738932.fig.001
Figure 1: Mass spectrum of 2{[2-amino-2-(phenyl)-acetylamino]-carboxy-methyl}-5-methyl-1-oxo-1,2,3,6-tetrahydro-1λ-4-[1,3]thiazine-4-carboxylic acid with its parent molecular ion peak at mass/charge at 382.0 amu.