Occurrence and Distribution of Phytochemicals in the Leaves of 17In vitroCulturedHypericumspp. Adapted to Outdoor Conditions.
A plethora of plants belonging to the genusHypericumhave been investigated so far owing to the biological efficacies of pharmacologically important secondary metabolites produced by severalHypericumspecies. However, there is currently a dearth of information about the localization (accumulation) of these compounds in the plantsin situ. In particular, the biosynthetic and ecological consequence of acclimatization ofin vitroculturedHypericumspp. to outdoor conditions is not fully known. Herein, we report an application of matrix-assisted laser desorption/ionization high-resolution mass spectrometry (MALDI-HRMS) to reveal the distribution of major naphthodianthrones hypericin, pseudohypericin, protohypericin, and their proposed precursor emodin as well as emodin anthrone, along with the phloroglucinol derivative hyperforin, the flavonoids quercetin, quercitrin, rutin and hyperoside (and/or isoquercitrin), and chlorogenic acid inHypericumleaves. Plants encompassing seventeenHypericumspecies classified into eleven sections, which were first culturedin vitroand later acclimatized to outdoor conditions, were studied. We focused both on the secretory (dark and translucent glands, other types of glands, and glandular-like structures) as well as the non-secretory leaf tissues. We comparatively analyzed and interpreted the occurrence and accumulation of our target compounds in different leaf tissues of the seventeen species to get an intra-sectional as well as inter-sectional perspective. The naphthodianthrones, along with emodin, were present in all species containing the dark glands. In selected species, hypericin and pseudohypericin accumulated not only in the dark glands, but also in translucent glands and non-secretory leaf tissues. Although hyperforin was localized mainly in translucent glands, it was present sporadically in the dark glands in selected species. The flavonoids quercetin, quercitrin, and hyperoside (and/or isoquercitrin) were distributed throughout the leaves. Rutin was present only within sectionsHypericum, Adenosepalum, Ascyreia, andPsorophytum. Our study provides insights into the prospects and challenges of usingin vitroculturedHypericumplants, further adapted to field conditions, for commercial purposes.
Institute of Biology and Ecology, Department of Genetics, Faculty of Science, Pavol Jozef Šafárik University in Košice Košice, Slovakia.
Andrea
A
Kucharíková
Institute of Environmental Research, Department of Chemistry and Chemical Biology, Chair of Environmental Chemistry and Analytical Chemistry, Technical University of Dortmund Dortmund, Germany.
Souvik
S
Kusari
Institute of Environmental Research, Department of Chemistry and Chemical Biology, Chair of Environmental Chemistry and Analytical Chemistry, Technical University of Dortmund Dortmund, Germany.
Selahaddin
S
Sezgin
Institute of Environmental Research, Department of Chemistry and Chemical Biology, Chair of Environmental Chemistry and Analytical Chemistry, Technical University of Dortmund Dortmund, Germany.
Michael
M
Spiteller
Institute of Biology and Ecology, Department of Genetics, Faculty of Science, Pavol Jozef Šafárik University in Košice Košice, Slovakia.
Eva
E
Čellárová
Hypericum spp.; inter-sectional; intra-sectional; localization; matrix-assisted laser desorption/ionization high-resolution mass spectrometry; secondary metabolites