Systematic and Geographic Occurrence of Picrotoxane-Containing Plants

Systematic and Geographic Occurrence of Picrotoxane-Containing Plants 

The first picrotoxanes discovered were isolated from the dried seeds of Menispermum cocculus (Anamirta cocculus) (1). Their characteristic features are two y-lactones and an oxrrane. M. cocculus belongs to the Menispermaceae ( moon seed family), which is in the order Ranunculales, and thus part of the primitive eudicots. So far, M. cocculus is the only species of the primitive eudicots recorded to contain picrotoxanes, and this species can be found in India, Sri Lanka, and southeast Asia. 

angustissima, C. pteroides, C. plumosa (New Zealand), and C. terminalis (Tibet), only C. nepalensis contains stmcturally deviant picrotoxanes, coriatone (53) and corianlactone (54) (69). Evidence of diurnal or seasonal fluctuation of picrotoxanes in plants has never been sought intentionally, but Jommi et al. (96) mentioned variable concentration levels of coriamyrtin and tutin in C. japonica. Thus the main picrotoxane, coriamyrtin, disappears in the autumn, when tutin (2-hydroxycoriamyr-tin) becomes the main picrotoxane. 

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