A synthetic chemistry approach to understanding the anti-biofilm activity of Rubus ulmifolius, an Italian medicinal plant used in the traditional treatment of skin infection

A major issue in the field of public health is the dramatic increase in the number of antibiotic-resistant bacteria.  One such pathogen is Staphylococcus aureus, which produces biofilms that protect it from the host immune response and antibiotic therapy.  A biofilm is an extracellular layer composed of polymeric substances, proteins, and eDNA.  Quave et al. (2012) recently discovered that an extract from the plant, Rubus ulmifolius, inhibits biofilm formation in S. aureus.  The extract is mostly composed of glycoside derivatives of ellagic acid (EA).  The aim of this project is to synthesize the EA derivatives (EA rhamnopyranoside, EA xylopyranoside, and EA mannopyranoside) found in the extract and to examine biofilm inhibitory properties of these individual constituents. Here, we discuss the anti-biofilm properties of these constituents in comparison to the complex plant extract, and describe how synthetic chemistry approaches can serve as useful complements to natural product research on traditional medicines.