| abstract |
A PEG linker as represented by formula (I), wherein n and m are respectively an integer from 1 to 7, providing the PEG linker with 1 to 49 linking sites. A ligand drug conjugate as represented by formula (II). The conjugate uses the PEG linker to increase a drug loading capacity and drug loading diversity, thereby improving pharmaceutical efficacy. n Y1-PEG1-{R 1 -PEG2-{Y4} n } m (I)n n TM-{R 2 -PEG1-{R 1 -PEG2-{R 3 -A′-drug} n } m } l (II) |