Pseudoindoxyl-type alkaloids

The iboga alkaloids distinguish themselves from most of Type I compounds by the ease with which they autodxidize to yield hydroperoxy- and hydroxyindolenines (Chart 9.1) whose further degradation products are 4-hydroxyquinolines, pseudoindoxyls and oxindoles (cf. Chapter III). Therefore, the isolation of these products from the plant cannot by itself be taken as proof of their natural occurrence. Why some of these bases are so susceptible to oxygen is not known and is certainly not so obvious as the... 

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