Results 171 to 180 of about 8,749 (218)

The Structure of Hypericin in Solution. Searching for Hypericin's 1,6 Tautomer¶

Photochemistry and Photobiology, 2001
Hypericin in organic solvents displays two types of electronic spectra: one type which shows a distinct solvatochromic effect, the stable form, and the other, the unstable form, which lacks this property. The latter type is formed in dry nonprotic solvents (e.g.
D, Freeman, L, Konstantinovskii, Y, Mazur   +2 more
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Synthese des Proto‐hypericins und Hypericins aus Emodin‐anthron‐(9)

Chemische Berichte, 1958
AbstractAus Emodin‐anthron‐(9) wurde durch „verknüpfende Oxydation”︁ mit Sauerstoff Proto‐hypericin und Hypericin dargestellt. Damit ist ein Syntheseweg gefunden, auf dem die beiden Hypericum‐Farbstoffe wahrscheinlich auch in der Pflanze aufgebaut werden.
Hans Brockmann, Heinrich Eggers
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Interaction between hypericin and hemoglobin

Journal of Photochemistry and Photobiology B: Biology, 2010
In the present work the hypericin interaction with hemoglobin was studied by absorption and fluorescence spectroscopy both under incubation in dark and visible light exposure. An absorption reduction in Soret band of hemoglobin (407 nm) was revealed under the photodynamic influence and incubation in dark with hypericin that had hypericin concentration ...
H R, Vardapetyan, A S, Martirosyan, S G, Tiratsuyan, A A, Hovhannisyan   +3 more
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Hypericin: chemical synthesis and biosynthesis

Chinese Journal of Natural Medicines, 2014
Hypericin is one of the most important phenanthoperylene quinones extracted mainly from plants of the genus Hypericum belonging to the sections Euhypericum and Campylosporus of Keller's classification. Widespread attention to the antiviral and anti-tumor properties of hypericin has spurred investigations of the chemical synthesis and biosynthesis of ...
Lin-Fang, Huang, Zeng-Hui, Wang, Shi-Lin, Chen   +2 more
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Concerning the Association of Hypericin Tautomers and their Hypericinate Ions

Monatshefte für Chemie/Chemical Monthly, 2000
The association of the like and unlike configured propeller and butterfly conformers of unionized and bay-ionized 7,14-, 1,6-, and 1,7-tautomers of hypericin was investigated by means of semiempirical calculations of the MM3 type. From the various possible stack dimers it was found that the homodimer with like configurations of the propeller ...
Christoph Etzlstorfer, Heinz Falk
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Totalsynthese des Hypericins

Chemische Berichte, 1957
AbstractAus 1‐Brom‐emodin‐trimethyläther, dessen Synthese sich ebenso wie die des Emodins erheblich verbessern ließ, wurde das 4.5.7.4′.5′.7′‐Hexahydroxy‐2.2′‐dimethyl‐meso‐naphthodianthron aufgebaut. Es erwies sich als identisch mit Hypericin aus Hypericum hirsutum. Damit ist die Konstitutionsformel des Hypericins auch durch Totalsynthese gesichert.
Hans Brockmann, Friedhelm Kluge, Hans Muxfeldt   +2 more
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LASER PHOTOSENSITIZATION OF CELLS BY HYPERICIN

Photochemistry and Photobiology, 1994
Abstract— Administering a light dose of 90 J/cm2 at 599 nm during incubation with hypericin to a highly differentiated normal epithelial cell line(FRTL–5), derived from Fisher rat thyroid, and to a neoplastic cell line(MPTK–6), derived from the lung metastases of a thyroid carcinoma induced in Fisher rats, produces cell kill at drug doses 1000 times ...
A. ANDREONI, A. COLASANTI, P. COLASANTI, M. MASTROCINQUE, RICCIO, PATRIZIA, ROBERTI, GIUSEPPE   +5 more
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Aromaticity and Electron Density of Hypericin

Journal of Natural Products, 2019
The influence of the substituents on the geometry of the central ring system of hypericin has been analyzed. Substitution that causes flattening of the hypericin central rings is connected with introducing the aromatic character of the empty rings. All the hypericin rings have an aromatic character illustrated by the Harmonic Oscillator Measure of ...
Sebastian Szymanski, Irena Majerz
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Exploring Modes of Photokilling by Hypericin

Photochemistry and Photobiology, 2020
AbstractEffects of photodynamic therapy (PDT) using the anthraquinone hypericin were explored with OVCAR‐5 cells in vitro. Irradiation resulted in ER > lysosomal photodamage. Paraptosis was identified as a primary death pathway resulting from ER perturbation. This is characterized by an extensive pattern of cytoplasmic vacuole formation.
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Die Konstitution des Hypericins

Chemische Berichte, 1951
AbstractDurch reduzierende Acetylierung des Hypericins wurde eine blaue, kristallisierte Verbindung dargestellt. Es wird gezeigt, daß sie 4.5.7.10.4′.5′.7′‐Heptaacetoxy‐2.2′‐dimethyl‐meso‐naphthodianthren ist und damit der endgültige Beweis für die Konstitution des Hypericins erbracht.
Hans Brockmann, Ernst Herbert Frhr. von Falkenhausen, Rütger Neeff, Alfons Dorlars, Guntmar Budde   +4 more
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