Insecticidal Sesquiterpene Pyridine Alkaloids from Maytenus chiapensis

The new sesquiterpene pyridine alkaloids chiapenines ES-I (<BO>1</BO>), ES-II (<BO>2</BO>), ES-III (<BO>3</BO>), and ES-IV (<BO>4</BO>), in addition to the known alkaloids wilfordine (<BO>5</BO>), alatamine (<BO>6</BO>), wilforidine (<BO>7</BO>), alatusinine (<BO>8</BO>), euonine (<BO>9</BO>), euonymine (<BO>10</BO>), ebenifoline E−I (<BO>11</BO>), forrestine (<BO>12</BO>), mayteine (<BO>13</BO>), and 4-hydroxy-7-epi-chuchuhuanine E-V (<BO>14</BO>), were isolated from the leaves of Maytenus chiapensis. Their structures were elucidated by 1D and 2D NMR spectroscopy, including homonuclear and heteronuclear correlation (COSY, ROESY, HSQC, and HMBC) experiments. Wilfordine, alatusinine, and euonine exhibited strong antifeedant activity against Spodoptera littoralis.