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.