Velutinalide C, a New Polycyclic Phragmalin Limonoid from the Leaves of Chukrasia tabularis var. velutina

Velutinalide C (4), a new polycyclic phragmalin limonoid featuring a C(15)-C(21) linkage and a C-4 unit at C(15), together with two known related compounds, chukfuransins C and D (2 and 3, resp.), was isolated from the leaves of Chukrasia tabularis var. velutina. The structure of the new compound 4 was elucidated on the basis of extensive spectroscopic analyses and comparison with literature data.