Antioxidant and Anti-inflammatory Phenylpropanoid Derivatives from Calamus quiquesetinervius

Eight new phenylpropanoid derivatives [quiquesetinerviusides A (1), B (2), C (3), D (4), and E (5), as well as quiquesetinerviusins A (6), B (7), and C (8)] and seven known compounds (8−15), were isolated from an EtOAc extract of Calamus quiquesetinervius stems. The structures of 1−8 were elucidated on the basis of 1D- and 2D-NMR spectroscopic data analysis. Bioassay results showed that 1−5 possess weak DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activity, but potent ^·OH radical scavenging activity (IC₅₀ 3.6−8.4 μM). Of the tested isolates, compounds 4−6 and 9 showed potent inhibition (IC₅₀ 9.2−29.5 μM) of LPS-stimulated NO production when compared with a positive control substance, quercetin (IC₅₀ 34.5 μM).