The present invention provides corynantheine derivatives of the general formula: ##STR1## wherein R is a hydrogen or alkali metal atom, an ammonium group or the residue of an amine or an alkyl radical containing up to 4 carbon atoms; and the physiologically acceptable acid-addition salts thereof. The present invention also provides processes for the preparation of these corynantheine derivatives and pharmaceutical compositions containing them. Furthermore, the present invention is concerned with the use of dihydrocorynantheine as an antihypertonic.
