Psycacoraone A (1), a new acorane-type sesquiterpene possessing rare spirobicyclic carbon skeleton, was isolated from the aerial parts of Psychotria yunnanensis. Its structure was elucidated on the basis of spectroscopic methods including HR-ESI-MS, 1D and 2D NMR. The absolute configuration of 1 was determined by calculation of electronic circular dichroism using density functional theory.
Keywords: Psychotria yunnanensis; Rubiaceae; acorane sesquiterpene; calculated ECD; psycacoraone A.