Cystine Disodium Salt Powder
As a salt of a dibasic amino acid, Cystine Disodium Salt exhibits typical amphoteric characteristics, with its ionization state closely dependent on the pH of the solution.
- In acidic conditions (pH < 3.0): The carboxylate anions (−COO−) accept protons and are converted back to carboxyl groups (−COOH). As the pH decreases, the solubility of the compound drops sharply, and free L-cystine precipitates out of the solution. This reaction is the basis for the industrial preparation of L-cystine from Cystine Disodium Salt—acidification with dilute hydrochloric acid or sulfuric acid triggers crystallization of L-cystine with high purity.
- In neutral to weakly alkaline conditions (pH 7.0–9.0): The compound exists stably as a zwitterion, with carboxylate groups in the anionic form and amino groups protonated to −NH3+. This is the most stable state for Cystine Disodium Salt in aqueous solutions, and it remains fully dissolved, making it suitable for formulating oral or injectable preparations.
- In strongly alkaline conditions (pH > 12.0, with heating): The disulfide bond is prone to cleavage under the action of strong bases (e.g., 40% NaOH solution), producing sodium cysteinate. Prolonged heating accelerates this hydrolysis reaction, which is a common method for preparing L-cysteine from Cystine Disodium Salt in the laboratory.
The isoelectric point (pI) of the corresponding free L-cystine is approximately 5.05, but Cystine Disodium Salt itself does not have a distinct isoelectric point due to its pre-ionized carboxylate groups; its solubility minimum occurs at pH close to the pI of L-cystine.
Send product request
Other supplier products
 |
L-Cysteine S-Sulfate Na Price | Density and Bulk Properties of L-Cysteine S-Sulfate Na Crystal density: The crystal density of the purified product is approximately 1.65–1.7... |
 |
N-Acetyl-L-Tryptophan Powder Manufacturer | N‑Acetyl‑L‑Tryptophan as Technical & Quality Specifications (Food Grade) Purity: ≥98% (food grade); ≥99% (pharma/functional food grade). ... |
 |
BOC-L-GLU(ME)-OME | BOC-L-GLU(ME)-OME (CAS is a protected amino acid building block, full name: N-(tert-Butoxycarbonyl)-L-glutamic acid dimethyl ester Also abbr... |
 |
Supply Phospho-L-Tyrosine Disodium Salt powder | Transportation Precautions of Phospho-L-Tyrosine Disodium SaltControl temperature during transportation: ship dry powder in an insulated container ... |
 |
High quality α-ketoglutaric acid | α-Ketoglutaric acid (often abbreviated as α-KG or 2-oxoglutarate) is an organic compound with the chemical formula C5H6O5. It is a key ... |
Same products
 |
Procaine | Seller: 862043 | CAS:59-46-1 |
 |
High Concentration Plastic Color Masterbatch Factory Direct Supply | Seller: 861445 | We are a professional color masterbatch manufacturer with years of R&D experience in plastic ... |
 |
Acid Ink Blue G Factory | Seller: TIANJIN LEADING IMPORT & EXPORT CO., LTD | Acid Ink Blue G Factory 【Application of Acid Ink Blue G 】 mainly used for making blue or ... |
 |
Acid Black ATT Factory | Seller: TIANJIN LEADING IMPORT & EXPORT CO., LTD | Acid Black ATT Factory 【What’s Acid Black ATT】 is made of acid black 10B and acid o... |
 |
Acid Black 10B Factory | Seller: TIANJIN LEADING IMPORT & EXPORT CO., LTD | Acid Black 10B Factory is mainly suitable for dyeing and printing wool ,silk and nylon fabri... |
