Isolation,Crystal Structure and Antitussive Activity of 9S,9aS-neotuberostemonine

The title compound 9 S,9 aS-neotuberostemonine(1) was isolated from the 95% ethanol extract of the roots of Stemona tuberosa. The crystal structure of 1, C_922)H_(33)NO_4, was determined by single-crystal X-ray diffraction analysis. The crystal belongs to orthorhombic system, space group P212121, with a = 9.0115(11), b = 10.612(4), c = 22.074(3) ?, V = 2110.9(8) ?~3, Z = 4, Mr = 375.49, Dc = 1.182 g/cm3, λ= 0.71079 ?, μ = 0.080 cm-1, F(000) = 816, S = 1.019, R = 0.0579 and w R = 0.1358. A total of 3109 unique reflections were collected, of which 2902 were observed(I 2σ(I)). The absolute configuration of 1 could be assigned by referring to the conserved configuration of the methyl groups at C(13) and C(20). In the solid state, the molecules were linked into a chain along the a-axis through weak hydrogen bond C(11)–H(11 A)…O(2). Compound 1 shows significant inhibition of cough by 24%, 44% and 65% at doses of 50, 100 and 150 mg/kg, respectively.