ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The structure and absolute configuration of a new acetylenic alkaloid gephyrotoxin isolated from skin extracts of the Colombian frog Dendrobates histrionicus, has been determined by Röntgen-ray crystallography. Gephyrotoxin, previously referred to as HTX-D, is a novel tricyclic alkaloid, [1 S, 3aS, 5aS, 6S(Z), 9a R, 10 R]dodeca-hydro-6-(2-penten-4-yl)pyrrolo[1,2-a]quinoline-1-ethanol. Dihydrogephyrotoxin, a minor skin constituent, contains a 6-(2,4-pentadienyl)substituent. Two further spiropiperidine alkaloids related in structure to histrionicotoxin, (6 R[6α[2S*(Z)],[7β(Z), 8α]]7-(1-buten-3-ynyl)-2-(2-penten-4-ynyl)-1-azaspiro [5.5]undecan-8-ol), have been isolated from Dendrobates histrionicus: allodihydrohistrionicotoxin which differs from histrionicotoxin in having a 2-(4-pentynyl)-substituent, while allotetrahydrohistrio-nicotoxin, a minor constituent, has 2-(4-pentynyl)- and 7-(1,3-butadienyl)-substituents. Three alkaloids related in structure to pumiliotoxin C, ([2 S, 4a S, 5R, 8a R]5-methyl-2-n-propyl-cis-decahydroquinoline), have been isolated from Dendrobates histrionicus. These alkaloids, with molecular weights of 195, 223, and 269, have, respectively, a 2-butylsubstituent, 2-propyl and 5-propyl-substituents, and 2-(3,4-pentadienyl) and 5-(2-penten-4-ynyl)-substituents. The last compound was hydrogenated to a dodecahydro-derivative identical in molecular weight, but not in other properties, with authentic dodecahydro-8-deoxy-histrionicotoxin, which was prepared from histrionicotoxin. Gephyrotoxin, in contrast to histrionicotoxin and pumiliotoxin C, is a muscarinic antagonist.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19770600336
