2-(4-oxo-2-thioxo-1,4-dihydropteridin-3(2H)-yl)propanoic acid 3(2H)-pteridineacetic acid, 1,4-dihydro-alpha-methyl-4-oxo-2-thioxo- InChI=1/C9H8N4O3S/c1-4(8(15)16)13-7(14)5-6(12-9(13)17)11-3-2-10-5/h2-4H,1H3,(H,15,16)(H,11,12,17