Title: Ouabagenin
CAS Registry Number: 508-52-1
CAS Name: (1b,3b,5b,11a)-1,3,5,11,14,19-Hexahydroxycard-20(22)-enolide
Synonyms: G-strophanthidin
Molecular Formula: C23H34O8
Molecular Weight: 438.51
Percent Composition: C 63.00%, H 7.82%, O 29.19%
Literature References: Prepn from ouabain with HCl in cold acetone: Mannich, Siewert,
Ber. 75, 737 (1942). Review of structure: Reichstein, Reich,
Annu. Rev. Biochem. 15, 155 (1946). Proof of this structure: Tamm
et al., Helv. Chim. Acta 40, 1469 (1957),
cf. Experientia 13, 185 (1957); Turner, Meschino,
J. Am. Chem. Soc. 80, 4862 (1958); Volpp, Tamm,
Helv. Chim. Acta 42, 1408, 1418 (1959).
Derivative Type: Monohydrate
Properties: Clusters of needles from water, mp 235-238°. One gram dissolves in about 10 ml boiling water. At room temp the soly in water is <1%. Also sol in dil alcohol. Practically insol in abs alcohol, ether, and chloroform. Becomes anhydr at 100°
in vacuo over P2O5. The anhydr compd is hygroscopic, mp 255-256°. [a]D17 +11.3° (c = 1.27).
Melting point: mp 235-238°; mp 255-256°
Optical Rotation: [a]D17 +11.3° (c = 1.27)
Derivative Type: Tetraacetylouabagenin trihydrate
Molecular Formula: C31H42O12.3H2O
Molecular Weight: 660.70
Percent Composition: C 56.35%, H 7.32%, O 36.32%
Properties: Needles from 10% alcohol, mp 282-285°.
Melting point: mp 282-285°
Derivative Type: Dihydroouabagenin
Molecular Formula: C23H36O8.CH3OH
Molecular Weight: 472.57
Percent Composition: C 61.00%, H 8.53%, O 30.47%
Properties: Solvated crystals from methanol + ether contg 1 mol methanol, mp 261°.
Melting point: mp 261°