Eudesmane sesquiterpenoid glycosides from the leaves of Pittosporum lenticellatum with anti-neuroinflammatory activity.

Chemical investigation of the EtOAc extract of the leaves of Pittosporum lenticellatum led to the isolation of twenty-five previously undescribed eudesmane sesquiterpenoid glycosides, pitlencosides A－Y (1 – 25); their structures were elucidated by extensive spectroscopic analysis, including 1D and 2D NMR, HR-ESI-MS, ECD spectra, and X-ray crystallographic analysis. Among them, compounds 4 , 5 , 7 , 8 , 15 and 16 exhibited significant inhibitory effects on the production of nitric oxide in lipopolysaccharide-induced BV-2 microglial cells by suppressing the expression of inducible nitric oxide synthase and cyclooxygenase-2, with IC 50 values ranging from 7.95 to 25.88 μM, which showed stereo-chemical and substituent dependents. Western blot analysis and molecular docking simulation confirmed the anti-inflammatory activity of compounds 4 , 5 , 7 , 8 , 15 and 16. Twenty-five undescribed eudesmane sesquiterpenoid glycosides were identified from P. lenticellatum. Some isolated compounds exhibited significant anti-neuroinflammatory activity, which was confirmed by Western blot analysis and molecular docking simulation. [Display omitted] • First report of chemical constituents of P. lenticellatum. • Twenty-five undescribed eudesmane glycosides were identified from P. lenticellatum. • Six compounds showed anti-neuroinflammatory activities. • The activity was confirmed by molecular docking and western blot analysis. [ABSTRACT FROM AUTHOR]