Exploring aigialomycin d and its analogues as protein kinase inhibitors for cancer targets.

The natural product aigialomycin D (1) is a member of the resorcylic acid lactone (RAL) family possessing protein kinase inhibitory activities. This paper describes the synthesis of aigialomycin D and a series of its analogues and their activity for the inhibition of protein kinases related to cancer pathways. A preliminary study of these compounds in the inhibition of CDK2/cyclin A kinase has found that aigialomycin D and analogues 11 and 23 are moderate CDK2/cyclin A inhibitors with IC50 values of ca. 20 μM. Kinase profiling of aigialomycin D against a panel of kinases has led to the identification of MNK2 as a promising target (IC50 = 0.45 μM), and preliminary structure-activity relationship studies have been carried out to identify the essential functional groups for activity.