The action of tertiary and quaternary arecaidine and dihydroarecaidine esters on the guinea pig isolated ileum.

Arecaidine, a constituent of the betel nut, exerts a stimulating action on cholinergically innervated structures (Marme, 1890; Plesch, 1895; Dixon, 1924; Stefansson, 1937; von Euler & Domeij, 1945; Holtz & Westermann, 1955; van Rossum, 1962). It therefore seemed of interest to modify the molecule of arecoline-i.e., arecaidine methyl estersystematically and to investigate the pharmacological properties of the new compounds, which were synthesized by Mutschler (1964). The results might give us a better general picture of the interaction between drugs and cholinoceptive receptors. This paper deals with the investigation of a number of arecaidine derivatives on the isolated ileum of the guinea-pig. The results suggested that the action of these compounds is dependent on the length of the side-chain, on hydrogenation of the double bond in the ring and on quaternization of the ring nitrogen atom. Formulae of the compounds investigated are represented in Table 3.