Carbazole Alkaloids from the Stems of <i>Clausena lansium</i>

Abstract

Ten new carbazole alkaloids, claulansines A–J (<b>1</b>–<b>10</b>), and seven known analogues (<b>11</b>–<b>17</b>) were isolated from the stems of <i>Clausena lansium</i>. Their structures were established on the basis of extensive spectroscopic analyses, and their absolute configurations were determined by CD experiments and computational methods. Screening results indicated that compounds <b>1</b>, <b>6</b>, <b>8</b>–<b>10</b>, <b>13</b>, <b>14</b>, and <b>17</b> showed selective neuroprotective effects at the concentration of 10 μM