Two new xanthone glycosides from Tripterospermum lanceolatum

Oleanolic acid, mangiferin, and two new xanthone glucosides, named lanceoside (1,8-dihydroxy-3,7- dimethoxyxanthone- 4-O-β-d-glucoside) and lancerin (C-4-β-d-glucosyl-1,3,7-trihydroxyxanthone), respectively, were isolated from the aerial parts of Tripterospermum lanceolatum.     

Preparative isolation of closely-related xanthones from Gentianella amarella ssp. acuta by High-speed countercurrent chromatography

Introduction –  A methanolic extract from Gentianella amarella ssp. acuta was shown to contain several xanthones exhibiting acetylcholinesterase inhibitory activity. These xanthones were difficult to separate by conventional LC techniques, which prevented the isolation of pure compounds in sufficient amounts to perform in‐depth biological testing. Objective –  To develop a suitable preparative method for the separation of closely related xanthones. Methodology –  The methanolic extract was first partitioned with solvents of increasing polarity, in order to separate glycosides from xanthone aglycones. High‐speed countercurrent chromatography (HSCCC) methods were then optimised for the fractionation of both polar and non‐polar extracts. Results –  The use of HSCCC enabled the separation of xanthones which co‐eluted by HPLC. Ten closely related xanthones—three of which were isomeric—were successfully isolated by developing suitable solvent systems. All compounds were obtained in sufficient amounts to allow further biological assays (e.g. up to 250 mg), including even minor compounds that were not detectable by analytical HPLC. Conclusion –  The orthogonality of HSCCC with HPLC and the absence of solid‐phase supports enabled the detection, separation and preparative isolation of closely related compounds which were difficult to resolve by other techniques. Copyright © 2008 John Wiley & Sons, Ltd.     

Flavonoid glycosides and a bitter principle from lomatogonium carinthiacum

Three flavone glycosides, including the novel 6-hydroxyluteolin 7-O-gentiobioside, and a bitter secoiridoid glycoside, swertiamarin, have been identified in the aerial parts of Lomatogonium carinthiacum. Four minor xanthone glycosides were also detected. Separations were made with droplet counter-current chromatography (DCCC) in combination with column chromatography. Structure elucidation was achieved by UV, ¹H and ¹³C NMR, FDMS and D/CIMS spectra.     

Mass spectrometric studies of underivatized polyphenolic glycosides

Flavonoid and xanthone glycosides were studied by mass spectrometry using soft ionization techniques such as desorption chemical ionization, fast atom bombardment and field desorption. In all cases a preliminary derivatization was not required. Information on the M_r, the sugar sequence and structure of the aglycone could be obtained.     

Campestroside,a new tetrahydroxanthone glucoside from Gentiana campestris

Campestroside has been isolated from the aerial parts of Gentiana campestris. From UV, MS, ¹H-NMR and ¹³C-NMR data its structure has been established as 1,3,5-trihydroxy-8-β-d-glucopyranosyl-5,6,7,8-tetrahydroxanthone. Campestroside which has also been detected in G. ramosa and G. germanica is the first reported tetrahydroxanthone glycoside.     

Flavonol glycosides from Anthyllis onobrychioides

A new flavonol glycoside, rhamnocitrin 3-O-β-D-galactopyranoside, has been isolated from aerial parts of Anthyllis onobrychioides, together with the known 3-O-β-D-galactopyranosides of quercetin, isorhamnetin and kaempferol.     

Xanthones,flavones and secoiridoids of american Gentiana species

Isoorientin, isoorientin-4′-O-glucoside, gentiopicrin, xanthones with 1,3,5,8 or 1,3,7,8-oxidation pattern have been isolated from five North American Gentiana species (G. affinis, G. algida, G. calycosa, G. detonsa, G. strictiflora) and one South American species (G. cerastioides). Separations were achieved with droplet counter-current chromatography (DCCC) or centrifugally accelerated preparative TLC. The distribution of the isolated compounds within the genus is discussed.     

Xanthone and flavonol constituents of Swertia hookeri

The whole plant of Swertia hookeri, collected at flowering has been shown to contain two tri- and nine tetraoxygenated free, glucosyloxy, and stearyl ester xanthones and one flavonol stearyl ester. Among these, three are previously unreported in nature and one was known previously only as a synthetic compound. The xanthones are based on 1,3,5,-, 1,3,5,8- and 1,3,7,8-oxygenated systems with the middle oxygenation pattern predominating. The two ester compounds appeared only at the flowering stage. Plants collected at the pre-flowering stage gave the corresponding free compounds. The biochemical and biological significance of these findings are appraised.     

Flavonol glycosides of Carya pecan

The flavonol glycosides characterized from the branches of Carya pecan include three new compounds, azaleatin 3-glucoside azaleatin 3-diglycoside and caryatin 3′- (or 4′-) rhamnoglucoside. together with azaleatin 3-rhamnoside. In the leaf tissue, quercetin 3-glucoside, quercetin 3-galactoside, quercetin 3-rhamnoside, quercetin 3-arabinoside and a small amount of kaempferol 3-monomethyl ether were identified.     

怀地黄叶片中总环烯醚萜苷及总苯乙醇苷含量快速分析模型的建立

本文旨在建立地黄叶片中总环烯醚萜苷及苯乙醇苷定量分析模型。利用紫外-可见分光光度法测定不同种质怀地黄生育期内的128份地黄叶片中总环烯醚萜苷及总苯乙醇苷的含量,并将其作为基础值,结合地黄叶片的近红外光谱图,利用TQ8.0分析软件结合偏最小二乘法(PLS),分别建立地黄叶片中总环烯醚萜苷及总苯乙醇苷的定量分析模型。地黄叶片中总苯乙醇苷定量校正模型决定系数(R2)为0.998 2,校正均方根偏差(RMSEC)为0.089 9,预测均方决定差(RMSEP)为0.142,交叉验证均方根偏差(RMSECV)为0.707 2;总环烯醚萜苷定量校正模型的内部交叉验证决定系数(R2)为0.972 1,校正均方差(RMSEC)为0.259,预测均方决定差(RMSEP)为0.095 4,交叉验证均方根偏差(RMSECV)为0.869 4。预测值与实测值差异无统计学意义。该定量模型可用于怀地黄叶片中总环烯醚萜苷及总苯乙醇苷含量的快速测定。     

Xanthones and C-glucosylflavones from Gentiana corymbifera

A new xanthone and twelve known compounds were isolated from the aerial parts of Gentiana corymbifera. The new xanthone was shown to be 3-methylcorymbiferin (1,8-dihydroxy-3,4,5-trimethoxy-9H-xanthen-9-one) by spectral and chemical procedures. The chemotaxonomic implications are discussed.     

Cardiac glycosides of the root bark of Nerium odorum

In addition to the known odorosides, the β-d-digitaloside and β-d-glucosyl-(1 → 4)-β-d-digitaloside of uzarigenin were isolated from the root bark of Nerium odorum. Odoroside B was obtained in remarkably high yield among the digitoxigenin and uzarigenin glycosides. With the aid of polyamide column chromatography, oleandrigenin β-gentiobiosyl-(1 → 4)-β-d-digitaloside ( = 16-O-acetylneogitostin) was isolated along with other oleandrigenin glycosides.     

New 1,3,5-trioxygenated xanthones in Canscora decussata

Aerial parts of Canscora decussata have been shown to contain 1-methoxy-3,5-dihydroxyxanthone and its 3-O-rutinosyl derivative. The identity of these compounds was established by chemical transformation and spectral (UV, IR, PMR, MS) evidence of the compounds and their derivatives. This is the first demonstration of the occurrence of the two compounds in nature.     

Two chromone glycosides from Cassia multijuga

Two new 2-methylchromone glycosides have been identified in the leaves of Cassia multiluga.     

辐状肋柱花的苷类成分

利用硅胶柱层析、Sephadex LH-20及反相硅胶RP-18分离及纯化技术,从辐状肋柱花全草乙醇提取物的正丁醇萃取部分得到7个水溶性成分,经1H NM R、13C NM R等波谱技术鉴定为异荭草苷、芒果苷、Sw ertipun i-cos ide、当药醇苷、异牡荆苷、当药黄素、和7-O-[α-L-吡喃鼠李糖-(1→2)-β-D-吡喃木糖]-1,8-二羟基-3-甲氧基口山酮.除异荭草苷外,其余化合物均首次从该植物中得到.     

Spirostanol glycosides from Asparagus plumosus

Three spirostanol glycosides were isolated from a methanol extract of the leaves of Asparagus plumosus and characterized.