Active Principles of the Thymelaeaceae

Abstract

By a combination of countercurrent distribution methods and chromatographic procedures, simplexin (S₈) and eight additional pimelea factors S₁-S₇ and S₉ with diterpenoid carbon skeletons were isolated from roots and aerial parts of Pimelea simplex. The structure of factor S₉ was determined to be a polyfunctional tigliane type related to mancinellin. Also factors S₁ and S₂ were tentatively assigned tigliane skeletons. Factor S₈ proved to be identical with simplexin, an orthoester of the daphnane type previously isolated from the plant. The structures of factors S₆ and S₇ (most probably epimers) were determined to be polyfunctional derivatives of the new lα-alkyldaphnane type, as well as factors S₃, S₄ and S₅. All factors isolated are highly irritant on the mouse ear as measured quantitatively by their irritant doses 50 (ID₅₀). Moreover, the ethyl acetate extract of the aerial parts of the plant and simplexin, the only pimelea factor tested as yet, were shown to exhibit tumour promoting activity on the back skin of mice.

Key Word Index

Pimelea Simplex - Thymelaeaceae - Irritants - Cocarcinogens - Diterpene-esters

1 2^nd communication, see loc. [10].

1 2^nd communication, see loc. [10].

2 part of dissertation A. Hafez, Universität Heidelberg (1978).