During a Lise-Meitner-Program research project, bioassay-guided fractionation of species belonging to Clusiaceae (Mammey Apple Family) was conducted to isolate new bioactive substances. Several species of Hypericum L. (St. John's Wort) have records of traditional use in topical applications for reducing inflammation and wound-healing [1]. Therefore, lipophilic extracts of 9 species of Hypericum (all belonging to tribe Hypericeae) were examined. In addition, lipophilic extracts from Triadenum walterii (tribe Hypericeae) and Clusia valerioi (tribe Clusieae) were studied. Results of anti-inflammatory bioassays for several isolated compounds against COX-1, COX-2, and 5-LOX, enzymes implicated in inflammation response, indicated that a new phloroglucinol derivative (1) from H. lissophloeus had the highest activity against COX-1 (IC50 9.5 uM) and a known xanthone (2) and phloroglucinol derivative (3) from H. canariense displayed the highest activity against COX-2 (IC50 16.9 uM) and 5-LOX (IC50 0.3 uM), respectively.
Acknowledgements: Thanks go to Dr. Wolfgang M. Schühly for help collecting material of several Hypericum species in the field in the southeastern United States. Katrina Dlugosch (University of California, Santa Cruz) is thanked for H. canariense material. The Austrian Science Foundation (FWF) is sincerely thanked for their financial support (Project M844-B05).
References: [1] Ernst, E. (Ed.) (2003) Hypericum: The Genus Hypericum, Taylor & Francis, London/New York.
