Rumpictuside A: Unusual 9,10-anthraquinone glucoside from Rumex pictus Forssk

A new 8-ionized hydroxylated 9,10-anthraquinone namely, 1-hydroxy-3-methyl-9,10-anthraquinone-6-O-beta-D-glucopyranoside-8-olate (Rumpictuside A, 1) along with five known flavonoids, apigenin 7-O-beta-D-glucoside (2), vitexin (3), quercetin 3-O-beta-D-glucouronide (4), orientin (5), and isorientin (6) were isolated from Rumex pictus. The structures of isolated compounds were identified by the extensive spectroscopic techniques such as, UV, FT-IR,1D, 2D NMR and HR-FAB-ESI-MS. The ionized hydroxyl group in the new anthraquinone (1) was rarely found for anthraquinone glycosides isolated from natural sources. All the isolated compounds were found inactive against influenza A virus infection. Compounds 2-6 exhibited significant antioxidant activity against DPPH and ABTS(+). The alcoholic extract exhibited moderate activity while the new anthraquinone 1 showed the lowest activity against both assays. (C) 2017 Elsevier Ltd. All rights reserved.