Alkaloids ofRhinopetalum stenantherum. II. The structure of stenanthine and stenanthidine

From a methanolic extract of the epigeal part ofRhinopetalum stenantherum have been isolated -chaconine (I) and the new glucoalkaloids stenanthine with mp 262–264°C ]_D 46.5°, C₄₅H₇₃NO₁₅ (II), and stenanthidine with mp 269–271°C, ]_D –47.5°, C₃₉H₆₃NO₁₁ (III). On the basis of the facts that partial hydrolysis of the trioside (II) formed the biosides (I) and (III), and that on the hydrolysis of the latter the monoside -chaconine was found, it may be assumed that stenanthine has the structure of solanidine 3-0-{0--D-glucosyl-(1 6)]-0--L-rhamnosyl-(1 4)]-D-glucoside}, and stenanthidine that of solanidine 3-0-0--D-glucosyl-(1 6)-D-glucoside].Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 349–356, May–June, 1981.