Abstract
From seed oil of the Chinese tallow tree skin irritant principles could be enriched; their diterpene parent was recognized as 12-deoxyphorbol(1a). Skin irritant Sapium factors S1 to S8 were isolated from roots; they represent 13-monoesters of 12-deoxyphorbol (1a) (S4-S8), 12,13-diesters of phorbol (2a) (S1 and S2) and of 6β,7β-epoxyphorbol (3a) (S3). The factors S1, S5 and a homologue of S3 are known as tumor promoters.