| Title:  Ouabagenin CAS Registry Number:  508-52-1 CAS Name:  (1b,3b,5b,11a)-1,3,5,11,14,19-Hexahydroxycard-20(22)-enolide Additional Names:  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°   |