PMID: 39633Sep 1, 1979

Photochemical reaction of chlorophyll a and pheophytin a with low concentrations of hydroquinone

V B Evstigneev, V A Gavrilova


It has been shown that when illuminating chlorophyll a solution (approximately 10(-5) M) in ethanol containing small concentrations of hydroquinone at pH higher than 7, a markable negative photopotential (-PhP) is initiated. Similar picture is also observed both in the presence of 2 . 10(-5) M parabenzoquinone and when using pheophytin a instead of chlorophyll. The data obtained are in favour of the idea that when illuminating the solutions of these pigments in ethanol containing pure p-benzoquinone at pH higher than the definite value, PhP initiation is conditioned by photochemical reaction of pigments with equilibrium amounts of hydroquinones or semiquinone always present in quinone solutions.

Related Concepts

Ethanol Measurement
Pheophytin a
Transcription Initiation
Chlorophyll a
Hydrogen-Ion Concentration

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