Biosynthesis of Hyperforin in <i>Hypericum </i><i>p</i><i>erforatum</i>

Cut sprouts of <i>Hypericum perforatum</i> were proffered solutions containing [1-<sup>13</sup>C]glucose or [U-<sup>13</sup>C<sub>6</sub>]glucose. Hyperforin was isolated and analyzed by quantitative NMR spectroscopy. The labeling patterns show that the biosynthesis of hyperforin involves five isoprenoid moieties, which are derived entirely or predominantly (>98%) via the deoxyxylulose phosphate pathway. The phloroglucinol moiety is generated via a polyketide type mechanism.