(2S)-2-{(R)-carboxy[(2-thienylacetyl)amino]methyl}-5-methyl-3,6-dihydro-2H-1,3-thiazine-4-carboxylic acid
(2s)-2-{(r)-carboxy[(2-thienylacetyl)amino]methyl}-5-methyl-3,6-dihydro-2h-1,3-thiazine-4-carboxylic acid