9-Demethyl FR-901235 was first isolated from an endophytic penicillium species in 2008 by Lin and colleagues from the Ocean University of China. 9-Demethyl FR-901235 has antitumor activity. FR-901235 itself is an immunomodulator reported to restore normal mitogen-induced lymphocyte proliferation after treatment with an immunosuppressive factor and to partially restore the impaired delayed-type hypersensitivity to sheep red blood cells in tumor-bearing mice. 9-Demethyl FR-901235 was recently reported as being co-produced with talauxins by Talaromyces stipitatus.