2,4-Dichlorobenzoic acid and a suite of models of chlorinated biphenyl carboxylic acids were found to be efficient sensitizers of the reactive oxygen species singlet oxygen (1O2).

A cyclodextrin dimer has been synthesized with two beta-cyclodextrins linked by a flexible chain containing a carbon-carbon double bond. This dimer binds and solubilizes a phthalocyanine-based photosensitizer that generates singlet oxygen on irradiation. When the complex is irradiated, the singlet oxygen cleaves the carbon-carbon link, and the cyclodextrins are released, liberating the photosen...

Thiosquaraine dyes have sulfur atoms instead of oxygens on the central squaraine core, and they are powerful singlet oxygen photosensitizers. Stability studies show that they are susceptible to attack by nucleophiles. This problem was circumvented by preparing a mechanically interlocked thiosquaraine rotaxane. NMR studies of the rotaxane indicate an unusual dynamic molecular structure due to a ...

Induction of gap junctional communication (GJC) and antioxidant activities of carotenoids have been considered as biochemical mechanisms underlying the cancer-preventive properties of these compounds. beta-Carotene and other carotenoids, including those lacking provitamin A activity, proved to be active in both these parameters. The beta-carotene analogs retrodehydro-beta-carotene, echinenone, ...

Astaxanthin is a coloring agent which is used as a feed additive in aquaculture nutrition. Recently, potential health benefits of astaxanthin have been discussed which may be partly related to its free radical scavenging and antioxidant properties. Our electron spin resonance (ESR) and spin trapping data suggest that synthetic astaxanthin is a potent free radical scavenger in terms of diphenylp...

Enabling the production of solar fuels on a global scale through artificial photosynthesis requires the development of water oxidation catalysts with significantly improved stability. The stability of photosystems is often reduced owing to attack by singlet oxygen, which is produced during light harvesting. Here, we report photochemical water oxidation by CoFPS, a fluorinated Co-porphyrin desig...