Luciferin dark oxidation

In slightly alkaline or slightly acid solutions luciferin undergoes a dark oxidation, spontaneously in the presence of molecular oxygen, or in the presence of certain agents such as ferricyanide or cerium sulfate (6). This reaction is slower in dilute hydrochloric acid or dilute sodium hydroxide. 

The collected results of experiments with crude and purified luciferin (99,100) indicate that it is a relatively small molecule, soluble in water, dilute acid, alkali and salt solutions, diffusible through cellophane, nonanti-genic, and not destroyed by trypsin. It has been estimated that luminescence visible to the dark-adapted eye may be obtained from luciferin in a dilution of 1 40,000,000,000 (94). With regard to some of the properties of luciferin, based on results obtained with crude extracts, it would be desirable to repeat the experiments with the purified material, inasmuch as different results are sometimes observed, e.g., cyanide apparently has no effect on the luminescent oxidation in crude extracts (91,185) but combines irreversibly with the luciferin in purified solutions (82). 

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