660427-19-0

3,6,9,12-Tetraazaheptadecanedioic acid,16-[[[5-[[(2-amino-1,4-dihydro-4-oxo-6-pteridinyl)methyl]methylamino]-2-thienyl]carbonyl]amino]-2,7-bis(mercaptomethyl)-8,13-dioxo-,(2R,7R,16S)-