Pardinumones A–D: Antibacterial Polyketide–Amino Acid Derivatives from the Mushroom Tricholoma pardinum

[Image: see text] Four polyketide–amino acid derivatives, pardinumones A–D (1–4), were isolated from the wild mushroom Tricholoma pardinum. Their structures together with absolute configurations were characterized by means of spectroscopic data analyses, as well as calculated electronic circular dichroism (ECD) and NMR with sorted training set (STS) protocol analysis. Compounds 1–4 exhibited antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, and Escherichia coli with MIC values in the range of 6.25–50 μg/mL.