Measurement of 1268 nm Emission for Comparison of Singlet Oxygen (1.DELTA.g) Production Efficiency of Various Dyes.

Abstract

Singlet oxygen generation from laser-excited photosensitive dyes was measured directly using a sensitive near-infrared emission spectrometer to monitor the O2(1 delta g)-->O2(3 sigma -g) transition at 1268 nm. The emission intensity was proportional to both the laser power and the concentration of the dyes. The singlet oxygen producing ability of the dyes was compared with that of eosin YS as a standard in methanol. The relative efficiencies of singlet oxygen generation were determined for rose bengal, erythrosine B, phloxine B and eosin YS as 2.39, 1.73, 1.38, 1.00, respectively, while uranine showed no emission in this spectral region. Using rose bengal, erythrosine B, phloxine B and eosin YS, the efficiency of singlet oxygen generation correlated with the photobleaching reaction rate of azo-dyes by these dyes, suggesting singlet oxygen to be a species responsible for causing the photobleaching of azo-dyes. The halogen substituent effect on the efficiency of singlet oxygen generation from laser-excited photosensitive dyes was also examined systematically.

Inhibition Mechanism of UDP-Glucuronosyltransferase 1A6 by Xanthene Food Dyes

“…[17][18][19][20][21][22] 8,14) Our previous results showed that the activity levels of CYP2A6 and UGT in bovine liver microsomes were similar to human liver microsomes 4,28,29) but differed from rat microsomes, as rat microsomes did not involve CYP2A6 activity. Thus, it was considered that bovine microsome data were very similar to human microsome data.…”

“…16) Meanwhile, phenyl-xanthene dyes, such as rose bengal (RB), ET, phloxine (PL), eosin (ES), uranine (UR), rhodamine (RM), and fluorescein are known as light-enhancing reagents (catalytic light reaction) by the generation of 1 O 2 on those dyes. [17][18][19][20][21][22][23] There are two types of reaction: the first is that drug energy enhanced by light is transferred to biomolecules and free radicals originate on the molecules. The second is that energy is transferred to oxygen, which changes to 1 O 2 .…”

EPR study of photochemical transformations of triarylmethane dyes

“…Acid Red 87 (Eosin Y) and C.I. Basic Blue 9 (Methylene Blue) in oxygenated media are defined as effective producers of singlet oxygen [53][54][55][56]. However, the information on the ability of triarylmethane dyes to generate 1 O 2 upon photoexcitation found in literature is not consistent.…”

Photodegradation of Environmental Mutagens by Visible Irradiation in the Presence of Xanthene Dyes as Photosensitizers

“…3 1) Although these dyes have been widely used as food additives for their bright color and stability, it is well known that the dyes with halogen substituents (erythrosine, rose bengal, and phloxine) act as efficient photosensitizers, as observed for porphyrin derivatives. [2][3][4][5][6][7] Under irradiation in aqueous solution, these xanthene dyes support the generation of reactive oxygen species such as singlet molecular oxygen ( 1 O 2 ) and superoxide anion radicals (O 2 − ) by energy transfer and electron transfer processes, respectively. [2][3][4][5][6][7] The strong oxidative action of the reactive oxygen species generated by these processes has been studied for a variety of applications including DNA scission 8) and photodynamic therapy, 9) among others.…”

“…[2][3][4][5][6][7] Under irradiation in aqueous solution, these xanthene dyes support the generation of reactive oxygen species such as singlet molecular oxygen ( 1 O 2 ) and superoxide anion radicals (O 2 − ) by energy transfer and electron transfer processes, respectively. [2][3][4][5][6][7] The strong oxidative action of the reactive oxygen species generated by these processes has been studied for a variety of applications including DNA scission 8) and photodynamic therapy, 9) among others. [10][11][12][13] Many environmental mutagens, such as 3-amino-1,4-dimethyl-5H-pyrido [4,3-b] indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido [4,3-b] indole (Trp-P-2), 2-amino-3-methyl-9H-pyrido [2,3-b] indole (MeAαC), and 2-amino-3-methyl-imidazo [4,5-f ] quinoline (IQ), are known to be present in our surrounding environment and have been identified as human carcinogens.…”