A novel natural chlorin metal complex containing gold(I) in the macrocycle periphery

An original synthesis of methyl ester of 13¹-thioketone pyropheophorbide A containing a gold(I) complex at the periphery of the macrocycle (at the E exocycle) via the formation of an S–Au bond is performed. The stability of this complex in aqueous solutions at various pH values as well as the effectiveness of its binding to DNA are evidenced.