Cranberry Phytochemicals:  Isolation, Structure Elucidation, and Their Antiproliferative and Antioxidant Activities

Bioactivity-guided fractionation of cranberries was used to determine the chemical identity of bioactive constituents. Twenty compounds were isolated using gradient solvent fractionation, silica gel and ODS columns, and preparative RP-HPLC. Their chemical structures were identified using HR-MS, 1D and 2D NMR, and X-ray diffraction analysis. Antiproliferative activities of isolated compounds against HepG2 human liver cancer and MCF-7 human breast cancer cells were evaluated. Among the compounds isolated, ursolic acid, quercetin, and 3,5,7,3‘,4‘-pentahydroxyflavonol-3-O-β-d-glucopyranoside showed potent antiproliferative activities against HepG2 cell growth, with EC50 values of 87.4 ± 2.7, 40.9 ± 1.1, and 49.2 ± 4.9 μM, respectively. Ursolic acid, quercetin, and 3,5,7,3‘,4‘-pentahydroxyflavonol-3-O-β-d-glucopyranoside showed potent inhibitory activity toward the proliferation of MCF-7 cells, with EC50 values of 11.7 ± 0.1, 137.5 ± 2.6, and 23.9 ± 3.9 μM, respectively. Quercetin, 3,5,7,3‘,4‘-pentahydroxyflavonol-3-O-β-d-glucopyranoside, 3,5,7,3‘,4‘-pentahydroxyflavonol-3-O-β-d-galactopyranoside, and 3,5,7,3‘,4‘-pentahydroxyflavonol-3-O-α-l-arabinofuranoside showed potent antioxidant activities, with EC50 values of ≈10 μM. These results showed cranberry phytochemical extracts have potent antioxidant and antiproliferative activities. Keywords: Cranberries; phytochemicals; structure identification; antioxidant; antiproliferative activities; cancer