Reported in EPA TSCA Inventory. EPA Genetic Toxicology Program.

The IUPAC name of this chemical is Disodium 3-oxo-2-(3-oxo-5-sulfonato-1H-indol-2-ylidene)-1H-indole-5-sulfonate. The CAS registry number is 860-22-0 and the EINECS registry number is 212-728-8. In addition, the molecular formula is C₁₆H₁₀N₂Na₂O₈S₂ and the molecular weight is 466.35. It is also called 1H-Indole-5-sulfonicacid, 2-(1,3-dihydro-3-oxo-5-sulfo-2H-indol-2-ylidene)-2,3-dihydro-3-oxo-,sodium salt (1:2). What's more, it is a kind of purple powder and belongs to the classes of Analytical Chemistry; Food Colors by Food Sanitation Law in Japan; Indicator (pH); pH Indicators; Indicator SolutionsTitration; Indicators; Redox Indicators; Titration.

Physical properties about this chemical are: (1)ACD/LogP: 1.63; (2)# of Rule of 5 Violations: 1; (3)ACD/LogD (pH 5.5): -2.87; (4)ACD/LogD (pH 7.4): -2.87; (5)ACD/BCF (pH 5.5): 1; (6)ACD/BCF (pH 7.4): 1; (7)ACD/KOC (pH 5.5): 1; (8)ACD/KOC (pH 7.4): 1; (9)#H bond acceptors: 10; (10)#H bond donors: 4; (11)#Freely Rotating Bonds: 2; (12)Polar Surface Area: 166.12 Å².

Preparation and uses of Disodium 3-oxo-2-(3-oxo-5-sulfonato-1H-indol-2-ylidene)-1H-indole-5-sulfonate: it can be prepared by indigotin and concentrated sulfuric acid through stlfonation reaction. After the stlfonation reaction, go through the operation of dilution by water, neutralization by soda, salting out, filtering, washing, drying to get the products. In addition, it can be used as food coloring, antioxidant, reduction indicator and biological dye. And it can be used in the determination of renal function.

When you are using this chemical, please be cautious about it as the following:
This chemical is harmful if swallowed and irritating to eyes, respiratory system and skin. During using it, wear suitable protective clothing, gloves and eye/face protection and avoid contact with skin and eyes. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. In addition, you should not breathe dust. Take off immediately all contaminated clothing.

You can still convert the following datas into molecular structure:
(1)SMILES: [Na+].[Na+].[O-]S(=O)(=O)c3cc4C(=O)\C(=C2\C(=O)c1cc(ccc1N2)S([O-])(=O)=O)Nc4cc3
(2)InChI: InChI=1/C16H10N2O8S2.2Na/c19-15-9-5-7(27(21,22)23)1-3-11(9)17-13(15)14-16(20)10-6-8(28(24,25)26)2-4-12(10)18-14;;/h1-6,17-18H,(H,21,22,23)(H,24,25,26);;/q;2*+1/p-2/b14-13+;;
(3)InChIKey: KHLVKKOJDHCJMG-AKPRSONXBD

The toxicity data is as follows: