Densely Functionalized Macrocyclic Sesquiterpene Pyridine Alkaloids from <i>Maytenus austroyunnanensis</i>
Kai‐Long Ji, Yao‐Yue Fan, Qi Gong, Qun‐Fang Liu, Ming-Jun Cui, Kai-Cong Fu, Haiyan Zhang, Jian‐Min Yue
Abstract
Eleven densely functionalized new dihydro-β-agarofuran sesquiterpenoid derivatives, named maytenoids A–K ( 1 – 11 ), as well as one known analog, were isolated and characterized from Maytenus austroyunnanensis . Their structures were assigned based on analysis of spectroscopic data and X-ray crystallography. Compounds 1 – 9 are macrocyclic sesquiterpene pyridine alkaloids generated by the respective acylation of the hydroxy groups at C-3 and C-13 of dihydro-β-agarofuran sesquiterpenoids via diverse pyridine dicarboxylic acids. Compounds 1, 2, 5 – 10, and 12 exhibited significant inhibitory effects on NO production at 10 μM in lipopolysaccharide (LPS)-stimulated BV2 cells.