Prenylated phloroglucinol derivatives from Hypericum sampsonii.

Six new acylphloroglucinol derivatives, sampsonols A-F (1-6), were isolated from the petroleum ether extract of the aerial parts of Hypericum sampsonii. The structures and relative configurations of sampsonols A-F were elucidated by extensive spectroscopic analyses. All these compounds were tested for their in vitro cytotoxic and anti-inflammatory activities. Sampsonols A and B (1 and 2) showed significant cytotoxicity against four human tumor cell lines with IC(50) values in the range of 13-28µM, whereas sampsonols C and F (3 and 6) showed potent inhibitory activities against LPS-induced NO production in RAW 264.7 macrophages with IC(50) values of 27.3 and 29.3µM, respectively.