1 C1X (z)-N~6~-[(4r,5s)-5-(2-carboxyethyl)-4-(carboxymethyl)dihydro-2h-thiopyran-3(4h)-ylidene]-L-lysine 1.000 2 OBS (z)-N^6-[(4s,5r)-5-(2-carboxyethyl)-4-(carboxymethyl)-1-hydroxydihydro-2h-thiopyranium-3(4h)-ylidene]-L-lysine 0.962 3 CYJ (z)-N~6~-[(4r,5s)-5-(2-carboxyethyl)-4-(carboxymethyl)piperidin-3-ylidene]-L-lysine 0.923