title: Isolation and identification of dihydroartemisinic acid hydroperoxide from artemisia annua: A novel biosynthetic precursor of artemisinin
abstract: Dihydroartemisinic acid hydroperoxide (2) was isolated for the first time as a natural product from the plant Artemisia annua in a 29% yield. Its structure was identified by (1)H and (13)C NMR spectroscopy. Compound 2 is known as an intermediate of the photochemical oxidation of dihydroartemisinic acid (1) leading to artemisinin (3). The presence of 1 and 2 in the plant and the conditions under which 1 can be converted into 2, which can very easily oxidize to 3, provide evidence for a nonenzymatic, photochemical conversion of 1 into 3, in vivo, in the plant.
authors.affiliation: Department of Pharmaceutical Biology, University Centre for Pharmacy, Groningen Institute for Drug Studies, University of Groningen, A. Deusinglaan 1, NL-9713 AV Groningen, The Netherlands.
authors.initials: TE
authors.lastname: Wallaart
authors.initials: N
authors.lastname: Pras
authors.initials: WJ
authors.lastname: Quax