OCCURRENCE OF CURARIMIMETIC INDOLES IN THE FLOWERS OF ARUNDO DONAX

Abstract

Nine simple indole bases (I–IV, VI, VIII–XI) have been isolated from the flowers of Arundo donax L. (Gramineae). Three of these bases, e.g., (IX–XI), are previously unreported in nature while (VIII) is reported for the first time in a gramineous plant.

The content of gramine in the flowers has been found to decrease with the appearance and increase of the corresponding metho hydroxide. The above and related observations indicate that gramine metho hydroxide rather that the N_b–oxide is involved in the metabolism of gramine in higher plants.

The total alkaloid and some of the individual entities from the flowers produced curarimimetic effect of the non–depolarizing type. The alkaloids produced pronounced hypotensive response and respiratory depression. The hypotensive response is, presumably, histamine–release mediated.

The effect of variation of the 3–alkyl side chain in indole–3–alkylamines as to their curari–like activity is discussed.