Sedative and antinociceptive activities of two new sesquiterpenes isolated from Ricinus communis.

Two new sesquiterpenes, trivially named ricinusoids A (1) and ricinusoids B (2), were isolated from ethyl acetate fraction of Ricinus communis. The structures of new compounds were elucidated by detailed spectroscopic techniques, including 1D- and 2D-NMR, UV, IR spectroscopy, and mass spectrometry. The compounds (1-2) were also assessed for in-vivo sedative and analgesic like effects in open field and acetic acid induced writhing tests respectively at 5, 10, and 20 mg·kg-1 i.p. Pretreatment of both test compounds caused significant (P ≤ 0.05) reduction in locomotive activity like sedative agents and abdominal constrictions like analgesics. Both compounds (1-2) possessed marked sedative and antinociceptive effects in animal models.