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SINGLET OXYGEN GENERATION BY HEMATOPORPHYRIN IX, UROPORPHYRIN I and HEMATOPORPHYRIN DERIVATIVE AT 546 nm IN PHOSPHATE BUFFER and IN THE PRESENCE OF EGG PHOSPHATIDYLCHOLINE LIPOSOMES
Author(s) -
Blum Aleksander,
Grossweiner Leonard I.
Publication year - 1985
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1985.tb03443.x
Subject(s) - hematoporphyrin , chemistry , singlet oxygen , phosphatidylcholine , liposome , quantum yield , dimer , porphyrin , histidine , phosphate , oxygen , phosphate buffered saline , derivative (finance) , nuclear chemistry , photochemistry , chromatography , fluorescence , photodynamic therapy , phospholipid , biochemistry , organic chemistry , membrane , quantum mechanics , financial economics , economics , amino acid , physics
— The quantum yield of singlet oxygen generation (φ) was measured at 546 nm with the p ‐nitrosodimethylaniline (RNO) method. The results obtained in pH 7.4 phosphate buffer (PB) were: φ(HP) = 0.44 ± 0.05: φ= 0.71 ± 0.07: φ(HpD‐A) = 0.06 ± 0.02. The value of φ was constant from 3 to 67 μM , attributed to the dominance of HP dimers; φ (HP) increased to 0.77 ± 0.13 in the presence of small egg phosphatidylcholine liposomes (SUV), attributed to solubilization and monomerization: φ (HpD‐A) increased to 0.87 ± 0.17 in the presence of SUV. attributed to monomerization of the impurity porphyrins and unfolding of the covalent dimer constituents. The quantum efficiency of the RNO system (100 μ M RNO plus 10 mM histidine) was approximately 0.015 at pH 7.4 and increased significantly at lower pH.