St John's Wort Research Today is a free monthly online journal that collates and summarizes the latest research about St John's Wort, including details on depression, anxiety, side-effects, dosage, benefits.

Biosynthesis of the hyperforin skeleton in Hypericum calycinum cell cultures.

Klingauf P, Beuerle T, Mellenthin A, El-Moghazy SA, Boubakir Z, Beerhues L

Institut für Pharmazeutische Biologie, Technische Universität Braunschweig, Mendelssohnstrasse 1, D-38106 Braunschweig, Germany.

Hyperforin is an important antidepressant constituent of Hypericum perforatum (St. John's wort). Cell cultures of the related species H. calycinum were found to contain the homologue adhyperforin and to a low extent hyperforin, when grown in BDS medium in the dark. Adhyperforin formation paralleled cell culture growth. Cell-free extracts from the cell cultures contained isobutyrophenone synthase activity catalyzing the condensation of isobutyryl-CoA with three molecules of malonyl-CoA to give phlorisobutyrophenone, i.e. the hyperforin skeleton. The formation of the hyperforins during cell culture growth was preceded by an increase in isobutyrophenone synthase activity. The cell cultures also contained benzophenone synthase and chalcone synthase activities which are involved in xanthone and flavonoid biosyntheses, respectively. The three type III polyketide synthases were separated by anion exchange chromatography.

Published 17 January 2005 in Phytochemistry, 66(2): 139-45.
Full-text of this article is available online (may require subscription).

© 2004-2008 St John's Wort Research Today. All Rights Reserved.