2.2.2 Picrotoxinin
Biological Sources It is the toxic component of picrotoxin obtained from the seed of Anamirta cocculus L. Wight & Arn. (Menispermaceae); and also found in Tinomiscium philippinense Diels.
Chemical Structure
[1aR – (1aα, 2aβ, 3β, 6β, 6aβ, 8aS*, – 8bβ, 9R*)]-Hexahydro-2a-hydroxy-8b-methyl-9-(1-methylethenyl)-3, 6-methano-8H-1, 5, 7-trioxacyclopenta [ij] cycloprop [a] azulene-4, 8 (3H)-dione; (C15H16O6).
Preparation Picrotoxinin may be prepared from picrotoxin by the method suggested by Horrmann.*
Characteristic Features
1. It is obtained in two different forms: first—as large prisms, and secondly—as small crystals containing water having mp 209.5°C.
2. Its specific optical rotations are: [α]17D + 4.4° (C = 4.28 in absolute alcohol); and + 3.49° (C =7.57 in acetone).
3. It is found to be soluble in hot common organic solvents; and also in cold chloroform and ethanol.
4. Nevertheless it has a very bitter taste.
Uses
1. It is employed as a CNS and respiratory stimulant.
2. It may also be used as an antidote to barbiturates.
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