Determination of the Flavonoids from Ginkgo Biloba Extract by High Performance Liquid Chromatography

HPLC method for analysis of the flavonoids from ginkgo biloba extract (GBE) was studied. By suitable selection of columns. symmetrical chromatographic peaks were obtained without using acidic modifier in the mobile phase, which can eliminate the time for cleaning the chromatographic system and simplify the analystic method for GBE Experimental conditions: column: Hypersil BDS C-18, 5mumx4x250 mm: column temperature: 35degreesC; mobile phase: 46% methanol-54% water; flow rate: 0.7 mL/min; detection wavelength: 360nm.

Extraction Process and Content Determination of Total Flavonoids in Ginkgo( Ginkgo biloba L. ) Leaves

[Objectives]This study was conducted to study the extraction process and the content determination of flavonoids in ginkgo( Ginkgo biloba L.) leaves.[Methods]Ethanol extraction and methanol extraction of total flavonoids in ginkgo leaves were studied,and the optimal extraction conditions for flavonoids were determined by orthogonal test; and with quercetin as reference substance,total flavonoid content in ginkgo leaves was determined by UV spectrophotometry.[Results]The optimal extraction process was 4 h of Soxhlet extraction with methanol; and the total flavonoid contents had a good linear relation in the range of 0. 006 5-0. 039 mg/ml( R^2= 0. 999 9),the average content was stabilized at 1. 135%,and the average recovery of the method was 102. 0%. [Conclusions]This study selected the optimal extraction process for total flavonoids in ginkgo leaves. The test method is simple with high accuracy and precision,and is suitable for the extraction and determination of total flavonoids in ginkgo leaves.

Ginkgo biloba Extract EGb 761® Improves Central Vestibular Vertigo in Patients Undergoing Vestibular Exercises: A Randomised Placebo-Controlled Trial

Background: Ginkgo biloba extract EGb 761® is widely used to treat various types of vertigo. Aims: An exploratory trial was conducted to evaluate the efficacy of EGb 761® in addition to vestibular exercises in central vestibular vertigo caused by vertebro-basilar ischaemia. Subjects and Methods: In this randomised, placebo-controlled, double-blind trial, 40 patients were enrolled in the vertigo clinic of a neurological university hospital and treated with daily doses of 240 mg EGb 761® or placebo for a period of 180 days. All patients regularly performed vestibular exercises in addition. Efficacy was assessed using: a visual analogue scale for the patients to rate the overall intensity of vertigo;a numeric scale for physician-rated change;a vertigo score based on intensity, duration, and frequency of vertigo;and electronystagmography. Results: Until day 180, the mean patient-rated intensity of vertigo decreased by 46% during EGb 761® treatment and by 19% with placebo (p ® group compared to the placebo group. Nystagmus or other eye movement disorders were present only in small subgroups of patients without sufficient statistical power to detect differences between treatment groups. Conclusions: EGb 761® alleviated vertigo caused by ischaemic lesions in the brainstem or cerebellum in patients undergoing vestibular exercises.

Effects of Ginkgo biloba extract on diabetic retinopathy:a meta-analysis and systematic review

Objective:The aim of present meta-analysis was to evaluate the clinical efficacy of Ginkgo biloba extract combined with conventional therapy in the treatment of diabetic retinopathy(DR).Methods:The randomized controlled trials(RCTs)of Ginkgo biloba extract adjuvant conventional therapy for treating DR were searched in PubMed,the Cochrane Library,China Knowledge Network(CNKI),China Biomedical Literature Service System(SinoMed),VIP Information Chinese Journal Service Platform(VIP),and Wanfang database.Two reviewers independently extracted data and conducted methodological quality assessment.Data analysis was performed using Revised Cochrane risk-of-bias tool for randomized trials(RoB 2).Results:A total of 9 RCTs involving 798 patients were included in current research.Meta-analysis showed that Ginkgo biloba extract combined with conventional medicine can improve total effective rate[OR=0.33,95%CI=(0.23,0.46),P<0.0001],visual acuity[OR=-0.11,95%CI=(-0.14,-0.07),P<0.0001]and visual field average defect[OR=0.59,95%CI=(0.53,0.65),P<0.0001].Conclusion:The available evidence indicated that Ginkgo biloba extract combined with conventional medicine can be beneficial for treating DR.However,our findings were warranted to verify by more large-scale,multi-center clinical trials.

Simultaneous quantification of flavonol glycosides, terpene lactones, polyphenols and carboxylic acids in Ginkgo biloba leaf extract by UPLC-QTOF-MS^E based metabolomic approach

Abstract： In the present study, we established an ultra performance liquid chromatography coupled with time-of-flight mass spectrometry （UPLC-QTOF-MSE） method to simultaneously quantify 33 components in Ginkgo biloba leaf extracts （GBEs）, including 17 flavonol glycosides, five terpene trilactones （TTLs）, four polyphenols and seven carboxylic acids. This optimized method was successfully applied to analyze the explicit compositions of GBE samples collected from different places. Furthermore, the data were processed through unsupervised principal component analysis （PCA） and supervised orthogonal partial least squared discrimination analysis （OPLS-DA） to evaluate the quality and compare the differences between the samples according to the contents of the 33 chemical constituents. Bilobalide, protocatechuic acid, shikimic acid, quinic acid, ginkgolide B, ginkgolide J, kaempferol-3-O-rutinoside, isorhamnetin-3-O-rutinoside, quercetin-3-O-ct-L-rhamnopyranocyl-2＂-（6＇＂-p-coumaroyl）-β-D-glucoside and rutin were recognized as characteristic chemical markers that contributed most to control the quality of GBEs. Based on the fact that GBEs should be standardized with the characteristic components as quality control chemical markers, it is most important to maintain the quality of GBEs stable and reliable, and this method also provided a good strategy to further rectify and standardize the GBEs market.

银杏中总黄酮不同提取方法比较及含量测定研究

分别采用超声提取法和溶剂回流提取法提取银杏中的总黄酮,比较不同提取方法的总黄酮得率,通过单因素实验优化提取条件,并对银杏不同部位总黄酮含量进行分析。结果表明超声提取法总黄酮得率高于溶剂回流提取法。银杏叶中总黄酮的最佳提取方法为超声提取法,提取工艺条件为:乙醇体积分数80%,料液比为1∶40(g∶mL),粉末粒度为0.25 mm(60目),提取时间为60 min,提取温度为70℃。采用最佳提取工艺对银杏叶和银杏果中总黄酮含量进行测定,结果表明银杏叶中黄酮含量为2.55%,银杏果中黄酮含量为1.15%,银杏果中总黄酮含量低于银杏叶。本研究为探索提高银杏总黄酮含量的提取方法和银杏资源的综合开发利用提供参考。

Box-Behnken Design响应面法优化银杏叶提取物醇提水沉工艺

目的优化银杏叶提取物的醇提水沉工艺。方法在单因素试验基础上,以总黄酮醇苷转移率、萜类内酯转移率及干物质得率为综合评价指标,通过Box-Behnken Design(BBD)响应面法对液料比、提取时间、提取次数、提取液浓缩倍数、加水倍数、冷沉时间进行考察。结果醇提水沉最佳工艺为液料比8∶1(V/m),提取时间1.0 h,提取次数3次,浓缩倍数3倍,加水倍数3倍,冷沉时间28.0 h。结论BBD响应面法优化得到的银杏叶提取物醇提水沉工艺科学、合理、稳定、可行。

超声波辅助醇提法提取银杏叶中多种活性成分

采用超声波辅助醇提法综合提取银杏叶中多种活性成分,通过溶剂萃取法脱脂、去叶绿素,经DM130大孔树脂吸附脱附后,再对银杏多糖、银杏莽草酸、银杏黄酮分阶段逐一分离纯化,并对工艺条件进行了优化。结果表明,在75%乙醇为提取溶剂、超声时间为2.0 h、石油醚为脱脂溶剂的最佳条件下,分别采用0.2%H 2O 2脱色法、石油醚沉淀法、酸碱除杂法对银杏多糖、银杏莽草酸、银杏黄酮进行分离纯化,得到高纯度银杏多糖、银杏莽草酸、银杏黄酮,其纯度分别为85.20%、98.25%、35.72%,产率分别为4.67%、3.80%、0.77%。该方法工艺简单、成本低、资源利用度高,为银杏叶的综合开发利用提供了参考。

银杏叶黄酮及多糖超声波辅助提取工艺优化

目的:对银杏叶黄酮及多糖类化合物超声波辅助提取工艺进行优化。方法:以银杏叶为原料,以料液比、提取溶剂即不同浓度乙醇、超声时间、超声功率4个因素进行单因素实验,研究不同因素对银杏叶黄酮提取率的影响;以超声时间、超声功率及超声温度3个因素进行单因素实验,研究不同因素对银杏叶多糖提取率的影响;在此基础上分别进行正交试验确定银杏叶最佳黄酮及多糖提取工艺条件。结果:银杏叶黄酮提取时,料液比为1∶20 g·mL^(-1)、提取溶剂为95%乙醇、超声时间为60 min及超声功率为300 W时,黄酮提取率最大为37.50 mg·g^(-1)。超声波辅助提取银杏叶多糖时,其最佳提取工艺为超声时间40 min、超声功率200 W及超声温度50°C,在此条件下,银杏叶多糖提取率为48.98 mg·g^(-1)。结论:建立了银杏叶黄酮及多糖有效成分超声波辅助提取工艺,为银杏叶相关保健产品的开发提供数据支撑。

银杏叶中活性成分提取工艺及进展分析

对银杏叶中4种活性成分黄酮、内酯、绿原酸、莽草酸的提取工艺条件进行了研究。通过对银杏叶中黄酮、内酯、莽草酸、绿原酸的萃取时间、萃取温度、料液比、乙醇浓度等因素的影响,利用正交试验,优选出最佳萃取条件。最佳条件:料液比为1∶15,乙醇浓度为70%,萃取时间为2 h,萃取温度为50℃。该方法可实现银杏叶中黄酮、内酯、绿原酸、莽草酸4种活性组分的高效分离。

银杏叶提取物联合多奈哌齐治疗阿尔茨海默病疗效和安全性的Meta分析

目的采用Meta分析法分析银杏叶提取物联合多奈哌齐治疗阿尔茨海默病(AD)的疗效及安全性。方法计算机检索中国知网、维普网、万方数据知识服务平台及PubMed、the Cochrane Library、Web of Science上公开发表的银杏叶提取物联合多奈哌齐治疗AD的疗效及安全性的文献,检索时间为建库至2022-09-01,观察组采用银杏叶提取物联合多奈哌齐治疗,对照组仅采用多奈哌齐治疗,采用RevMan 5.4软件进行Meta分析,绘制漏斗图评估文献发表偏倚风险。结果最终纳入18篇文献,共1431例患者,其中观察组716例,对照组715例。Meta分析结果显示,观察组临床总有效率[RR=1.25,95%CI(1.14,1.38)]、简易精神状态检查量表(MMSE)评分[MD=2.98,95%CI(2.51,3.46)]高于对照组,14项日常生活活动能力量表(ADL)评分[MD=-4.29,95%CI(-5.34,-3.24)]、阿尔茨海默病认知部分评定量表(ADAS-Cog)评分[MD=-5.10,95%CI(-6.86,-3.34)]低于对照组(P<0.001)。2组不良反应发生率比较,差异无统计学意义[RR=0.94,95%CI(0.67,1.32),P=0.73]。绘制漏斗图结果显示,报道MMSE评分、ADL评分的文献散点左右分布基本对称,提示不存在发表偏倚。结论银杏叶提取物联合多奈哌齐治疗AD具有较好的临床效果,可有效改善认知功能,提高日常生活活动能力,且不会增加不良反应。

A Simple High-Performance Liquid Chromatography Method for the Assay of Flavonoids in Ginkgo biloba Leaves

Objective:Ginkgo biloba leaves,as an herbal medicine or dietary supplement,have been widely used worldwide.In this study,an integrated analytical method was established for the comprehensive analysis of flavonoids in G.biloba leaves.Materials and Methods:A practical chromatographic method combining high-performance liquid chromatography fingerprint analysis and quantitation was used to simultaneously determine 11 flavonoids(6 flavonol glycosides and 5 biflavones)in G.biloba leaves from different regions.Results:A total of 11 characteristic peaks were identified accurately,and the similarity of fingerprints ranged from 0.944 to 0.996.Methodology validation revealed appropriate linearity(R^(2)≥0.9997),precision,repeatability,stability,and recovery.The total contents of the six flavonol glycosides and five biflavones were within the range of 2.142-8.378 mg/g and 3.759-5.675 mg/g in 19 batches of samples,respectively.Among them,two coumaroyl flavonol glycosides were the predominant components.Conclusions:In this study,a convenient and reliable approach was successfully employed for the comprehensive evaluation of flavonoids in G.biloba leaves,which also provided a reference for its quality standard.

超声法提取银杏叶黄酮的研究

研究了银杏叶黄酮的超声提取法,并与连续热回流中的索氏提取作了比较研究。实验表明:超声提取法优于索氏提取法。超声提取法的最佳操作条作为:超声波频率40KHZ, 处理时间10min,静置时间12h。

超临界流体色谱法测定银杏叶提取物中的黄酮类化合物

采用超临界流体色谱法分离测定了银杏叶提取物水解后的三个甙元——槲皮素、山奈酚、异鼠李素的含量.以苯基柱为固定相,二氧化碳-乙醇-磷酸(90:9. 98:0.02 V/V)为流动相,三个黄酮甙元获得良好的分离,利用各甙元的转换因子计算了黄酮化合物的总黄酮的含量.这种方法定量结果准确,重现性好.

银杏黄酮苷提纯工艺研究

根据黄酮苷的物性选择丙酮 ,正丁醇 ,正丙醇 ,乙酸乙酯为萃取剂。单因素实验优选出正丙醇为萃取黄酮苷的主萃取剂。对其进行改性 ,通过单因素实验和正交实验优化出 :水∶正丙醇 =1∶ 2 5为萃取黄酮苷的较佳萃取剂。T =2 5℃ ,t=10 m in,固液比 =15∶ 1(g/ 10 0 m L)为其最佳萃取工艺参数。最后得到纯度 >5 0 % ,得率 >80 %的总黄酮苷产品。

响应曲面法优化酶法提取银杏叶总黄酮

本文研究了酶法提取银杏叶总黄酮的工艺。在单因子试验结果的基础上,采用响应曲面法(responsesur-facemethodology,RSM)研究了酶浓度、pH值、酶解温度和酶解时间对银杏叶总黄酮提取得率的影响。结果表明,纤维素酶具有较好的酶解能力,当酶浓度为100U/ml,酶解时间为116min,温度为40℃,pH4.5时,总黄酮得率达到2.63%,相对单一醇提法得率提高了约30%。

银杏叶中黄酮类化合物最佳提取工艺研究(Ⅰ)

用正交实验探讨银杏叶中黄酮类化合物的最佳提取工艺。研究结果表明：在９０℃条件下用９倍于叶重体积的７０％乙醇回流提取４次，每次１ｈ，银杏叶黄酮糖苷提取效果最好，其平均浸出率可达（９５．６±１）％。分光光度法测总黄酮的回收率为１０２．８％，７次平行测定的相对标准偏差ＣＶ为０．４１％。

银杏黄酮苷的水浸提方法研究

研究水浸提银杏黄酮苷的方法，探讨了影响黄苷浸出率的主要因素以及最适的精制方法。结果表明：水为提取剂，在９０℃水溶回流浸提银杏叶２次，每次４ｈ。经沉淀，过滤，浓缩后，用树脂精制。冷冻干燥后，制得总黄酮苷含量高的提取物。采用ＨＰＬＣ法监控工艺过程及产品质量。

银杏黄酮测定时水解条件的研究

目的:寻找水解率高、耐用性好的银杏黄酮测定的水解条件。方法:在预防氧化降解反应方面,比较不同保护措施的效果;在充分的保护措施下考察不同的加热方式、盐酸浓度、甲醇浓度、加热时间等水解条件。结果:预防氧化降解的发生能有效提高水解液的稳定性,并使密封加热在优选的条件下,测得量比回流加热水解高10%以上。结论:溶剂脱气、充氮气排除接触供试液的空气中的氧、避光等可有效防止氧化降解反应的发生;水解方式采用密封加热优于回流加热。

银杏叶总黄酮苷的HPLC法分析水解条件

研究银杏叶中总黄酮苷的HPLC法分析水解条件。结果表明 :1g银杏叶甲醇提取物溶于 30ml甲醇中 ,加入 5ml 8 3mol·L-1的HCl,于 (85± 1)℃水浴水解 6 0min ,此法则得槲皮素、山柰素、异鼠李素的回收率分别为 10 1 4%、10 2 %、98%。