Formation Mechanism of the Colored Compounds Derived from Eserine (Physostigmine)

Francisco Sánchez-Viesca^1, and Reina Gómez¹

¹Organic Chemistry Department, Faculty of Chemistry, National Autonomous University of Mexico, Mexico City (CDMX), Mexico

Cite this paper:
Francisco Sánchez-Viesca and Reina Gómez. Formation Mechanism of the Colored Compounds Derived from Eserine (Physostigmine). World Journal of Organic Chemistry. 2020; 8(1):1-4. doi: 10.12691/wjoc-8-1-1

Abstract

Physostigmine (eserine) is an indole alkaloid isolated from a plant of Western Africa. It is interesting due its striking properties: a potent venom and a drug for open-angle glaucoma treatment. It gives two color reactions, a dark red due to rubreserine, a three ring o-quinone, and a seven ring phenoxazone with a splendid blue color. Though the structures of these compounds have been determined, there is no reaction mechanism related to their formation. We provide the reaction pathway and the electron flow for each reaction. Especially interesting is the case of eserine blue, to know how the molecule is integrated through many reaction intermediates and electron shifts.

Keywords:
Calabar bean eserine blue indole alkaloid physostigmine reaction intermediates reaction mechanisms

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References:

[1]	Sánchez-Viesca, F. and Gómez, R., “On the mechanism of the Froehde reaction”, World J. Org. Chem., 7(1), 1-4, 2019.
[2]	Sánchez-Viesca, F. and Gómez, R., “On the mechanism of the Neumann-Wender glucose test”, Am. J. Chem., 9(4), 123-126, 2019.
[3]	Sánchez-Viesca, F., Berros, M. and Gómez, R., “A complete and sustained Clemmensen reduction mechanism”, Am. J. Chem., 8(1), 8-12, 2018.
[4]	Sánchez-Viesca, F. and Gómez, R., “Reactivities involved in the Seliwanoff reaction”, Modern Chemistry, 6(1), 1-5, 2018.
[5]	Sánchez-Viesca, F., Berros, M. and Gómez, R., “On the mechanism of the Baeyer-Drewsen synthesis of indigo”, Am. J. Chem., 6(1), 18-22, 2016.
[6]	Jobst, J and Hesse, O, “Preparation of physostigmin”, Am. J. Pharm., 36, 334-336, 1864.
[7]	Jobst, J. and Hesse, O., “New alkaloid from the Calabar bean”, Am. J. Pharm., 36, 365-366, 1864.
[8]	Lloyd, J. U., Physostigma Venenosum (Calabar), The Western Druggist, Chicago, USA, 1897, 1-8.
[9]	Proudfoot, A., “The early toxicology of physostigmine”, Toxicol. Rev., 25(2), 99-138, 2006; references 50-53.
[10]	Veé, A. and Leven, M., “De l’alcaloïde de la fève de Calabar et expériences physiologiques avec ce même alcaloïde”, Journ. de Pharm. et de Chim.., [4], 1, 70-72, 1865. (Gallica, BnF).
[11]	Vee, A. and Leven, M., “On eserine, the alkaloid of the Calabar bean”, Chemical News (London), 11, 78, 1865.
[12]	Petit, A. and Polonovsky, M., “Étude sur l’ésérine”, Bull. Soc. Chim. France, [3], 9, 1008-1015, 1893.
[13]	Paech, K. and Tracey, M. V., Eds., Modern Methods of Plant Analysis, Springer, Berlin, Germany, 1955, vol. 4, 391-392.
[14]	Polonovski, M. and Polonovski, M., “Constitution de l’ésérine et des dérivés oxéséreniques”, Bull. Soc. Chim. France, 37, 744-759, 1925.
[15]	Karrer, P., Organic Chemistry, 3rd. ed., Elsevier, Amsterdam, The Netherlands, 1947, 877-878.
[16]	Stedman, E. and Barger, G., “Physostigmine (eserine). Part III”, J. Chem. Soc (London), 127, 247-258, 1925.
[17]	Morton, H. A., The Chemistry of Heterocyclic Compounds, McGraw-Hill, New York, USA, 1946, 116-117.
[18]	Pauling, P., and Petcher, T. J., “Crystal and molecular structure of eserine (physostigmine)”, J. Chem. Soc., Perkin Trans., (RSC), 2(10), 1342-1345, 1973.
[19]	Ellis, S., “Chemical studies on physostigmine breakdown products and related epinephrine derivatives”, J. Pharmacol. & Exp. Ther., 79(4), 364-372, 1943.
[20]	Autcrhoff, H. and Hamacher, H., “Color reactions of eserine”, Arch. Pharm., 300(10), 849-856, 1967; Chem. Abstr., 68, 6207y, 1968.
[21]	Petit A., “Sur une nouvelle matière colorante bleue dérivé de l’ésérine”, Compt. Rend. Acad. Sci., 62, 569-570, 1871.
[22]	Manske, R. H. F. and Holmes, H. L., Eds., The Alkaloids: Chemistry and Physiology, Academic Press, New York, USA, 1971, vol. 13, p 221.