硫酸化高山红景天多糖(RSASL)的制备及鉴定

从高山红景天中分离出一种酸性杂多糖（ＲＳＡ）．该多糖由阿拉伯糖（Ａｒａ）、鼠李糖（Ｒｈａ）、半乳糖（Ｇａｌ）、木糖（Ｘｙｌ）、葡萄糖（Ｇｌｃ） 与半乳糖醛酸（ＧａｌＡ）组成,其单糖摩尔比为１．００∶３ ．２３∶０ ．２６∶０ ．３４∶０ ．８４∶１０．２４．用氯磺酸－吡啶法制备硫酸化高山红景天多糖（ＲＳＡＳＬ）．用离子色谱法测定ＲＳＡＳＬ 中Ｓ的质量分数为１１．０１％ ,其硫酸基取代度为０．８５．用红外光谱,紫外光谱,Ｓｅｐｈａｒｏｓｅ ＣＬ－４Ｂ柱层析,激光解吸电离飞行时间质谱等方法鉴定,ＲＳＡＳＬ均显示了多糖硫酸酯的特征     

The structure of the flavonoids from Rhodiola algida. II

Summary New flavonoid glycosides have been obtained from the roots ofRhodiola algida: rhodalgin (I), composition C₂₀H₁₈O₁₁, mp 239–240°C; acetylrhodalgin (II) C₂₂H₂₀O₁₂, mp 223–224°C; diacetylrhodalgin (III), C₂₄H₂₂O₁₃, mp 208–209°C; and triacetylrhodalgin (IV), C₂₆H₂₄O₁₄, mp 230–231°C.It has been established that they have the following structures: (I), 3,4,5,7,8-pentahydroxyflavone 8-O--L-arabinopyranoside; (II), 3,4,5,7,8-pentahydroxyflavone 8-O-(3-O-acetyl--L-arabinopyranoside; (III), 3,4,5,7,8-pentahydroxyflavone 8-O-(2,3-di-O-acetyl)--D-xylopyranoside; and (IV), 3,4,5,7,8-pentahydroxyflavone 8-O-(2,34-tri-O-acetyl)--D-xylopyranoside. The -L-arabinopyranose and -D-xylopyranose are present in these compounds in the C1 conformations.In the performance of this investigation, the authors consulted O. S. Chizhov, and M. B. Zoltarev (N. D. Zelinskii Institute of Organic Chemistry of the Academy of Sciences of the USSR) and V. I. Sheichenko (All-Union Institute of Medicinal plants).All-Union Scientific-Research Institute of Medicinal Plants. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 712–720. November–December, 1975.     

超声波辅助提取茶叶总黄酮及抗氧化活性分析

采用超声波辅助法探讨了铁观音茶叶中总黄酮的最佳提取工艺条件,并测定了铁观音茶叶总黄酮清除羟基自由基的能力.结果表明,超声波功率400 W,料液比1∶30 g·mL~(-1),浸提时间30 min,乙醇浓度50%为超声波辅助提取铁观音茶叶总黄酮的最佳工艺条件,总黄酮提取率为4.74%;抗氧化实验表明随着铁观音茶叶总黄酮浓度的增大,其对羟基自由基的清除能力增大,当浓度达到0.80 g/L,清除率为65.14%,与BHT相比具有较强的抗氧化能力.     

Structure-function analysis of the radioprotective and antioxidant activity of flavonoids

The recombination kinetics of a series of flavonoids with stable DPPH radicals are studied. Flavonols are the most reactive. Polarization of the carbonyl in flavones reduces the reactivity. Substitution on C-7 and the B ring has practically no effect on the reactivity. Glycosylation of C-3 reduces the reactivity if the sugar can form two intramolecular H-bonds. The reactivity of the flavonoid phenol hydroxyls, with the exception of the hydroxyl on C-5, is proportional to their number. The most promising antioxidants are lespedin, kaempferitrin, kaempferol, kaempferol-7-rhamnoside, kaempferol-3-robinobioside, and robinin.I. G. Kutateladze Institute of Pharmacochemistry, Georgian Academy of Sciences, Tbilisi, fax (99532)-25-00-26. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 42–46, January–February, 2000.     

Authentication of Rhodiola rosea,Rhodiola quadrifida and Rhodiola rosea liquid extract from the Ukrainian market using HPTLC chromatographic profiles

Abstract

Rhodiola rosea and Rhodiola quadrifida are widely distributed and sold in Eastern Europe. The purpose of this paper was to identify R.rosea, R.quadrifida and Rhodiola rosea liquid extract (RRLE) in the Ukrainian market and bring out adulteration cases using chromatographic characterisation by HPTLC. The multiple samples of R.rosea, R.quadrifida and RRLE were compared; the optimal chromatographic conditions for identification of R.rosea and RRLE based on the presence of rosavins and salidroside as well as for identification of R.quadrifida based on the presence of salidroside were proposed; the specific HPTLC fingerprints were obtained; the acceptance criteria for each product were set. The adulteration cases for R.rosea and RRLE samples were established. The dependence on handling R.rosea and presence of rosavins was determined. It was assumed that low-quality raw materials or inefficient technology process were used for RRLE. The consistency of HPTLC fingerprints for R.quadrifida samples was established.     

Quantitative antioxidant activity of the ethylacetate extract of Larix sibirica bark and its individual components

The antioxidant [AO] properties of the ethylacetate extract of Larix sibirica bark and the flavonoids quercetin and dihydroquercetin found in it were studied using a model radical-chain oxidation of propan-2-ol in the kinetic regime. The quantitative characteristics of their AO activity were determined as effective rate constants fk_ln. It was found that dihydroquercetin had the highest AO activity among the studied natural compounds. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 131–133, March–April, 2006.     

Estimation of the antioxidant activities of flavonoids from their oxidation potentials.

A simple electrochemical method for estimating the antioxidant activity (AA) of flavonoids has been developed. The proposed method is based on a measurement of the half-wave potential (E1/2) of the first oxidation wave of flavonoids by using flow-through column electrolysis. At the same time, the lipid peroxidation (LPO) inhibiting effects of these flavonoids were determined. A quantitative structure-activity relationship was obtained to describe the AA of flavonoids: IC50(microM) = 30.36 + 151.50 E1/2 (V) -12.63 log P (r = 0.852), where IC50 represents the concentration for 50% inhibition of LPO, and P represents the octanol/water partition coefficient. This method is expected to be useful for the quick screening of flavonoid antioxidants, and evaluating the AA of flavonoid-containing foods and medicinal plants.     

Dioclins A and B,new antioxidant flavonoids from Dioclea reflexa

Dioclins A (1) and B (2), the new flavonoids, have been isolated from the ethyl acetate soluble fraction of the roots of Dioclea reflexa along with 3,5-dihydroxy-4 methoxybenzoic acid (3), lupeol (4) and the rare dipeptide, auratiamide acetate (5). Their structures have been elucidated by spectroscopic techniques. The compounds 1 and 2 showed a significant antioxidant activity in DPPH radical scavenging assay.     

Analysis of antioxidant flavonoids from asteraceae and moraceae plants by capillary electrophoresis

Summary Antioxidant flavonoids from the plantsSolidago gigantea Ait.,Taraxacum officinale Wiggers and Webers (Asteraceae) andMorus nigra L. (Moraceae) have been analysed by capillary electrophoresis (CE).Solidago gigantea was investigated because of its diuretic, spasmolytic, antiphlogistic, and wound-healing effect,Taraxacum officinale because it has been shown to have good diuretic and choleretic activity, andMorus nigra because it is also widely regarded as a diuretic and antidiabetic agent. Aqueous and methanolic extracts of these plants have antioxidant properties. Because their flavonoid composition might be important in their free-radical-scavenging activity, a capillary electrophoretic method was developed for characterization of the flavonoids present. We identified quercetin-3-O-β-rutinoside (rutin), quercetin-3-O-β-d-glucoside (isoquercitrin), and chlorogenic acid as the most abundant compounds inSolidago gigantea andMorus nigra, and apigenin-7-O-β-glucoside, luteolin-7-O-β-glucoside, and chlorogenic acid inTaraxacum officinale. We also discovered that quercetin-3-O-α-rhamnoside (quercitrin) and quercetin-3-O-β-galactoside (hyperoside) were absent from our sample ofSolidago gigantea and quercitrin fromMorus nigra. Quantitative analysis of these extracts was performed by high-performance liquid chromatography (HPLC). Presented at Balaton Symposium '01 on High-Performance Separation Methods, Siófok, Hungary, September 2–4, 2001     

Identification of flavonoids and chlorogenic acids in elm fruits from the genus Ulmus and their antioxidant activity

Elm fruits were once an important food source in the years of famine. Research on the functional compounds in elm fruits was almost unavailable. In this study, we established an efficient high‐performance liquid chromatography method for the simultaneous separation of eight chlorogenic acids and 28 flavonoids in elm fruits for the first time. Total flavonoid contents ranged from 286 mg/100 g (Ulmus laciniata) to 1228 mg/100 g (U. pumila). High concentrations of rutin, quercetin 3‐O‐glucoside, and kaempferol derivatives were present in U. laevis, U. castaneifolia, and U. pumila, respectively. Furthermore, the fruit extracts of U. americana, U. castaneifolia, U. davidiana, and U. pumila showed higher antioxidant activity. These results suggest that fruits of these species can be used as bioresources for the extraction of the corresponding functional compounds. This work provides informative data and can be an important reference for future research on elm fruits as a renewed food resource.     

Proliferative and antioxidant activity of Symphytum officinale root extract

The root of Symphytum officinale L. is commonly used in folk medicine to promote the wound healing, reduce the inflammation and in the treatment of broken bones. The objective of our investigation was to analyse the extract from S. officinale in term of its antioxidant activity and the effect on cell viability and proliferation of human skin fibroblast (HSF). Moreover, the quantification of main phenolics and allantoin was conducted using HPLC–DAD method. Five compounds were found: rosmarinic, p-hydroxybenzoic, caffeic, chlorogenic and p-coumaric acid. DPPH, FRAP and TPC assay showed the high antioxidant activity of the extract. MTT test proved the stimulatory effect on cell metabolism and viability of HSF cells. Moreover, no changes in cytoskeleton structure and cells shape were observed. The obtained results indicate that non-toxic extract from S. officinale root has strong antioxidant potential and a beneficial effect on human skin fibroblasts.     

A sulphated flavone glycoside from Livistona australis and its antioxidant and cytotoxic activity

A new flavone glycoside tricin 7-O-β-glucopyranoside-2″-sulphate sodium salt along with 14 known flavonoid compounds were isolated and identified from the aqueous methanol extract of Livistona australis leaves. Their structures were established on the basis of extensive NMR (1H, 13C, HSQC and H-H COSY) and ESIMS data. Antioxidant and cytotoxicity properties of the methanol extract of the leaves as well as the new compound were investigated.     

A new biflavonoid from Solanum dulcamara L. and investigation of anti-hyperglycaemic activity of its fruit extract

A new biflavone, 6,2′,3″,5″,4?-pentahydroxy-3,7″-biflavone, has been isolated from the fruits of Solanum dulcamara L., in addition to two known compounds, β-sitosterol and stigmasterol. Their structures were established on the basis of UV, IR, 1D, 2D NMR and HR-ESI-MS spectroscopic methods. The anti-hyperglycaemic effect of S. dulcamara was investigated using diabetic rats. The anti-hyperglycaemic activity of the fruit extract of S. dulcamara was presented for the first time in this study.     

A comparative study of phytochemical metabolites and antioxidant properties of Rhodiola

Rhodiola crenulata (RC) and Rhodiola fastigiata (RF) are representative species of Rhodiola with well-accepted health benefits; the roots are the medicinal part. However, prior to this study, the differences in phytochemicals between these two species and different parts of the same species remained unclear. Using LC-ESI-MS/MS, HS-SPME-GC–MS, chemical and sensory analyses, volatile compounds and non-volatile compounds, and antioxidant activities of the roots of Rhodiola crenulata and Rhodiola fastigiata and four parts (roots, leaves, flowers, and above-ground stems) of RC were investigated. The volatile compounds and non-volatile compounds of RC roots exhibited upregulation overall compared to those of RF roots, and the odorousness, phenolic content, and antioxidant activity were more pronounced in the RC roots. The phenolic content and antioxidant activity of roots and leaves, alongside the odorousness of roots and flowers, were more significant among the four parts of RC, and the RC roots and RC flowers exhibited similar odorousness. Comparison of non-volatile differential metabolites between RC roots and RC leaves showed upregulations of saccharides and phospholipids, and minor upregulations of flavonoids and phenylpropanoids in the roots; in addition, amino acids, organic acids, and vitamins were upregulated in the leaves. These results revealed the following: 1) RC roots are superior to RF roots regarding volatile compounds and non-volatile compounds, and antioxidant activity; 2) it is more favorable to select RC roots for exploiting volatile compounds compared with RC flowers in consideration of the biomass available; 3) in terms of non-volatile compounds, and antioxidant ability, RC leaves are also of great value in addition to RC roots, though these two parts show distinct characteristics.     

Isoiridomyrmecin rich essential oil from Nepeta erecta Benth. and its antioxidant activity

The essential oil composition of the aerial parts of Nepeta erecta Benth. (Family: Lamiaceae) from Uttarakhand, India was analysed by capillary gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). A total of 34 constituents were identified representing 94.6% of the oil composition. Oxygenated monoterpenes (74.0%) constituted the major proportion of the oil, dominated by isoiridomyrmecin (70.6%) as a single major constituent. Other significant constituents were caryophyllene oxide (9.6%), β-Bourbonene (2.0%), humulene epoxide II (1.7%) and linalool (1.0%). The in?vitro antioxidant activity (AOA) was assessed using β-Carotene bleaching assay, reducing power, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and inhibition of lipid peroxidation methods. The oil was found to exhibit AOA by inhibiting β-Carotene bleaching (54.6?±?2.52%) and by scavenging DPPH free radical (IC(50)?=?0.74?±?0.12?mg?mL(-1)). The AOA of the essential oil of N. erecta and its major compound isoiridomyrmecin has not been reported so far.     

西藏红景天超临界流体萃取及萃取物的GC-MS分析

探讨了西藏红景天的超临界流体萃取工艺,应用GC-MS方法对萃取物成分进行了分析.结果表明,最佳提取工艺条件为:夹带剂乙醇的体积分数为85%,萃取温度为55℃,萃取压力为30 MPa,萃取时间为2 h.此条件下红景天萃取物得率为5.65%.GC-MS分析鉴定出32种组分,主要为醇类、酯类、烷烃、烯烃等化合物,并应用峰面积归一化法测定了其相对含量.     

Study of antioxidant properties of flavonoids by voltammetry

Flavonoids are a large group of natural phenolic compounds contained in high concentrations in vegetables, fruits, etc. Antioxidant and redox properties of some flavonoids such as catechin, quercetin, dihydroquercetin, and rutin were investigated in this work. Optimal concentration and time of action of flavonoids were obtained. To determine the more effective range of antioxidant activity, mathematical models and the response surfaces of investigated flavonoids were determined using methods of experiment design. Oxidation potentials of the compounds were also obtained, E?=?0.3?÷?0.4?V. Moreover, the antioxidant activity of flavonoids depends on the redox properties and the structure of the flavonoids. The antioxidant activity of flavonoids, which is correlated to reversible potentials for this compound is good. Finally, the use of these substances as antioxidants with therapeutic effects has been recommended in human diet.     

Benzophenones and flavonoids from Hypericum maculatum and their antioxidant activities

The occurrence of three known benzophenones, namely annulatophenonoside, acetylannulatophenonoside and annulatophenone as well as a flavonol O-glycoside guajaverin in the aerial parts of Hypericum maculatum Crantz was established. In addition, hyperoside, isoquercitrin and miquelianin were isolated from this plant, as well. Radical scavenging and antioxidant activities of the isolated compounds were examined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) free radicals, ferric reducing antioxidant power (FRAP) assay and inhibition of lipid peroxidation in linoleic acid system by the ferric thiocyanate method. Isoquercitrin demonstrates the highest DPPH radical scavenging (96.6?±?0.3%), FRAP (23.8?±?0.2 Trolox equivalent, TE?mol?1) and antioxidant activity in linoleic acid system. Guajaverin and acetylannulatophenonoside show significantly strong ABTS radical scavenging activity (93.9?±?0.4% and 93.4?±?0.6%, respectively), which is comparable to that of ascorbic acid (96.2?±?0.4%).