Y

 C9H11NO3(181.19)

2.20

9.11

10.07

5.66

-1.3
Valine

Val

V

 C5H11NO2(117.15)

2.32

9.62

-

5.96

4.2