Anti-bacterial prenylated phenols from the Kurdish medicinal plant Onobrychis carduchorum (Fabaceae)

Onobrychis carduchorum C.C. Towns. is a plant widely employed in the Kurdish traditional medicine, to cure inflammations and other skin diseases. We isolated ten different phenolic metabolites from an acetone extract of leaves and flowers. The phenolic compounds belong to three different classes, i.e.: 1. iso-flavones, having a genistein skeleton; 2. flavanones, bearing a naringenin skeleton; 3. dihydro-stilbenes. Many of them have a prenyl unit on an aromatic ring. The above compounds have been found to date mostly in other Fabaceae, as Glycyrrhiza glabra L. (liquorice)1. However, their bioactivities are largely unknown. In this work we reported a strong inhibition activity on the growth of Staphylococcus aureus, a well-known human pathogen. In particular, compound (Fig. 1) shows an inhibitory activity on growth, comparable to that of vancomycin, using the agar-diffusion standard method.