New Indole Alkaloids from the Bark of <i>Alstonia </i><i>s</i><i>cholaris</i>

A new indole alkaloid, akuammiginone (<b>1</b>), and a new glycosidic indole alkaloid, echitamidine-<i>N</i>-oxide 19-<i>O</i>-β-d-glucopyranoside (<b>2</b>), together with the five known alkaloids, echitaminic acid (<b>3</b>), echitamidine <i>N</i>-oxide (<b>4</b>), <i>N</i><sup>b</sup>-demethylalstogustine <i>N</i>-oxide (<b>5</b>), akuammicine <i>N</i>-oxide (<b>6</b>), and <i>N</i><sup>b</sup>-demethylalstogustine (<b>7</b>), were isolated from the trunk bark of <i>Alstonia scholaris</i> collected in Timor, Indonesia. The structures of all compounds were elucidated by spectroscopic methods. This is the first report of compounds <b>3</b>−<b>5 </b>and <b>7</b> in <i>A. scholaris</i>. Some NMR assignments of the known compounds were revised.