1H-NMR resonances associated with the gem-dimethyl groups of (A) 1 mM NAP, (B) product resulting from the reaction of 1 mM NAP with 10 mM IAA and, (C) product remaining after treatment of B with 20 mM DTT, (D) 1 mM MCPD in D2O, (E) product resulting from the reaction of 1 mM MCPD and 10 mM iodoacetamide in pH 7.4 buffer and, (F) product resulting from the reduction of E with 20 mM DTT. Except for (D) spectra were measured in 0.1 M phosphate buffer (pH 7.4) with 10 % D2O.