Vom Photosensibilisator Hypericin zum Photorezeptor Stentorin – die Chemie der Phenanthroperylenchinone

Falk, Heinz

doi:10.1002/(sici)1521-3757(19991102)111:21<3306::aid-ange3306>3.0.co;2-e

Cited by 23 publications

(12 citation statements)

References 194 publications

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“…A compilation of the most prominent steps in the biogenesis of (proto)hypericin is given in the Supporting Information, Fig. 1S which is composed from data in reference [3]. In detail, hypericin can act as an antidepressant, has antibiotic properties, and is used in cancer therapy as a marker for tumors [4].…”

Section: Several Of the Secondary Metabolites Found Inmentioning

confidence: 99%

Influence of the Habitat Altitude on the (Proto)Hypericin and (Proto)Pseudohypericin Levels ofHypericumPlants from Crete

et al. 2008

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Environmental factors are known to influence strongly the accumulation of secondary metabolites in plant tissues. In a previous paper, we studied the contents of (pseudo)hypericin and its immediate precursors in wild populations of various HYPERICUM species on the island of Crete, Greece, in dependence on their developmental stage. In this study, we investigated the effect of the habitat altitude on the total hypericins content of the plants, which is defined as the sum of protohypericin, hypericin, protopseudohypericin and pseudohypericin. Taking into account our previous finding that the highest accumulation is found during the flowering period in June, we collected the aerial parts of spontaneously growing H. PERFORATUM L. , H. TRIQUENTRIFOLIUM Turra , H. EMPETRIFOLIUM Willd. and H. PERFOLIATUM L. during that time frame at elevations between 100 and 600 m above sea level, however, bearing in mind the time lag in development with increasing altitude. HPLC analysis of the plant material, separated again into a flowers and a leaves/petioles fraction, revealed great differences in the total hypericin content in dependence on the altitude of the habitat. Specifically, a clear trend was revealed, showing an increase of the total hypericin content with increasing altitude. However, no changes could be observed in the ratio of hypericin to protohypericin and in that of pseudohypericin to protopseudohypericin. The habitats of the employed plants were again randomly distributed all over Crete. It is proposed that higher light intensities accompanied by enhanced UV-B radiation and lower air temperature might be responsible for the increasing levels of total hypericins with increasing altitude

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Section: Several Of the Secondary Metabolites Found Inmentioning

confidence: 99%

Influence of the Habitat Altitude on the (Proto)Hypericin and (Proto)Pseudohypericin Levels ofHypericumPlants from Crete

et al. 2008

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“…St. John’s wort ( Hypericum perforatum , L.) is the most common representative of this genus. Extracts from Hypericum were used in folk medicine since antiquity (11). Due to their widespread use in traditional medicine, Hypericum plants and their extracts have been of scientific interest for many years.…”

Section: Introductionmentioning

confidence: 99%

Photosensitizing and Radiosensitizing Effects of Hypericin on Human Renal Carcinoma Cells in Vitro

Wessels¹,

Busse²,

Rave-Fränk³

et al. 2007

Photochem & Photobiology

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The renal cell carcinoma (RCC) is extremely resistant to chemotherapy and radiotherapy. The prognosis of patients with metastatic RCC still remains poor, the median survival is less than 12 months. Therefore, new therapeutic options are desirable. The aim of this study was to investigate the photosensitizing and radiosensitizing effects of hypericin on human RCC cells in vitro. First the RCC-derived cell lines A498 and ACHN were incubated with different concentrations of hypericin. In vitro uptake and intracellular distribution of hypericin were confirmed by fluorescence microscopy. Subsequently cells were illuminated and irradiated with a dose of 2-8 Gy, respectively. Finally, metabolic activity, apoptosis and clonogenic survival were investigated. Uptake of hypericin was observed for almost all cells. Hypericin treatment combined with illumination led to a 94-97% decrease in metabolic activity and caused apoptosis in nearly 100% of RCC cells. Hypericin enhanced the radiosensitivity of A498 cells in vitro. The clonogenic survival after irradiation was significantly reduced by hypericin treatment. Taken together, the photosensitizing and radiosensitizing effects of hypericin on human RCC cells we found in this investigation could be of clinical relevance, e.g. for radiotherapy and intraoperative photodynamic therapy, respectively.

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“…Anthraquinone (AQ) and its derivatives are a constituent of the chromophore of hypericin, which is naturally occurring in St. John’s wort and other plants of the Hypericum genus. Hypericin is used as a photosensitizer in photodynamical therapy of cancer and displays photoinduced virucidal (anti-viral, anti-retroviral) and antitumor activities 6 7 8 9 10 . Moreover, when anthraquinone is designed as photonucleases and reacts with DNA, they can cleave the single or double-strand DNA at special sites 11 12 13 14 .…”

mentioning

confidence: 99%

Ultrafast investigation of photoinduced charge transfer in aminoanthraquinone pharmaceutical product

Zhang

Sun

Zhou

et al. 2017

Sci Rep

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We investigated the mechanism of intramolecular charge transfer and the following radiationless dynamics of the excited states of 1-aminoanthraquinone using steady state and time-resolved absorption spectroscopy combined with quantum chemical calculations. Following photoexcitation with 460 nm, conformational relaxation via twisting of the amino group, charge transfer and the intersystem crossing (ISC) processes have been established to be the major relaxation pathways responsible for the ultrafast nonradiative of the excited S1 state. Intramolecular proton transfer, which could be induced by intramolecular hydrogen bonding is inspected and excluded. Time-dependent density functional theory (TDDFT) calculations reveal the change of the dipole moments of the S0 and S1 states along the twisted coordinate of the amino group, indicating the mechanism of twisted intra-molecular charge transfer (TICT). The timescale of TICT is measured to be 5 ps due to the conformational relaxation and a barrier on the S1 potential surface. The ISC from the S1 state to the triplet manifold is a main deactivation pathway with the decay time of 28 ps. Our results observed here have yield a physically intuitive and complete picture of the photoinduced charge transfer and radiationless dynamics in anthraquinone pharmaceutial products.

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Vom Photosensibilisator Hypericin zum Photorezeptor Stentorin – die Chemie der Phenanthroperylenchinone

Cited by 23 publications

References 194 publications

Influence of the Habitat Altitude on the (Proto)Hypericin and (Proto)Pseudohypericin Levels ofHypericumPlants from Crete

Influence of the Habitat Altitude on the (Proto)Hypericin and (Proto)Pseudohypericin Levels ofHypericumPlants from Crete

Photosensitizing and Radiosensitizing Effects of Hypericin on Human Renal Carcinoma Cells in Vitro

Ultrafast investigation of photoinduced charge transfer in aminoanthraquinone pharmaceutical product

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