Planta Med 2016; 82 - PC44
DOI: 10.1055/s-0036-1578746

Structure Elucidation Of Ursene And Oleanene Derivatives From Castanea Sativa (European Chestnut) That Inhibit Staphylococcus Aureus Virulence And Pathogenesis

JT Lyles 1, JS Kavanaugh 2, K Nelson 3, CP Parlet 2, HA Crosby 2, KP Heilmann 2, AR Horswill 2, CL Quave 1, 3
  • 1Center for the Study of Human Health, Emory University, 550 Asbury Circle, Candler Library 107, Atlanta, GA 30322 USA
  • 2Department of Microbiology, Roy. J. and Lucille A. Carver College of Medicine, University of Iowa, 431 Newton Road, Iowa City, IA 52242 USA
  • 3Department of Dermatology, Emory University School of Medicine, 615 Michael Street, Whitehead 105L, Atlanta, GA 30322 USA

Alarming trends in the spread of antibiotic resistance among pathogens, including Staphylococcus aureus, have pushed mankind toward what has been coined as the “post-antibiotic era.” Therefore, an indirect therapy is proposed, quorum quenching. Investigation of botanical folk medicines used in the Mediterranean for the treatment of skin and soft tissue infections identified Castanea sativa (European Chestnut) for its potential antibacterial activity. This work demonstrates the quorum sensing inhibitory activity of a methanolic C. sativa leaf extract against all S. aureus accessory gene regulator (agr) alleles (IC50 1.56 – 25 µg mL-1). The extract is nontoxic to human keratinocytes and does not inhibit the growth of S. aureus or skin commensal bacteria. The bioactivity guided fractionation identified several compounds with ursene (1) and oleanene (2) backbones as the active compounds. The isolation and complete structure elucidation was performed using LC FT-MS and a suite of 1D and 2D NMR experiments.

Fig. 1

Acknowledgements: This work was supported by a grant from the National Institutes of Health, National Center for Complementary and Integrative Health (R01 AT007052). The content is solely the responsibility of the authors and does not reflect the views of NCCIH or NIH.

References: [1] Quave CL, Lyles JT, et al. (2015) PLoS ONE 10(8): e0136486.