Compound: RESAZURIN
SMILES: O=c1cc-2oc3c(ccc(c3)O)[n+](c2cc1)[O-]
InChIKey: PLXBWHJQWKZRKG-UHFFFAOYSA-N
Synonyms: RESAZURIN, 550-82-3, Diazoresorcinol, Azoresorcin, Resazoin, Resazurine, 7-Hydroxy-3H-phenoxazin-3-one 10-oxide, 3H-Phenoxazin-3-one, 7-hydroxy-, 10-oxide, RHODALUX, DTXSID4060280, 1FN9YD6968, NSC-10438, NSC-56323, 7-hydroxy-10-oxido-phenoxazin-10-ium-3-one, reazurin, reazurine, Alamarblue, RefChem:178890, DTXCID3041823, 208-987-1, Alamar blue, 7-Hydroxy-3-oxo-3H-phenoxazine 10-oxide, 7-hydroxy-10-oxidophenoxazin-10-ium-3-one, 153796-08-8, 3H-Phenoxazin-3-one, 10-oxide, WLN: T C666 BN FV IOJ BO LQ, EINECS 208-987-1, NSC 10438, BRN 0221382, UNII-1FN9YD6968, 3H-Phenoxazin-3-one,7-hydroxy-, 10-oxide, 7-Hydroxy-3H-fenoxazin-3-on-10-oxid [Czech], PLXBWHJQWKZRKG-UHFFFAOYSA-N, MFCD00066739, 7-Hydroxy-3H-fenoxazin-3-on-10-oxid, RESAZURIN [MI], MolMap_000044, SCHEMBL6338, 7-hydroxy-3-oxo-3H-phenoxazin-10-ium-10-olate, 4-27-00-03594 (Beilstein Handbook Reference), CHEBI:8806, orb1685453, SCHEMBL1502340, CHEMBL1616414, SCHEMBL29370889, GLXC-04913, NSC10438, NSC56323, FR11890, 7-Hydroxy-3-oxo-3H-phenoxazine10-oxide, BS-28553, DA-49598, NCI60_000106, HY-118540, CS-0066314, NS00021208, D84267, 7-HYDROXY-3H-PHENOXAZINE-3-ONE 10-OXIDE, Q409628, 7-Hydroxy-10-oxo-3H-10lambda~5~-phenoxazin-3-one
Theoretical properties:
molecular_formula: C12H7NO4
molecular_weight: 229.19 g/mol
exact_mass: 229.03750770 g/mol
formal_charge: 0
hydrogen_bond_donor_count: 1
hydrogen_bond_acceptor_count: 4
rotatable_bond_count: 0
heavy_atom_count: 17
topological_polar_surface_area: 75.3 Å²
isotope_atom_count: 0
covalently_bonded_unit_count: 1
Physical properties:
Descriptions:
pubchem: Resazurin is a phenoxazine.
chembl: RESAZURIN is a small molecule listed in the ChEMBL database but has not progressed to an approved clinical phase.
wikipedia: Resazurin (7-Hydroxy-3H-phenoxazin-3-one 10-oxide) is a phenoxazine dye that is weakly fluorescent, nontoxic, cell-permeable, and redox‐sensitive. Resazurin has a blue to purple color above pH 6.5 and an orange color below pH 3.8. It is used in microbiological, cellular, and enzymatic assays because it can be irreversibly reduced to the pink-colored and highly fluorescent resorufin (7-Hydroxy-3H-phenoxazin-3-one). At circum-neutral pH, resorufin can be detected by visual observation of its pink color or by fluorimetry, with an excitation maximum at 530-570 nm and an emission maximum at 580-590 nm.
When a solution containing resorufin is submitted to reducing conditions (Eh < -110 mV), almost all resorufin is reversibly reduced to the translucid non-fluorescent dihydroresorufin (also known as hydroresorufin) and the solution becomes translucid (the redox potential of the resorufin/dihydroresorufin pair is -51 mV vs. standard hydrogen electrode at pH 7.0). When the Eh of this same solution is increased, dihydroresorufin is oxidized back to resorufin, and this reversible reaction can be used to monitor if the redox potential of a culture medium remains at a sufficiently low level for anaerobic organisms.

Resazurin solution has one of the highest values known of Kreft's dichromaticity index. This means that it has a large change in perceived color hue when the thickness or concentration of observed sample increases or decreases.
Usually, resazurin is available commercially as the sodium salt.