Denudatin A, a Dimeric Acylphloroglucinol from Hypericum denudatum Presents an Antinociceptive Effect in Mice.

A new dimeric acylphloroglucinol, denudatin A ( 1 ), was isolated from the flowering aerials parts of Hypericum denudatum , along with the known phloroglucinols selancin A ( 2 ), hyperbrasilol A ( 3 ), uliginosin B ( 4 ), and isouliginosin B ( 5 ). The structure of 1 was elucidated using 1D, 2D NMR, and MS experiments, and by comparison with previously reported data for Hypericum dimeric acylphloroglucinols. Denudatin A ( 1 ) and selancin A ( 2 ) were administered orally to mice displaying antinociceptive activity in the hot plate test. The compounds did not induce motor impairment in the rotarod apparatus.