[3] Direct detection of singlet oxygen via its phosphorescence from cellular and fungal cultures

2002 ◽  
pp. 41-52 ◽  
Author(s):  
Piotr Bilski ◽  
Margaret E. Daub ◽  
Colin F. Chignell
Keyword(s):  
Singlet Oxygen ◽  
Direct Detection

scholarly journals Hydrogen Bond Acceptors and Additional Cationic Charges in Methylene Blue Derivatives: Photophysics and Antimicrobial Efficiency

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Ariane Felgenträger ◽  
Tim Maisch ◽  
Daniel Dobler ◽  
Andreas Späth
Keyword(s):  
Methylene Blue ◽  
Singlet Oxygen ◽  
Direct Detection ◽  
Photophysical Properties ◽  
Red Light ◽  
Quantum Yields ◽  
Antimicrobial Efficiency ◽  
Highly Active ◽  
Light Region ◽  
Multiresistant Bacteria

Photodynamic inactivation of bacteria (PIB) by efficient singlet oxygen photosensitizers might be a beneficial alternative to antibiotics in the struggle against multiresistant bacteria. Phenothiazinium dyes belong to the most prominent classes of such sensitizers due to their intense absorption in the red-light region ( ca. 600–680 nm,  L mol−1 cm−1), their low toxicity, and their attachment/penetration abilities. Except simple substituents like alkyl or hydroxyalkyl residues, nearly no modifications of the phenothiaziniums have been pursued at the auxochromic sites. By this, the properties of methylene blue derivatives and their fields of application are limited; it remains unclear if their potential antimicrobial efficacy may be enhanced, also to compete with porphyrins. We prepared a set of six mainly novel methylene blue derivatives with the ability of additional hydrogen bonding and/or additional cationic charges to study the substituents’ effect on their activity/toxicity profiles and photophysical properties. Direct detection of singlet oxygen was performed at 1270 nm and the singlet oxygen quantum yields were determined. In suspensions with both, Gram-positive and Gram-negative bacteria, some derivatives were highly active upon illumination to inactivateS. aureusandE. coliup to 7 log10steps (99.99999%) without inherent toxicities in the nonirradiated state.

Direct detection of singlet oxygen from isolated Photosystem II reaction centres

1993 ◽  
Vol 1143 (3) ◽  
pp. 301-309 ◽  
Author(s):  
Alisdair N. Macpherson ◽  
Alison Telfer ◽  
James Barber ◽  
T.George Truscott
Keyword(s):  
Photosystem Ii ◽  
Singlet Oxygen ◽  
Direct Detection ◽  
Reaction Centres

Direct detection and quantification of singlet oxygen during ischemia and reperfusion in rat hearts

1995 ◽  
Vol 269 (4) ◽  
pp. H1229-H1236 ◽  
Author(s):  
X. Zhai ◽  
M. Ashraf
Keyword(s):  
Cardiac Function ◽  
Singlet Oxygen ◽  
Present Method ◽  
High Performance ◽  
Direct Detection ◽  
Beta Carotene ◽  
Ischemia And Reperfusion ◽  
Rat Hearts ◽  
Major Factors ◽  
Isolated Rat

To detect singlet oxygen (1O2) in postischemic reperfused hearts, 5,8-endoperoxide, an oxidation product of beta-carotene, was used as a marker for 1O2 generation and was quantified using high-performance liquid chromatography (HPLC). Isolated rat hearts were subjected to ischemia for 5, 10, 20, 30, and 60 min followed by 10 min of reperfusion with buffer containing 25 microM beta-carotene. The coronary effluent was collected, extracted, and injected into the HPLC unit. The production of 5,8-endoperoxide was maximum during the first 2 min of reperfusion. Maximal accumulated amount of 1O2 was observed in hearts subjected to 60-min ischemia (36.2 +/- 1.7 nmol.10 min-1.g-1) as compared with 10-min ischemia (6.2 +/- 1.0 nmol.10 min-1.g-1). There was a good correlation between the amount of 1O2 production and cardiac function. Treatment with 25 mM histidine significantly decreased 5,8-endoperoxide from 7.02 +/- 0.47 to 0.98 +/- 0.11 nmol.min-1.g-1 (P < 0.01) and improved cardiac function in the group with 60-min ischemia. This study demonstrates that 1) the present method is useful and reliable for the measurement of 1O2 in the heart, 2) 1O2 production during reperfusion is dependent on the duration of initial ischemia, and 3) 1O2 is one of the major factors in postischemic reperfusion injury.

DIRECT DETECTION OF SINGLET OXYGEN SENSITIZED BY HAEMATOPORPHYRIN AND RELATED COMPOUNDS

1986 ◽  
Vol 43 (2) ◽  
pp. 117-120 ◽  
Author(s):  
J. P. Keene ◽  
D. Kessel ◽  
E. J. Land ◽  
R. W. Redmond ◽  
T. G. Truscott
Keyword(s):  
Singlet Oxygen ◽  
Direct Detection ◽  
Related Compounds

scholarly journals Direct Detection of Singlet Oxygen Generated by UVA Irradiation in Human Cells and Skin

2007 ◽  
Vol 127 (6) ◽  
pp. 1498-1506 ◽  
Author(s):  
Jürgen Baier ◽  
Tim Maisch ◽  
Max Maier ◽  
Michael Landthaler ◽  
Wolfgang Bäumler
Keyword(s):  
Singlet Oxygen ◽  
Direct Detection ◽  
Human Cells ◽  
Uva Irradiation
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