Z-Hyoscine

The same author found Z-hyoscine sixteen to eighteen times as active as the d-isomeride in antagonising the action of pilocarpine on the termination of nerves in the salivary glands, -while both isomerides are equally active on nerve ends in striated and unstriated muscle and on the central nervous system. 

The same color display is observed in the case of the modified Vitali test. The alkaloid is ground with sodium nitrate and moistened with sulfuric acid, and subsequently treated with potassium hydroxide reagent. This color reaction has been applied to sixty alkaloids and only veratrine Z-Scopolamine will be used throughout this chapter in preference to Z-hyoscine so as to avoid any possibility of confusion of this alkaloid with Z-hyoscyamine. 

When Z-scopolamine (Z-hyoscine) is warmed with barium hydroxide (52, 56, 232), dilute alkalies (232), or acids (60, 212) it is hydrolyzed to tropic acid and a new base (CsHisOjN), scopoline (oscine). Depending on the conditions of the experiment, the tropic acid recovered may be either the pure Z-form or the partially racemized acid, or may even be dehydrated to atropic acid (52, 64, 232). The scopoline isolated from these experiments is invariably optically inactive (212). By analogy with Z-hyoscyamine, Z-scopolamine would appear to be a base (scopoline) in which the alcoholic... 

The chief representatives of this group are the tropane alkaloids, atropine, its fero-isomer, Z-hyoscyamine, and Z-scopolamine (Z-hyoscine). They are all powerful mydriatic and cycloplegic drugs. Atropine is the most important in ophthalmology, and it is usually used as its neutral sulfate in 1% solution. When such a solution is instilled into the human eye, mydriasis begins in about half an hour and is complete in about an hour ... 

When warmed with barium hydroxide, dilute alkalis or acids, hyoscin is hydrolysed, yielding tropic acid and a new base, CgHjsOjN, oscine o scopoline. Depending on the conditions of experiment, the tropic aci obtained may be either the pure Z-form or the partially racemised acid but the oscine obtained is invariably inactive. 

It appeared to follow from this that the three known forms of hyoscin are respectively Z-tropyl-dZ-oscine, d-tropyl-dZ-oscine and dZ-tropyl-dZ-oscim the optical activity of the first two being conditioned solely by the activit of the tropyl radicle. This subject was discussed by King, who confirme... 

The alkaloids of the tropane group show a series of common chemical characteristics, particularly that of being esters of organic acids combined with bicyclic hydramines. They include Z-hyoscyamine and its isomer atropine, cocaine, scopolamine or hyoscine, and a series of secondary alkaloids. 

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