A new cytotoxic polycyclic polyprenylated acylphloroglucinol from Garcinia nujiangensis screened by the LC-PDA and LC-MS.

A new polycyclic polyprenylated acylphloroglucinol ( 1 ), nujiangefolin D, together with five known analogues ( 2-6 ), were isolated from the fruits of Garcinia nujiangensis . Compound 1 was screened by the LC-MS and LC-PDA. The structure of 1 was elucidated on the basis of extensive spectroscopic techniques including 1 D and 2 D NMR and MS analyses. The compounds isolated were evaluated for their cytotoxic activities against three cancer cell lines, 1 showed moderate cytotoxic activity against Hela, PANC-1, and MDA-MB-231 cell lines with IC ₅₀ values of 5.6 ± 0.1, 9.1 ± 0.2, and 8.3 ± 0.2  μ M, respectively. The antitumor mechanism was explained via virtual docking of 1 to the main sites in the human serine/threonine-protein kinase mTOR (mTOR) crystal structure (PDB code: 4DRI). Furthermore, 1 may inhibit Hela cell proliferation through mTOR by the western blotting analysis. Taken together, 1 may be a potential mTOR inhibitor used for the treatment of cervical cancer.