Phloroglucinol Derivatives from Two Mediterranean Hypericum L. (Clusiaceae) Species

The flowering plant genus Hypericum L. (St. John's Wort, Clusiaceae) is the subject of considerable interest due to the use of H. perforatum extracts as treatment for mild to moderate depression. Extensive phytochemical and pharmacological research on this species has revealed many bioactive substances, including flavonoid glycosides, naphthodianthrones (hypericin) and phloroglucinol derivatives (hyperforin) [1]. The latter class of substances is interesting both chemically and pharmacologically [2]. As part of our continuing research on phytochemistry of the genus Hypericum, two species – H. polyphyllum Boiss. & Balansa (section Olympia) and H. empetrifolium Willd. (section Coridium) – occurring in Mediterranean region were phytochemically studied. A phloroglucinol derivative (1) previously isolated from H. jovis and H. stypheloides was isolated from the DCM extract of H. empetrifolium fruits. Two new flavones, one major (2) and one minor one, were isolated from the DCM extract of H. polyphyllum fruits.

Acknowledgements: The Graz Botanical Garden is thankfully acknowledged for their help with cultivation of H. polyphyllum. We are grateful to Dr. Norman K. B. Robson for allowing the collection of H. empetrifolium from his garden in Great Britain.

References: [1] Ernst, E. (Ed.) (2003) Hypericum: The Genus Hypericum, Taylor & Francis, London/New York.