Six new iridoid glucosides, patriridosides D-I (1-6), and one new iridoid, scabrol A (7), along with 12 known non-glycosidic and glycosidic iridoids (8-19), have been isolated from an ethanolic extract of the roots of Patrinia scabra. The cytotoxic activity of the isolated compounds against human cervical carcinoma HeLa cells and gastric carcinoma MNK-45 cells was evaluated using the MTT assay. Compounds 1, 4-6, 8, and 18 showed cytotoxic activities against the MNK-45 cell line with respective IC₅₀ values of 15.6, 8.7, 9.4, 30.9, 23.8, and 11.2 μM, while only compound 10 showed cytotoxicity against the HeLa cell line, with an IC₅₀ value of 24.5 μM.

To probe the chemical constituents of Patrinia scabra, we undertook the phytochemical investigation on its roots, which led to the isolation and elucidation of three new iridoid glucosides, scabroside A-C (1-3), along with three known iridoids, jatamanin J (4), isopatriscabroside I (5) and loganic acid (6) from the aqueous fraction of the ethanolic extract of the roots. The structures and relative configurations of the three new compounds were elucidated by spectroscopic methods including IR, UV, MS, 1D and 2D NMR experiments. Compound 3 was an unusual iridoid with an oxygen bridge connecting C-3 and C-8.

One new diarylheptanoid, namely (4E,6E)‐7‐(3,4‐dihydroxy‐5‐methoxyphenyl)‐1‐(4‐hydroxy‐3‐methoxyphenyl)hepta‐4,6‐dien‐3‐one (1), was isolated from the rhizomes of Zingiber officinale, along with ten known ones, tetrahydrocurcumin (2), curcumin (3), 5‐hydroxy‐1,7‐bis(4‐hydroxy‐3‐methoxyphenyl)heptan‐3‐one (4), gingerenone A (5), 7‐(3,4‐dihydroxyphenyl)‐5‐hydroxy‐1‐(4‐hydroxy‐3‐methoxyphenyl)heptan‐3‐one (6), (E)‐1,7‐bis(4‐hydroxy‐3‐methoxyphenyl)hept‐1‐ene‐3,5‐dione (7), (E)‐7‐(4‐hydroxy‐3‐methoxyphenyl)‐1‐(4‐hydroxyphenyl)‐hept‐1‐ene‐3,5‐dione (8), shogasulfonic acid A (9), 1,5‐epoxy‐3‐hydroxy‐1‐(3,4‐dihydroxy‐5‐methoxyphenyl)‐7‐(4‐hydroxy‐3‐methoxyphenyl)heptane (10), and (3S,5S)‐3,5‐diacetoxy‐1,7‐bis(3,4‐dihydroxyphenyl)heptane (11). Their structures were elucidated on the basis of spectral evidence and comparisons with literature data. The free radical scavenging activity of 1–11 was evaluated by the 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) assay. Most of the isolated compounds were found to be better antioxidants than the positive control ascorbic acid. These compounds were also evaluated for their cytotoxicity against HeLa and MNK‐45 cells using the MTT assay. Our results suggest that compounds 3 and 5–8 inhibited HeLa cells, and 3, 5, 7 and 8 inhibited MNK‐45 cells. It was found that compound 5 was markedly cytotoxic against HeLa and MNK‐45 cell lines with IC50 values of 6.4 and 7.8 µmol/L, respectively.

Three New Iridoid Glucosides from the Roots of Patrinia scabra -[isolation and structures of three new iridoid glucosides, scabroside A (I), B (II) and C (III)]. -(DI, L.; LI*, N.; ZU, L.-B.; WANG, K.-J.; ZHAO, Y.-X.; WANG, Z.; Bull. Korean Chem. Soc. 32 (2011) 9, 3251-3254, http://dx.