SociCtC suisse de chimie, B&le -Societa svizzera di chimica, Basilca Nachdruck verboten -Tous droits rCservCs -Printed by Birkhauser AG., Basel, Switzerland Erscheint 9mal jahrlich -Paralt 9 fois par an 175. Indolalkaloide aus den Blattern von Hedranthera barteri (Ho0k.f.) Pichon 1)Stimnmavy . From the leaves of the West African plant (Apocynaceae Hedranthera barteri) has been isolated the phenolic (-)-desmethyl-vobtusine (3), alongside the already known bisindolc alkaloids ( -)-goziline (1) and (-)-vobtusinc (2). The new allraloid 3 has bcen spectroscopically charactcrised and correlated with ( -)-vobtusine (2). Furthermore, the 'monomeric' alkaloids (-)-herlrantherine (4) and ( -)-17-hydroxy-hedrantherine ( 5 ) wcre found in the leaves of H . barteri. Both of these alkaloids contain a cyclic semiacetal group. These bases and their derivatives possessing an unchanged @-anilinoacrylester group show, in the mass spectrometer, the same characteristic fragmentation as vincadifformine ( l l ) , whilst their 2.3-dihydroderivatives bear more of a resemblance to aspidospcrminc. From thc strongly negative Cotton effect of 4 and 22 a t 300-350 nm follows the absolute configuration in these bases o f centre 12.Hedrantherinc (4) represents the lower half of the bisindole type of vobtusine bases. The upper half has previously been encountered in form of the alkaloid beninine in the rootbark of H . barteri.Von der westafrikanischen Apocynaceae Hedranthera barteri (Hook. f.) Pichon ist bisher nur die Wurzelrinde hinsichtlich ihres Alkaloidgehaltes eingehend untersucht worden. Die folgenden Indolalkaloide wurden bisher isoliert und charakterisiert :