Catalysis and Photocatalysis by Phthalocyanines for Technology, Ecology and Medicine

Kaliya, O. L.; Luk’yanets, E. A.; Vorozhtsov, Georgy N.

doi:10.1002/(sici)1099-1409(199908/10)3:6/7<592::aid-jpp180>3.0.co;2-g

Cited by 91 publications

(22 citation statements)

References 18 publications

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“…Antioxidants, as the name suggests are assumed as well as reported to be protective against damaging effect due to photo-oxidation (Jakus and Farkas, 2005;Stockert and Herkovits, 2003) yet sometimes the behavior may change for example in the presence of catalytic metals or at higher concentration they exhibit pro-oxidant activity (Jakus and Farkas, 2005;. In the case of PDT, some antioxidant molecules are reported to enhance the photodamaging effect of photosensitizer used in photodynamic therapy with various sensitizers and tumor models such as α-Tocopherol (Jakus and Farkas, 2005;Melnikova et al, 1999), Ascorbic acid (Bachowski et al, 1988;Buettner et al, 1993;Girotti et al, 1985;Jakus and Farkas, 2005;Kaliya et al, 1999;Kelley et al, 1997;Rosenthal and Ben-Hur, 1992), water-soluble vitamin E analog, Trolox (Jakus and Farkas, 2005;Melnikova et al, 2000) and BHA (Jakus and Farkas, 2005;. Therefore, few antioxidants can exaggerate the effects of photodynamic therapy with unknown mechanism.…”

Section: Introductionmentioning

confidence: 99%

Quenching of singlet oxygen by natural and synthetic antioxidants and assessment of electronic UV/Visible absorption spectra for alleviating or enhancing the efficacy of photodynamic therapy

2016

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Photodynamic therapy (PDT) is one of the methods involved in cancer therapy exploiting singlet oxygen as a weapon to kill cancer cells. Singlet oxygen, a bizarre reactive oxygen species as it is not related to electron transfer to O2 but it is one of the most active intermediate involved in biochemical reactions as it directly reacts with all the major macromolecules like DNA, protein, lipids etc, various photosensitized oxidations and in the photodegradation of dyes and polymers. Recent studies about the usage of antioxidant along with the photo-sensitizer involved in photodynamic therapy have shown concentration- dependent dual behavior like usually it retards the efficacy of PDT but at a higher dose mostly, it actually enhances the damaging effect of PDT. The natural and synthetic antioxidants are being used in our day to day life in order to increase the shelf life of various food ingredients and processed foods. In this paper, we have compared natural and synthetic antioxidants along with the known singlet oxygen quencher (DABCO) in order to understand the quenching potential of singlet oxygen (1O2) which is lowest electronically excited state of molecular oxygen. The singlet oxygen can be artificially generated through various methods such as sunlight, phosphate, ozonides, NaOCl & H2O2 etc. We have studied the mechanisms of the few antioxidant effects on the bleaching of RNO linked with the energy decay of 1O2 produced by the Mallet reaction (H2O2+HOCl → HCl+H2O+1O2). β-Carotene, α-Tocopherol, Ascorbic acid and Quercetin exhibited best dose-dependent singlet quenching ranging from 92.3 to 56.5 % at 100μM among others. Overall singlet oxygen is a major concern of light-related properties so we have analyzed the theoretical aspect of electronic UV/visible absorption spectra of the antioxidants studied through ZINDO CI semi-empirical Hamiltonian method. We have compared only the first singlet state of molecules in order to understand whether the structure of the molecules has any influence on the quenching potential. Considering the main features associated with singlet states, we have seen a drastic correlation between known sensitizer of singlet oxygen, i.e. Rose Bengal and DABCO, known scavenger of singlet oxygen in terms of energy and wavelength. This study is important as it highlights the behavior of antioxidant which can improve the effects of photosensitizer used in photodynamic therapy.

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Section: Introductionmentioning

confidence: 99%

Quenching of singlet oxygen by natural and synthetic antioxidants and assessment of electronic UV/Visible absorption spectra for alleviating or enhancing the efficacy of photodynamic therapy

2016

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“…Interestingly, some studies have shown the combinational use of certain antioxidants can also enhance the activity of PDT, in which process antioxidants exhibit pro-oxidant activities, especially in the presence of catalytic metals 103. Several research groups have reported results on the PDT enhancing activities of certain antioxidant molecules, such as ascorbate,104 3(2)-tetra-butyl-4-hydroxyanisole,105 epigallocatechin-3-gallate,106 α-tocopherol,107 and trolox ([±]-6-hydroxyl-2, 5, 7, 8-tetramethyl chromane-2-carboxylic acid, a water soluble vitamin E analogue) 108. Based on these intriguing results, some antioxidant carrier sensitizers (ACSs) which conjugated PSs and antioxidants together were designed and studied for their photodynamic anticancer109 and antibacterial activities 110.…”

Section: Pdtmentioning

confidence: 99%

Advance in Photosensitizers and Light Delivery for Photodynamic Therapy

2013

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The brief history of photodynamic therapy (PDT) research has been focused on photosensitizers (PSs) and light delivery was introduced recently. The appropriate PSs were developed from the first generation PS Photofrin (QLT) to the second (chlorins or bacteriochlorins derivatives) and third (conjugated PSs on carrier) generations PSs to overcome undesired disadvantages, and to increase selective tumor accumulation and excellent targeting. For the synthesis of new chlorin PSs chlorophyll a is isolated from natural plants or algae, and converted to methyl pheophorbide a (MPa) as an important starting material for further synthesis. MPa has various active functional groups easily modified for the preparation of different kinds of PSs, such as methyl pyropheophorbide a, purpurin-18, purpurinimide, and chlorin e6 derivatives. Combination therapy, such as chemotherapy and photothermal therapy with PDT, is shortly described here. Advanced light delivery system is shown to establish successful clinical applications of PDT. Phtodynamic efficiency of the PSs with light delivery was investigated in vitro and/or in vivo.

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“…Heme is one of the most important biological catalysts, so this similarity suggests that phthalocyanines in general and FePc in particular might be excellent catalyst materials for oxidation and other chemical reactions. 4,[7][8][9][10][11] Indeed, phthalocyanines have, e.g., been employed in the cathodic oxygen dissociation in fuel cells. [12][13][14][15][16][17][18][19][20][21][22][23] However, under fuel cell standard conditions, i.e., using pure hydrogen as the feed, the activity of FePc remains below that of the widely used precious metal catalysts such as platinum.…”

Section: Introductionmentioning

confidence: 99%

Electron spectroscopy study of the initial stages of iron phthalocyanine growth on highly oriented pyrolitic graphite

Isvoranu

Åhlund

Wang

et al. 2009

The Journal of Chemical Physics

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The nature of the intermolecular and substrate bonds of iron phthalocyanine adsorbed on highly oriented pyrolitic graphite has been investigated by x-ray photoelectron spectroscopy and x-ray absorption spectroscopy. We find that the molecules grow in a highly ordered fashion with the molecules essentially plane-parallel to the surface in both the mono- and multilayers. The spectra obtained on both types of film are virtually identical, which shows that the bonds both between the adsorbate and substrate and between the molecular layers have a pure van der Waals nature. Supporting density functional theory results indicate that the layers are stabilized by weak hydrogen bonds within the molecular layers.

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Catalysis and Photocatalysis by Phthalocyanines for Technology, Ecology and Medicine

Cited by 91 publications

References 18 publications

Quenching of singlet oxygen by natural and synthetic antioxidants and assessment of electronic UV/Visible absorption spectra for alleviating or enhancing the efficacy of photodynamic therapy

Quenching of singlet oxygen by natural and synthetic antioxidants and assessment of electronic UV/Visible absorption spectra for alleviating or enhancing the efficacy of photodynamic therapy

Advance in Photosensitizers and Light Delivery for Photodynamic Therapy

Electron spectroscopy study of the initial stages of iron phthalocyanine growth on highly oriented pyrolitic graphite

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