Thirteen phenolic compounds were isolated from pear (Pyrus ussuriensis Maxim.) peels and leaves extracts by using various column chromatography techniques with a guided DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging assay, the result of antioxidant activity of phenolic compounds is then verified by measurement of ROS (reactive oxygen species). The isolated compounds were identified as rutin (1), (-)-catechin (2), orobol (3), daidzein (4), tricin 4'-O-[threo-β-guaiacyl-(7″-O-methyl)-glyceryl] ether (5), tricin 4'-O-[threo-β-guaiacyl-(7″-O-methyl-9″-O-acetyl)-glyceryl] ether (6), 5,7,3',5'-tetrahydroxyflavanone (7), artselaeroside A (8), trilobatin (9), 3-(2,4,6-trihydroxyphenyl)-1-(4-hydroxyphenyl)-propan-1-one (10), quercetin-3-O-(3″-O-galloyl)-α-l-rhamnopyranoside (11), apigenin (12) and quercetin (13) on the basis of nuclear magnetic resonance spectroscopy along with comparison with literature data. Among these compounds, quercetin and quercetin-3-O-(3″-O-galloyl)-α-l-rhamnopyranoside exhibited potent DPPH radical-scavenging activity with IC50 (Half Maximal Inhibitory Concentration) value of 6.06 and 9.60μg/mL, respectively. The results revealed that P. ussuriensis could be used in the fields of food and medicine to prevent human aging diseases.
Keywords: (−)-Catechin (2) (PubChem CID: 73160); 3-(2,4,6-Trihydroxyphenyl)-1-(4-hydroxyphenyl)-propan-1-one (10) (PubChem CID: 70018969); 5,7,3′,5′-Tetrahydroxyflavanone (7) (PubChem CID: 11483087); Antioxidant activities; Apigenin (12) (PubChem CID: 5280443); Artselaeroside A (8) (PubChem CID: 100930979); Bioactive compounds; Daidzein (4) (PubChem CID: 5281708); Orobol (3) (PubChem CID: 5281801); Phenolic compounds; Phytochemical; Pyrus ussuriensis Maxim.; Quercetin (13) (PubChem CID: 5280343); Quercetin-3-O-(3″-O-galloyl)-α-l-rhamnopyranoside (11) (PubChem CID: 23786426); Rutin (1) (PubChem CID: 5280805); Tricin 4′-O-[threo-β-guaiacyl-(7″-O-methyl)-glyceryl] ether (5) (PubChem CID: 49785092); Tricin 4′-O-[threo-β-guaiacyl-(7″-O-methyl-9″-O-acetyl)-glyceryl] ether (6) (PubChem CID:12986874); Trilobatin (9) (PubChem CID: 6451798).
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