Anti-inflammatory metabolites from the fruits of Pittosporum elevaticostatum.

The investigation on the fruits of Pittosporum elevaticostatum Chang et Yan led to the isolation of two undescribed metabolites (1 – 2, named pitelevatin A and B) and twelve known ones (3 – 14), including one phthalide (1), four monoquiterpenoids (2 – 5), two sesquiterpenoids (6 – 7), two diterpenoids (8 – 9), and five phenolic analogues (10 – 14). The structures of 1 and 2 were elucidated based on spectroscopic methods, including high resolution electrospray ionization mass spectroscopy (HR-ESI-MS), one demension (1D) and 2D nuclear magnetic resonance (NMR), ultraviloet (UV), electronic circular dichroism (ECD) spectra and experimental and calculated specific optical rotation (SOR). Compounds 1 – 3 , 7 and 11 showed significant nitric oxide (NO) production inhibitory activity in lipopolysaccharide (LPS)-induced BV-2 microglial cells by inhibiting the expression of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), with IC 50 values ranging from 6.35 to 25.75 μ M. Western blot analysis confirmed the results above. [Display omitted] • First report of chemical constituents of P. elevaticostatum Chang et Yan. • Fourteen compounds, including two undescribed ones were isolated and identified from P. elevaticostatum fruits. • Pitelevatin A (1) showed NO production inhibition in BV-2 cells (IC 50 6.35 µM). Western blot analysis revealed the possible anti-inflammatory mechanism. [ABSTRACT FROM AUTHOR]