Strophiofimbrins A and B: Two Rearranged Norditerpenoids with Novel Tricyclic Carbon Skeletons from Strophioblachia fimbricalyx

• DOI: 10.1021/acs.joc.3c00301
• Publication Date: 2023-04-12T20:34:35Z
• Authors: Hou-Li Jiang; Yan-Yan Zhang; Hao-Yu Mao; Yue Zhang; Yin-Xue Cao; Hong-Yan Yu; Xiao-Yun Dong; Li Tao; Chang-Shui Yang
• Keywords: Tricyclic; Euphorbiaceae

Two rearranged norditerpenoids with novel tricyclic carbon skeletons, strophiofimbrin A (1) and B (2), were isolated from Strophioblachia fimbricalyx. Their structures established by 1D/2D NMR spectroscopy, HRESIMS, quantum chemistry calculations, X-ray diffraction analyses. 1 2 represented the first examples of diterpenoids unprecedented 5/6/7-fused ring systems. In proposed biosynthetic pathway, they suspected to derive cleistanthane via opening, expansion, cyclization, rearrangement based on existence phenanthrenone Trigonostemon, two closely related genera Euphorbiaceae family. Furthermore, compounds exhibited significant proliferation inhibition obvious neuroprotective effects.