Erythrina americana

Epilhelantha micromeris (Eng.) Wbb.-i07,4o8 Ervatamia orientaUs (R. Br.) Domin.-37i-2 Erythrina americana Miller-423 Erythrina flabelliformis Kearney—423 Erythrina glauca Willdenow—217,270 Erythrinapoeppigana (Walp.) Cook-217,270 Erythroxylum coca Lamarck vax. ipadu Plowman—214,219,221,270,273 Erythroxylum sp.—212... 

Folkers and Major (12) isolated an active principal, which they called 8-erythroidine, from an extract of Erythrina americana Mill, which had been known for some time to exhibit a paralyzing action. Subsequent chemical investigations showed it to contain a tertiary nitrogen rather than a quaternary one, but it and certain of its derivatives have an effective paralyzing action they are effective orally and have been used clinically with some success. 

The extracts of seeds of plants of the Erythrina species have been known for over 60 years to exhibit a paralyzing action in animals (83). Lehman (84) showed that the paralytic action of alcohol extracts of the seeds of Erythrina americana is peripheral, and that the extract was effective in reducing convulsions in various test animals. Systematic examination of some 51 species of Erythrina showed that all contained alkaloids with paralyzing activity, the potency varying widely (85, 86). 

The biological activity of extracts of Erythrina species is known for a long time. Thus, concentrated extracts were used as arrow poisons by the natives of South America, as antidote against strychnine, or as hypnoticum and epilepticum (4). On the other hand when an alcoholic seed extract from Erythrina americana was applied to dogs in different doses an activity similar to that of d-tubocurarine was already observed in 1877 (2, 113) and confirmed much later (7, 114-118). 

The first crystalline pharmacologically active alkaloid was isolated from Erythrina americana mentioned above (7) and was called ery-throidine. This name had already been used by Altamirano referring, however, to the unknown constituents of the plant (774). Further analytical investigations revealed the material isolated to be a mixture of isomeric alkaloids, which were subsequently named a- and /3-erythroidines (14 and 225, see Figs. 2 and 4). 

Folkers K, Major RT (1937) Isolation of Erythroidine, an Alkaloid of Curare Action, from Erythrina americana Mill. J Am Chem Soc 59 1580... 

Lehman AJ (1936) Curare-Actions of Erythrina americana. Proc Soc Exp Biol Med 33 501... 

Lehman AJ (1937) Action of Erythrina americana, a Possible Curare Substitute. J Pharmacol Exp Ther 60 69... 

Ramirez E, Rivero MD (1935) Pharmacodynamic Action of Erythrina americana Mill [family Leguminoseae]. Anales Inst. Biol. (Mex.) 6 301 (Chem Abstr (1936) 30 3088 )... 

Garcia-Mateos R, Garin-Aguilar ME, Soto-Hemandez M, Martinez-Vasquez M (2000) Effect of /)-Erythroidine and /J-Dthydroerythroidine from Erythrina americana on Rats Aggressive Behaviour. Pharm Pharmacol Lett 10 34... 

Garin-Aguilar ME, Ramirez Luna JE, Soto-Hemandez M, del Toro GV, Vazquez MM (2000) Effect of Crude Extracts of Erythrina americana Mill, on Aggressive Behavior in Rats. J Ethnopharmacol 69 189... 

Garcia-Mateos, R. Peiez-Pacheco, R. Rodriguez-Hemandez, C. Soto-Hemandez, M. Toxicidad de alcaloides de Erythrina americana en larvas de mosquito Culex quinquefasciatus. Rev. Fitotec. Mex., 2004,27, 297-303. 

Alkaloid with curare-like action isolated from seeds of Erythrina americana. Mill. M.p. 94 -6°. Sol. HjO, MeOH, EtOH, CHa, C H . Mod. 

Erythroidine, CigHigOgN, as isolated from the seeds of Erythrina americana Mill by Folkers and Major,was described as having m.p. 94-6°, and yielding a hydrochloride, m.p. 228-9° (dec.), [a]f/° + 109-7° (HgO). It is also obtainable from many other Erythrina spp. and was subsequently shown to be a mixture of two stereoisomers, a- and jS-erythroidines. ( >... 

The beanlike seeds of the trees and shrubs of the genus Erythrina, a member of the legume family, contain substances that possess curare-like activity. The plants are widely distributed in the tropical and subtropical areas of the American continent, Asia, Africa, and Australia, but apparently they are not used by the natives in the preparation of arrow poisons. Of 105 known species, the seeds from more than 50 have been tested, and all were found to contain alkaloids with curariform properties. Erythroidine, from E. americana, was the first crystalline alkaloid of the group to be isolated. It consists of at least two isomeric alkaloids, a and P-erythroidine both are dextrorotatory. Most experimental and clinical study has centered on the b form because it is more readily obtainable in pure state. P-Erythroidine is a tertiary nitrogenous base. Several hydrogenated derivatives of p-erythroidine have been prepared of these, dihydro-P-erythroidine has been studied most carefully and subjected to clinical trial. Conversion of P-erythroidine into the quaternary metho salt (p-erythroidine methiodide) does not enhance, but rather almost entirely, abolishes its curariform activity this constitutes a notable exception to the rule that conversion of many alkaloids into quaternary metho salts results in the appearance of curare-like action. 

Traditionally, Erythrina species have found use amongst different communities for various ailments. The bark of E. fusca and E. indica, for example, has been used for the treatment of fever, malaria, rheumatism, toothache, boils and fractures. Boiled roots of the same were taken internally as a remedy for beriberi. In Kenya, a concoction of dried bark of E. ahyssinica has been used for the treatment of trachoma (oral) and elephantiasis (external) and its roots against malaria and syphilis, while the pounded green stem bark is taken as an antihelminthic [3]. The water extract of flowers of E. americana have been used in Mexico for the treatment of insomnia. The resl of other documented traditional medicinal uses are listed in Table 1. 

Compds. in both enantiomeric series appear to occur naturally but in most cases the abs. config.was not detd. Isol. from Anthyllis vulneraria, Erythrina sandwicensis, Hosackia americana, Lablab niger, Lotus spp., Phaseolus vulgaris and Tetragonolobus spp. 

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