Four New Sesquiterpene Pyridine Alkaloids from the Roots of Tripterygium wilfordii Hook. f. - Wang, Ya-Dan; Li, Yu-Tong; Wang, Yong-Jian; Zhang, Zhong-Mou; Zou, Bo-Rui; Dai, Ying-Lin; Yang, Hui-Ying; Wu, Xian-Fu (Molecules, 2026)