Tests for Alkaloids

This solution is extracted several times with 5% acetic acid, until the silico-tungstate test (an identification test for alkaloids) yields a negative result, and the acetic solutions are washed with 10 ml ether. 

Nitrogenous compounds are known (betacyanins and belaxan-lliins) but no alkaloids in the strictest sense have been described. Betaines often give positive tests for alkaloids, which may account for the report of several unnamed alkaloids in nine genera. 

There has been but one positive test for alkaloids recorded for this small gymnosperm family (A gal his australis). A lest of this species was negative as well as tests on A. moorei, A. ovata, A. robusta, Agathis sp., A. vitensis, Araucaria bididellii, A. cookii, A. cunninghamii,A. excelsa, and A. rulei. 

Positive tests for alkaloids were obtained with llie following species previously known to be alkaloidal Aristolochia elegans, A. giganlea, A. tagala. In addition, an unidentified Aristolochia sp. was found to be positive (1/3). 

One sample of an undetermined species gave a positive test for alkaloids in this study. The chemistry of the family is otherwise unknown, although alkaloids are known for the Zygophyllaceae. 

One species, Balanops australiana, gave a negative test for alkaloids. Nothing is known of the chemistry of the family. 

Only one species, Coriaria myrlifolia, has been reported to give a test for alkaloids in this study six samples representing four species of the genus were negative C. japonica, C. papuana, C. ruscifolia, C. thymifolia. 

This is a family of tropical America little of its chemistry is known. Right samples and eight species were tested for alkaloids with negative results Marcgravia harlii, M. elegans, M. noruntes,... 

Occasional positive tests for alkaloids have been noted earlier in the family. Here, of 22 samples representing 18 species, only three gave positive tests Galearia celehica, Microdesmis puberula (branches), and Pandanus teciorius (1/3). 

Five samples representing four species were tested for alkaloids with the following results Azima tctracantha (1/3) was known to be positive while three species of Salvadora gave negative results S. angustifolia, S. indica, S. australis. 

In early reports, two species of Sarracenia gave positive tests for alkaloids but more recent references mention only the presence of amino acids. 

A few species of the genus have been reported to give positive tests for alkaloids, but three species tested in this study were negative Tacca chanlrieri, T. leontopetalnides, T. pinnatifida. 

Positive tests for alkaloids have been noted for a few species, but apparently they have not yet been characterized. Ten samples of... 

Not much is known of its chemistry. Positive tests for alkaloids have been obtained in several species S-hydroxytryptamine has been identified in Urlica the substance responsible for the burning sensation from the leaves of Laporlea is a complex octapeptidc piperidine derivatives are found in the family as well. 

Ephedrine occurs in white, rosette, or needle crystals, or as an unctuous mass. It is soluble in water, alcohol, chloroform, ether, and in liquid petrolatum, the latter solution being turbid if the ephedrine is not dry. Ephedrine melts between 34 and 40°C, depending upon the amount of water it contains it contains not more than 0.1% of ash its solutions are alkaline to litmus it readily forms salts with acids and it responds to the usual tests for alkaloids. Ephedrine excites the sympathetic nervous system, depressing smooth and cardiac muscle action, and produces effects similar to those of epinephrine. It produces a rather long-lasting rise of blood pressure and mydriasis and diminishes hyperemia. The alkaloid may be used in 0.5 to 2% oil spray. 

Alkaloids are widespread in plants and include some very well-known poisons (notably coniine and strychnine), hallucinogens (morphine, cocaine and muscimol) and other potentially lethal compounds that are nevertheless used in medical practice (e.g. atropine, codeine, colchicine and morphine). As indicated by the preliminary snap-shot above, alkaloids typically have names ending in -ine and which are often related to the plant source or properties. Thus, morphine was named after Morpheus (the God of sleep) and coniine derives from Conium maculatum (hemlock), the plant used in the judicial murder of Socrates (399 BC). Various chemical tests for alkaloids are used as preliminary indicators of alkaloid presence in crude plant extracts. Finally, it should be noted that alkaloids can also exist as jVoxides of the alkaloid base. 

Newer methods of chemical analysis led to the isolation of the major alkaloids from crude drug preparations. By 1833, aconitine, atropine, codeine, hyoscyamine, morphine, nicotine, and strychnine had been isolated from plants. Color tests for alkaloids were developed between 1861 and 1882 by 1890 quantitative analysis methods became available. Physiological tests for alkaloids, particularly strychnine, first used in 1856, were employed well into the twentieth century. Tests for alcohol, devised by Lieben (iodoform crystal test, 1870) and others, were later perfected for the quantitative analysis of alcohol in body fluids and tissues. Qualitative tests for carbon monoxide in the blood were developed about this time and in 1880, Fodor developed a palladium chloride reduction method to quantitate carbon monoxide in blood. 

Use Analysis (testing for alkaloids and cesium), dyeing intermediates, as chlorine carrier in organic chlorinations. 

Use Microanalysis (testing for alkaloids), preparing Rohrbach solution. 

Table 1. Species Giving Positive Tests for Alkaloids in Regional Surveys 6... 

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