Isoprenylated flavonoids from Morus nigra and their PPAR γ agonistic activities.

A novel dihydroflavonol unprecedentedly with a prenyl group at C-2, nigragenon A ( 1 ), four new sanggenon-type flavonones, nigragenons B–E ( 2 – 5 ), along with six known isoprenylated flavonoids ( 6 – 11 ) were isolated from the twigs of Morus nigra . Their structures were elucidated through extensive analysis of spectroscopic data. Interestingly, compound 1 was the first reported biogenetic precursor of sanggenon-type flavanones and the biogenetic pathway from 1 to sanggenol F was proposed. The PPAR γ agonistic activity was investigated in HEK293 cells using dual luciferase reporter assay. Compounds 2 , 4 , 7 , and 9 showed obvious agonistic activities on PPAR γ, and compound 2 was a potential PPAR γ partial agonist. Moreover, the preliminary structure-activity relationships for the tested compounds were discussed. [ABSTRACT FROM AUTHOR]