Cathepsin B Inhibitory Tetraene Lactones from the Fungus <i>Talaromyces wortmannii</i>

Abstract

Abstract magnified image Wortmannilactones E–H ( 1 – 4 ), four new cathepsin B inhibitors, were produced and isolated from the culture of the soil filamentous fungus Talaromyces wortmannii. Their structures and relative configurations were elucidated on the basis of 1D‐ and 2D‐NMR techniques, three of them ( 1, 2 , and 4 ) posses an oxabicyclo[2.2.1]heptane moiety. Compounds 1 – 4 showed inhibitory activities against cathepsin B with IC 50 values of 4.3, 6.5, 13.0, and 6.0 μ M , respectively.