O3125 Sigma-Aldrich

Ouabain octahydrate

≥95% (HPLC), powder

Synonym: 1β,3β,5β,11α,14,19-Hexahydroxycard-20(22)-enolide 3-(6-deoxy-α-L-mannopyranoside), Acocantherine, G-Strophanthin

  • CAS Number 11018-89-6

  • Empirical Formula (Hill Notation) C29H44O12 · 8H2O

  • Molecular Weight 728.77

  •  Beilstein/REAXYS Number 101712

  •  EC Number 211-139-3

  •  MDL number MFCD00149240

  •  PubChem Substance ID 24278610

  •  NACRES NA.77



Related Categories A to C, Adenosinetriphosphatase, Bioactive Small Molecule Alphabetical Index, Bioactive Small Molecules, Biochemicals and Reagents,
Quality Level   200
biological source   plant seeds (Strophantus gratus)
assay   ≥95% (HPLC)
form   powder
optical activity   [α]25/D −31 to −32.5° in H2O(lit.)
impurities   ~8 mol/mol water
color   white
mp   260 °C
solubility   H2O: 10 mg/mL (cold)
  ethanol: 10 mg/mL
  H2O: 50 mg/mL (hot)
ε (extinction coefficient)   15.5 at 220 nm in H2O at 1 mM
storage temp.   room temp
SMILES string   O.O.O.O.O.O.O.O.C[C@@H]1O[C@@H](O[C@H]2C[C@@H](O)[C@]3(CO)[C@H]4[C@H](O)C[C@]5(C)[C@H](CC[C@]5(O)[C@@H]4CC[C@]3(O)C2)C6=CC(=O)OC6)[C@H](O)[C@H](O)[C@H]1O
InChI   1S/C29H44O12.8H2O/c1-13-22(34)23(35)24(36)25(40-13)41-15-8-19(32)28(12-30)21-17(3-5-27(28,37)9-15)29(38)6-4-16(14-7-20(33)39-11-14)26(29,2)10-18(21)31;;;;;;;;/h7,13,15-19,21-25,30-32,34-38H,3-6,8-12H2,1-2H3;8*1H2/t13-,15-,16+,17+,18+,19+,21+,22-,23+,24+,25-,26+,27-,28+,29-;;;;;;;;/m0......../s1
Gene Information   human ... ATIC(471)
rat ... Atp1b1(25650)


General description

Ouabain is a steroid hormone, naturally present in mammals.


Ouabain octahydrate has been used:
• to determine the effect of salt and ammonia in the external environment on the rate of activity of Na+ /K+ in either silver or golden perch
• in the basolateral compartment to induce maximal baseline short-circuit current in rat fetal distal lung epithelial (FDLE) cells
• as an Na+/K+ ATPase inhibitor to study the relation between blister formation and adenosine triphosphate (ATP) dependent maintenance of plasma membrane homeostasis

Biochem/physiol Actions

Cardiac glycoside, inhibits Na(+)/K(+) ATPase, regulates transcription of MDR (increase, Pgp) and MRP (increase MRP1 and decrease CFTR, cyctic fibrosis transport receptor or cAMP-activated Cl- channel) genes, also alters localization of MRP1. Ouabain resistance is associated with appearance of Na(+)/K(+) ATPase isoforms with low binding affinity.

Ouabain has its specific binding site on integral proteins of the plasma membrane. Heart disease is treated using ouabain derivatives. Increased ouabain production is observed during exercise in humans. Abnormally high levels of ouabain are indicated in congestive heart failure and hypertension. Ouabain signalling affects intracellular calcium levels, which is known to activate nuclear factor κB (NFκB).

Features and Benefits

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Aqueous solutions can be autoclaved.

Legal Information

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Safety & Documentation

Safety Information

Signal word 
Hazard statements 
UN 1544PSN1 6.1 / PGI
WGK Germany 
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