Isolation and identification of FR198248, a hydroxylated 1,3-dihydroisobenzofuran, from Aspergillus flavipes as an inhibitor of peptide deformylase

Two highly hydroxylated 1,3-dihydroisobenzofurans, FR198248 (1) and FR202306 (2), were isolated as peptide deformylase (PDF) inhibitors from Aspergillus flavipes. Compounds 1 and 2 inhibited Staphylococus aureus PDF with IC(50) values of 3.6 and 2.5 microM, respectively, and also showed Antibacterial activity with an MIC value of 25 microg/ml. In contrast, 6-O-methyl derivative 3 of compound 2 was inactive against both PDF and S. aureus.