Psiguadiols A–J, Rearranged Meroterpenoids as Potent PTP1B Inhibitors from Psidium guajava
journal contributionposted on 2019-11-18, 14:49 authored by Ji-Qin Hou, Chun-Lin Fan, Xin Pei, Pei-Lin Zhang, Fan Deng, Wan-Qiang Jiang, Guo-Cai Wang, Xiao-Qi Zhang, Wen-Cai Ye, Hao Wang
Psiguadiols A–J (1–10), new meroterpenoids with rearranged skeletons, were isolated from the leaves of Psidium guajava. Compounds 1–3 represent the first examples of 6,8-diformyl-5,7-dihydroxy-4-phenylchromane-coupled sesquiterpenoids with an unprecedented C-8-spiro-fused 6/6/9/4 tetracyclic ring system. Compounds 4 and 5 represent two unusual scaffolds featuring 1β,6β- and 3α,5α-epoxy rings, respectively. The combination of spectroscopic data analyses, comparison of experimental and calculated ECD data, and single-crystal X-ray diffraction data of 1, 6, and 8 allowed for the assignment of the structures. A putative biosynthetic pathway for 1–10 is discussed. Compounds 1, 7, and 8 exhibited inhibitory activities against PTP1B with IC50 values of 4.7, 6.2, and 9.2 μM, respectively. In addition, molecular docking was performed to investigate the mechanism of action.