RT Journal Article SR Electronic T1 STUDIES ON PHYSOSTIGMINE AND RELATED SUBSTANCES IV. CHEMICAL STUDIES ON PHYSOSTIGMINE BREAKDOWN PRODUCTS AND RELATED EPINEPHRINE DERIVATIVES JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 364 OP 372 VO 79 IS 4 A1 SYDNEY ELLIS YR 1943 UL http://jpet.aspetjournals.org/content/79/4/364.abstract AB 1. Methods are described for the preparation of eseroline, rubreserine, eserine blue, eserine brown, and adrenochrome. 2. Rubreserine is shown to contain a substituted 2,3-dihydroindole-5,6-quinone group and thus to be structurally related to adrenochrome, the oxidation product of epinephrine. 3. The absorption spectra in the range 2200-6000Å of rubreserine, 2-iodoadrenochrome, and adrenochrome are reported. The spectra are similar in that each has a maximum at about 3000Å and another absorption peak in the range of 4900-5400Å.