BTBE (0.3 mM) was incorporated to EYPC and DLPC liposomes (30 mM) and exposed to peroxynitrite either as a single bolus (■) or by slow infusion (○) in order to achieve final concentrations of (0.2–2 mM). Samples were analyzed for 3-nitro-BTBE, 3,3´-di-BTBE and MDA content. EYPC: (A) MDA (B) 3-nitro-BTBE (C) 3,3´-di-BTBE; DLPC: (D) 3-nitro-BTBE and 3,3´-di-BTBE (inset); (E) BTBE (0.3 mM) containing liposomes were exposed to slow infusion of peroxynitrite (1 mM) in the presence and absence of oxygen and 3-nitro-BTBE and 3,3´-di-BTBE was measured as previously.