Antioxidant Nature Adds Further Therapeutic Value: An Updated Review on Natural Xanthones and Their Glycosides

Plants have so much to offer as far as the discovery of new bioactive molecules is concerned.Among the several classes of phytochemicals,xanthones offer greater structural diversity and pharmacological value.They are variable but definitely antioxidant in nature.Thus they are attractive targets for natural product and medicinal chemists.Xanthones and their glycosides possess broad spectrum interesting biological activities,such as cytotoxic,anti-inflammatory,antioxidant,anti-bacterial,neuroprotective,anti-HIV,enzyme inhibition,and hypoglycemic.The radical scavenging ability of these molecules accounts for most of their added therapeutic values.This paper intended to serve as a guide for future endeavors in quest for these molecules.Structure-Activity Relationship(SAR)and mechanism of action is given for better understanding of their role as pharmacological agents.The most recent advances in the isolation of bioactive xanthones and their glycosides were presented here.This paper will assist in directed approaches towards the discovery of analogues of xanthones.

New Xanthones from Swertia decora

From the CHCl3 part of Swertia decora Franch., a traditional medicinal herb of China, two new xanthones, swertiadecoraxanthone-I and swertiadecoraxanthone-II along with four known compounds have been isolated and identified on the basis of spectral analysis and chemical evidence.

含氧取代xanthone类化合物的电喷雾质谱裂解规律研究

目的研究从传统藏药藏茵陈植物中分离得到的12种含氧取代xanthone类化合物的质谱裂解规律。方法采用多级串联质谱(HPLC-ESI-MSn)技术对xanthone类化合物在正负离子模式下的电喷雾多级质谱进行分析。结果①xanthone苷元结构中取代基的数目和位置不同,则断裂中性分子的顺序会有所不同;②xanthone苷内糖基的^0,2X0和^0,3X0断裂可能为xanthone碳-苷的特征碎裂方式。结论以上规律的总结将有助于天然药物中含氧取代xanthone类化合物结构的快速鉴定。

Two New Xanthone Glycosides from Polygala tenuifolia

Two new xanthone glycosides, polygalaxanthone IV and V were isolated from the roots of Polygala tenuifolia Willd. Their structures were established as 6-O-[a-L-rhamnopyranosyl- (12)-b-D-glucopyranosyl]-1-hydroxy-3, 7-dimethoxyxanthone (polygalaxanthone IV), and 6-O- [a-L-rhamnopyranosyl-(12)-b-D-glucopyranosyl]-1, 3-dihydroxy-7-methoxyxanthone (polyga- laxanthone V), respectively, on the basis of chemical and spectral evidence.

Xanthone对大鼠不全脑缺血再灌损伤的保护作用

目的 :研究Xanthone(Xan)对大鼠不全脑缺血再灌损伤的保护作用。方法 :分别给大鼠ivXan 5 0mg/kg和 10mg/kg 10天 ,麻醉后常规分离双侧颈总动脉 ,用鼠动脉夹同时夹闭 30min后再灌 45min ,迅速断头取脑 ,测脑含水量、LDH活性和Ca2 + 、MDA含量。结果 :Xan高剂量降低大鼠脑含水量 6 .36 %、MDA含量 2 2 .12 %及钙离子浓度 2 0 .10 % ,提高LDH活性达 12 .44 %。结论 :Xan对大鼠不全脑缺血再灌注损伤有一定保护作用。

Xanthone对实验性脑缺血再灌注损伤的作用机制

分别以 5 0 m g· kg- 1 和 10 mg· kg- 1 的 1,8- dihydroxy,3,5 - dim ethoxyxanthone(XT)给大鼠静脉给药 3 d,探讨其对实验性脑缺血再灌注损伤的保护作用及机理。实验结果显示 ,XT明显减轻缺血再灌注引起的大鼠脑水肿 ,减少大脑皮层 MDA含量 ,提高 CAT和 SOD活性 ,提高 GSH含量 ,并使皮层的 ATP含量增多 ,乳酸含量降低。

Xanthone对小鼠反复脑缺血再灌流后行为学的影响

观察Xanthone (XT)对小鼠反复脑缺血再灌流后行为学的影响。将 40只小鼠分为 4组 ,经反复脑缺血再灌流加降血压法造模后 ,分别给予注射用水、XT静脉注射高剂量 5 0mg/kg和低剂量 10mg/kg ,术后进行跳台、水迷宫实验测试。结果显示 ,模型组小鼠潜伏期缩短 ,游全程时间延长、错误次数增多 ;XT高、低二个剂量组均使上述指标改善 ,有显著性差异。揭示XT可对抗反复脑缺血再灌流后行为学的障碍 。

Crystal Structure of 1-Hydroxy-2,3,4,7-tetramethoxyxanthone, a Xanthone Isolated from Halenia Elliptica

In an attempt to identify bioactive compounds from a Tibetan medicinal herb Halenia elliptica, four known compounds were isolated. The crystal structure of the title compound 1-hydroxy-2,3,4,7-tetramethoxyxanthone was characterized by X-ray single-crystal structure analysis. The crystal belongs to monoclinic, space group P21/n with a = 7.155(2), b = 13.232(1), c = 16.037(2) ? b = 95.06(2), V = 1512.4(5) 3, C17H16O7, Mr = 332.30, Z = 4, Dc = 1.459 g/cm3, l(MoKa) = 0.71073 ? m(MoKa) = 1.15 cm-1 and F(000) = 696. It exhibits a characteristic approximate plane structure consisting of 13 carbon atoms (C(1) to C(13)) and all of the seven oxygen atoms (O(1) to O(7)). An intra-hydrogen bond was formed between O(6) and O(5)H(5).

Isolation and Crystal Structure of Xanthones from Swertia Chirayita

In order to study the relationship between biological and pharmacological activities with their structures, a series of tri- and tetra-oxygenated xanthones including 1-hydroxyl-2,3,4,7- tetramethoxy xanthone 1, 1-hydroxyl-2,3,4,5-tetramethoxyl xanthone 2, 1-hydroxyl-3,5-dimethoxy- xanthone 3, 1,8-dihydroxyl-3,5-dimethoxyl xanthone 4 and 1,5,8-trihydroxyl-3-methoxy xanthone 5 have been isolated from Swertia chirayita. Their structures were established on the basis of spectral and chemical evidences. The crystal structure of 5 was also investigated by single-crystal X-ray diffraction analysis. It crystallizes in the triclinic system, space group P?with a = 7.1540(10), b = 7.520(2), c = 10.671(2) , V = 562.7(2) 3 , α = 86.50(3), β = 80.06(3) , γ = 85.00(3), Z = 2, Dc = 1.618 g/m3, R = 0.0405, wR = 0.1028 and F(000) = 284. The molecular structure of 5 is nearly planar and four substituents are much closer to the plane. Compound 5 contains three intermolecular hydro- gen bonds. A recent study shows that phenolic hydroxyls in xanthones are the main active groups capable of scavenging OH and O2.

Xanthones from the bark of Garcinia Xanthochymus

Two novel xanthones, 1,6-dihydroxy-4,5-dimethoxyxanthone （1） and 1,5,6-trihydroxy-7,8-di（3-methyl-2-butenyl）-6＇,6＇-dimethylpyrano（2＇,3＇：3,4）xanthone （2） were isolated from the bark of Garcinia xanthochymus by normal phase and reverse phase silica gel column chromatography. Their structures were elucidated by spectroscopic methods, especially 2D-NMR techniques.

藤黄中xanthone类化合物的定性定量分析(英文)

目的:定性定量分析藤黄中的xanthone类化合物。方法:应用一种简便快捷的高效液相色谱方法。结果:从藤黄药材中鉴定出其中xanthone类主要成分:isomorellic acid(1),morellic acid(2),isogambogenic acid(3),gambogenic acid(5),isogambogic acid(6),gambogic acid(7)and 30-hydroxygambogic acid(4),并进行了有关的定量分析。同时对采自中国及印度不同地区的7份藤黄药材进行了HPLC色谱分析,以上述其中xanthone类化合物为指标成分,对藤黄药材的HPLC色谱特征进行了描述。结论:该方法简便快捷,能有效地应用到藤黄药材的质量控制中。

A new cytotoxic caged polyprenylated xanthone from the resin of Garcinia hanburyi

A new caged polyprenylated xanthone, gambogic aldehyde （1）, was isolated from the resin of Garcinia hanburyi. Its structure was elucidated on the basis of spectral data including 1D and 2D NMR data. In addition, the antiproliferative ability of compound 1 was determined in mouse leukemia P388 and P388/ADR cells.

Apoptotic activity of caged xanthones from Garcinia hanburyi in cholangiocarcinoma cell lines

AIM:To investigate the growth inhibitory mechanism of four caged xanthones from Garcinia hanburyi in cholangiocarcinoma(CCA) KKU-100 and KKU-M156 cells.METHODS:Four caged xanthones,selected on the basis of their anticancer potency and chemical structure diversities(i.e.isomorellin,isomorellinol,forbesione and gambogic acid) were used in this study.Growth inhibition of these caged xanthones was determined using the sulforhodamine B assay.Induction of apoptosis was assessed by observing cell morphology,ethidium bromide and acridine orange staining and DNA fragmentation assay.Levels of apoptotic-related gene and protein expressions were determined by a real-time reverse transcriptase polymerase chain reaction and Western blotting analysis,respectively.RESULTS:The compounds were found to inhibit growth of both cell lines in a dose-dependent manner and also showed selective cytotoxicity against the cancer cells when compared with normal peripheral blood mononuclear cells.Growth suppression by these compounds was due to apoptosis,as evidenced by the cell morphological changes,chromatin condensation,nuclear fragmentation,and DNA ladder formation.At the molecular level,these compounds induced down-regulation of Bcl-2 and survivin proteins with up-regulation of Bax and apoptosisinducing factor proteins,leading to the activation of caspase-9 and-3 and DNA fragmentation.The functional group variations did not appear to affect the anticancer activity with regard to the two CCA cell lines;however,at a mechanistic level,isomorellinol exhibited the highest potency in increasing the Bax/Bcl-2 protein expression ratio(120 and 41.4 for KKU-100 and KKU-M156,respectively) and in decreasing survivin protein expression(0.01 fold as compared to control cells in both cell lines).Other activities at the molecular level indicate that functional groups on the prenyl side chain may be important.CONCLUSION:Our findings for the first time demonstrate that four caged xanthones induce apoptosis in CCA cells which is mediated through a mitochondriadependent signaling pathway.

Three New Xanthones from Polygala crotalarioides

Three new xanthones, 3, 6-dihydroxy-1, 2, 7-trimethoxyxanthone 1, 1, 3, 6-trihydroxy-2, 7, 8-trimethoxyxanthone 2, and 3, 6-dihydroxy-1, 2, 7, 8-tetramethoxyxanthone 3, were isolated from the roots of Polygala crotalarioides. Their structures were elucidated by spectral and chemical methods.

Two New Xanthone Glycosides from Securidaca inappendiculata

Two new xanthone glycosides, securixanside B and C, were isolated from the stems of Securidaca inappendiculata. Their structures were determined as 3-O-b-D-glucopyranosyl- 1,7-dihydroxy-2-methoxyxanthone and 6-O-b-D-glucopyranosyl-1-hydroxy-4,7-dimethoxyxan- thone by spectroscopic methods.

Optimized Separation of Pharmacologically Active Xanthones from Securidaca inappendiculata by Capillary Electrophoresis

A capillary electrophoresis (CE) method has been firstly used for the separation of the therapeutically important xanthones from Securidaca inappendiculata. The separation of the nine xanthones was systematically optimized with respect to pH, concentration of running buffers, addition of sulfated b-CD, applied voltage and column temperature. Baseline separation was achieved for the nine xanthones in less than 15 minutes using a background electrolyte consisting of 200 mmol/L borate (pH 9.5) and 10 mmol/L sulfated b-CD.

Studies of Thermodynamic Properties and Relative Stability of Polybrominated Xanthones by Density Functional Theory

The thermodynamic properties of xanthone（XTH） and 135 polybrominated xanthones（PBXTHs） in the standard state have been calculated at the B3LYP/6-31G＊ level using Gaussian 03 program.The isodesmic reactions were designed to calculate the standard enthalpy of formation（△fHθ） and standard free energy of formation（△fGθ） of PBXTH congeners.The relations of these thermodynamic parameters with the number and position of Br atom substitution（NPBS） were discussed,and it was found that there exist high correlation between thermodynamic parameters（entropy（Sθ）,△fHθ and △fGθ） and NPBS.According to the relative magnitude of their △fGθ,the relative stability order of PBXTH congeners was theoretically proposed.The relative rate constants of formation reactions of PBXTH congeners were calculated,Moreover,the values of molar heat capacity at constant pressure（Cp,m） from 200 to 1000 K for PBXTH congeners were also calculated,and the temperature dependence relation of them was obtained,suggesting very good relationships between Cp,m and temperature（T,T^1 and T^2） for almost all PBXTH congeners.

Two New Xanthone Glycosides from Swertia Tetraptera

Two new xanthone glycosides, tetraswerosides A and B, were isolated from the whole plant of Swertia tertraptera. Their structures were determined as 3-O-beta -D-glucopyranosyl-1-hydroxy-4,7-dimethoxyxanthone and 3-O-[beta -D-xylopyranosyl-(1-->6)-beta -D-glucopyranosyl]-1- hydroxy-4,7-dimethoxyxanthone by spectroscopic methods.

A New Xanthone Derivative from Hypericum Erectum

A new xanthone, 1,2-dihydro-3,6,8-trihydroxy-1,1-bis (3-methylbut -2-enyl)-5-(1, 1-dimethylprop-2-enyl)xanthen-2,9-dione (1), has been isolated from the aerial part of Hypericum erectum.

Gas Phase Thermodynamic Properties of Polychlorinated Xanthones Predicted with DFT Method and Cl Substituted Position

The gas phase thermodynamic properties of 135 polychlorinated xanthones(PCXTs)are calculated using a combination of quantum mechanical computations performed with the Gaussian 03 program at the B3LYP/6-311G**level.It is found that the chlorine substitution pattern strongly influences the thermodynamic properties of the compounds.The thermodynamic properties of congeners with the same number of chlorines also depend on the chlorine substitution pattern,especially for ortho-substituted congeners.PCXT congeners with one phenyl ring fully chlorinated are found to be the least stable among the analogues.The effect of the chlorine substitution pattern is quantitatively studied by considering the number and position of Cl atom substitution(NPCS).The results show that the NPCS model may be used to predict the thermodynamic properties for all 135 PCXT congeners. In addition,the values of molar heat capacities at constant pressure(cp,m)from 200 to 1000 K for PCXT congeners are calculated,and the temperature dependence relation of this parameter is obtained using the least-squares method.