AbstractA terpene synthase from Nonomuraea coxensis was identified as (+)‐1‐epi‐cubenol synthase. The enzyme is phylogenetically unrelated to the known enzyme of the same function that is widespread in streptomycetes. Isotopic labelling experiments were performed to unambiguously assign the NMR data and to investigate hydrogen migrations during terpene cyclisations. Epoxidations of (+)‐1‐epi‐cubenol and of the plant derived compounds (−)‐cubenol and (−)‐1‐epi‐cubenol confirmed the structure of a natural product isolated from the brown alga Dictyopteris divaricata and allowed to conclude on its absolute configuration. The crystal structures of the epoxides from (+)‐ and (−)‐1‐epi‐cubenol and the acid catalysed conversion into an isomeric ketone are reported.
摘要 从 Nonomuraea coxensis 中鉴定出一种萜烯合成酶,即 (+)-1-epi-cubenol 合成酶。该酶在系统发育上与已知的广泛存在于链霉菌中的具有相同功能的酶无关。为了明确核磁共振数据的归属,并研究萜烯环化过程中的氢迁移,我们进行了同位素标记实验。(+)-1-epi-cubenol 的环氧化作用以及植物衍生化合物 (-)-cubenol 和 (-)-1-epi-cubenol 的环氧化作用证实了从褐藻 Dictyopteris divaricata 中分离出来的天然产物的结构,并得出了其绝对构型的结论。报告了 (+)- 和 (-)-1-epi-cubenol 环氧化物的晶体结构以及酸催化转化为异构酮的过程。