Phytochemical Studies on Meliaceous Plants. III. : Structures of Two New Pregnane Steroids, Toosendansterols A and B, from Leaves of Melia toosendan SIEB. et ZUCC.

Abstract

Two new pregnane steroids, named toosendansterols A (1) and B (2), have been isolated, together with loliolide (3), from leaves of Melia toosendan SIEB. et ZUCC. (Meliaceae). Based on chemical, physicochemical, and spectral evidence, the structures of 1 and 2 have been elucidated as 3β, 20S-dithydroxy-5α-pregnan-16-one and 3α, 20S-dihydroxy-5α-pregnan-16-one, respectively. In addition, this is the first identification of 3 in meliaceous plants.