Fig. 6.
Electrospray ionization (ESI)-MS spectrum of the EAS endoperoxides formed by the reaction of LAxOxOH (x = 16 or 18) with HOCl. (A) LA16O16OH (5 mM) was reacted with 10 mM HOCl in 0.1 M phosphate buffer, pH 7.4. (B) LA18O18OH (5 mM) was reacted with 10 mM HOCl in 0.1 M phosphate buffer, pH 7.4 in 85% D2O, 10% H2O, and 5% MeOH. (C) Reaction described in B without oxygen.