Finally, because Ch, EA, and its derivatives all add to G>P, we evaluated the reactivity of other amino alcohols found in biological phospholipid headgroups, 2 namely, serine (Ser) and threonine (Thr). The nucleophilic attack of the two amino acids on G>P resulted in the formation of glycerophosphoserines (GPSs) and glycerophosphothreonines (GPTs) in both the presence and absence of EA ( 31 P-NMR; Fig. ).