title: Chemical constituents of gold-red apple and their α-glucosidase inhibitory activities.
abstract: Ten compounds were isolated and purified from the peels of gold-red apple (Malus domestica) for the 1st time. The identified compounds are 3β, 20β-dihydroxyursan-28-oic acid (1), 2α-hydroxyoleanolic acid (2), euscaphic acid (3), 3-O-p-coumaroyl tormentic acid (4), ursolic acid (5), 2α-hydroxyursolic acid (6), oleanolic acid (7), betulinic acid (8), linolic acid (9), and α-linolenic acid (10). Their structures were determined by interpreting their nuclear magnetic resonance and mass spectrometry (MS) spectra, and by comparison with literature data. Compound 1 is new, and compound 2 is herein reported for the 1st time for the genus Malus. α-Glucosidase inhibition assay revealed 6 of the triterpenoid isolates as remarkable α-glucosidase inhibitors, with betulinic acid showing the strongest inhibition (IC50 = 15.19 μM). Ultra-performance liquid chromatography-electrospray ionization MS analysis of the fruit peels, pomace, flesh, and juice revealed that the peels and pomace contained high levels of triterpenes, suggesting that wastes from the fruit juice industry could serve as rich sources of bioactive triterpenes.
authors.affiliation: College of Life Sciences, Inner Mongolia Univ, 235 Daxuexilu, Huhhot, 010021, China.
authors.forename: Qian-Qian
authors.initials: QQ
authors.lastname: He
authors.forename: Liu
authors.initials: L
authors.lastname: Yang
authors.forename: Jia-Yu
authors.initials: JY
authors.lastname: Zhang
authors.forename: Jian-Nan
authors.initials: JN
authors.lastname: Ma
authors.forename: Chao-Mei
authors.initials: CM
authors.lastname: Ma
mesh_terms: D005638:Fruit / Q000737:chemistry*; D065089:Glycoside Hydrolase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D027845:Malus / Q000737:chemistry*; D009828:Oleanolic Acid / Q000031:analogs & derivatives; D053978:Pentacyclic Triterpenes; D021241:Spectrometry, Mass, Electrospray Ionization; D014315:Triterpenes; D000520:alpha-Glucosidases / Q000378:metabolism*; D017962:alpha-Linolenic Acid / Q000032:analysis; D000094062:Betulinic Acid; D000097245:Ursolic Acid
chemical_list: D065089:Glycoside Hydrolase Inhibitors; D009828:Oleanolic Acid; D053978:Pentacyclic Triterpenes; D014315:Triterpenes; D000520:alpha-Glucosidases; D017962:alpha-Linolenic Acid; D000094062:Betulinic Acid; D000097245:Ursolic Acid; C412810:2-hydroxyursolic acid; C007695:euscaphic acid; C412811:maslinic acid
keywords: 20β-dihydroxyursan-28-oic acid; 3β; Malus domestica; quantification; triterpene; α-glucosidase inhibition