1 4OV (2r)-2-[(1r)-2-[(2s)-2-amino-2-carboxyethoxy]-1-{[(2r)-2-amino-2-phenylacetyl]amino}-2-oxoethyl]-5-methyl-3,6-dihydro-2h-1,3-thiazine-4-carboxylic acid 1.000 2 63U (2s)-2-[(1r)-1-{[(2r)-2-amino-2-phenylacetyl]amino}-2-oxoethyl]-5-methyl-3,6-dihydro-2h-1,3-thiazine-4-carboxylic acid 0.774 3 3S3 (1r)-2-({(R)-carboxy[(2r,5s)-4-carboxy-5-methyl-5,6-dihydro-2h-1,3-thiazin-2-yl]methyl}amino)-2-oxo-1-phenylethanaminium 0.750 4 CD6 (2r)-5-methylidene-2-{(1r)-2-oxo-1-[(phenylacetyl)amino]ethyl}-5,6-dihydro-2h-1,3-thiazine-4-carboxylic acid 0.742