posted on 2021-12-14, 15:03authored byXiao Han, Qi Wang, Xiangchao Luo, Xuli Tang, Zhe Wang, Di Zhang, Shugeng Cao, Pinglin Li, Guoqiang Li
Three
novel sesquiterpenoids, lemnalemnanes A–C (1–3), were obtained from marine soft corals Paralemnalia
thyrsoides and Lemnalia sp.
Their structures were determined by 1D/2D NMR spectroscopy, HRESIMS,
single-crystal X-ray diffraction analysis (Cu Kα), Mosher’s
method, and ECD quantum chemistry calculations. Lemnalemnane A (1) possessed an intriguing basket-like structure with a spiro[bicyclo[3.3.1]nonane-furan
core, while lemnalemnanes B (2) and C (3) exhibited unusual 6/6/5 and 6/5/5 carbon skeletons, respectively.
In the proposed biosynthesis pathway, 1–3 were suspected to originate from the same precursor, 4-O-deacetylparalemnolin D (4), a compound coisolated
from both aforementioned species. Furthermore, lemnalemnane C (3) exhibited strong in vivo promoting-angiogenesis
activity.