银杏叶的化学成分及其抗氧化活性

目的：研究银杏叶中化学成分的抗氧化活性。方法：对银杏叶提取物进行化学成分的分离鉴定，采用化学发光法，测定所得成分对邻苯三酚-鲁米诺-碳酸缓冲液体系产生的超氧阴离子（O2ˉ）的清除能力，以及对大鼠中性粒细胞（PMN）呼吸爆发的抑制作用。结果：分得9种黄酮类成分及4种萜内酯类成分，分别为：槲皮素（Ⅰ）、山柰酚（Ⅱ）、异鼠李素（Ⅲ）、木犀苹素（Ⅳ）、异银杏素（Ⅴ）、槲皮苷（Ⅵ）、芦丁（Ⅶ）、槲皮素-3-0-（2″-0．（6′″-对羟基-反式-桂皮酰）-β-D-葡萄糖）-α-L-鼠李糖苷（Ⅷ）、苜蓿草素-7—O-β-D-葡萄糖苷（Ⅸ）、银杏内酯A（Ⅹ）、银杏内酯B（Ⅺ）、银杏内酯C（Ⅻ）、白果内酯（ⅩⅢ），其中化合物Ⅸ为首次从银杏叶中分离得到。黄酮类化合物均具有不同程度的清除O2ˉ及抑制PMN呼吸爆发作用，活性对结构依赖性明显；内酯类成分不能清除自由基，仅对PMN呼吸爆发有微弱抑制作用。结论：银杏叶体外抗氧化作用的主要活性成分为黄酮类成分，内酯类成分无明显抗氧化作用。     

邳州银杏叶黄酮类成分分析

目的：探索银杏叶黄酮类成分之间的相互关系。方法：采用HPLC法(二级管阵列检测器DAD)分别测定了银杏叶中各黄酮的含量。结果与结论：银杏叶中槲皮素和山柰素的含量随树龄的增长而下降，含量的相对关系会发生变化，二、三年树龄叶以槲皮素为主，四年以上树龄叶山柰素所占比例相对较大。     

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??OBJECTIVE To study flavonoids from the leaves of Zelkova serrata.METHODS The leaves were extracted with 70% ethanol by continuous thermal reflux.The extract was separated and purified by silica gel column chromatography, polyamide column chromatography, preparative TLC and other isolation techniques.Their structures were identified by their physical properties and spectroscopic data.RESULTS Eight flavonoids were isolated and identified as myricetin(1), dihydromyricetin(2), quercetin(3), myricitrin(4), myricetin-3-O-??-D-xyloside(5), quercetin-3-O-??-D-xyloside(6), quercitrin(7), and rutin(8).CONCLUSION All compounds were isolated from Schneider Zelkova leaves for the first time.     

银杏叶中黄酮类成分的研究

 目的分离鉴定银杏叶中的黄酮类成分。方法95%乙醇提取,硅胶及Sephadex LH20柱层析分离,用UV,IR,NMR和MS等方法确定结构。结果分得7个黄酮类成分,分别为槲皮素(quercetin,Ⅰ)、山萘酚(kaempferol,Ⅱ)、异鼠李素(isorhamnetin,Ⅲ)、芫花素(ginkwanin,Ⅳ)、金松双黄酮(sciadopitysin,Ⅴ)、银杏素(ginkgetin-Ⅵ)、和异银杏素(isoginkgetin,Ⅶ),以及7个其它类型成分,分别为三十烷酸(triacontanoic acid,Ⅷ)、二十八醇(octacosanol,Ⅸ)、白果醇(ginnol,Ⅹ)、二十九烷(nonacosane,Ⅺ)、β谷甾醇(βsitosterol,Ⅻ)、棕榈酮(palmitone,ⅩⅢ)和胡萝卜苷(daucosterol,ⅩⅣ)。结论其中化合物Ⅳ,Ⅷ,Ⅸ,Ⅺ,ⅩⅢ,ⅩⅣ为首次从银杏叶中分离得到。     

银杏叶提取物中酚酸的含量测定及去除方法考察

目的:建立银杏叶提取物中银杏酚酸含量测定方法,并考察其去除方法.方法:运用HPLC测定银杏酚酸的含量;以槲皮素为对照品,HPLC测定总黄酮醇苷含量,考察银杏酚酸的去除方法.结果:用吸附剂及离子交换树脂合用法去除银杏酚酸效果较好,银杏叶提取物处理后银杏酚酸含量为2.77 μg·g-1.结论:该研究得到的银杏叶提取物中酚酸含量符合国际标准要求,且其去除方法不影响银杏总黄酮含量.     

不同寄主来源的桑寄生药材槲皮苷与槲皮素含量分析

目的了解不同寄主植物来源的桑寄生药材槲皮苷与槲皮素含量。方法采用RP-HPLC法对桑寄生槲皮苷与槲皮素含量进行测定,槲皮苷采用甲醇超声提取,用Agilent Eclipse XDB-C18柱,乙腈-水(18:82)为流动相,流速1.0ml/min,检测波长254 nm;槲皮素采用甲醇-盐酸(4:1)回流提取,用Agilent Eclipse XDB-C18柱,甲醇-0.05%磷酸溶液(45:55)为流动相,流速1.0 ml/min,检测波长254 nm。结果槲皮苷与槲皮素的线性范围0.35～3.5μg(r=0.999 9)与0.41～4.1μg(r=0.999 9),平均回收率分别为101.2%与100.4%,寄主植物不同,桑寄生药材茎枝槲皮苷与槲皮素含量为0～0.14 mg/g与0～0.85 mg/g不等,药材叶槲皮苷与槲皮素含量为0.41～2.48 mg/g与2.42～6.89 mg/g不等。结论寄主植物不同桑寄生药材槲皮苷与槲皮素的含量明显不同,药材的槲皮苷与槲皮素主要存在于药材叶中,茎枝中的含量较低,有的寄主的桑寄生茎枝中甚至检测不到槲皮苷与槲皮素。     

银杏叶注射液治疗冠心病心绞痛45例

[目的]评价银杏叶提取物注射液联合硝酸酯类药物治疗心绞痛的疗效与安全性。[方法]90例随机分为两组,每组45例,两组均常规治疗,对照组予硝酸甘油0.5mg,日3次,共14日,治疗组在对照组的基础上加用银杏叶提取物注射液20mL,用5%葡萄糖注射液250mL稀释后静点,日1次,共14天。观察两组心绞痛,心电图改善疗效。[结果]治疗组改善总有效率为95.46%,对照组80.00%心电图改善总有效率分别为95.56%和73.33%。两组均无不良反应发生。[结论]银杏叶提取物注射液加用硝酸酯类药物治疗对心绞痛更能改善心绞痛发作,且安全可靠。     

Preliminary pharmacological studies on Eugenia uniflora leaves: xanthine oxidase inhibitory activity

Eugenia uniflora is widely used in Paraguayan folk medicine. A hydroalcoholic extract of the leaves showed some central nervous system activity in hippocratic screening when given intraperitoneally, but little to no acute or subacute toxicity in doses up to 4200 mg/kg orally in BALB c mice. The LD50 of the extract was 220 mg/kg i.p. in mice. A decoction or infusion of the leaves is recommended for treating gout by native herbalists. The known flavonoids quercitrin, quercetin, myricitrin and myricetin were found to be responsible for the xanthine oxidase inhibitory action of the plant extract.     

内生青霉菌纤维素酶在银杏总黄酮提取中的应用研究

目的:利用筛选的高产纤维素酶内生青霉菌的发酵液辅助提取银杏黄酮。方法:采用单因素分析和正交试验,以银杏总黄酮提取率为指标,对酶辅助提取中影响总黄酮提取效果的主要因素(如酶解时间,温度,pH,酶料比等)进行研究。结果:通过单因素试验和正交试验,得出纤维素酶发酵液酶解银杏叶的最佳条件为:发酵液以酶料比15∶1加入银杏干粉中,在pH5.0、温度50℃下,酶解处理3 h,该条件下的银杏黄酮提取率达到了1.33%,比常规醇提法提高了18.75%,与纯酶辅助提取率相近。结论:内生青霉菌发酵液辅助法是提取银杏总黄酮的有效方法。     

Inhibition of fowlpox virus by an aqueous acetone extract from galls of Guiera senegalensis J. F. Gmel (Combretaceae)

An aqueous acetone extract from the galls of Guiera senegalensis was screened for in vitro antiviral activity against fowlpox virus (FPV). Cytopathic effect (CPE) inhibition and plaque inhibition assays were used to show presence of antiviral effects against FPV, whilst cytotoxicity assays established the relative safety of the extract for cells in vitro. Phytochemical analyses revealed the presence of phenolic compounds including flavonoids, tannins and anthocyanins as well as steroids and alkaloids. Thin-layer chromatographical (TLC) analysis also revealed the presence of quercitrin, quercetin, kaempferol, apigenin, rutin, gallic acid as well as unknown flavonoids and unknown phenolic acids. The antiviral effect of the extract was partially attributed to phenolic components including flavonoids.     

Cytoprotection by Achyrocline satureioides (Lam) D.C. and some of its main flavonoids against oxidative stress

Epidemiological studies indicate that dietary antioxidants can influence the incidence of neurodegenerative diseases. Among them flavonoids have been proposed to be effective cytoprotectors. Consequently, herbs with a high concentration of these compounds such as Achyrocline satureioides, Ginkgo biloba and Epilobium parviflorum are of special interest. In this context a comparative study of the cytoprotective capacity of infusions from the three plants against an oxidative insult was performed. Hence, the cytoprotective activity of each infusion against H2O2 injury to PC12 cells was tested and the antioxidant capacity was assessed by the ABTS*+ radical bleaching assay. Free and glycosylated flavonoids contained in the infusions were identified by HPLC and the cytoprotective effect of some of these individual flavonoids was tested. The analysis of the flavonoid content of the infusions revealed different profiles. Epilobium parviflorum infusion showed the highest antioxidant capacity but only Achyrocline satureioides infusion proved to be cytoprotective. Moreover, the free flavonoids quercetin and luteolin contained in this infusion were also cytoprotective. In conclusion, the free radical scavenger capacity did not correlate with the cytoprotective profile of the infusions. The special mixture of unglycosylated Achyrocline satureioides flavonoids could be a clue to explain the unique effect of this plant.     

High performance liquid chromatographic determination of quercetin in the extract of Ginkgo biloba L. leaves]

This paper reports the HPLC determination of one of the flavones quercetin in the extract of Ginkgo biloba leaves. Quercetin was separated completely on an YWG-C18 column(0.46 cm x 15 cm), using a mixture of methanol, water and phosphoric acid(50:49.8:0.2) as mobile phase, with UV detection at 360 nm. The results have shown the recoveries to be between 95.3%-103.2% and RSD 1.86%.     

Hypoglycemic effects of Cecropia pachystachya in normal and alloxan-induced diabetic rats

Ethnopharmacological relevance

Leaves of Cecropia pachystachya are described in the folk medicine as possessing antitusive, expectorant, antiasthmatic and hypoglycemic effects.

Aim of the study

To investigate the hypoglycemic and antioxidant effects of methanolic extract from the leaves of Cecropia pachystachya. The total amount of phenolic and flavonoids compounds was determined and the qualitative composition of the extract was analyzed.

Materials and methods

The hypoglycemic effect of the extract was tested in normal, glucose loading and alloxan-induced diabetic rats. The antioxidant activity was assessed by DPPH free radical scavenging and reduction power assays. The total amount of phenolic and flavonoids compounds was determined by Folin-Denis and AlCl₃ reagent method, respectively. The qualitative composition of the extract was analyzed using a HPLC-DAD system.

Results

The glucose tolerance test showed that in diabetic rats, the extract caused a significant hypoglycemic effect with a blood glucose reduction of 68% after 12 h. The administration of the extract in alloxan-induced diabetic rats also produced a significant reduction in the blood glucose levels at all points being more pronounced at 90 min (reduction of 60%). After 120 min, no significant difference was observed between the blood levels of the rats treated with the extract and those treated with the standard drugs (metformin and glibenclamide). The extract also presented relevant antioxidant activity with IC₅₀ = 3.1 μg/ml (DPPH assay) and EC₅₀ = 10.8 μg/ml (reduction power). Results were compared with the reference antioxidants quercetin, rutin, and ascorbic acid. The content of flavonoids was 83 mg/g plant and that of phenolics was 326 mg/g plant. Chlorogenic acid and the C-glycosylated flavones, orientin and isoorientin, were identified in the extract.

Conclusions

In conclusion, the findings showed that the folk medicinal plant Cecropia pachystachya possesses hypoglycemic and antioxidant effects which confirmed the traditional use of the plant in the treatment of diabetes. Chlorogenic acid and the C-glycosylated flavonoids may explain these activities.     

The effect of Ginkgo biloba extract on mitochondrial oxidative phosphorylation in the normal and ischemic rat heart

Free radical‐induced myocardial damage and impairment of vascular endothelium‐dependent relaxation are amongst the most important mechanisms responsible for ischemic heart injury. Ginkgo biloba leaf extract (GE) has been reported to improve blood circulation in the brain and have a beneficial impact on the cardiovascular system but its cardioprotective effects have not been elucidated yet. Therefore, this study investigated the influence of GE in 70% ethanol (1:5) administered orally to rats on the functions of isolated heart mitochondria under normal and ischemic conditions. Wistar rats were given GE or ethanol (solvent control) at a dosage of 0.32 mL/kg in drinking water for 10 and 18 days, while the control animals received untreated drinking water. Mitochondrial respiration rates were determined oxygraphically. Pyruvate and malate, succinate or palmitoyl‐l ‐carnitine and malate were used as substrates. The GE treatment partially uncoupled mitochondrial oxidation from phosphorylation, reduced the generation of free radicals in the mitochondria, diminished the ischemia‐induced V₃ decrease and the degree of respiration stimulation by exogenous cytochrome c. Thus, these results indicate that GE exerts cardioprotective effects reducing ischemia‐caused impairment of the functions of heart mitochondria. Copyright © 2011 John Wiley & Sons, Ltd.     

The effect of crataegus fruit extract and some of its flavonoids on mitochondrial oxidative phosphorylation in the heart

Crataegus (Hawthorn) fruit extracts (CE) are widely used for the treatment of various cardiovascular diseases (arrhythmias, heart failure, myocardial weakness, etc). Despite the fact that many of these diseases are associated with disturbances of the mitochondria, no data have been found on the effect of CE on their function. The aim of this study was to perform an oxygraphic investigation of the effect of CE (in concentration range from 70 ng/mL to 13.9 µg/mL of Crataegus phenolic compounds (PC)) and its several pure flavonoids on isolated rat heart mitochondria respiring on pyruvate + malate, succinate and palmitoyl‐L‐carnitine + malate. CE at doses under 278 ng/mL of PC had no effect on mitochondrial functions. At concentrations from 278 ng/mL to 13.9 µg/mL of PC, CE stimulated State 2 respiration by 11%–34% with all used substrates, and decreased the mitochondrial membrane potential by 1.2–4.4 mV measured with a tetraphenylphosphonium‐selective electrode and H₂O₂ production measured fluorimetrically. Similar uncoupling effects on mitochondrial respiration were observed with several pure CE flavonoids. The highest CE concentration also slightly reduced the maximal ADP‐stimulated and uncoupled respiration, which might be due to inhibition of the mitochondrial respiratory chain between flavoprotein and cytochrome c. Whether or not the uncoupling and other effects of CE on mitochondria may be realized in vivo remains to be determined. Copyright © 2009 John Wiley & Sons, Ltd.     

紫荆花总黄酮的分离纯化与光谱分析

目的:从紫荆花中分离、纯化总黄酮,对其黄酮成分及含量进行光谱分析。方法:以55%乙醇于100℃水浴回流提取紫荆花中的总黄酮,用聚酰胺树脂柱层析进行分离纯化,以芦丁、槲皮素、山柰酚为对照品,在200~600nm波长范围内进行紫外-可见吸收光谱扫描及含量测定,用KB r压片法在400~4000 cm-1范围内进行红外光谱扫描。结果:粗黄酮平均得率为7.32%,纯化后的生药中总黄酮得率为2.20%;紫外-可见吸收及红外扫描光谱结果显示,紫荆花总黄酮纯品中含有芦丁、槲皮素、山柰酚3种黄酮甙元,含量分别为0.8271、0.2169、0.3007 mg/ml。结论:经聚酰胺树脂柱层析纯化的紫荆花黄酮纯品中的总黄酮甙含量为24.30%。总黄酮含量为0.5346%。     

追风伞中黄酮类成分的研究

目的:对追风伞中的黄酮类成分进行分离、鉴定。方法:追风伞干燥全草用95%乙醇溶液加热回流提取,减压回收乙醇,浓缩液依次用石油醚、氯仿萃取后,水层部分利用大孔吸附树脂、硅胶柱色谱、反相Rp-18柱色谱及重结晶等方法进行分离及纯化,并通过1H-NMR,13C-NMR,EI-MS及理化常数对分离化合物进行结构鉴定。结果:从追风伞提取物中分离鉴定9个黄酮类化合物,分别为:木犀草素(1),木犀草素-4′-O-β-D-葡萄糖苷(2),刺槐素-7-O-β-D-葡萄糖苷(3),芦丁(4),刺槐素(5),槲皮素(6),槲皮素-3-O-β-D-葡萄糖苷(7),山柰酚-3-O-β-D-葡萄糖苷(8),异鼠李素-3-O-β-D-葡萄糖苷(9)。结论:所得化合物均为首次从追风伞中分离鉴定。     

地耳草黄酮类成分分析

 目的 分析不同产地、不同商品地耳草药材中黄酮类成分的含量。方法 用HPLC同时测定不同产地、商品地耳草中的芦丁、异槲皮苷、金丝桃苷、槲皮苷、槲皮素、山柰酚的含量。结果 初步建立了地耳草6种黄酮HPLC同时测定方法;发现不同产地、商品地耳草中黄酮类成分具有一定差异。 结论 本方法准确可靠,重现性良好,可用于地耳草药材内在质量的评价和控制。     

良种银杏幼苗叶质量分析(Ⅰ)

目的 进行良种银杏幼苗叶质量分析。方法 采用HPLC方法测定银杏叶总黄酮含量。结果 实生苗6月份含量明显高于8月份与11月份,极显著地高于嫁接苗;2岁树龄实生苗总黄酮含量是50年树龄的2.5-3.8倍,嫁接苗6月份高于8月份,雌性高于雄性。结论 活性成分含量与生长季节、树龄、培育方式、生长环境,基地条件等诸因素有关。     

Effects of extracts of Zanthoxylum fruit and their constituents on spontaneous beating rate of myocardial cell sheets in culture

In the course of our studies on naturally occurring cardioactive agents, we investigated the effects of water and methanol extracts of a Chinese crude drug “Huajiao” the dried fruit of Zanthoxylum bungeanum, on the spontaneous beating rate (BR) of embryonic mouse myocardial cell sheets in culture. Both extracts significantly increased the BR. Through bioassay directed fractionation of the extracts, hydroxy-β-sanshool (1b), xanthoxylin (2) and two quercetin glycosides, hyperin (4) and quercitrin (6), were found to increase the BR in a standard medium (2.1 mM Ca²⁺). In a low Ca²⁺ medium (0.5 mM Ca²⁺), these compounds suppressed the decrease of BR, which was induced by low Ca²⁺. Of 16 flavonoids related in structure with hyperin (4) and quercitrin (6), quercetin, isoquercitrin, rutin, myricetin and myricitrin also increased the BR in the standard medium, while kaempferol and luteorin decreased the BR in the standard medium. When compared with control, hydroxy-β-sanshool (1b) and xanthoxylin (2) stimulated 13–15 fold calcium uptake of the cultured myocardial cells, which might have caused the positive chronotropic effect. Hyperin (4) and quercitrin (6) did not affect calcium uptake of the myocardial cells, Na⁺–K⁺ ATPase activity or Ca²⁺-ATPase activity of sarcoplasmic reticulum.