Guanidine Alkaloids from <i>Plumbago zeylanica</i>

Eleven new guanidine alkaloids, plumbagines A–G (<b>2</b>–<b>8</b>) and plumbagosides A–D (<b>9</b>–<b>12</b>), as well as two known analogues (<b>1</b>, <b>13</b>), were isolated from the aerial parts of <i>Plumbago zeylanica</i>. Their structures were elucidated by spectroscopic analyses including 1D and 2D NMR, MS, IR, and CD methods. The absolute configuration of <b>1</b> was determined by single-crystal X-ray diffraction of its derivative (<b>1a</b>).