Present invention relates to a formulation from natural product. The formulation is LDV liposomal formulation of Photo System-I (PSI)  which causes apoptotic death of cancer cells through ROS generation and a simple way for targeted delivery of the said formulation  specifically to melanoma cancer cell. LDV liposomal formulation of PSI was prepared for targeted delivery to melanoma cancer cell.  Through this targeted delivery inventors have shown that LDV liposomal formulation of PSI specifically kills melanoma cancer cells  leaving normal cells unaffected. The present invention elucidates that LDV liposomal formulation of PSI is more potent anti-cancer agent  than doxorubicin for melanoma.