BRANCHED POLYETHYLENE GLYCOL LINKED WITH DIACYL GLYCEROL, PROCESS FOR PRODUCING THE SAME, AND POLYETHYLENE GLYCOL MODIFIED LIPOSOME

摘要

Provided is a polyethylene glycol derivative which contains two PEG chains, which is bound to a diacylglycerol, which has high purity, and which enhances the stability of liposomes. Polyethylene glycol is represented by the following formula (1) and which is bound to a diacylglycerol:;In Formula (1), R¹ is a hydrocarbon group containing 1 to 7 carbon atoms, R² is an alkyl or alkenyl group containing 9 to 21 carbon atoms, n is the average number of moles of added polyethylene glycol chains, 10 n 100, and X is a linker site between branched polyethylene glycol and the diacylglycerol and is represented by the following formula (2):In Formula (2), Y is an ether bond, an ester bond, a urethane bond, an amide bond, or a carbonate bond and 1 and m are an integer of 0 to 6.