Persicaside has been isolated as a new alkaloid natural compound from a methanol (EtOA)-soluble extract of Prunus persica seed. It was purified by a combination of chromatographic techniques and recrystallization. The structure of Persicaside was determined by extensive NMR experiments and mass ppectroscopic data. It inhibited nitric oxide (NO) and prostaglandin E 2 (PGE2) production via suppression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2 expression in rat osteoblast sarcoma cells (ROS 17/2.8) in concentration-dependent manner whereas it spares the COX-1 enzyme activity.