| abstract |
Disclosed are a heterofunctionalized polyethylene glycol derivative (formula I), a preparation method, and a bio-related substance modified by the derivative. The derivative has a Y-shaped structure, which is a branched central structure U c constituted by a trivalent group U and linking groups L 1 , L 2 , and L 3 , and is provided with two different functional groups F 1 and F 2 ; three PEG chains respectively have the degrees of polymerization of n 1 , n 2 , and n 3 and discretely have either polydispersity or monodispersity; extremities of the PEG chains respectively are connected to at least one functional group via branching groups G 1 , G 2 , and G 3 ; when g 1 , g 2 , and g 3 are 1, the extremities are provided with multiple active sites; the numbers of repeating units of bivalent linking groups L 4 and L 6 are p 1 , p 2 , and p 3 ; and, any one of the link groups or any linking group formed with an adjacent heteroatom group can either remain stable or be degraded. The functionalized polyethylene glycol is flexible and diverse in terms of branch structures and the lengths of branching arms, has various parameters and performance indicators that are adjustable and easy to control, and has a broad applicability. |