On the basis of the structure of (R)-rosmarinic acid, a series of small chemical compounds with a different scaffold was synthesized as inhibitors for lck SH2 domain. From ELISA results, most of all chemical compounds showed a similar or a little lower binding activity for lck SH2 domain compared to the lead compound,(R)-rosmarinic acid. It was characterized that the backbone rigidity between two catechol substructures was required for the full ...