The reactivity of catecholamine neurotransmitters and the related metabolites were precisely investigated toward 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and reactive oxygen species. Catecholamines reacted immediately with DPPH radicals, their reactivity being stronger than that of ascorbic acid as a reference. Superoxide scavenging activities of catecholamines determined by WST-1 and elec...

Treatment of hydrogen peroxide with a polymer-supported hypervalent iodine compound, poly[4-diacetoxyiodo] styrene (PDAIS), generates singlet molecular oxygen (O2) . Singlet oxygen generation was proved by trapping with typical organic compounds such as conjugated dienes, aromatic dienes, and electron-rich alkene. When compared to monomer analogue, the use of PDAIS in peroxidation of substrates...

The photosensitized generation of singlet oxygen within tumor tissues during photodynamic therapy (PDT) is self-limiting, as the already low oxygen concentrations within tumors is further diminished during the process. In certain applications, to minimize photoinduced hypoxia the light is introduced intermittently (fractional PDT) to allow time for the replenishment of cellular oxygen. This con...

A Bodipy-based energy transfer cassette with a singlet oxygen reactive linker between the donor and acceptor modules has an interesting emergent property, if the acceptor module is also a photosensitizer. Singlet oxygen produced by the photosensitizer reacts rapidly with the molecule itself to liberate the energy donor, resulting in an enhanced fluorescence emission. The result is a self-report...

A microphotoreactor device was developed to generate bubbles (1.4 mm diameter, 90 μL) containing singlet oxygen at levels toxic to bacteria and fungus. As singlet oxygen decays rapidly to triplet oxygen, the bubbles leave behind no waste or byproducts other than O(2). From a comparative study in deaerated, air saturated, and oxygenated solutions, it was reasoned that the singlet oxygen bubbles ...

Singlet oxygen ((1)O(2)) is a highly reactive form of molecular oxygen that may harm living systems by oxidizing critical cellular macromolecules. The oxyR gene product regulates the expression of the enzymes and proteins that are needed for cellular protection against oxidative stress. In this study, the role of oxyR in cellular defense against a singlet oxygen was investigated using Escherich...

Both singlet oxygen and the hydroxyl radical are generated in mammalian ccHs by UVA (~3Z0---~3{50 rim) and possibly near-visible (~{50--420 nm) radiation. We have modulated the cellular levels of these two reactive oxygen species in order to compare their involvement in the induction of the human heme 0xygenase (I40) gene by broad spectrum UVA/nearvisible light 0LIVA/NVL). Irradiation in deuter...

Both singlet oxygen and the hydroxyl radical are generated in mammalian ccHs by UVA (~3Z0---~3{50 rim) and possibly near-visible (~{50--420 nm) radiation. We have modulated the cellular levels of these two reactive oxygen species in order to compare their involvement in the induction of the human heme 0xygenase (I40) gene by broad spectrum UVA/nearvisible light 0LIVA/NVL). Irradiation in deuter...