Piotr J Bilski

Learn More
The Cercospora nicotianae SOR1 (singlet oxygen resistance) gene was identified previously as a gene involved in resistance of this fungus to singlet-oxygen-generating phototoxins. Although homologues to SOR1 occur in organisms in four kingdoms and encode one of the most highly conserved proteins yet identified, the precise function of this protein has,(More)
Vitamin B6 (pyridoxine, 1) and its derivatives: pyridoxal (2), pyridoxal 5-phosphate (3) and pyridoxamine (4) are important natural compounds involved in numerous biological functions. Pyridoxine appears to play a role in the resistance of the filamentous fungus Cercospora nicotianae to its own abundantly produced strong photosensitizer of singlet molecular(More)
Singlet molecular oxygen (1O2) is one of the major agents responsible for (photo)oxidative damage in biological systems including human skin and eyes. It has been reported that the neural hormone melatonin (MLT) can abrogate 1O2-mediated cytotoxicity through its purported high antioxidant activity. We studied the interaction of MLT with 1O2 in deuterium(More)
Reactions of tryptophan residues in proteins with radical and other oxidative species frequently lead to cleavage of the indole ring, modifying tryptophan residues into N-formylkynurenine (NFK) and kynurenine. Tryptophan modification has been detected in physiologically important proteins and has been associated with a number of human disease conditions.(More)
Norfloxacin is a fluoroquinolone (FQ) antibiotic that has been reported to cause cutaneous photosensitivity in animals and occasionally in humans. We have studied the fluorescence and singlet oxygen (1O2)-generating properties of norfloxacin. Upon UV excitation the drug fluoresces in water, and the relative intensities of two major fluorescence bands at ca(More)
Sterols are important lipid components that may contribute to phototoxicity. We have found that phototoxic response in earthworms is related to sterols extractable with lipophilic solvents. The photochemically active compounds in worm lipids are 5,7,9(11),22-ergostatetraen-3 beta-ol (9-DHE) and 5,7,9(11)-cholestartien-3 beta-ol (9-DDHC), respectively. Human(More)
In this study we report the phototoxicity toward HaCaT keratinocytes that results from the photogeneration of superoxide and singlet oxygen ((1)O(2)) by four different "water-soluble" fullerene (C(60)) preparations-monomeric (gamma-CyD)(2)/C(60) (gamma-cyclodextrin bicapped C(60)) and three aggregated forms-THF/nC(60) (prepared by solvent exchange from THF(More)
We have undertaken electron paramagnetic resonance and spin trapping investigations of the photochemistry of kynurenine (KN), a natural component of the human eye and close analog of the principal chromophore in the young human lens 3-OH-kynurenine O-glucoside (3HKG). 5,5-Dimethyl-1-pyrroline N-oxide (DMPO) was employed as a spin trap. We found that upon UV(More)
Nanoparticles have been explored recently as an efficient means of delivering photosensitizers for cancer diagnosis and photodynamic therapy (PDT). Silicon phthalocyanine 4 (Pc4) is currently being clinically tested as a photosensitizer for PDT. Unfortunately, Pc4 aggregates in aqueous solutions, which dramatically reduces its PDT efficacy and therefore(More)
Curcumin, bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione, is a natural yellow-orange dye derived from the rhizome of Curcuma longa, an East Indian plant. In order to understand the photobiology of curcumin better we have studied the spectral and photochemical properties of both curcumin and 4-(4-hydroxy-3-methoxy-phenyl)-3-buten-2-one (hC, half(More)