Turrapubesins A and B, First Examples of Halogenated and Maleimide-Bearing Limonoids in Nature from Turraea pubescens

Two novel tetranortriterpenoids, turrapubesins A (1) and B (2), representing the first examples of halogenated and maleimide-bearing limonoids,
were isolated from the twigs and leaves of Turraea pubescens. The structures of 1 and 2 were elucidated by extensive spectroscopic analysis.
Their absolute configurations were determined by X-ray crystallography of 1 and by CD analysis of a dihydrogenated derivative of 2. Turrapubesin
A (1) exhibited weak cytotoxicity against the P-388 tumor cell line.

两种新颖的四环三萜烯类化合物，即土腊皮布西因A（1）和土腊皮布西因B（2），作为卤代化和马来酰亚胺基的柠檬苦素类化合物的首次实例，已从土腊皮布西恩树（Turraea pubescens）的枝条和叶片中分离得到。通过广泛的波谱分析方法，确定了1和2的结构。1的绝对构型通过X射线晶体学方法确定，而2的氢化衍生物的CD分析则用于确定其绝对构型。土腊皮布西因A（1）对P-388肿瘤细胞系表现出微弱的细胞毒性。