Amino-PEG-t-butyl ester is a type of compound that belongs to the class of PEGylation reagents. It is a versatile compound that can be used for modifying different biomolecules such as peptides, proteins, and small molecules. The functional groups of this compound include an amino group and a t-butyl ester group, which provide a high degree of stability and water solubility to the modified biomolecules. The use of Amino-PEG-t-butyl ester in pharmaceutical research and development has been widely explored due to its ability to improve the pharmacokinetics and pharmacodynamics of drugs. By modifying drugs with this compound, the drug molecules can have enhanced stability, reduced immunogenicity, prolonged circulation time, and improved target specificity. These properties make Amino-PEG-t-butyl ester a valuable tool in drug discovery and development, and its applications continue to be investigated in various therapeutic areas.