Quaternary Ammonium Compounds--II. Antiacetylcholinesterase Activity and Charge Distribution in Aliphatic Quaternary Ammonium Compounds

The Preparation and Measurement of the Surface Activity of A Series of 4-Alkyl-1, 1′-Spirobipiperidinium Bromides

The preparation of a series of 4-alkyl-1, 1′-spirobipiperidinium bromides is described. The measurement of the surface tension of aqueous solutions of these quaternary salts is reported. Within the concentration ranges studied none of the spiran quaternary compounds form micelles. The relationship between micelle formation of quaternary ammonium ions and antibacterial activity is discussed.

Efficient Approaches toward the Solid-Phase Synthesis of New Heterocyclic Azoniaspiro Ring Systems: Synthesis of Tri- and Tetrasubstituted 10-Oxo- 3,9-diaza-6-azoniaspiro[5.5]undecanes

[Reaction: see text]. An efficient approach for the parallel solid-phase synthesis of novel heterocyclic azoniaspiro ring systems is described. The target compounds, the 1,8,9-trisubstituted 10-oxo-3,9-diaza-6-azoniaspiro[5.5]undecanes, were obtained starting from resin-bound reduced dipeptides. The azoniaspiro cation was formed by intramolecular attack of a tertiary nitrogen on pendent alpha-bromocarbonyl. N-3 acylated and N-3 alkylamino carbonyl derivatives of the 1,8,9-trisubstituted 10-oxo-3,9-diaza-6-azoniaspiro[5.5]undecanes were obtained following in solution treatment of the N-3 azoniaspiro derivatives with different carboxylic acids and isocyanates.

Potentiation of acetylcholinesterase by a series of quaternary ammonium compounds

Eleven spiran, and two non-spiran, quaternary ammonium compounds have been examined and some of these compounds found to potentiate the hydrolysis of acetylcholine by acetylcholinesterase at high substrate concentrations. The experiments were made in three reaction media, each differing in its ionic composition. The results obtained in these media differ both quantitatively and qualitatively. The mechanism of the potentiation is discussed in terms of the effect of quaternary ammonium compounds on the deacetylation step of acetylcholine hydrolysis.