Natural Hydroxamate-Containing Siderophore Acremonpeptides A–D and an Aluminum Complex of Acremonpeptide D from the Marine-Derived Acremonium persicinum SCSIO 115

Four new hydroxamate-containing natural product cyclopeptides designated acremonpeptides A–D (1–4), together with Al­(III)–acremonpeptide D (5) were obtained from the marine fungus Acremonium persicinum SCSIO 115. The planar structures of 1–5 were established on the basis of HRMS as well as 1D and 2D NMR data sets. Moreover, the amino acid absolute configurations were determined using Marfey’s method. Compounds 1–5 all feature three 2-amino-5-(N-hydroxyacetamido)­pentanoic acid (N 5-hydroxy-N 5-acetyl-l-ornithine) metal ion chelating moieties. Beyond their discovery and structure elucidation, in vitro bioassays revealed acremonpeptides A (1), B (2), and Al­(III)–acremonpeptide D (5) as moderate antiviral agents for herpes simplex virus 1 with EC50 values of 16, 8.7, and 14 μM, respectively.