| Title:  Histrionicotoxin CAS Registry Number:  34272-51-0 CAS Name:  (2S,6R,7S,8S)-7-(1Z)-1-Buten-3-ynyl-2-(2Z)-2-penten-4-ynyl-1-azaspiro[5.5]undecan-8-ol Additional Names:  HTX;  (-)-HTX 1;  (-)-histrionicotoxin Molecular Formula:  C19H25NO Molecular Weight:  283.41 Percent Composition:  C 80.52%, H 8.89%, N 4.94%, O 5.65% Literature References:  One of a family of piperidine alkaloids isolated from the skin of the poison arrow frog Dendrobates histrionicus.  Noncompetitive inhibitor of nicotinic acetylcholine receptors characterized by an unusual spirocyclic cis-enyne structure.  Virtually nontoxic, the family was originally misnamed because of the source.  Isoln:  J. W. Daly et al., Proc. Natl. Acad. Sci. USA 68, 1870 (1971).  Isoforms:  idem et al., Helv. Chim. Acta 60, 1128 (1977).  Acetylcholine antagonism:  M. Glavinovic et al., Can. J. Physiol. Pharmacol. 52, 1220 (1974); as allosteric inhibitor:  S. M. Sine, P. Taylor, J. Biol. Chem. 257, 8106 (1982).  Total synthesis:  S. C. Carey et al., Tetrahedron Lett. 26, 5887 (1985); stereospecific synthesis:  G. M. Williams et al., J. Am. Chem. Soc. 121, 4900 (1999).  Review:  J. W. Daly, J. Nat. Prod. 61, 162-172 (1997). Properties:  Viscous oil; on storage at -15°C crystals slowly form, mp 75-76°.  uv max:  224 nm (e 15500).  [a]D20 -112° (c = 0.34 in ethanol). Melting point:  mp 75-76° Optical Rotation:  [a]D20 -112° (c = 0.34 in ethanol) Absorption maximum:  uv max:  224 nm (e 15500) Use:  Biochemical probe for neuromuscular transmission.  |