Name | L-Cystine |
Synonyms | Cystine L-Cystine 1-cystine Dicysteine (H-Cys-OH)2 H-(Cys)_2-OH L-Cystine,food grade 3,3'-Dithiodialanine 3,3'-dithiobis-l-alanin Alanine, 3,3'-dithiobis- (H-Cys-OH)2 (Disulfide bond) L-Cystine, synthetically derived 3,3'-dithiobis(2-aminopropanoicacid) 3,3'-Dithiobis(2-aminopropanoic acid) (-)-3,3-Dithiobis(2-aminopropionic acid) L(-)-3,3-Dithiobis(2-aminopropanoic acid) (r-(r*,r*))-3,3'-dithiobis(2-aminopropanoicacid) 3,3'-dithiobis(2-amino-,(r-(r*,r*))-propanoicaci (2R,2'S)-3,3'-disulfanediylbis(2-ammoniopropanoate) 2-Amino-3-[(2-amino-2-carboxyethyl)dithio]propanoic acid |
CAS | 56-89-3 24645-67-8 |
EINECS | 200-296-3 |
InChI | InChI=1/C3H6NO2S3/c5-3(6)2(4-7)1-9-8/h2H,1,4H2,(H,5,6) |
InChIKey | LEVWYRKDKASIDU-IMJSIDKUSA-N |
Molecular Formula | C6H12N2O4S2 |
Molar Mass | 240.3 |
Density | 1.68 |
Melting Point | >240 °C (dec.) (lit.) |
Boling Point | 468.2±45.0 °C(Predicted) |
Specific Rotation(α) | -224 º(c=2 in 1M HCl) |
Water Solubility | 0.112 g/L (25 ºC) |
Solubility | Very slightly soluble in water; insoluble in ethanol and other organic solvents, easily soluble in dilute acids and alkaline liquids, and easily decomposed in hot lye |
Appearance | White crystal |
Color | White |
Merck | 14,2782 |
BRN | 1728094 |
pKa | 1.0, 2.1, 8.02, 8.71(at 25℃) |
Storage Condition | 2-8°C |
Stability | Stable. Incompatible with strong oxidizing agents. |
Sensitive | Sensitive to light |
Refractive Index | -222.5 ° (C=1, 1mol/ |
MDL | MFCD00064228 |
Physical and Chemical Properties | Properties white hexagonal plate-like crystals or white crystalline powder. soluble in dilute acid and alkali solution, extremely difficult to dissolve in water, insoluble in ethanol. |
Use | Used in medicine, food, cosmetics and other industries |
Risk Codes | R36/37/38 - Irritating to eyes, respiratory system and skin. R22 - Harmful if swallowed |
Safety Description | S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36 - Wear suitable protective clothing. S24/25 - Avoid contact with skin and eyes. |
UN IDs | 2811 |
WGK Germany | 3 |
RTECS | HA2690000 |
TSCA | Yes |
HS Code | 29309014 |
Hazard Note | Irritant |
Packing Group | III |
Raw Materials | Charcoal Sodium hydroxide Hydrochloric acid |
Reference Show more | 1. Hou Lijuan, Yan Chao, Qi Xiaoru, Wang Min. Study on the aroma difference of jujube wine produced by different varieties of jujube [J]. Food industry 2017(5):208-212. 2. Yan Chao, Hou Lijuan, Qi Xiaoru, etc. Analysis on the changes of amino acids and organic acids in fermented grains during the fermentation process of jujube and Brandy [J]. Science and Technology of food industry, 2017, 38(014):121-125. 3. Wang Tingting, Changyu steel, Changpu, Zhao Yan, he Zhongmei, Zhu Hongyan, Zhang Lianxue. Changes of main components of compound mailuqi ginseng preparation and its anti-tumor effect in H22 tumor-bearing mice [J]. Journal of Jilin University (Medicine edition),2017,43(04):698-704 858-859. 4. Zhao, Zheng, et al. "Cholinium amino acids-glycerol mixtures: New class of solutions for pretreating wheat straw to facilitate enzymatic hydrolysis." Bioresource technology 245 (2017): 625-632.https://doi.org/10.1016/j.biortech.2017.08.209 5. [IF=4.952] Fengfeng Qu et al."Effect of different drying methods on the sensory quality and chemical components of black tea."Lwt Food Sci Technol. 2019 Jan;99:112 |
of hydrochloric acid with a concentration of 10 mol/L was added to the hydrolysis tank, heated to 70~80 °c, quickly put in 100 of human hair or pig hair, and then heated to °c, and 1~1. Within 5h temperature to 110~117 deg C, hydrolysis of 6.5~7H (from 100 deg C), cooling, filtration. The filtrate was added with 30% ~ 40% industrial sodium hydroxide solution under stirring. When the pH value reached 3.0, the alkali solution was decelerated and added until the pH value was 4.8, that is to get the cystine crude product (work), the mother liquor contains glutamic acid, arginine and leucine. Weigh the crude cystine (1) 150kg, add about 90kg of 10 mol/L hydrochloric acid, 360kg of water, heat to 65~70 °c, stir and dissolve 0. 5h, then add activated carbon 12kg, heating to 80~90 degrees Celsius, heat preservation 0. 5h, Plate and Frame pressure filtration. The filtrate was heated to 80-85 °c and 30% sodium hydroxide was added with stirring until the pH was stopped at 4.8. The mixture was allowed to stand, and the crystals were precipitated. The supernatant liquid was sipped, and the precipitate was separated from the bottom, and then centrifuged and dried to obtain cystine crude product (II). Weigh the crude cystine (II) lOOkg, add 1 mol/L hydrochloric acid 500L, heat to 70 ° C., and add 3-5kg of activated carbon. Then, the temperature was raised to 85 °c, and the mixture was stirred for 0.5h, followed by plate-and-frame pressure filtration. The filtrate was added with distilled water about 1.5 times the volume of the filtrate, heated to 75-80 ° C., and neutralized with 12% aqueous ammonia under stirring to pH 3.5-4.0, at which point cystine crystallized out. Centrifugal spin drying of crystallization, washing with distilled water to no chloride ion, and vacuum drying to obtain cystine finished product. The yield of human hair was 8%, and the yield of pig hair was 5%.