Fostriecin is a natural inhibitor of serine/ threonine phosphatases.
[3] It is a phosphate monoester produced by fermentation beer of
Streptomyces pulveraceus.
[3][4] Fostriecin is a strong inhibitor of protein phosphatases type 2A and 4 (PP2A and PP4) and a weak inhibitor of protein phosphatases type 1 and 5 (PP1 and PP5).
[3] It exhibits anti-tumor activity against several tumor cells
in vitro and L1210 and P388 leukemias
in vivo.
[4] The anti-tumor activity of fostriecin is due to its ability to interfere with the reversible phosphorylation of proteins that are involved in the progression of the cell cycle.
[4] It also exhibits cytotoxic effects.
[3] Fostriecin can inhibit the DNA, RNA and protein synthesis.
[4]