Three minor new p-quinonoid aporphine alkaloids, sonodione (1), demethylsonodione (2), and norsonodione (3), have been additionally isolated from the stem bark of Hernandia sonora. The structures of these compounds were elucidated by spectral analysis. Among the isolates obtained till now, five compounds, ovigerine (4), hernangerine (5), N-methylhernangerine (6), (+)-malekulatine (7), and isovanillin (8) showed moderate antiplatelet aggregation activity in vitro.