ESR-spin trapping analysis for hydroxyl radicals and superoxide anion radicals generated in photo-irradiated proanthocyanidin aqueous solution.

<p>(A) Representative ESR signals of DMPO-OH (open circle) and DMPO-OOH (solid circle) obtained when proanthocyanidin aqueous solution was irradiated with the laser-light for 15 s. (B) The yields of DMPO-OH and DMPO-OOH after given concentrations of proanthocyanidin were irradiated with the laser-light for 15 s. Each value is the mean of three independent measurements with the standard deviation.</p

Absorbance of 1 mg/mL proanthocyanidin at each wavelength.

<p>Each value is the mean of three independent measurements with the standard deviation. Significant differences in the absorbance at given wavelengths are shown as p<0.01 (**).</p

Changes in the antibacterial effect of disinfection treatment with photolysis of H₂O₂ in four bacteria.

<p><i>Staphylococcus aureus</i>, <i>Enterococcus faecalis</i>, <i>Escherichia coli</i>, and <i>Streptococcus salivarius</i> were exposed 40 times to disinfection treatment. Each value represents the mean ± standard deviation (n = 3).</p

MICs on the first, fifth, and tenth exposure of each bacterial species to antibacterial agents.

<p>Each value represents the mean of duplicate determinations.</p><p>Asterisks indicate induction of bacterial resistance to corresponding antibacterial agents as defined by an increase of four times or more in MIC over the initial MIC.</p

Schematic illustrations of susceptibility testing.

<p>(a) Antibacterial agents and (b) disinfection treatment with photolysis of H₂O₂ are shown.</p

Fold increases in MICs of antibacterial agents against four bacterial species during exposure to these agents.

<p>Each bacterial species was exposed 10 times. Each initial MIC is regarded as 1 MIC. Each value represents the mean of duplicate determinations.</p

A schema showing oxidation of a sterically hindered amine TPC (2,2,5,5-tetramethyl-3-pyrroline-3-carboxamide) by singlet oxygen to give rise to the nitroxide radical, and representative ESR spectra of the laser-irradiated mixtures containing rose bengal and a sterically hindered amine TPC.

<p>The mixture containing 450 mM TPC and 0, 1 or 10 µM rose bengal was irradiated by the laser light with a wavelength of 532 nm for 60 s. Open circle and closed circle indicate Mn²⁺ marker and the nitroxide radical, respectively.</p

The yield of DMPO-OH and DMPO-OOH generated by photo-irradiation of 1 mg/mL proanthocyanidin at different wavelengths.

<p>Photo-irradiation at each wavelength was performed at irradiance of 30 mW/cm² for 120 s. Each value is the mean of three independent measurements with the standard deviation. Significant differences between the conditions are demonstrated by the same alphabetic letters. p<0.01 (a, b). ND: not detected.</p

Influence of L-histidine, a singlet oxygen quencher, on the bactericidal effects of laser-irradiated photosensitizers.

<p>L-Histidine (25 and 100 mM) was added to the bacterial suspension containing 10 μM rose bengal, phloxine, or erythrosine, followed by laser-irradiation for 60 s. Each vealue represents the mean of nonuplicate determinations with standard deviation. Statistically significant differences from the corresponding P (−)L(−) group are shown as ** (p<0.01).</p

The yield of DMPO-OH and DMPO-OOH generated by photo-irradiation of 1 mg/mL proanthocyanidin with or without argon gas replacement.

<p>The laser irradiation was performed at an output power of 300 mW for 30 s. Each value is the mean of three independent measurements with the standard deviation. Significant differences between the conditions are shown as p<0.01 (**).</p