Buxaustroines A–N, a Series of 17(13→18)<i>abeo</i>-Cycloartenol Triterpenoidal Alkaloids from <i>Buxus austro-yunnanensis</i> and Their Cardioprotective Activities

Buxaustroines A–N (1–14), a series of triterpenoidal alkaloids featuring a novel 17(13→18)abeo motif, were obtained from the extract of Buxus austro-yunnanensis. Their structures were assigned based on NMR data analysis and X-ray diffraction crystallography. A putative biosynthetic pathway for one of the alkaloids from a co-isolate 15 is proposed. In the assessment of their bioactivities, some of the compounds displayed protective effects against doxorubicin-induced injury of myocardial cells. Preliminary structure–activity relationship studies of 1–14, which are based on the same skeleton, were conducted.滇南黄杨碱A–N（1–14）系一类具有新型17(13→18)移位型母核的三萜类生物碱，从滇南黄杨（Buxus austro-yunnanensis）的提取物中分离得到。其结构通过核磁共振（NMR）数据分析与X射线衍射晶体学方法得以确证。本研究针对共分离得到的同系物15，提出了其中一种生物碱的推定生物合成途径。在生物活性评价中，部分化合物展现出对阿霉素诱导心肌细胞损伤的保护作用。针对具有相同母核骨架的1–14号化合物，本研究开展了初步的构效关系研究。