Isolation and Identification of the Xanthone Constituents from Swertia mussotii Franch

Swertia mussotii Fraeh (Family Gentianaceae) is a herb used as medicine for liver diseases in Tibetan. Its principal antihepatitisic constituents, oleanolic acid and mangiferin, have been reported. The present paper reports eight xanthones obtained from this plant. Their structures have been identified as 1,8-dihydroxy-3,5-dimethoxyxanthone Ⅰ, 1-hydroxy-3,5-dimethoxyxanthone Ⅱ, 1-hydroxy-3,7,8-trimethoxyxanthone Ⅲ, 8-hydroxy- 1,3,5-trimethoxyxanthone Ⅳ, 1,8-dihydroxy-3,7-dimethoxyxanthone Ⅴ, 1,7,8-trihydroxy- 3-methoxyxanthone Ⅵ, 1,7-dihydroxy-3,4,8-trimethoxyxanthone Ⅶ, and 1,3,8-trihydro- xy-5-methoxyxanthone Ⅷ. Of them, 1,7-dihydroxy-3,4,8-trimethoxyxanthone is a new natural product.     

Xanthones of Centaurium pulchellum

1-Hydroxy-3,7,8-trimethoxyxanthone, 1,8-dihydroxy-3,7-dimethoxyxanthone and 1,8-dihydroxy-3,5-dimethoxyxanthone have been isolated from the whole plant of Centaurium pulchellum; the compounds were characterized by UV and NMR spectroscopy.     

The Chemical Constituents of Swertia przewalskii Pissjauk.

Seven xanthonenoid compounds and a triterpenic acid have been isolated from Swertia przewalskii Pissjauk. Their structures were identified as 1,8-dihydroxy-3,7-dimethoxyxarthone(Ⅰ), 1,7-dihydroxy-3,8-dimethoxyxanthone (Ⅱ), oleanolic acid (Ⅲ), l-hydroxy-3,7,8-trimethoxyxanthone (Ⅳ), 1,7,8-trihydroxy-3-methoxyxanthone (Ⅴ), 8-0-[β-D-xylopyranosyl-(l--6)-β-D-glucopyranosyl]- 1,7-dihydr0xy- 3-methoxyxanthone (Ⅵ), 1-O- [β-D-xylopyranosyl-(1-6)-β-D-glucopyranosyl]-7,8-dihydroxy- 3-methoxyxanthone (Ⅶ) and 1-O- [β-D-xylopyranosyl-(1-6)-β-D-glucopyranosyl]-8-hydroxy-3,7-dimethoxyanthone (Ⅷ) respectively, by means of chemical and spectral methods or comparing with the authentic samples directly.     

Three New Xanthones from Halenia elliptica D. Don

Previously, we obtained five xanthoncs from Halenia elliptica D. Don. Recently, other five xanthones have been obtained from the same plants. Among them three are new natural products and their structures are identified as 1, 7-dihydroxy-2, 3, 4, 5-tetramethoxyxanthone (Ⅵ), 1, 5-dihydroxy-2, 3, 7-trimethoxyxanthonc (Ⅶ) and 1, 2-dihydroxy-3, 4, 5-trimethoxyxanthone (Ⅹ). Other two have been known as 1, 5-dihydroxy-2, 3-dimethoxy-xanthone (Ⅷ) and 1, 7-dihydroxy-2, 3-dimethoxyxanthone (Ⅸ).     

Xanthones from Frasera albomarginata and F. speciosa

Seven 1-hydroxyxanthones have been isolated from the roots of Frasera albomarginata. There were 1-hydroxy-3,7-dimethoxy-, 1-hydroxy-3,5-dimethoxy-, 1,8-dihydroxy-3,5-dimethoxy-, 1-hydroxy-2,3,4,7-tetramethoxy-, 1-hydroxy-2,3,4,5-tetramethoxy-, 1-hydroxy-3,4,7-trimethoxy- and 1-hydroxy-2,3,5-trimethoxyxanthone. Six 1-hydroxyxanthones were obtained from the roots of F. speciosa. These were 1-hydroxy-2,3,4,5-tetramethoxy-, 1-hydroxy-2,3,4,7-tetramethoxy-, 1-hydroxy-2,3,5-trimethoxy-, 1,7-dihydroxy-2,3,4-trimethoxy-, 1,7-dihydroxy-2,3-dimethoxy- and 1,3-dihydroxy-4,5-dimethoxyxanthone.     

Polyoxygenated xanthones of Centaurium littorale

Two apolar tetra-oxygenated xanthones (1,8-dihydroxy-3,5-dimethoxyxanthone and 1-hydroxy-3,5,8-trimethoxyxanthone) and two hexaoxygenated xanthones (1,8-dihydroxy-3,5,6,7-tetramethoxyxanthone and 1-hydroxy-3,5,6,7,8-pentamethoxyxanthone) have been isolated from the root of Centaurium littorale. The isolation and structure of these xanthones are reported and details of the TLC analysis are given. The ¹³C NMR and high resolution EIMS spectra of the two hexaoxygenated xanthones are reported. The xanthones found within the genus Centaurium Hill are reviewed.     

Study on Chemical Constituents of Gentianopsis barbata var. Stennocalyx H. W. Li ex T.N. Ho

Nine compounds were isolated from Gentianopsis barbata var. stennocalyx H. W. Li ex. T.N.Ho. Their structures are identified as 1-hydroxy4, 7, 8-trimethoxyxanthone (Ⅰ), 1, 7-dihydroxy-3, 8-dimethoxyxanthone (Ⅱ), 1, 7, 8-trihydroxy-3-methoxyxanthone (Ⅲ), 1-O-(β-D- xylopyranosyl-(1→6)-β-D-glucopyranosyl)-3, 7, 8-trimethoxyxanthone (Ⅳ), 1-O-(β-D-xylopy- ranosyl- (1→6)-β-D-glucopyranosyl)-7-hydroxy-3, 8-dimethoxyxanthone (Ⅴ), 1-O-(β-D-xylo- pyranosyl-(1→6)-β-D-glucopyranosyl)-7, 8-dihydroxy-3-methoxyxanthone (Ⅵ), luteolin-7-O- β-D-glucoside (Ⅶ), oleanolic acid (Ⅷ) and ursolic acid (Ⅸ) by means of chemical methods and UV, IR and NMR determinations respectively.     

Study on Chemical Constituents of Swertia verticillifolia

Eight compounds have been isolated from Swertia verticillifolia by means of silica-gel column chromatography. Their structure have been identified as 1,5,8-trihydroxy-3-methoxyxanrhone(Ⅰ); 1,3,5,8-tetrahylroxyxanthone(Ⅱ);1,3,7,8-tetrahydroxyxanthone(Ⅲ);8-O-B-D-glu-copyranosyl-1, 5-dihydroxy-3-methoxyxanthone(Ⅳ);8-O-B-D-glucopyranosyl-l,3,5-trihydro-xyxanthone(Ⅴ); 1-O-B-D-glucopyranosyl-3, 8-dihydroxy-7-methoxyxanthone (Ⅵ); ursolic acid (Ⅶ) and B-sitosterol(Ⅷ), on the basis of UV, IR, NMR analyses and chemical methods.     

The Glucosides from Swertia mussotii Franch

Swertia mussotii Franch. is a herb used for treatment of liver disease in Qinghai-Tibcran Plateau folk. Further investigation on chemical constituents in aqueous extract of Swertia mussotii Franch. has been reported here. Seven compounds (Ⅰ, Ⅲ–Ⅷ) were achieved except mangiferin (Ⅱ) isolated previously by a chromatograph. They belong in secoiridoids, flavonoids and xanthonoids, respectively. The structures of known compounds were identified as amarogentin(Ⅲ), swertisin(Ⅷ), 8-O-β-D-glucopyranosyl-1, 3, 5-trihydroxyxanthone(Ⅶ) and 8-O-β-D-glucopyranosyl-(1-6)-β-D-glucopyranosyl)-I, 7-dihydroxy-3-methoxyxanthone (Ⅵ). The structures of other three new compounds have been elucidated as 7-O-β-D-xylopy-ranosyl-1, 8-dihydroxy-3-methoxyxanthone (Ⅳ), 7-O-[α-L-rhamnopyranosyl- (1-2)-β-D-xylopyranosyl]-l,8-dihydroxy-3-methoxyxanthone(Ⅰ)and 3-O-β-D-glucopyranosy 1,8-dihydroxy-5-methoxyxanthone (Ⅴ), by means of the chemical and spectral methods. Mangiferin, amarogentin and 7-0- [α-L-rhamnopyranosyl-(1-2)-β-D-xylopyranosyl]-l,8-dihydroxy-3-methoxyxanthone are the principal glucosides in this plant.     

小叶黄杨化学成分的研究

小叶黄杨氯仿组分通过硅胶柱色谱分离纯化,从中分离得到9个化合物,分别鉴定为:β-谷甾醇(β-Sitosterol,Ⅰ)、豆甾醇(Stigmasterol,Ⅱ)、胡萝卜甙(daucosterol,Ⅲ)、水杨酸(salicylis acid,Ⅳ)、香草酸(vanillicacid,Ⅴ)、5,4′-二羟基-3,3′,7-三甲氧基-黄酮(5,4′-dihydroxy-3,3′,7-trimethoxy-flavone,Ⅵ)、5,4′-二羟基-3,3′,6,7-四甲氧基-黄酮(5,4′-dihydroxy-3,3′,6,7-tetramethoxy-flavone,Ⅶ)、Cleomiscosin A(Ⅷ)、3,5-二羟基-4′,6,7-三甲氧基-黄酮-3′-O-β-D-葡萄糖甙(3,5-dihydroxl-4′,6,7-trimethoxyl-flavone-3′-O-β-D-glucopyranoside,Ⅸ),其中化合物Ⅳ、Ⅴ、Ⅵ、Ⅶ均首次从该属植物中分离得到。     

Xanthones from Calophyllum teysmannii var. inophylloide

Further study of the wood of Calophyllum teysmannii Miq. var. inophylloide yielded xanthones 7-hydroxy-1,2,8-trimethoxyxanthone, 6-hydroxy-1,2,5-trimethoxyxanthone, and 2-carbomethoxy-6-methoxyxanthone in addition to 3,8-dihydroxy-1,2,4-trimethoxyxanthone, 3-hydroxy-2,4-dimethoxyxanthone, 1,7-dihydroxy-3-methoxyanthone (gentisin) and 2-hydroxyxanthone.     

The Xanthones of Swertia erythtrosticta Maxim

Swertia erythrosticta Maxim. (Gentianaceae) is a herb used for curing some diseases in Tibetan traditional medicine system. Eight xanthones were isolated from this species. Their structures were identified as 1,8-dihydroxy-3,7-dimethoxyxanthone(Ⅰ), 1,5,8-trihydroxy-3-methoxyxanthone (Ⅱ), 1,3,8-trihydroxy-5-methoxyxanthone (Ⅲ), 1,7,8-trihydroxy-3-methoxyxanthone (Ⅳ), 1,3,5,8-tetrahydroxyxanthone (Ⅴ), 1,3,7,8-tetrahydroxyxanthone(Ⅵ), as well as 8-O-β-D-glucopyranosyl-1, 5-dihydroxy-3 -metho xy xanthone(Ⅶ), 8-O-β-D-gl ucopyr anosyl- 1,3,5- trihydroxyxanthone(Ⅷ) by means of chemical methodes and spectral analyses.     

Chemical constituents of Polygala tenuifolia roots and their inhibitory activity on lipopolysaccharide-induced nitric oxide production in BV2 microglia

A methanolic extract of the roots of Polygala tenuifolia (Polygalaceae) significantly attenuated nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated BV2 microglia cells. Five xanthones, 1-hydroxy-7-methoxyxanthone (1), 3,6-dihydroxy-1,2,7-trimethoxyxanthone (2), 1,3,6-trihydroxy-2,7-dimethoxyxanthone (3), 1,7-dihydroxy-2,3-dimethoxyxanthone (4) and 1,7-dihydroxy-3-methoxyxanthone (5), and five phenylpropanoids, 4-hydroxy-3-methoxypropiophenone (6), methyl 4-hydroxy-3-methoxycinnamic acid (7), 3,4,5-trimethoxycinnamic acid (8), 4-methoxycinnamic acid (9) and β-d-(3-O-sinapoyl) fructofuranosyl-α-d-(6-O-sinapoyl)glucopyranoside (10), were isolated from CHCl(3) fraction using bioactivity-guided fractionation. Among these compounds, compounds 1, 2, 4, 5 and 7 showed significant inhibitory effects on LPS-induced NO production in BV2 microglia cells at the concentration ranging from 10.0 to 100.0 μM.     

蔓生百部的化学成分研究

从蔓生百部(Stemona japonica)根中分离得到13个化合物,通过波谱数据,它们鉴定为β-谷甾醇(1)、豆甾醇(2)、5,11-豆甾二烯-3β-醇(3)、苯甲酸(4)、4-甲氧基苯甲酸(5)、1,8-二羟基-3-甲基蒽醌(6)、1,8-二羟基-6-甲氧基-3-甲基蒽醌(7)、氧代狭叶百部碱(8)、百部定碱(9)、异狭叶百部碱(10)、绿原酸(11)、栀子苷(12)和藏红花素A(13).所有化合物均为首次从该植物中分离得到.     

Lack of altitudinal trends in phytochemical constituents of Swertia franchetiana (Gentianaceae)

Diverse biological characters commonly vary with altitude in species that have a wide altitudinal distribution, partly at least as a result of adaptation to differences in aridity, but whether such variation exists for phytochemical constituents remains unknown. Therefore, levels of seven important phytochemical constituents of Swertia franchetiana (swertiamarin, oleanolic acid, swertisin, mangiferin, 1,5,8-trihydroxy-3-methoxyxanthone, 1,8-dihydroxy-3,7-dimethoxyxanthone and 1,8-dihydroxy-3,5-dimethoxyxanthone) were studied and statistically compared, using materials collected from sites ranging from 2200 to 3960 m in altitude. Swertiamarin was the most abundant in all samples, then mangiferin, oleanolic acid and the other three xanthones. Throughout the distributional range of this species, no altitudinal trend was detected for other constituents except 1,8-dihydroxy-3,7-dimethoxyxanthone, which showed a negative correlation with altitude. However, the concentration of 1,8-dihydroxy-3,7-dimethoxyxanthone and mangiferin showed a significantly latitudinal and longitudinal correlation.     

Xanthones as inhibitors of microsomal lipid peroxidation and TNF-alpha induced ICAM-1 expression on human umbilical vein endothelial cells (HUVECs)

Xanthones bearing different functionalities, namely 1-hydroxyxanthone (1), 3-hydroxyxanthone (2), 1,4-dihydroxyxanthone (3), 2,6-dihydroxyxanthone (4), 1,2-diacetoxyxanthone (5), 2,6-diacetoxyxanthone (6), 3-methoxyxanthone (7), 1,3,7-trimethoxyxanthone (8) and 1,5-dihydroxy-6-methoxyxanthone (9) were synthesised and examined for their effect on nicotinamide adenine dinucleotide phosphate (NADPH)-catalysed liver microsomal lipid peroxidation and on tumour necrosis factor-alpha (TNF-alpha) induced expression of intercellular adhesion moledule-1 (ICAM-1) on endothelial cells, with a view to establish structure-activity relationship. Hydroxy- and acetoxyxanthones showed potent inhibitory effects on NADPH-catalysed lipid peroxidation and TNF-alpha induced expression of ICAM-1 on endothelial cells.     

Diarylheptanoids from the rhizomes of Zingiber officinale

Seven new diarylheptanoids, i.e., (3S,5S)-3,5-diacetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptane, (3R,5S)-3-acetoxy-5-hydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptane, (3R,5S)-3,5-dihydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-7-(4-hydroxy-3-methoxyphenyl)heptane, (5S)-5-acetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptan-3-one, 5-hydroxy-1-(3,4-dihydroxy-5-methoxyphenyl)-7-(4-hydroxy-3-methoxyphenyl)heptan-3-one, 5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-7-(3,4-dihydroxy-5-methoxy-phenyl)heptan-3-one and 1,5-epoxy-3-hydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-7-(4-hydroxy-3-methoxyphenyl)heptane were isolated from the rhizomes of Chinese ginger (Zingiber officinale Roscoe), along with 25 known compounds, i.e., 8 diarylheptanoids, 14 gingerol analogs, a diterpene and 2 steroids. Their structures were elucidated by spectroscopic and chemical methods.     

New antifungal xanthones from the seeds of Rhus coriaria L

Phytochemical investigations of the ethanolic extract of the seeds of Rhus coriaria L. (Anacardiaceae) led to the identification of four new xanthones, characterized as 2,3-dihydroxy-7-methyl xanthone (1), 2,3,6-trihydroxy-7-hydroxymethylene xanthone-1-carboxylic acid (2), 2-methoxy-4-hydroxy-7-methyl-3-O-beta-D-glucopyranosyl xanthone-1,8-dicarboxylic acid (4), and 2-hydroxy-7-hydroxymethylene xanthone-1,8-dicarboxylic acid 3-O-beta-D-glucopyranosyl-(2'-->3")-3"-O-stigmast-5-ene (5), along with the known steroidal glucoside beta-sitosterol-beta-D-glucoside (3). The structures of the isolated compounds have been identified on the basis of spectral data analysis and chemical reactions. All xanthones were active against Aspergillus flavus.     

Phenanthrenoids from the wetland Juncus acutus

Nine 9,10-dihydrophenanthrenes, three phenanthrenes and a related pyrene have been isolated from the wetland plant Juncus acutus. The structures have been attributed by means of their spectral data and chemical correlation. 5-(1-Ethoxy-ethyl)-2-hydroxy-7-methoxy-1,8-dimethyl-9,10-dihydrophenanthrene and 5-(1-phytoxy-ethyl)-2-hydroxy-7-methoxy-1,8-dimethyl-9,10-dihydrophenanthrene, 2,7-dihydroxy-1-methyl-5-vinylphenanthrene, 2,7-dimethoxy-1,6-dimethyl-5-vinylphenanthrene and 2,7-dihydroxy-1,6-dimethylpyrene are described for the first time. Many of the compounds showed in vitro phytotoxicity against Selenastrum capricornutum, a microalga used in aquatic tests.     

巴戟天中蒽醌类化合物及生物活性研究

采用硅胶柱层析结合制备液相从巴戟天(Morinda officinalis)中分离得到8个蒽醌类化合物。根据化合物的波谱数据并与文献对照进行了结构鉴定,分别为2-羟甲基-3-羟基蒽醌(2-hydroxymethyl-3-hydroxyanthraquinone,1)、3-羟基-2-羟甲基-1-甲氧基蒽醌(3-hydroxy-2-hydroxymethyl-1-methoxyanthraquinone,2)、2-羟基-1-甲氧基蒽醌(2-hydroxy-1-methoxyanthraquinone,3)、3-羟基-1,2-二甲氧基蒽醌(3-hydroxy-1,2-dimethoxyanthraquinone,4)、甲基异茜草素-1-甲醚(rubiadin-1-methyl ether,5)、1,3-二羟基-2-甲氧基蒽醌(1,3-dihydroxy-2-methoxyanthraquinone,6)、1,3-二羟基-2-乙氧甲基蒽醌(ibericin,7)、1,2-二羟基-3-甲基蒽醌(1,2-dihydroxy-3-methylanthraquinone,8)。其中蒽醌(2)为首次从该植物中分得。利用MTT法对分离出的蒽醌的体外抗癌活性进行筛选,结果显示蒽醌(3)、(5)和(7)对肝癌细胞SMMC-7721增殖有明显的抑制作用,当蒽醌的浓度为400μmol/L时,蒽醌(3)、(5)和(7)对肝癌细胞的抑制率分别为44. 63%、20. 52%、54. 89%。