AUTHOR=Fontaine Benjamin M. , Nelson Kate , Lyles James T. , Jariwala Parth B. , García-Rodriguez Jennifer M. , Quave Cassandra L. , Weinert Emily E. 

TITLE=Identification of Ellagic Acid Rhamnoside as a Bioactive Component of a Complex Botanical Extract with Anti-biofilm Activity

JOURNAL=Frontiers in Microbiology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.00496

DOI=10.3389/fmicb.2017.00496

ISSN=1664-302X

ABSTRACT=<p><italic>Staphylococcus aureus</italic> is a leading cause of hospital-acquired infections. It is listed among the top “serious threats” to human health in the USA, due in large part to rising rates of resistance. Many <italic>S. aureus</italic> infections are recalcitrant to antibiotic therapy due to their ability to form a biofilm, which acts not only as a physical barrier to antibiotics and the immune system, but results in differences in metabolism that further restricts antibiotic efficacy. Development of a modular strategy to synthesize a library of phenolic glycosides allowed for bioactivity testing and identification of anti-biofilm compounds within an extract of the elmleaf blackberry (<italic>Rubus ulmifolius</italic>). Two ellagic acid (EA) derivatives, EA xyloside and EA rhamnoside, have been identified as components of the <italic>Rubus</italic> extract. In addition, EA rhamnoside has been identified as an inhibitor of biofilm formation, with activity comparable to the complex extract 220D-F2 (composed of a mixture of EA glycosides), and confirmed by confocal laser scanning microscopy analyses.</p>