Synthesis and biological evaluation of analogs of the marine alkaloids granulatimide and isogranulatimide

► Two new pyrazolic series of the marine granulatimide alkaloids were prepared. ► A pyrolic series of granulatimide was completed. ► The most interesting compounds exhibited growth inhibitory activity with IC50 of 10 μM. ► A unique compound revealed a G2 checkpoint abrogating effect similar to that observed with the natural alkaloids. ► Some compounds have shown weak to actual inhibitory activities with poor selectivity in a small kinase panel.