Measurement of rate constants for quenching singlet oxygen with a Cypridina luciferin analog (2-methyl-6-[p-methoxyphenyl]-3,7-dihydroimidazo[1,2-a]pyrazin-3-one) and sodium azide |
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| Authors: | Shinro Mashiko Nobutaka Suzuki Satoshi Koga Minoru Nakano Toshio Goto Toshihiko Ashino Iwao Mizumoto Humio Inaba |
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| Abstract: | The rate constants for 1O2] MCLA] and 1O2]NaN3] were measured by quenching the near-infrared emission (1Δg→3∑g) in steady state with MCLA and NaN3, respectively. 1O2 was constantly generated by energy transfer to O2 from Ar laser-excited Rose Bengal. The Stern—Volmer plots yielded the second-order rate constants of 2.94 × 109 M?1 S?1 and 3.83 × 108 M?1 S?1 for quenching 1O2 with MCLA and NaN3 in water at pH 5.4, respectively. The 1O2 + MCLA reaction emitted light with maximum at 465 nm at pD 4.5 identical to the O2? + MCLA reaction. |
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| Keywords: | Singlet oxygen Cypridina luciferin analogue MCLA quenching of singlet oxygen |
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