Semisynthesis of Forsyshiyanine A and a Derivative with Significant Anti-Pancreatic Cancer Activity

Forsyshiyanine A (<b>8</b>), a trinorditerpene alkaloid isolated from <i>Forsythia suspensa</i> exhibiting <i>in vitro</i> anti-inflammatory and antiviral activities, has been synthesized for the first time from <i>trans</i>-communic acid (<b>12a</b>) and labdane cupressic acid (<b>13</b>). Furthermore, a series of derivatives were efficiently prepared and screened for cytotoxic activities against five human tumoral cell lines. Derivative <b>25</b> showed cytotoxicity (IC₅₀ = 6.5 μM) against the Mia PaCa-2 pancreatic cancer cell line, making it an interesting candidate for future structure-activity relationship (SAR) investigations.