Antioxidant phenolic compounds isolated from wild Pyrus ussuriensis Maxim. fruit peels and leaves

Abstract 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 IC 50 (Half Maximal Inhibitory Concentration) value of 6.06 and 9.60 μg/mL, respectively. The results revealed that P. ussuriensis could be used in the fields of food and medicine to prevent human aging diseases.