Anti-osteoporotic and antioxidant activities of chemical constituents of the aerial parts of Ducrosia ismaelis.

Abstract A new pterocarpan glycoside, glycinol-3- O- β- d -glucopyranoside ( 1 ), and a new dihydrochalcone glycoside, ismaeloside A ( 2 ), were isolated together with 13 known compounds, including several flavonoids ( 3 – 8 ), lignan s ( 9 – 11 ), and phenolic compounds ( 12 – 15 ), from the methanol extract of the aerial parts of Ducrosia ismaelis . The chemical structures of these compounds were elucidated from spectroscopic data and by comparison of these data with previously published results. The anti-osteoporotic and antioxidant activities of the isolated compounds were assessed using tartrate-resistant acid phosphatase (TRAP), oxygen radical absorbance capacity (ORAC), and reducing capacity assays. Compound 15 exhibited a dose-dependent inhibition of osteoclastic TRAP activity with a TRAP value of 86.05 ± 6.55% of the control at a concentration of 10 μM. Compounds 1 , 3 – 5 , and 8 showed potent peroxyl radical-scavenging capacities with ORAC values of 22.79 ± 0.90, 25.57 ± 0.49, 20.41 ± 0.63, 26.55 ± 0.42, and 24.83 ± 0.12 μM Trolox equivalents (TE) at 10 μM, respectively. Only compound 9 was able to significantly reduce Cu(I) with 23.44 μM TE at a concentration of 10 μM. All of the aforementioned compounds were isolated for the first time from a Ducrosia species.