Two new cytochalasan derivatives from Chaetomium globosum SNSHI-5, a fungus derived from extreme environment

Abstract

Two new cytochalasan derivatives, isochaetoglobosin D_b (1) and cytoglobosin A_b (2), were isolated from an ethyl acetate extract of Chaetomium globosum SNSHI-5, a fungus derived from extreme environment. The structures of the new compounds were comprehensively characterized by HR-ESI-MS, ¹H NMR, ¹³C NMR and 2D-NMR. Cytotoxic activity against H292 human lung cancer cell of the new compounds was tested. Isochaetoglobosin D_b (1) showed potent cytotoxicity with IC₅₀ of 3.5 μM, while cytoglobosin A_b was inactive (IC₅₀ > 10 μM).

Keywords: Chaetomium globosum SNSHI-5; cytochalasan derivatives; cytoglobosin Ab; cytotoxic activity; isochaetoglobosin Db.