Novel degraded polycyclic polyprenylated acylphloroglucinol and new polyprenylated benzophenone from Hypericum sampsonii.

Norhypersampsone A ( 1 ), a novel degraded polycyclic polyprenylated acylphloroglucinol (PPAP) derivative, 3-(2-hydroxy-7-methyl-3-methyleneoct-6-enyl)-5-isoprenyl-2,4,6-trihydroxybenzophenone ( 2 ), a new polyprenylated benzophenone derivative, and nine known compounds ( 3 – 11 ) were isolated from Hypericum sampsonii . Their structures were elucidated by comprehensive spectroscopic techniques. Compound 1 represents a novel cyclohexenone monocyclic-PPAP formed by losing the fragment of C-2–C-4 and the side chains at C-3 and C-5 in the phloroglucinol ring. The results of the inhibitory effects of compounds 1 – 11 on the nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW 264.7 macrophages showed that compounds 1 , 6 – 8 , and 10 exhibited weak activities with IC 50 values in the range of 20.3–37.1 μM. [ABSTRACT FROM AUTHOR]