Diterpenoids and Limonoids from the Leaves and Twigs of Swietenia mahagoni

Three new compounds, including two diterpenoids, nemoralisins H and I (1 and 2), and a limonoid, 2-methoxy khayseneganin E (3), along with four known constituents (4-7), were isolated from the leaves and twigs of Swietenia mahagoni. Their chemical structures were elucidated by means of spectroscopic analysis. The cytotoxities of these isolated constituents were assayed.