Title:  Okadaic Acid 
CAS Registry Number:  78111-17-8 
CAS Name:  9,10-Deepithio-9,10-didehydroacanthifolicin 
Additional Names:  halochondrine A 
Molecular Formula:  C44H68O13 
Molecular Weight:  805.00 
Percent Composition:  C 65.65%, H 8.51%, O 25.84% 
Literature References:  First ionophoric polyether identified in marine organisms; isolated from marine black sponges, Halichondria (okadai or melanodocia).  Tumor promoting cytotoxin associated with diarrhetic seafood poisoning.  Isoln:  K. Tachibana et al., J. Am. Chem. Soc. 103, 2469 (1981).  Total synthesis:  M.  Isobe et al., Tetrahedron 43, 4767 (1987).  Contractile effects:  S. Shibata et al., J. Pharmacol. Exp. Ther. 223, 135 (1982).  Inhibition of protein phosphatases:  A. Takai et al., FEBS Lett. 217, 81 (1987); C. Bialojan, A. Takai, Biochem. J. 256, 283 (1988).  Tumor promoting activity:  M. Suganuma et al., Proc. Natl. Acad. Sci. USA 85, 1768 (1988).  Review of mechanism of action and use as a probe for cellular regulation:  P. Cohen et al., Trends Biochem. Sci. 15, 98-102 (1990); A. Schönthal, New Biol. 4, 16-21 (1992).  Review of tumor promoting activity:  H. Fujiki, M. Suganuma, J. Biochem. 115, 1-5 (1994). 
Properties:  Crystals from dichloromethane/hexane, mp 171-175°.  [a]D20 +21° (c = 0.33 in CHCl3).  Also reported as crystals from benzene-CHCl3, mp 164-166°.  [a]D25 +25.4° (c = 0.24 in CHCl3).  LD50 i.p. in mice: 192 mg/kg (Shibata). 
Melting point:  mp 171-175°; mp 164-166° 
Optical Rotation:  [a]D20 +21° (c = 0.33 in CHCl3); [a]D25 +25.4° (c = 0.24 in CHCl3) 
Toxicity data:  LD50 i.p. in mice: 192 mg/kg (Shibata) 
Use:  Biochemical tool as tumor promoter and probe of cellular regulation.   |