Dolichocarpols A-F, Unprecedented Macrocyclic Humulene-Type Sesquiterpenoids from Anaxagorea dolichocarpa

摘要

Six sesquiterpenoids with unprecedented macrocyclic humulene-type structures, namely, dolichocarpols A-E (1 –5 ) with ether-bridged bicyclic rings between C-10 and C-2, C-10 and C-7, C-10 and C-6 (×2), and C-6 and C-3 and dolichocarpol F (6 ) cyclized between C-7 and C-2 and with an ether bridge between C-10 and C-3, were isolated from Anaxagorea dolichocarpa roots. The structures of the compounds were elucidated by NMR, MS, and IR data. Absolute configurations of compounds 1 –3 and 6 were established on the basis of data from electronic circular dichroism, whereas relative configurations of compounds 4 and 5 were suggested by the NOESY spectrum. In addition, a putative biosynthetic pathway of the compounds is proposed. Furthermore, the cytotoxicity of 3 , 4 , and 6 against HCT-116 (human colorectal carcinoma) and L929 (murine fibroblast) was evaluated.