Iridoids and other constituents from the aerial parts of Patrinia rupestris and their inhibitory effects on nitric oxide production

Forty-three compounds, including nine undescribed compounds, five iridoids (patrirupesins A−E, 1−5) and four bis-iridoids (patrirupesins F–I, 6−9), were isolated from the EtOAc-soluble fraction of the aerial parts of Patrinia rupestris (Pall.) Dufr., and their structures were elucidated based on Mass spectrometry and NMR spectroscopy. The absolute configuration of patrirupesins A−E (1−5) and I (9) was determined by experimental and calculated electronic circular dichroism (ECD). In addition, patrirupesin E (5), patrirupesin H (8), 8,9-didehydro-7-hydroxydolichodial (17), 5,6-epoxy-3-hydroxy-7-megastigmen-9-one (19), iso-seco-tanapartholide (24) and 3-hydroxy-2-methyl-4-(3-oxoprop-1-en-2-yl)cyclopent-1-enecarbaldehyde (43) showed in vitro anti-inflammatory activity on NO production in RAW 264.7 cells stimulated by lipopolysaccharide (LPS) with IC50 values of 9.32 ± 3.83, 4.63 ± 1.23, 8.31 ± 4.05, 17.23 ± 5.19, 8.30 ± 6.17 and 27.38 ± 4.69 μM, respectively.