Aldehydes Atropine

An extensive use of radioactive tracer technique permits a deeper insight into the formation of the tropane skeleton in vivo. Hyoscyamine-(methyl-i C) (76), atropine- C, tropic acid-i C (77), and succindi-aldehyde-2,3-i4C (78) were synthesized. The last was not incorporated at all by D. stramonium seedlings (78), while the former feeding experiments with ornithine-a-i4C proved its incorporation into hyoscyamine (79) hjD. stramonium (see Volume VI, pp. 172-173). More recently two independent teams (80, 81) reported that this incorporation takes place asymmetrically. 

The limited quantities of teloidine so far available have precluded an investigation of its structure. However, from the marked similarity of its chemical reactions with those of tropine and oscine and from the association of meteloidine with atropine and 1-scopolamine in Datura meteloides, teloidine was considered to be one of the stereoisomers of the trihydroxytropane, XCI. This has been confirmed by synthesis. Teloidinone, the Cj-ketone of teloidine, has been synthesized (3) (mesotartaric aldehyde, methylamine, and acetonedicarboxylic acid) under physiological conditions. Teloidine and an isomer were formed in the reduction of this ketone. 

Choline nitrite, or pseudo-muscarine, was at one time thought to be identical with natural muscarine, the highly poisonous alkaloid of the mushroom Amanita muscaria (Fly Agaric), and to be the aldehyde corresponding to choline. Both suppositions are wrong. The natural alkaloid is much more toxic than choline nitrite, and its effects are antagonised by atropine, which has little protective effect against the synthetic ester. 

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