Antioxidant Activities and Chemical Constituents of Extracts from Cordyline fruticosa (L.) A. Chev. (Agavaceae) and Eriobotrya japonica (Thunb) Lindl, (Rosaceae)

Background and Objective: Cordyline fruticosa (Agavaceae) and Eriobotrya japonica (Rosaceae) are two medicinal plants used for the treatment of various diseases such as infections of mammary glands, sore throat and neck pain for the first plant, diabetes, cough, ulcers, protection against oxidative stress and cognitive deficits for the latter. The present study was designed to evaluate the antioxidant activity of the different extracts of these two plants as well as to isolate and identify their chemical constituents. Materials and Methods: The plant extract was prepared by maceration in methanol, compounds were isolated from EtOAc and n-BuOH extracts of the two plants using column chromatography and their structures were determined by means of NMR and MS analysis as well as in comparison with published data. Antioxidant tests (DPPH, ferric reduction antioxidant power and anti-hemolytic) were performed over the MeOH, EtOAc and n-BuOH extracts of the plants. Results: The antioxidant-guided phytochemical investigation of the MeOH extracts of the two plants led to the isolation of twelve compounds identified as: Farrerol 1, quercetin helichrysoside 2, apigenin 8-C-β-D-glucopyranoside 3, isoquercitrin 4 and rutin 5 from C. fruticosa, β-sitosterol 6, catechin 7, oleanolic acid 8, lyoniresinol 9, cinchonain IIb 10, lyoniresinol 2-a-O-β-D-xylopyranoside 11 and β-sitosterol-3-O-β-D-glucopyranoside 12 from E. japonica. Amongst the isolated compounds, the most important antioxidant ones were identified as helichrysoside and rutin from C. fruticosa, catechin, cinchonain IIb, lyoniresinol 2-a-O-β-D-xylopyranoside from E. japonica with EC50 of 8.73, 9.91, 4.11, 3.14 and 10.61 μg mL–1, respectively. Conclusion: Based on the obtained results, it can be concluded that the high ability to scavenge free radicals, reducing power of Fe3+ and hemolysis activity exerted by extracts of C. fruticosa and E. japonica were due to their high content of phenolic compounds, thus the structure-activity relationships of the isolated flavonoids were discussed. The results of this study suggest that the extracts from these two plants could serve as potential source of antioxidant compounds