Effect of hydroxylic compounds on the photophysical properties of ellipticine and its 6-methyl derivative: The origin of dual fluorescence

Miskolczy, Zsombor; Biczók, László; Jablonkai, István

doi:10.1016/j.cplett.2006.06.045

Cited by 23 publications

(43 citation statements)

References 23 publications

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“…Berberine, a clinically important natural isoquinoline derivative and the major alkaloid in Goldenseal ( Hydrastis canadensis L.), has been the subject of several thermodynamic, photophysical and photochemical studies (1–23). Similar studies have been reported for palmatine (4,5) and other related alkaloids, such as coralyne (24–29), sanguinarine (30–33), ellipticine (34–39) and flavopereirine (40). The molecular structures for these compounds are presented in Scheme 1.…”

Section: Introductionsupporting

confidence: 83%

“…For ellipticine in benzene, the sum of the quantum yield of singlet oxygen formation (Φ Δ = 0.45 in Table 4) and fluorescence (Φ f = 0.40) is close to unity indicating that intersystem crossing is the dominant radiationless deactivation pathway from the singlet excited state. The smaller Φ Δ = 0.28 (Table 4) and Φ f = 0.34 (37) values in acetonitrile imply that internal conversion gains in importance in polar solvent. For coralyne and flavopereirine, the photophysical characteristics are essentially independent of solvent.…”

Section: Resultsmentioning

confidence: 96%

“…The various alkaloids have been studied by spectroscopic means (1–40,48–51). They are salts, except for ellipticine, and are present as cations in solvents of sufficiently large polarity, whereas ion pair formation occurs in dichloromethane.…”

Section: Resultsmentioning

confidence: 99%

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Photoreduction and Ketone‐sensitized Reduction of Alkaloids

Görner¹,

Miskolczy

Megyesi

et al. 2011

Photochem & Photobiology

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The photoprocesses of berberine, palmatine, coralyne, sanguinarine, flavopereirine and ellipticine were studied in several solvents. The quantum yields Φ(Δ) of singlet molecular oxygen formation of berberine, palmatine and sanguinarine are moderate in dichloromethane (0.2-0.6) and much smaller in acetonitrile or trifluoroethanol. For the other alkaloids examined, Φ(Δ) is rather independent of solvent polarity. The direct and ketone-sensitized photolysis, using steady-state irradiation at 313 nm or 248/308 nm laser pulses, was studied by absorption and fluorescence spectroscopy. Thereby, radicals were observed yielding eventually dihydro derivatives as major products, which are thermally back-converted on admission of oxygen. The quantum yield of conversion of alkaloids to dihydroalkaloids is enhanced in the presence of triethylamine. The reaction in the presence of ketones and electron or H-atom donors has a quantum yield of close to unity.

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Section: Introductionsupporting

confidence: 83%

Section: Resultsmentioning

confidence: 96%

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Photoreduction and Ketone‐sensitized Reduction of Alkaloids

Görner¹,

Miskolczy

Megyesi

et al. 2011

Photochem & Photobiology

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“…The interaction with hydrogen bond acceptors and donors also led to substantial variation in the fluorescence characteristics of a pyridocarbazole alkaloid, ellipticine. [17][18][19] It was demonstrated that its dual fluorescence in methanol arose from excited state intermolecular proton transfer from the solvent to the nitrogen of the six-membered heterocyclic ring of the fluorophore. 19,20 In the present work, we focused on the fluorescent behavior of luotonin A (LuA).…”

Section: Introductionmentioning

confidence: 99%

“…[17][18][19] It was demonstrated that its dual fluorescence in methanol arose from excited state intermolecular proton transfer from the solvent to the nitrogen of the six-membered heterocyclic ring of the fluorophore. 19,20 In the present work, we focused on the fluorescent behavior of luotonin A (LuA). This is a natural pyrroloquinazolinoquinoline alkaloid (Scheme1) isolated from the Chinese plant Peganum nigellastrum, which has been used for the treatment of rheumatism, abscess, and inflammation.…”

Section: Introductionmentioning

confidence: 99%

Effect of hydrogen bonding and complexation with metal ions on the fluorescence of luotonin A

Miskolczy

Biczók

2013

Photochem Photobiol Sci

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Fluorescence characteristics of a biologically active natural alkaloid, luotonin A (LuA) was studied by steady-state and time-resolved spectroscopic methods. The rate constant of the radiationless deactivation from the singlet-excited state diminished by more than one order of magnitude when the solvent polarity was changed from toluene to water. Dual emission was found in polyfluorinated alcohols of large hydrogen bond donating power due to photoinitiated proton displacement along the hydrogen bond. In CH 2 Cl 2 , LuA produced both

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Study of DNA–ellipticine interaction by capillary electrophoresis with laser‐induced fluorescence detection

et al. 2012

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Ellipticine (5,11-dimethyl-6H-pyrido[4,3-b]carbazole), an alkaloid isolated from Apocynaceae plants, exhibits an antitumor activity, which is exceptionally high against several specific types of tumors. Ellipticine is also interesting as an anticancer drug as it has limited side effects and lacks of hematological toxicity. Various methods to study intercalating activity of this drug have been developed. However, to our best knowledge, capillary electrophoresis (CE) as a technique combining high separation resolution with various detection options has never been used for these purposes. In this study, a novel separation method based on CE with laser-induced fluorescence (CE-LIF) detection has been developed for the determination of ellipticine and for the monitoring of ellipticine-DNA interaction. Sodium acetate (50 mM, pH 4.5) was used as a background electrolyte and LIF detection at λ(ex) = 488 nm. The limit of detection for ellipticine was determined to be 5 × 10⁻⁸ M. A total of 20% dimethyl sulfoxide was found optimal as sample solvent. Additionally, intercalation of ellipticine into the double-stranded DNA was investigated. Signal corresponding to ellipticine was decreasing and a new peak appeared and was growing. It can be concluded that CE-LIF is a method applicable to in vitro studies of ellipticine-DNA complexes.

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Effect of hydroxylic compounds on the photophysical properties of ellipticine and its 6-methyl derivative: The origin of dual fluorescence

Cited by 23 publications

References 23 publications

Photoreduction and Ketone‐sensitized Reduction of Alkaloids

Photoreduction and Ketone‐sensitized Reduction of Alkaloids

Effect of hydrogen bonding and complexation with metal ions on the fluorescence of luotonin A

Study of DNA–ellipticine interaction by capillary electrophoresis with laser‐induced fluorescence detection

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