title: Chromone glycosides from Knoxia corymbosa.
abstract: Four new chromone glycosides, corymbosins K1-K4 (3-6), together with two known compounds, noreugenin (1) and undulatoside A (2), were isolated from the whole plant of Knoxiacorymbosa (Rubiaceae). The structures of the new compounds were established through extensive NMR or X-ray spectroscopic analysis as 7-O-beta-D-allopyranosyl-5-hydroxy-2-methylchromone (corymbosin K1, 3), 7-O-beta-D-6-acetylglucopyranosyl-5-hydroxy-2-methylchromone (corymbosin K2, 4), 7-O-[6-O-(4-O-trans-caffeoyl-beta-D-allopyranosyl)]-beta-D-glucopyranosyl-5-hydroxy-2-methylchromone (corymbosin K3, 5) and 7-O-[6-O-(4-O-trans-feruloyl-beta-D-allopyranosyl)]-beta-D-glucopyranosyl-5-hydroxy-2- methylchromone (corymbosin K4, 6). Compounds 2-5 were subjected to test their immunomodulatory activity invitro.
authors.affiliation: School of Pharmacy, Yunnan University, Kunming, China. yubowang1217@vip.sina.com
authors.forename: Y-B
authors.initials: YB
authors.lastname: Wang
authors.forename: R
authors.initials: R
authors.lastname: Huang
authors.forename: H-B
authors.initials: HB
authors.lastname: Zhang
authors.forename: L
authors.initials: L
authors.lastname: Li
mesh_terms: D000818:Animals; D001681:Biological Assay; D002681:China; D002867:Chromones / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification; D018360:Crystallography, X-Ray; D006027:Glycosides / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification; D018655:Lymphocyte Count; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry*; D019666:Rubiaceae / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission; D013154:Spleen / Q000276:immunology
chemical_list: D002867:Chromones; D006027:Glycosides