Chlorophyll aa′ epimerization in organic solvents

Watanabe, Tadashi; Mazaki, Hitoshi; Nakazato, Masataka

doi:10.1016/0005-2728(87)90175-7

Cited by 40 publications

(11 citation statements)

References 28 publications

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“…Our previous studies (8)(9)(10)(11) have shown that the Chl a is effectively solubilized in aqueous environment by means of various *Corresponding author email: p.cosma@chimica.uniba.it (Pinalysa Cosma) CDs. In these aqueous systems, Chl a results to be much more stable than when it is solubilized using alcohol as cosolvent (12)(13)(14)(15). Our studies indicate the formation of inclusion complexes between Chl a and CDs characterized by different binding constants and stoichiometry (9,11,16) depending on CD chemical nature taken into exam.…”

Section: Introductionmentioning

confidence: 77%

Identification of Ros Produced by Photodynamic Activity of Chlorophyll/Cyclodextrin Inclusion Complexes

Cellamare

Fini

Agostiano

et al. 2012

Photochem & Photobiology

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Photodynamic therapy (PDT) is a way of treating malignant tumors and hyperproliferative diseases. It is based on the use of photosensitizer, herein the chlorophyll a (chl a), and a light of an appropriate wavelength. The interaction of the photosensitizer (PS) with the light produces reactive oxygen species (ROS), powerful oxidizing agents, which cause critical damage to the tissue. To solubilize chl a in aqueous solution and to obtain it as monomer, we have used cyclodextrins, carriers which are able to interact with the pigment and form the inclusion complex. The aim of this study is to examine which types of ROS are formed by Chl a/cyclodextrin complexes in phosphate buffered solution and cell culture medium, using specific molecules, called primary acceptors, which react selectively with the reactive species. In fact the changes of the absorption and the emission spectra of these molecules after the illumination of the PS provide information on the specific ROS formation. The (1) O2 formation has been tested using chemical methods based on the use of Uric Acid (UA), 9,10-diphenilanthracene (DPA) and Singlet oxygen sensor green (SOSG) and by direct detection of Singlet Oxygen ((1) O2 ) luminescence decay at 1270 nm. Moreover, 2,7-dichlorofluorescin and ferricytochrome c (Cyt Fe(3+) ) have been used to detect the formation of hydrogen peroxide and superoxide radical anion, which reduces Fe(3+) of the ferricytochrome to Fe(2+) , respectively.

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Section: Introductionmentioning

confidence: 77%

Identification of Ros Produced by Photodynamic Activity of Chlorophyll/Cyclodextrin Inclusion Complexes

Cellamare

Fini

Agostiano

et al. 2012

Photochem & Photobiology

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“…At this time there is no feasible way of determining whether this is because of incidental Chl d epimerization or true stoichiometric adjustment of the photosystems. The high variations in chlorophyll epimerization that have been reported (28) suggest that the quantitative use of Chl dЈ as a measure of PSI (1) is inappropriate.…”

Section: Discussionmentioning

confidence: 99%

Effect of Iron on Growth and Ultrastructure of Acaryochloris marina

Swingley

Hohmann‐Marriott

Olson

et al. 2005

Appl Environ Microbiol

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The cyanobacterial genus Acaryochloris is the only known group of oxygenic phototrophs that contain chlorophyll d rather than chlorophyll a as the major photosynthetic pigment. Studies on this organism are still in their earliest stages, and biochemical analysis has rapidly outpaced growth optimization. We have investigated culture growth of the major strains of Acaryochloris marina (MBIC11017 and MBIC10697) by using several published and some newly developed growth media. It was determined that heavy addition of iron significantly enhanced culture longevity. These high-iron cultures showed an ultrastructure with thylakoid stacks that resemble traditional cyanobacteria (unlike previous studies). These cultures also show a novel reversal in the pigment ratios of the photosystem II signature components chlorophyll a and pheophytin a, as opposed to those in previous studies.

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“…Thus, only the propionate group of the RCC D-ring is commonly recognized by hydrophilic interactions in chains A and B. The C13 2 position of chlorophylls is easily epimerized in organic solvent, 27 although most of the chlorophylls that are bound to lightharvesting complexes are not epimerized in vivo. It would be conceivable that chlorophylls and chlorophyll catabolites are epimerized during chlorophyll degradation because these wasted pigments are not always bound to proteins.…”

Section: Rcc-binding Mechanismsmentioning

confidence: 99%