Undescribed Lignanamide and Flavone C-Glucoside Isolated from the Aerial Parts of Piper Samentosum with NO Production Inhibitory Activity in LPS Activated RAW 264.7†Cells.

In this study, two undescribed compounds (1 and 2), together with eight known compounds (3-10) were isolated from the aerial parts of Piper samentosum by various chromatography methods. Their chemical structures were determined to be 7'''-oxolyciumamide N (1), vitexin 2''-O-ß-D-(6'''-feruloyl)-glucopyranoside (2), 1,2-dihydro-6,8-dimethoxy-7-hydroxy-1-(3,4-dihydroxyphenyl)-N1,N2-bis-[2-(-hydroxyphenyl)ethyl]-2,3-napthalene dicarboamide (3), vitexin 6''-O-ß-D-glucopyranoside (4), vitexin 2''-O-α-L-rhamnopyranoside (5), methyl 2-hydroxybenzoate-2-O-ß-D-apiofuranosyl-(1→2)-O-ß-D-glucopyranoside (6), ficuside G (7), methyl 2-O-ß-D-glucopyranosylbenzoate (8), methyl 2,5-dihydroxybenzoate-5-O-ß-D-glucopyranoside (9), and 3,7-dimethyloct-1-ene-3,6,7-triol 6-O-ß-D-glucopyranoside (10) by spectroscopic data analysis including HR-ESI-MS, 1D-, and 2D-NMR spectra. Compounds 1-5 inhibited nitric oxide production in LPS-stimulated RAW264.7 macrophages with the IC50 values of 27.62, 74.03, 38.54, 70.39, and 44.95 µM, respectively. The NMR data of 9 were firstly reported herein.

Cytotoxic sesquiterpene glucosides from Fissistigma pallens.

Six undescribed sesquiterpene glucosides, fissispallins A-F, and one known sesquiterpene glucoside, fissispallin, were discovered in the leaves of Fissistigma pallens (Finet & Gagnep.) Merr. The structures were determined using spectroscopic methods, including 1D, 2D NMR, and MS. All compounds were evaluated for cytotoxic activity against three human cancer cell lines, HT-29, A-2058, and A-549. Fissispallin A showed potent activity with the IC50 values less than 1.5 µM against all tested human cancer cell lines. Fissispallin also showed potent activity with IC50 value of 0.4 ± 0.3 on the A-2058 cancer cell lines. Fissispallins B-D showed significant cytotoxic activity against all the tested cancer cell lines with IC50 values ranging from 3.8 to 7.2 µM.

Three new flavonol glycosides from Fissistigma pallens.

Three new flavonol glycosides, fissflavosides A-C (1-3), together with six known flavonol glycosides, kaempferol 3-O-α-L-rhamnopyranosyl-(1→2)-ß-D-galactopyranoside (4), kaempferol 3-O-α-L-rhamnopyranosyl-(1→6)-ß-D-galactopyranoside (5), kaempferol 3-O-α-L-rhamnopyranosyl-(1→6)-ß-D-glucopyranoside (6), rhamnetin 3-O-α-L-rhamnopyranosyl-(1→2)-ß-D-glucopyranoside (7), rutin (8), and isorhamnetin 3-O-α-L-rhamnopyranosyl-(1→2)-ß-D-galactopyranoside (9) were isolated from the methanol extract of the Fissistigma pallens leaves. Their chemical structures were determined by 1D-, 2D-NMR, and MS data as well as in comparison with reported data in the literature. Compounds 1-9 showed weak cytotoxic activity on three human cancer cell lines, HT-29, A-2058, A-549 with IC50 ranging from 134.6 to 162.6 µM. In addition, the antioxidant capacities of compounds were also tested by ORAC assay. All compounds showed significant antioxidant with trolox equivalents ranging from 4.4 to 8.6 µM at the concentration of 1.0 µM. The results indicated 7 and 8 having meaningful reducing capacity of copper (I) ions of 2.7 to 6.9 µM at the concentrations of 1 and 2 µM.