New sesquiterpenes from Senecio oxyodontus

The South African plant, Senecio oxyodontus, contained in addition to known compounds several new sesquiterpenes, which were all of the bisabolene type. The structures were elucidated by spectroscopic methods and some chemical transformations. The constituents were closely related to those from one other South African Senecio species and in contrast to most Senecio species which contain very different structural types, mainly of the furanoeremophilanes type.