Quercetin-3-O-amino acid-esters, a new type of quercetin derivatives, were successfully prepared for the
first time. Different from quercetin, the novel compounds show higher selectivity as inhibitors against
Src tyrosine kinase (IC50 values ranging from 3.2 mM to 9.9 mM) than against EGFR tyrosine kinase.
Molecular docking reveals that both hydrophobic and hydrogen bonding interactions are important to
the selectivity. Therefore, this study provides a new promising scaffold for further development of new
anticancer drugs targeting Src tyrosine kinase.