Sortase A-Inhibitory Coumarins from the Folk Medicinal Plant .

Thirteen coumarins (-), including five new compounds (-), were isolated from the folk medicinal plant . Combined spectroscopic analyses revealed that coumarins - are bis-isoprenylated coumarins with diverse oxidation patterns, while is an enantiomeric di-isoprenylated coumarin. The absolute configurations of the stereogenic centers in the isoprenyl chains were assigned through MTPA and MPA methods, and those of the known compounds triphasiol () and ponciol () were also assigned using similar methods. These coumarins inhibited significantly -derived sortase A (SrtA), a transpeptidase responsible for anchoring surface proteins to the peptidoglycan cell wall in Gram-positive bacteria. The present results obtained indicated that the bioactivity and underlying mechanism of action of these coumarins are associated with the inhibition of SrtA-mediated adhesion to eukaryotic cell matrix proteins including fibrinogen and fibronectin, thus potentially serving as SrtA inhibitors.