A new pyridoacridine alkaloid named sagitol C (2) together with two known compounds; kuanoniamine C (1) and sagitol (3) were isolated from the EtOAc fraction of the Indonesian sponge Oceanapia sp. Their chemical structures were established on the basis of physical and spectroscopic methods 1D and 2D NMR, in addition to mass spectrometry and comparison with literature data. Sagitol C was found to exhibit cytotoxic activity when tested against different cancer cell lines