Photochemical studies of A2-E.
Lipofuscin is thought to be involved in age-related macular degeneration as is one of its proposed components, an amphiphillic pyridinium-based bis-retinoid with a quaternary nitrogen atom, known as A2-E. We report the triplet state spectra obtained from photosensitisation using anthracene and 1-nitronaphthalene in benzene and methanol. The triplet state of A2-E has lambda(max) at 550 nm and a lifetime of approximately 30 micros, it is efficiently quenched by molecular oxygen with a second-order quenching rate constant of approximately 1 x 10(9) dm(3) mol(-1) s(-1). There is no significant triplet state formation from direct laser excitation of A2-E and hence its quantum yield of triplet state formation must be <0.01.
Cantrell
A
A
School of Chemistry and Physics, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG, UK. a.cantrell@chem.keele.ac.uk
McGarvey
D J
DJ
Roberts
J
J
Sarna
T
T
Truscott
T G
TG
D000873:Anthracenes / Q000737:chemistry; D001554:Benzene / Q000737:chemistry; D000432:Methanol / Q000737:chemistry; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry; D010777:Photochemistry; D010782:Photolysis; D012176:Retinoids / Q000737:chemistry*
C112040:A2-E (N-retinylidene-N-retinylethanolamine); D000873:Anthracenes; D009281:Naphthalenes; D012176:Retinoids; C016614:1-nitronaphthalene; C034020:anthracene; D001554:Benzene; D000432:Methanol