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Substance Name: Congo red [USP]
RN: 573-58-0
UNII: 3U05FHG59S
InChIKey: IQFVPQOLBLOTPF-HKXUKFGYSA-L

Note

  • An acid dye used in testing for hydrochloric acid in gastric contents. It is also used histologically to test for AMYLOIDOSIS.

Molecular Formula

  • C32-H24-N6-O6-S2.2Na

Molecular Weight

  • 696.674
 

Classification Codes

  • Coloring Agents
  • Drug / Therapeutic Agent
  • Human Data
  • Mutation Data
  • Reproductive Effect
  • Skin / Eye Irritant
  • TSCA Flag S (Substance is Identified in a Proposed or Final SNUR (Significant New Use Rule) under TSCA)
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Names and Synonyms

Name of Substance

  • C.I. Direct Red 28
  • Congo red
  • Congo red [USP]

MeSH Heading

  • Congo red

Synonyms

  • 1-Naphthalenesulfonic acid, 3,3'-((1,1'-biphenyl)-4,4'-diylbis(azo))bis(4-amino-, disodium salt
  • AI3-63036
  • Atlantic Congo Red
  • Atul Congo Red
  • Azocard Red Congo
  • Benzo Congo Red
  • Brasilamina congo 4B
  • C.I. 22120
  • C.I. Direct Red 28
  • C.I. Direct Red 28, disodium salt
  • CCRIS 2277
  • Cerven kongo
  • Cerven kongo [Czech]
  • Cerven prima 28
  • Cerven prima 28 [Czech]
  • Congazone sodium
  • Congo red
  • Congo Red 4B
  • Congo Red 4BX
  • Congo Red CR
  • Congo Red H
  • Congo Red ICI
  • Congo Red L
  • Congo Red M
  • Congo Red N
  • Congo Red R
  • Congo Red W
  • Congo Red WS
  • Cotton Red 4BC
  • Cotton Red 5B
  • Cotton Red L
  • Diacotton Congo Red
  • Direct Red 28
  • Direct Red C
  • Direct Red DC-CF
  • Direct Red K
  • EINECS 209-358-4
  • Erie Congo 4B
  • Haemomedical
  • Haemonorm
  • Hemorrhagyl
  • Hispamin congo 4B
  • HSDB 4225
  • Kayaku Congo Red
  • Kongorot
  • Kongorot [German]
  • Mitsui Congo Red
  • Natrium-salz der diphenyl-bis-azo-bis-naphthylamin-4-sulfonsaeure
  • Natrium-salz der diphenyl-bis-azo-bis-naphthylamin-4-sulfonsaeure [German]
  • NSC 56651
  • NSC 7232
  • Peeramine Congo Red
  • Red K
  • Sodium diphenyldiazo-bis(alpha-naphthylaminesulfonate)
  • Solucongo
  • Sugai Congo Red
  • Tertrodirect Red C
  • Trisulfon Congo Red
  • UNII-3U05FHG59S
  • Vondacel Red CL

Systematic Names

  • 1-Naphthalenesulfonic acid, 3,3'-((1,1'-biphenyl)-4,4'-diylbis(2,1-diazenediyl))bis(4-amino-, sodium salt (1:2)
  • 1-Naphthalenesulfonic acid, 3,3'-((1,1'-biphenyl)-4,4'-diylbis(azo))bis(4-amino-, disodium salt
  • 1-Naphthalenesulfonic acid, 3,3'-(4,4'-biphenylenebis(azo))bis(4-amino-, disodium salt
  • C.I. Direct Red 28
  • C.I. Direct Red 28, disodium salt (8CI)
  • Disodium 3,3'-((1,1'-biphenyl)-4,4'-diylbis(azo))bis(4-aminonaphthalene-1-sulphonate)

Registry Numbers

CAS Registry Number

  • 573-58-0

FDA UNII

  • 3U05FHG59S

Other Registry Numbers

  • 1000818-40-5
  • 550-08-3
  • 70248-72-5
  • 87440-95-7

System Generated Number

  • 0000573580

Molecular Formulas

Molecular Formula

  • C32-H24-N6-O6-S2.2Na

Molecular Formula Fragments

  • C32-H24-N6-O6-S2
  • COMPONENT
  • Na

Structure Descriptors

InChI

1S/C32H24N6O6S2.2Na/c33-31-25-7-3-1-5-23(25)29(45(39,40)41)17-27(31)37-35-21-13-9-19(10-14-21)20-11-15-22(16-12-20)36-38-28-18-30(46(42,43)44)24-6-2-4-8-26(24)32(28)34;;/h1-18H,33-34H2,(H,39,40,41)(H,42,43,44);;/q;2*+1/p-2/b37-35+,38-36+;;

InChIKey

IQFVPQOLBLOTPF-HKXUKFGYSA-L

Smiles

c12c(c(c(\N=N\c3ccc(c4ccc(\N=N\c5c(c6c(cccc6)c(c5)S(=O)(=O)[O-])N)cc4)cc3)cc1S(=O)(=O)[O-])N)cccc2.[Na+].[Na+]

Toxicity

Organism Test Type Route Reported Dose (Normalized Dose) Effect Source
cat LDLo intravenous 100mg/kg (100mg/kg) BEHAVIORAL: SOMNOLENCE (GENERAL DEPRESSED ACTIVITY)

LUNGS, THORAX, OR RESPIRATION: CHRONIC PULMONARY EDEMA

BLOOD: CHANGE IN CLOTTING FACTORS		 American Journal of the Medical Sciences. Vol. 198, Pg. 73, 1939.
man LDLo intravenous 1429ug/kg (1.429mg/kg) BLOOD: CHANGE IN CLOTTING FACTORS

LUNGS, THORAX, OR RESPIRATION: DYSPNEA

BEHAVIORAL: CONVULSIONS OR EFFECT ON SEIZURE THRESHOLD		 Deutsche Medizinische Wochenschrift. Vol. 89, Pg. 1845, 1964.
man LDLo oral 143mg/kg (143mg/kg) VASCULAR: OTHER CHANGES "Toxicology of Drugs and Chemicals," Deichmann, W.B., New York, Academic Press, Inc., 1969Vol. -, Pg. 185, 1969.
mouse LDLo intravenous 250mg/kg (250mg/kg)   Journal of Immunology. Vol. 68, Pg. 53, 1952.
pigeon LDLo intravenous 120mg/kg (120mg/kg) LUNGS, THORAX, OR RESPIRATION: CHRONIC PULMONARY EDEMA

BEHAVIORAL: SOMNOLENCE (GENERAL DEPRESSED ACTIVITY)

BLOOD: CHANGE IN CLOTTING FACTORS		 American Journal of the Medical Sciences. Vol. 198, Pg. 73, 1939.
rabbit LDLo intravenous 230mg/kg (230mg/kg) BLOOD: CHANGE IN CLOTTING FACTORS

LUNGS, THORAX, OR RESPIRATION: CHRONIC PULMONARY EDEMA

BEHAVIORAL: SOMNOLENCE (GENERAL DEPRESSED ACTIVITY)		 American Journal of the Medical Sciences. Vol. 198, Pg. 73, 1939.
rabbit LDLo oral 6gm/kg (6000mg/kg)   Office of Toxic Substances Report. Vol. OTS,
rabbit LDLo skin 4gm/kg (4000mg/kg)   Office of Toxic Substances Report. Vol. OTS,
rat LCLo inhalation 50gm/m3/1H (50000mg/m3)   Office of Toxic Substances Report. Vol. OTS,
rat LD50 oral 15200mg/kg (15200mg/kg)   Office of Toxic Substances Report. Vol. OTS,
rat LDLo intravenous 160mg/kg (160mg/kg) BLOOD: CHANGE IN CLOTTING FACTORS

LUNGS, THORAX, OR RESPIRATION: CHRONIC PULMONARY EDEMA

BEHAVIORAL: SOMNOLENCE (GENERAL DEPRESSED ACTIVITY)		 American Journal of the Medical Sciences. Vol. 198, Pg. 73, 1939.

Physical Properties

Physical Property Value Units Temp (deg C) Source
Melting Point >360 deg C   EXP
log P (octanol-water) 2.630 (none)   EST
Water Solubility 1.16E+05 mg/L 25 EXP
Vapor Pressure 2.24E-30 mm Hg 25 EST
Atmospheric OH Rate Constant 2.33E-11 cm3/molecule-sec 25 EST

Physical property data is provided to ChemIDplus by SRC, Inc.