Muscarine alkaloids

Certain mushrooms, especially those of the genus Inocybe, contain muscarinic alkaloids. Ingestion of these mushrooms causes typical signs of muscarinic excess within 15-30 minutes. These effects can be very uncomfortable but are rarely fatal. Treatment is with atropine, 1-2 mg parenterally. (Amanita muscaria, the first source of muscarine, contains very low concentrations of the alkaloid.)... 

A review concerning the chemistry, biogenesis, and pharmacology of Amanita muscaria components includes a comprehensive coverage of the muscarine alkaloids. (+)-i -4-Hydroxypyrrolidin-2-one has been isolated from this source. A method for the identification of stereoisomeric muscarines by combination vacuum pyrolysis-g.c. analysis has been described. A micro method for the determination of ibotenic acid and other 3-hydroxyisoxazoles has been developed. Stereospecific syntheses for DL-muscarine and DL-a//o-muscarine have been reported. Pyrolysis of (1) yielded the carboxylic acid (2) and the bromolactone (3) which served as key compounds in the synthesis of the muscarines. The minor component (3) was shown to be an intermediate in the formation of (2) and therefore the conversion [(3)- -(2)] could be written as an intramolecular Sn2 displacement on an a-lactone (4). However, treatment of (3) with... 

This method has been extended to prepare muscarine alkaloids, constituents... 

An organometallic route to muscarine derivatives has been developed (Scheme 1). Reduction of the aa -dibromo-ketone (1) with Fe2(CO)9 in the presence of DMF provided the furanone (2) in good yield. Acetylation of (2) afforded the corresponding enol acetate, which upon Mannich reaction with dimethylamine and formaldehyde gave the furan derivative (3). Deacetylation followed by dissolving-metal reduction and quaternization with methyl iodide gave two isomeric 4-methyl-muscarine salts (4). These compounds showed physiological properties characteristic of the muscarine alkaloids. 

Other Sources of Imidazole Alkaloids Lythraceae alkaloids Maytansinoids Antitumor Activity Other Biological Activity Muscarine Alkaloids Naphthylisoquinoline Alkaloids Peptide Alkaloids Purine or Xanthine Alkaloids Biosynthesis... 

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