4-Methylumbelliferyl thymidine 5'-phosphate 4-Mut-5-P 4MUpT 5'-Thymidylic acid, mono(4-methyl-2-oxo-2H-1-benzopyran-7-yl) ester 80180-70-7 Ammonium 4-methylumbelliferyl 5'-thymidylate