From the seeds of Senna sophera, a new hydroanthracene derivative named presengulone [9-(6' methoxy-3'-methyl-3',8',9'-trihydroxy-1'-oxo-1',2',3',4'-tetrahydroanthracen-7'-yl)-5,10-dihydroxy-2-methoxy-7-methyl-1,4-anthraquinone] was isolated, together with physcion, physcion bianthrone, xanthorin, floribundone-I, isosengulone, sengulone, and anhydrophlegmacin-9,10-quinones A₁ and B₂.