Cevane skeleton

A simpler group of compounds with the cevane skeleton occurs in the genus Fritillaria (Liliaceae). Medicinally, the most important alkaloids of Veratrum are the polyesters of protoverine (87) that have hypotensive properties. 

Thus, the C2 7-steroid alkaloids with C-nor-D-homo ring system, that is, with a jervane or cevane skeleton, with 18-nor-17j8-methylcholestane skeleton (23-27) or other alterations of the C27-carbon skeleton of cholestane, found in Liliaceae but not yet in Solanaceae, are not included. They are described exhaustively in other volumes of this series by Kupuchan and By (28) as well as by Tomko and Voticky (29). On the other hand, some Veratrum bases, for instance, teinemine and baikeine, belong to the 5o/amim-type alkaloids and are mentioned in this chapter. 

Thus, the C27-steroid alkaloids with C-nor-D-homo [14(13->-12)-abeo] ring system, that is, with a jervane (5) or cevane (6) skeleton, found in Liliaceae but until now not in Solanaceae, are not included they will be described exhaustively in another chapter of this volume by S. M. Kupchan. On the other hand, the tertiary Veratrum bases rubijervine, isorubijervine, and veralobine belong to the solanidanes and will be mentioned briefly in this chapter, but a detailed description of these alkaloids and their derivatives will also be given by S. M. Kupchan. 

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