The Properties of Janus Green B as a Hill Oxidant.

Abstract

Janus Green B is shown to be reduced to diethyl safranine and dimethyl-paraphenylenediamine in a Hill-type reaction with illuminated chloroplasts isolated from Swiss chard or market spinach. The total yield of oxygen versus dye concentration goes through a maximum, and the percentage yield of oxygen from the dye falls continually with increasing dye concentration. "Hill''s solution" gives a far faster oxygen evolution than Janus Green B under comparable conditions. The inhibition of oxygen evolution rate which a first dose of Janus Green B exercises over a subsequent dose of Janus Green B is percentagewise far greater than the inhibition over a subsequent dose of "Hill''s solution" or quinone.