Inhibitory Effects of Metachromins L–Q and Its Related Analogs Against Receptor Tyrosine Kinases EGFR and HER2

Metachromins are a series of sesquiterpenoid quinones isolated from Okinawan marine sponges. Inhibitory effects of metachromins L-Q (1-6), sesquiterpenoid quinones with an amino acid residue, and their related analogs (7-18) prepared from metachromins A (19) and C (20) against receptor tyrosine kinases EGFR and HER2 were investigated. Two analogs 11 and 12 showed relatively stronger inhibitory activity against EGFR, while metachromins L-Q (1-6) and seven analogs (8, 10, 11, and 15-18) showed inhibitory activities against HER2.