Indigo Carmine

Indigo carmine is an indigoid dye and a redox indicator. Upon reduction, indigo carmine shifts from blue to yellow with absorbance maxima of 610 and 407 nm, respectively. Formulations containing indigo carmine have been used as color additives in food and pharmaceutical preparations.Formal Name: 2-(1,3-dihydro-3-oxo-5-sulfo-2H-indol-2-ylidene)-2,3-dihydro-3-oxo-1H-indole-5-sulfonic acid, disodium salt. CAS Number: 860-22-0. Synonyms: Acid Blue 74, FD and C Blue 2, C.I. 73015, C.I. 75781, indigo disulfonate, Indigotine. Molecular Formula: C16H8N2O8S2 . 2Na. Formula Weight: 466.4. Purity: >70%. Formulation: (Request formulation change), A crystalline solid. Solubility: DMF: slightly soluble, DMSO: 1 mg/ml, PBS (pH 7.2): 10 mg/ml. lambdamax: 252, 287, 600 nm. SMILES: O=C1C2=CC(S([O-])(=O)=O)=CC=C2N/C1=C3NC4=CC=C(S([O-])(=O)=O)C=C4C\3=O.[Na+].[Na+]. InChi Code: InChI=1S/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-,,. InChi Key: KHLVKKOJDHCJMG-HLBFIJABSA-L.