Description_x000D_ Biochem/physiol Actions_x000D_ Cercosporamide was initially identified as a phytotoxin with broad-spectrum anti-fungal activity. Studies have shown that cercosporamide is a specific, highly potent fungal inhibitor of the cell wall integrity-signaling pathway mediator, protein kinase (Pkc1) inhibitor. Semisynthetic cercosporamide analogues demonstrated hypoglycemic activity and therefore, serve as candidates for potential new anti diabetic drugs. Cercosporamide was found to block eIF4E (Eukaryotic Initiation Factor) phosphorylation in cultured cancer cells, inducing apoptosis, suppressing proliferation, and reducing soft agar colonization. Its eIF4E phosphorylation inhibitory effect was also shown when administrated orally on xenograft human tissue and mouse liver tissue. Cercosporamide is a potent and selective Mnk inhibitor. It reduces tumor growth in xenografted HCT116 tumor and suppresses the outgrowth of B16 melanoma lung metastases. Hence, blocking Mnk function and eIF4E phosphorylation may be an attractive anticancer strategy._x000D_ Preparation Note_x000D_ DMSO solution (1 mg/ml), kept at -20 °C, is stable for at least three months.