Penisimplicins A and B: Novel Polyketide–Peptide Hybrid Alkaloids from the Fungus <i>Penicillium simplicissimum</i> JXCC5

Abstract

In this study, two previously undescribed nitrogen-containing compounds, penisimplicins A (1) and B (2), were isolated from Penicillium simplicissimum JXCC5. The structures of 1 and 2 were elucidated on the basis of comprehensive spectroscopic data analysis, including 1D and 2D NMR and HRESIMS data. The absolute configuration of 2 was determined by Marfey’s method, ECD calculation, and DP4+ analysis. Both structures of 1 and 2 feature an unprecedented manner of amino acid-derivatives attaching to a polyketide moiety by C-C bond. The postulated biosynthetic pathways for 1 and 2 were discussed. Additionally, compound 1 exhibited significant acetylcholinesterase inhibitory activity, with IC50 values of 6.35 μM.

Keywords

• <i>Penicillium simplicissimum</i>
• polyketide
• nitrogen-containing compounds
• structural elucidation
• computational chemistry
• acetylcholinesterase inhibition