Further sesquiterpenoids from Pittosporum qinlingense and their anti-inflammatory activity.

Four new sesquiterpenoid glycoside esters, Pitqinlingoside N - Q (1 – 4), together with eleven known metabolites (5 – 15), were isolated from 95% EtOH extract of the twigs, fruits and leaves of P. qinlingense. The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses, including IR, UV, HRMS, NMR and electronic circular dichroism spectra. Unusal glycoside esters are characterized by the presence of polyacylated β -D-fucopyranosyl and β - d -glucopyranosyl units. Pitqinlingoside N (1), O (2), P (3), boscialin (5) and arvoside C (6) showed significant nitric oxide production inhibition in lipopolysaccharide (LPS)-induced BV-2 microglial cells with IC 50 values ranging from 1.58 to 28.74 μM. Structure-activity relationships of the isolated compounds are discussed. [Display omitted] • P. qinlingense is a new species of Pittosporum , native from Qinling mountains, Shaanxi Province, China. • Four new sesquiterpenoid glycoside esters were isolated from P. qinlingense twigs and leaves. • Pitqinlingoside P (3) showed significant nitric oxide production inhibition in LPS-induced BV-2 microglial cells with IC 50 value 1.58 μM. [ABSTRACT FROM AUTHOR]