https://www.repositorio.ufop.br/bitstream/123456789/805/6/ARTIGO_TrioxygenatedNaturallyOccurring.pdf

Tetraoxygenated naturally occurring xanthones

Bio-assay guided isolation and identification of α-glucosidase inhibitors from the leaves of Aquilaria sinensis

Three new C-glucosylxanthones, 2-(2‘-O-trans-caffeoyl)-C-β-d-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone (1), 2-(2‘-O-trans-cinnamoyl)-C-β-d-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone (2), and 2-(2‘-O-trans-coumaroyl)-C-β-d-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone (3), were isolated from the stems of Arrabidaea samydoides, in addition to three known C-glucosylxanthones, mangiferin (4), 2-(2‘-O-benzoyl)-C-β-d-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone (5), and muraxanthone (6). Their chemical structures were assigned on the basis of MS and 1D and 2D NMR experiments. Xanthones 1−6 showed moderate free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) as well as antioxidant activity evidenced by redox properties measured on ElCD-HPLC.

New antioxidant C-glucosylxanthones from the stems of Arrabidaea samydoides.

Chemical constituents from Mahkota dewa.

by Yan Yanga)b), Lei Zhaoa)b), Yu-Fang Wanga), Man-Li Changa), Chang-Hong Huoa), Yu-Cheng Gua)c), Qing-Wen Shi*a), and Hiromasa Kiyota*d) a) Department of Medicinal Natural Product Chemistry, School of Pharmaceutical Sciences, Hebei Medical University, Shijiazhuang 050017, P. R. China (phone: þ86-311-86265634; e-mail: shiqingwen@hebmu.edu.cn) b) The Tumor Hospital of Yunnan Province, the Third Affiliated Hospital of Kunming Medical University, 519 Kunzhou Road, Kunming 650118, P. R. China c) Jealott s Hill International Research Centre, Syngenta, Berkshire, RG426EY, UK d) Laboratory of Applied Bioorganic Chemistry, Division of Life Science, Graduate School of Agricultural Sciences, TohokuUniversity, 1-1 Tsutsumidori-Amamiya, Aoba-ku, Sendai, 981-8555, Japan (phone/fax: þ81-22-7178785; e-mail: kiyota@biochem.tohoku.ac.jp)

Chemical and pharmacological research on plants from the genus Senecio.

A xanthone from Senecio mikanioides leaves

A new p-hydroxybenzoylated xanthone, [ 2-(2′-O-p- hydroxybenzoyl) -C-β- d -glucopyranosyl-1,3,6,7-tetrahydroxyxanthone ], muraxanthone, and four known xanthones have been isolated from the leaves of Senecio mikanioides. The structure of the new compound has been defined by means of FAB-mass spectrometry and a combination of homo- and hetero-nuclear one- and two-dimensional NMR techniques.

Stefano Luschi

Papers

A xanthone from Senecio mikanioides leaves

A Xanthone from Senecio mikanioides Leaves.