The content of chemical constituents in thinned young pears. (A) 28 phenolic acids, (B) 16 phenolic glycosides, (C) 33 flavones, (D) 25 flavan-3-ols and procyanidins, (E) total polyphenloic compounds, (F) 16 triterpenoids. (1) quinic acid; (3) arbutin; (12) (+)-catechin; (13) chlorogenic acid; (24) (−)-epicatechin; (52) rutin; (59) quercetin-3-O-glucoside; (78) isorhamnetin-3-O-rutinoside; (86) isorhamnetin-3-O-glucoside; (87) kaempferol-3-O-glucoside; (94) kaempferol-acylated-galactoside; (96) isorhamnetin-acylated-glucoside; (4′) pomolic acid isomer; (14′) oleanolic acid; (15′) ursolic acid.