title: Preparative isolation, quantification and antioxidant activity of dihydrochalcones from Sweet Tea (Lithocarpus polystachyus Rehd.).
abstract: Dihydrochalcones are the main active components of Lithocarpus polystachyus Rehd. (Sweet Tea), they are directly related to the sweet tonic beverage and traditional herb. In this work, two runs of preparative high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of n-hexane/ethyl acetate/ethanol/water (1:4:3:4, v/v) were employed to separate three dihydrochalcones (phloridzin, trilobatin and phloretin) from Sweet Tea. About 6.4mg of phloridzin, 48.4mg of trilobatin, and 4.7mg of phloretin with purities of 96.7%, 98.4% and 98.1% were obtained from 130mg of the crude Sweet Tea extract. Phloridzin, trilobatin, and phloretin had effective radical scavenging activities, with IC50 values of 866.80, 20.16 and 179.47μg/mL, respectively, in a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical method. The contents of phloridzin, trilobatin and phloretin in dried old leaves and tender leaves of tea were in the range of 10.1-18.0, 113.7-128.8, 3.6-4.3mg/g and 9.3-9.8, 82.9-103.1, 1.9-2.5mg/g, respectively. The results indicated that the HPLC had good precision, accuracy and repeatability for the determination of three dihydrochalcones in samples.
authors.affiliation: Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, 130112 Changchun, China. Electronic address: sunyinshi2015@163.com.
authors.forename: Yinshi
authors.initials: Y
authors.lastname: Sun
authors.affiliation: College of Chinese Medicinal Material, Jilin Agricultural University, 130118 Changchun, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, 130112 Changchun, China.
authors.forename: Zhengbo
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D047188:Chalcones / Q000032:analysis / Q000302:isolation & purification* / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D013662:Tea / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D047188:Chalcones; D013662:Tea
keywords: Antioxidant activity; Dihydrochalcone; Preparative separation; Quantification; Sweet Tea