Streptomyces A-Factor is a microbial hormone found in Streptomyces griseus. A-factor triggers streptomycin biosynthesis and cell differentiation by binding a repressor-type receptor protein (ArpA) and dissociating it from DNA.
Reticulol is an isocoumarin derivative produced by certain species of Streptomyces. Reticulol inhibits cAMP phosphodiesterase (IC50 = 41 µM). Recticulol (M.W. 222.2) exhibits a potent in vitro cytotoxicity against the human lung tumor cell line A427 and the mouse melanoma cell line B16F10.