A new quinolone alkaloid, melimoluccanin (1) along with two known alkaloids, leptanoine C (2) and 7-O-isoprenyl-γ-fagarin (3) were isolated from the leaves of Melicope moluccana T.G. Hartley. Structures all of compounds were elucidated using spectroscopic methods such as UV, IR, HRESIMS, 1D and 2D NMR. Compounds 1-3 were evaluated for their cytotoxicity against P-388 cells and for antimalaria activity using giemsa methods. The cytotoxic data of compounds 1-3 showed IC50 of 0.63; 5.85 and 2.09 μg/mL, respectively. The antiplasmodial activity of compound 1-3 showed IC50 value of 4.28; 2,28 and 0.18 μg/mL, respectively. Based on the data, it can be concluded that compound 1 has high activity against P-388 cells and compound 3 is potential as antimalaria. © Published under licence by IOP Publishing Ltd.