title: Xanthones from Swertia mussotii and their α-glycosidase inhibitory activities.
abstract: Two new xanthones, 1,8-dihydroxy-3-methoxyxanthone 7-O-[α-L-rhamnopyranosyl(1 → 2)-β-D-glucopyranoside] (1) and 1,8- dihydroxy-3-methoxyxanthone 7-O-[α-L-rhamnopyranosyl(1 → 3)-α-L-rhamno-pyranosyl (1 → 2)-β-D-xylopyranoside] (2), together with 26 known xanthones (3-28), were isolated from the aqueous ethanol extract of the traditional Chinese herb Swertia mussotii. Their structures were elucidated via spectroscopic analyses including 2D NMR. The inhibition of α-glucosidase by the isolated xanthones was evaluated by an in vitro high-throughput screening assay. Our results indicated that 1,3,5,8-tetrahydroxyxanthone is the best inhibitor with an IC50 value of 5.33 ± 0.09 µM, while the O-glycosylated xanthones were poor α-glycosidase inhibitors.
authors.affiliation: Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, Guangzhou, P. R. China.
authors.forename: Cui-Ting
authors.initials: CT
authors.lastname: Luo
authors.affiliation: Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, Guangzhou, P. R. China.
authors.forename: Huan-huan
authors.initials: HH
authors.lastname: Zheng
authors.affiliation: Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, Guangzhou, P. R. China.
authors.forename: Shuang-Shuang
authors.initials: SS
authors.lastname: Mao
authors.affiliation: Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, Guangzhou, P. R. China.
authors.forename: Mao-xun
authors.initials: MX
authors.lastname: Yang
authors.affiliation: State key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, P. R. China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Luo
authors.affiliation: Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, Guangzhou, P. R. China.
authors.forename: Heru
authors.initials: H
authors.lastname: Chen
mesh_terms: D006026:Glycoside Hydrolases / Q000037:antagonists & inhibitors*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D012984:Software; D029967:Swertia / Q000737:chemistry*; D044004:Xanthones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D010936:Plant Extracts; D044004:Xanthones; D006026:Glycoside Hydrolases