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Biosynthesis of hyperforin and adhyperforin from amino acid precursors in shoot cultures of Hypericum perforatum.

Karppinen K, Hokkanen J, Tolonen A, Mattila S, Hohtola A

Department of Biology, University of Oulu, P.O. Box 3000, FIN-90014 Oulu, Finland.

Hyperforin and adhyperforin contribute to the antidepressant effects of Hypericum perforatum. The involvement of branched-chain amino acids in the biosynthesis of hyperforin and adhyperforin was demonstrated in H. perforatum shoot cultures. l-[U-(13)C(5)]Valine and l-[U-(13)C(6)]isoleucine, upon administration to the shoot cultures, were incorporated into acyl side chain of hyperforin and adhyperforin, respectively. Feeding the shoot cultures with unlabelled l-isoleucine at a concentration of 2mM induced a 3.7-fold increase in the production of adhyperforin. The addition of 3mM l-threonine, a precursor of isoleucine, stimulated a 2.0-fold increase in the accumulation of adhyperforin. The administration of l-valine at concentrations of 0-5mM had no stimulating effect on the hyperforin production in H. perforatum shoot cultures.

Published 20 March 2007 in Phytochemistry, 68(7): 1038-45.
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