Densely Functionalized Macrocyclic Sesquiterpene Pyridine Alkaloids from Maytenus austroyunnanensis .

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.