Chaetomadramines A–E, a class of siderophores with potent neuroprotective activity from the fungus Chaetomium madrasense cib-1

Abstract

Five hydroxamate siderophores, chaetomadramines A–E (1–5), along with seven known compounds were isolated from the fermented rice culture of the fungus Chaetomium madrasense cib-1. Compounds 1–5 were structurally elucidated on the basis of spectroscopic data, which were a group of unusual hydroxamate siderophores, bearing a long fatty acyl on the α-NH2 of the Nδ-hydroxylated ornithine. Compounds 2–5 were new. The structural elucidation and spectroscopic data of 1 were reported for the first time. Compounds 2–4 significantly improved the survival rates of PC12 cells in the neuroprotective activity assay at the concentration of 40 μM.