5572. Lophotoxin

Nomenclature

CAS number: 78697-56-0
(1R,2S,4S,10R,12R,14R,15R)-2-(Acetyloxy)-12-methyl-4-(1-methylethenyl)-17-oxo-11,16,18,19-tetraoxapentacyclo[12.2.2.16,9.01,15.010,12]nonadeca-6,8-diene-7-carboxaldehyde; LTX.
C22H24O8; mol wt 416.42.
C 63.45%, H 5.81%, O 30.74%.

Description and references

A novel neuromuscular toxin isolated from several spp of Pacific gorgonians (sea fans and whips) of the genus Lophogorgia. Although it belongs to the cembrene class of diterpenoids, the ability of LTX to cause irreversible postsynaptic blockade at the neuromuscular junction resembles the mode of action of the protein snake venom α-bungarotoxin (cf. bungarotoxins). Isoln and structure: W. Fenical et al., Science 212, 1512 (1981). Molecular mode of action: J. R. Smythies, Med. Hypotheses 7, 1457 (1981), C.A. 96, 137527 (1982). Toxicity study: P. Culver, R. S. Jacobs, Toxicon 19, 825 (1981). Description of the cytotoxic, ichthytoxic, and antibacterial activity of alcoholic extracts of gorgonians: R. S. Jacobs et al., Fed. Proc. 40, 26 (1981); V. J. Paul, W. Fenical, J. Org. Chem. 45, 3401 (1981).

Chemical structure

Properties

White needles, mp 164-166°. [α]D27 +14.2° (c = 1.7 in chloroform). LD50 in mice (mg/kg): 8.9 s.c. (Culver, Jacobs).