Spectral and photochemical characteristics of the photosensitizers chlorin e 6 and photolon in the presence of melanin

Parkhots, M. V.; Lapina, V. A.; Butorina, Daria N.; Sobchuk, A. N.; Lepeshkevich, S. V.; Krasnovskiï, A. A.; Джагаров, Б. М.

doi:10.1134/1.1890515

Cited by 6 publications

(8 citation statements)

References 19 publications

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“…Thus, in answer to the question posed in the work, i.e., can ME in principle bind and retain CHTC or DC through complexation, we have positive results (in contrast with previous results for chlorin e 6 and photolon [18]). Furthermore, the signatures and certain properties of the complex formed by CHTC and ME are described by spectroscopic methods.…”

contrasting

confidence: 54%

“…A more detailed study of the decay curves as a function of λ de for only ME solutions showed that changing the detection wavelength from 425 to 630 nm changes the characteristic times τ i by less than 10%, the decay times being greater for λ de = 425 nm. Our measurements that showed little shift and shape change of the ME band as a function of λ ex and previous work [18] indicate that instantaneous FS of ME solutions do not change shape in 0-8.5 nsec, indicating that ME solutions do not exhibit significant spectral-time heterogeneity. Fig.…”

supporting

confidence: 51%

“…Knowledge of the mechanisms causing the development of oxidative stress and the mechanisms capable of influencing this process would enable the discovery of ways to reduce the phototoxicity of photosensitizers while preserving their useful properties. It has been shown [18] that not all photosensitizers are capable of binding ME. Naturally, this heightens the interest in studying complexation between ME and photosensitizing drugs.…”

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confidence: 99%

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Complexation in two-component chlortetracycline-melanin solutions

et al. 2008

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UDC (541.14+541.15):615.015The spectra and kinetics of fluorescence of two-component solutions of the chlortetracycline (CHTC)-DOPAmelanin (melanin or ME) system in water have been investigated. The data obtained have been compared to similar data for solutions of CHTC-melanosome from bull eye (MB), which contains natural melanin, in Kphosphate buffer at pH 7.4. The overall results indicate the occurrence of complexation between molecules of CHTC and ME as they are being excited. The studies of complexation in the solution of CHTC-MB in the buffer are complicated by the formation of a CHTC-buffer complex. The effect of optical radiation in the range 330-750 nm on the CHTC-ME complex shows selectivity: the greatest change in the spectrum occurs when the wavelength of the exciting radiation coincides with the long-wavelength band maximum of the fluorescence excitation spectrum of the CHTC-ME complex in aqueous solution. In this range, CHTC and especially ME show high photochemical stability. The nature of the radiation effect on the studied compounds in the hard UV range (λ < 330 nm) differs greatly from that in the range 330-750 nm. It is apparently accompanied by significant photochemical transmutations of all system components. By comparing the characteristics of the CHTC-ME systems with those of the related drug doxycycline (DC-ME), the conclusion has been made that the chlorine atom plays a vital role in formation of the short-wavelength band in the fluorescence spectrum of the CHTC-ME complex.

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confidence: 54%

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confidence: 51%

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confidence: 99%

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Complexation in two-component chlortetracycline-melanin solutions

et al. 2008

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“…Melanin pigments, in addition to their functions as a singlet oxygen quenching agent, an inhibitor of free-radical reactions, a chemical protector etc. [19,20], also play the role of a unique sunscreen for radiation in the UV and visible region of the spectrum, significantly reducing the radiation intensity and photobiological activity [21].…”

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Effect of exposure of sturgeon roe to low-intensity laser radiation on the hardiness of juvenile sturgeon

Plavskiia

Barulin

2008

J Appl Spectrosc

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We present data on the effect of polarized laser radiation in the near IR region of the spectrum with wavelength 808 nm on the resistance of juvenile sturgeon to oxygen deficiency in the habitat when the fertilized roe are briefly exposed to radiation in the organogenesis stage. The magnitude of the stimulating effect depends on the exposure time (t) and power density (P) of the radiation and also on its modulation frequency (F). For optimal irradiation parameters (cw mode, P = 2.9 mW/cm 2 , t = 60 sec), the hardiness of the juveniles increases by a factor of ~1.5 compared with the control group. The maximum differences in the sensitivity of embryos to cw and pulsed radiation are observed for F = 1 Hz; as the modulation frequency increases up to F = 50 Hz, the magnitude of the photobiological effect approaches a level typical for cw exposure. We show that the duration of the dark period (pause time) between pulses is the critical parameter determining the dependence of the stimulating effect on the modulation frequency. We discuss questions concerning use of the indicated physical factor in the technology for raising sturgeon under industrial fish farming conditions. Introduction. Economically sound technologies for industrial raising of valuable fish species (sturgeon, salmon, whitefish) have attracted the attention of an increasing number of fish farms [1][2][3]. In this case, fish farming efficiency is mainly determined by the hardiness of the juvenile at the time it is released into artificial and natural bodies of water, in which it is subject to the effect of diverse biotic and abiotic habitat factors. The concentration of dissolved oxygen is an important factor in an aquatic environment, which fluctuates significantly both under artificial conditions and under farm conditions for raising a standard fish juvenile. When there is a deficiency of oxygen dissolved in the water, for the farm-raised juvenile we may observe a number of morphological deviations: head deformities, microcephaly (reduced brain size), underdeveloped gills, defects in the olfactory organs, etc. Most often, such a fish considerably lags behind normally developing individuals in size-weight parameters [1]. Furthermore, a significant deficiency of oxygen dissolved in the water can cause large-scale kills of fish fry. This is why development of methods for improving the resistance of juvenile fish to oxygen deficiency is an important problem in modern fish farming practice. There are quite good grounds for the interest of ichthyologists [4][5][6][7][8][9][10][11] in the stimulating effect of optical (including laser) radiation, which has been successfully used for a long time for treatment of human diseases [12,13], treatment and stimulation of weakened animals [14,15], and also for stimulation of plants [16,17]. However, attempts to use laser radiation in the red region of the spectrum (helium-neon laser, λ = 632.8 nm) in fish farming have shown that its effect on sturgeon and stellate sturgeon either proves to have (de-

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“…The porphyrin-photosensitized oxygenation of biologically important compounds (photodynamic action) is widely used in medicine for treatment of cancer and infectious diseases (photodynamic therapy, PDT). [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Usually, oxygenation is due to the reactivity of singlet oxygen, which is generated by triplet molecules of photosensitizers. In some cases, the triplet molecules can oxidize biosubstrates directly, but the efficiency of the porphyrin involvement in these reactions is usually very low.…”

Section: медные комплексы хлоринов производных хлорофилла а как потmentioning

confidence: 99%

Copper Сomplexes of Сhlorin Derivatives of Chlorophyll a as Potential Photosensitizers for Medical Purposes

Белых¹,

Kozlov²,

Pylina³

et al. 2019

MHC

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The absorption and fluorescence properties, singlet oxygen photosensitization and photoinduced cytotoxic activity in the HeLa cells line were investigated for copper complexes of chlorins (methylpyropheophorbide a and exocyclefree 13-amide derivatives of chlorin e 6 dimethyl ether) obtained by chemical modification of chlorophyll a. The results are compared with the properties of metal-free analogs. It is shown that both copper complexes and metal free chlorins generate singlet oxygen under photoexcitation in solutions and show distinct phototoxicity in living cells. The photosensitizing effect of copper complexes is 4-13 times smaller, but remains rather high. According to the biological experiments, the activity of copper complexes is sufficient for photodynamic killing of HeLa cells. At the same time, the dark toxicity of copper complexes is lower than that of metal free chlorins. These data allow us to consider copper complexes of chlorins as a new class of photosensitizers, potentially suitable for the use in PDT.

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Spectral and photochemical characteristics of the photosensitizers chlorin e 6 and photolon in the presence of melanin

Cited by 6 publications

References 19 publications

Complexation in two-component chlortetracycline-melanin solutions

Complexation in two-component chlortetracycline-melanin solutions

Effect of exposure of sturgeon roe to low-intensity laser radiation on the hardiness of juvenile sturgeon

Copper Сomplexes of Сhlorin Derivatives of Chlorophyll a as Potential Photosensitizers for Medical Purposes

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