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

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-C-13(5)]Valine and L-[U-C-13(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 2 mM induced a 3.7-fold increase in the production of adhyperforin. The addition of 3 MM 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 0-5 mM had no stimulating effect on the hyperforin production in H. perforatum shoot cultures. (C) 2007 Elsevier Ltd. All rights reserved.