Solanaceous alkaloids

The names, formulae and structures of these alkaloids are given in the following table. The esters of tropine or -tropine are known as tropeines or -tropeines respectively. The first eleven items in the table are sometimes called the solanaceous alkaloids, but they are not the only alkaloids, or even the only type of alkaloid, found in the botanical family Solanaceas. They are also sometimes referred to as the mydriatic alkaloids though other alkaloids also exert this action. 

Solanaceous alkaloids, 64 analytical methods, 69 distribution in plants, 65-7 pharmacological action, 105 Solandra spp., 66, 82 Solandrine, 82 Solaneine, 662... 

Tropane Group. SolanaceOus Alkaloids, Convolvine and Allied Alkaloids, Dioscorine, Alkaloids of Coca Leaves (Erythroxylon coca). ... 

Of the remaining types of solanaceous alkaloids, the nor- bases, such as norhyoscyamine, could be provided for by an alternative suggestion, based on the observation that a mixture of the ammonium salts of aa -diaminoadipic and citric acids could be oxidised by hydrogen peroxide to nortropinone. 

Many alkaloids are obtained in such small quantities that it is not possible to describe them in detail, and recourse must be had to giving characteristics for picrates, aurichlorides and similar compounds. The reineckates, first used by Christensen and later by Rosenthaler, are a useful addition to such compounds, and have been so used recently by Evans and Partridge for the characterisation of solanaceous alkaloids. 

Similarly, the French soldiers who poisoned themselves in 1813 by naively consuming wild berries containing solanaceous alkaloids also soon became delirious. M. Gaultier, the attending military physician, described the victims as ... 

Tropane is formed when pyrrolidine and piperidine are condensed. Closely related to tropane are tropine, the principal nucleus of the solanaceous alkaloids, atropine, hyoscyamine, hyoscine, and belladonnine, and ecgonine, the nucleus of cocaine (Figure 11.7). 

The time to peak serum levels of solanaceous alkaloids is variable and depends on the species and amount ingested. Reports suggest peak levels are attained in 4-8 h. Solanine is converted to solanidine by hydrolysis. Solanine is rapidly excreted in urine and feces. The elimination half-life of solanidine is reported to be 11 h. 

Gastrointestinal and neurological effects predominate in toxicity form in the solanaceous alkaloids. Reported clinical effects include nausea, vomiting, diarrhea, hyperthermia, tachycardia, bradycardia, hypotension, dehydration, blurred vision, mydriasis, salivation, flushing, diaphoresis, muscular cramps, headache, drowsiness, confusion, weakness, hallucinations, delirium, paresthesias, coma, and death. 

The mechanism of human toxicity has not been clearly delineated. In animal models, solanaceous alkaloids inhibit cholinesterase activity and demonstrate cardiac glycoside activity. Solanine inhibits hepatic microsomal enzymes and can cause hemolysis. 

Table 3.2 Derivatives of Solanaceous Alkaloids and Their Semisynthetic Substitutes"... 

All the solanaceous alkaloids are esters of the dicyclic amino alcohol 3-tropanol (tropine, 1). Atropine is an ester of (+)-tropicacid and tropine. In scopolamine the organic base is sco-... 

There are some other alkaloids that are members of the solanaceous alkaloids (e.g., apoatropine, noratropine, belladonnine) but they are not of sufficient therapeutic value to be discussed in this context. 

The carbon a to the carboxyl group of tropic add is asymmetric and is easily racemized during the isolation of the solanaceous alkaloids. Atropine and atroscine are racemic forms. The corresponding levo isomers, (-)-hyoscyamine and (-)-scopolamine(hyoscine), occur naturally in the solanaceous plants. 

Early attempts to modfy the atropine molecule (4) were aimed at converting the solanaceous alkaloids containing the tertiary nitrogen into quaternary ammonium compounds and N-oxides. Later developments have been to retain the tropine (or scopine) portion of the molecule and substitute various acids for... 

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