GC-MS测定家犬血浆中银杏内酯A、B的含量

银杏叶制剂作为治疗和预防动脉粥样硬化的有效药物,越来越为人们关注。银杏叶成分复杂,其中银杏黄酮具有扩张血管,降血脂,改善微循环的作用;银杏内酯是血小板活化因子强拮抗剂,对免疫系统,中枢神经系统,缺血损伤有保护作用,并有抗休克、抗过敏及抗炎作用。由于银杏内酯含量较低,对其进行的药动力学研究较少,且多采用的是非特异性的生物测定方法。我们参照中国药典有关药物制剂生物利用度和生物等效性试验的指导原则和相关实验方法,建立的GC-MS-SIM方法,可准确测定血浆中银杏内酯A(GA)和银杏内酯B(GB)的含量,为其药动力学的研究提供了可靠的分析手段。     

毛细管柱气相色谱法测定银杏叶提取物中银杏萜内酯含量

对银杏叶提取物中银杏萜内酯(包括BB和GA,GB,GC,GJ)的毛细管柱气相色谱分离条件作了试验,达到银杏萜内酯成分的良好分离.选择了内标物角鲨烷,理论计算并直接测定了银杏萜内酯的相对质量校正因子,采用内标法测定了各组分的含量.BB、GA、GB、GC回收率依次为95.2 9%,95.5%,94.6%,96.1%.     

银杏发根中有机酸的离子色谱分析

银杏是我国的珍贵树种,其提取物中含银杏黄酮和银杏内酯等有效成分,在心、脑血管等疾病的治疗中有独到的疗效.目前主要从银杏叶片中提取有效成分,受产地、气候、季节等自然因素影响较大.国外有通过银杏细胞培养技术生产银杏天然药物的报道[1],但细胞培养的生长速度较慢.孙天恩等采用发根培养技术,利用发根农杆菌Ri质粒转化技术,诱导产生银杏发根,建立了悬浮培养无性系,发根生长速度快,分化水平高,为银杏天然药物的生产开辟了新的途径[2].     

银杏叶中银杏萜内酯的GC/MS分析研究

银杏萜内酯是银杏叶中具有特殊药用价值的活性成分.目前已建立了多种对银杏萜内酯的研究方法.如超临界提取法~([1])、气相色谱/质谱联用技术~([2])等,但分别存在着前处理复杂或未能检测到GJ的不足.本研究对利用GC/MS联用技术进行分析研究,取得了银杏叶中银杏萜内酯五种活性组分较好分离的结果.     

ClO--鲁米诺流动注射-抑制化学发光法测定银杏黄酮

基于在碱性条件下,银杏黄酮对ClO--鲁米诺体系有显著的抑制作用,结合反相流动注射技术,建立了流动注射-抑制化学发光测定银杏提取物中的银杏黄酮.银杏黄酮质量浓度在0.4～14.0 μg/mL范围与相对发光强度呈线性关系,检出限为0.06 μg/mL,采样频率为120次/h,对10.0 μg/mL的银杏黄酮平行测定11次,其RSD为1.2%,回收率为98.0%～104%.该方法可用于银杏黄酮制剂的测定.     

磺化木质素系聚合物的结构及其在氧化铝上的吸附特性

以造纸黑液中的碱木质素为主要原料,通过磺化和缩聚反应制备了磺化木质素高分子聚合物SBAL.TEM和1H-NMR测试结果表明SBAL是以木质素的疏水骨架为中心,以磺酸基和羧基组成亲水性侧链的球形结构.GPC测试结果表明其重均分子量达到了24880 Da,是碱木质素的7.38倍,电位滴定测试结果表明,其磺化度达到2.70 mmol.g-1.通过流变曲线、吸附等温线、zeta电位、XPS测试研究了其对氧化铝在水中的分散机理及其吸附特性.掺SBAL的氧化铝浆体,在pH=3～12范围内SBAL对其具有良好的分散降黏作用.溶液pH对SBAL的分子构型和吸附特性有较大的影响,随pH增加,SBAL中磺酸基、羧基和酚羟基逐渐电离,分子的伸展程度逐渐增大.随pH增加,SBAL在氧化铝上的吸附质量减少,吸附层由致密逐渐变得疏松,pH小于等电点时以静电吸附为主,pH大于等电点时以非静电的特性吸附为主.当SBAL的用量小于临界值(0.5 wt%)时,其在氧化铝表面形成单分子层吸附,在颗粒间起到静电排斥作用;当用量大于临界值时,其在颗粒表面形成聚集体吸附而起到空间位阻作用.     

银杏内酯衍生物和类似物的合成及PAFR和GlyR拮抗活性研究进展

银杏内酯是从银杏树中分离的二萜内酯成分,它的结构是由6个五元环形成的笼状骨架并嵌有一个独特的叔丁基.研究已证实银杏内酯是血小板活化因子受体(PAFR)和甘氨酸受体(GlyR)的强有力拮抗剂,它的结构变化将引起生物活性的改变.因此,为了寻找更优的PAFR和GlyR拮抗剂,人们合成了许多银杏内酯衍生物及类似物.重点综述了近年来银杏内酯类化合物的构效关系研究.     

含糖基大孔吸附树脂的合成及对银杏 黄酮的吸附性能研究

本文以葡萄糖为原料,合成了甲基丙烯酸葡萄糖酯单体,与马来松香丙烯酸乙二醇酯共聚合成含糖基大孔吸附树脂。采用FT-IR、紫外、热重、扫描电镜、核磁等分析方法进行表征。以芸香叶苷为模拟物,研究了含糖基大孔吸附树脂对芸香叶苷的吸附性能,结果表明吸附动力学过程符合拟一级动力学方程及液膜扩散方程,Freundlich可较好的描述含糖基大孔吸附树脂对芸香叶苷的吸附过程,为"优惠吸附"过程,是吸热、自发的慢过程。在此优化的条件下,将含糖基大孔吸附树脂对银杏黄铜进行分离纯化,可将黄酮含量为25%的银杏提取物提纯到80.9%;树脂重复使用10次后吸附量仍为7.9 mg·g~(-1)。     

银杏内酯提取物中微量成分的LC-DAD-ESI-MS分析及结构鉴定

银杏叶ginkgo biloba .L中含有多种二萜内酯和倍半萜内酯.Furukawa.S于1932年首次分离得到银杏内酯混合物;直到1967年,才由Koji Nakanishi和Okabe.K等人鉴定出其中各个成分的结构,并分别命名为Ginkgolide A、B、C、M(简称GA、GB、GC、GM)[1];Weinges K等分别于1969年和1987年分离并鉴定出白果内酯(Bilobalide,BD)[2]和Ginkgolide J[3](GJ).银杏内酯具有抗血小板活化因子(PAF)的作用[4],引起了世界医疗行业的广泛关注.对银杏内酯的HPLC分析常见的检测方法主要有UV、RI和近年出现的ELSD[5],但这些检测方法都有各自的缺陷,UV需在末端检测,易受干扰;RI不适合作梯度洗脱;ELSD灵敏度相对较低.随着对该类化合物的深入研究,发现银杏内酯提取物中尚有一些微量成分,用这些检测方法不足以获得较好的信号响应,本实验以质谱作为检测器,获得了较高的检测灵敏度,结合UV和MS提供的光谱信息,有利于分析鉴别微量成分.     

H2O2-Luminol流动注射-抑制化学发光法测定银杏黄酮

基于在碱性条件下,银杏黄酮对H2O2 Luminol体系有显著的抑制作用,结合反相流动注射技术,首次建立了流动注射 抑制化学发光测定银杏提取物中的银杏黄酮。银杏黄酮质量浓度在0.2～20.0μg mL范围与相对发光强度呈线性关系,检出限为0.1μg mL,采样频率为140次 h,对10.0μg mL的银杏黄酮平行测定11次,其RSD为1.5%,回收率为100.0%～100.2%。该方法可用于银杏黄酮制剂的测定。     

PURIFICATION OF GINKGO LEAVES EXTRACT WITH MACROPOROUS ADSORBENT BASED ON UREA-FORMALDEHYDE CONDENSED POLYMERS

I INTRODUCTIONGinkgo biloba L. is one of the important economic trees, which is widely distributed inChina. In recent years, medicinal and healthful preparations based on the extractS from ginkgoleaves have been rapidly developed for the treatment of peripheral circulatory and cerebralinsufficiencyl']. Such eXtracts contain flavonol glycosides and terpene lactones as thepharmacologically active compounds. Organic-solvent extraction is one of the earliest methodsto prepare the extracts o…     

PURIFICATION OF GINKGO LEAVES EXTRACT WITH MACROPOROUS ADSORBENT BASED ON UREA—FORMALDEHYDE CONDENSED POLYMERS

The relationship between the adsorption properties for the active components of ginkgo leaves and the structure of the adsorbents based on urea-formaldehyde condensed polymers was investigated.The results revealed that these adsorbents showed very high adsorpton selectivity for both flavonol glycosides and terpene lactones contained in ginkgo leaves.Thus,an adsorption separation procedure for purification of ginkgo leaves extracts was developed.     

Chromatographic fingerprint analysis for evaluation of <Emphasis Type="Italic">Ginkgo biloba</Emphasis> products

The flavonoids and the terpene lactones are regarded as the two main active components of Ginkgo biloba that affect human health. In the work discussed in this paper, two analytical methods for the characterization of G. biloba authentic materials and commercial products, an LC–UV chromatographic fingerprinting method and a traditional flavonol quantification method, were compared. The traditional method was used to determine the total flavonol content (as glycosides) after acid hydrolysis. The fingerprinting method examined the chromatographic profiles of methanol–water extracts using chemometric methods. The traditional method showed that all the commercial products met the current voluntary standard of 24% flavonols by weight. The chromatographic fingerprinting method revealed significant variations in the commercial products with regard to the relative concentration of individual flavonols.     

Liquid chromatography/electrospray mass spectrometry of bioactive terpenoids in Ginkgo biloba L

Standardized extracts of Ginkgo biloba leaves are mainly used in the treatment of peripheral and celebral circulation disorders, and also as a remedy against asthma, coughs, bladder inflammation, blenorrhagia and alcohol abuse. The leaf extracts contain biflavones, flavonol glycosides and terpene lactones. This paper reports a method based on liquid chromatography coupled with electrospray mass spectrometry for the analysis of terpenoids in G. biloba extracts. This method allows the rapid isocratic separation of underivatized ginkgolides (GA, GB, GC and GJ) and bilobalide at very low levels (10 pg on the column) and their quantitative detection by external standardization with relative standard deviations of 3 and 5% for intra- and inter-day analyses, respectively.     

Adsorption separation of terpene lactones from Ginkgo biloba L. extract using glass fiber membranes modified with octadecyltrichlorosilane

In this study porous glass fiber membranes were modified by reaction with octadecyl-trichlorosilane to form C18 hydrophobic membranes. The contact angle and the CH2 vibration bands at 2855 and 2920 cm(-1) found by FTIR measurements verified the successful immobilization of C18 groups on the glass fiber membranes. The resulting C18 hydrophobic membranes were used to adsorb terpene lactones from crude Ginkgo biloba L. extracts. In batch adsorption processes, the modified C18 membranes exhibited a better adsorption performance than commercial C18 solid phase extraction adsorbents. Different desorption solvents were tested and ethyl acetate was found to preferentially desorb terpene lactones from the modified C18 membranes. In flow adsorption experiments at 1 mL/min, terpene lactone contents higher than 6 wt% (the standardized content) could be achieved in the elution step using ethyl acetate.     

超高效液相色谱-二极管阵列检测-串联质谱法测定茶叶中15种黄酮醇糖苷类化合物

采用ACQUITY UPLC HSS T3色谱柱,以含0.1%(v/v)甲酸的乙腈-水为流动相,梯度洗脱,建立了超高效液相色谱-二极管阵列检测-串联质谱(UPLC-PDA-MS/MS)联用技术测定茶叶中黄酮醇糖苷类化合物的方法。结合色谱保留时间、紫外光谱、一级和二级质谱参数等信息,在绿茶和红茶中共识别了15种黄酮醇糖苷类化合物,包括3种杨梅素糖苷、6种槲皮素糖苷和6种山柰素糖苷类化合物。定量分析中采用串联四极杆质谱检测,以槲皮素-3-葡萄糖-鼠李糖二糖糖苷(Q-GRh)为标准品,其他黄酮醇糖苷进行相对定量。结果表明,绿茶和红茶中黄酮醇糖苷类化合物的含量和分布差异显著,绿茶中的黄酮醇糖苷总量是红茶的1.7倍,绿茶中的黄酮醇糖苷主要以杨梅素-3-半乳糖糖苷(M-Ga)、杨梅素-3-葡萄糖糖苷(M-G)、槲皮素-3-葡萄糖-鼠李糖-葡萄糖三糖糖苷(Q-GaRhG)、槲皮素-3-半乳糖-鼠李糖-葡萄糖三糖糖苷(Q-GRhG)、山柰素-3-半乳糖-鼠李糖-葡萄糖三糖糖苷(K-GaRhG)和山柰素-3-葡萄糖-鼠李糖-葡萄糖三糖糖苷(K-GRhG)为主,而红茶中主要以Q-GRh、槲皮素-3-葡萄糖糖苷(Q-G)、山柰素-3-葡萄糖-鼠李糖二糖糖苷(K-GRh)和山柰素-3-半乳糖糖苷(K-Ga)为主。本方法简单快速,准确性好,可用于茶叶中黄酮醇糖苷类化合物的分析。     

Chemical analysis and quality control of Ginkgo biloba leaves,extracts, and phytopharmaceuticals

The chemical analysis and quality control of Ginkgo leaves, extracts, phytopharmaceuticals and some herbal supplements is comprehensively reviewed. The review is an update of a similar, earlier review in this journal [T.A. van Beek, J. Chromatogr. A 967 (2002) 21–55]. Since 2001 over 3000 papers on Ginkgo biloba have appeared, and about 400 of them pertain to chemical analysis in a broad sense and are cited herein. The more important ones are discussed and, where relevant, compared with the best methods published prior to 2002. In the same period over 2500 patents were filed on Ginkgo and the very few related to analysis are mentioned as well. Important constituents include terpene trilactones, i.e. ginkgolide A, B, C, J and bilobalide, flavonol glycosides, biflavones, proanthocyanidins, alkylphenols, simple phenolic acids, 6-hydroxykynurenic acid, 4-O-methylpyridoxine and polyprenols. In the most common so-called “standardised” Ginkgo extracts and phytopharmaceuticals several of these classes are no longer present. About 130 new papers deal with the analysis of the terpene trilactones. They are mostly extracted with methanol or water or mixtures thereof. Supercritical fluid extraction and pressurised water extraction are also possible. Sample clean-up is mostly by liquid–liquid extraction with ethyl acetate although no sample clean-up at all in combination with LC/MS/MS is gaining in importance. Separation and detection can be routinely carried out by RP-HPLC with ELSD, RI or MS, or by GC/FID or GC/MS after silylation. Hydrolysis followed by LC/MS allows the simultaneous analysis of terpene trilactones and flavonol aglycones. No quantitative procedure for all major flavonol glycosides has yet been published because they are not commercially available. The quantitation of a few available glycosides has been carried out but does not serve a real purpose. After acidic hydrolysis to the aglycones quercetin, kaempferol and isorhamnetin and separation by HPLC, quantitation is straightforward and yields by recalculation an estimation of the original total flavonol glycoside content. A profile of the genuine flavonol glycosides can detect poor storage or adulteration. Although the toxicity of Ginkgo alkylphenols upon oral administration has never been undoubtedly proven, most suppliers limit their content in extracts to 5 ppm and dozens of papers on their analysis were published. One procedure in which a methanolic extract is directly injected on a C8 HPLC column appears superior in terms of sensitivity (<5 ppm), separation, simplicity and validation and will be incorporated in the European Pharmacopoeia. Alternatively GC/MS and ELISA methods can be used. A sharp contrast to the plethora of papers on terpene trilactones, flavonol glycosides, and ginkgolic acids forms the low number of papers on biflavones, proanthocyanidins, simple phenolics, simple acids, and other constituents that make up the remaining 70% of Ginkgo standardised extracts. More research in this direction is clearly needed. For the analysis of Ginkgo proanthocyanidins (7%) for instance, no reliable assays are yet existing. Finally the growing literature on pharmacokinetic and fingerprinting studies of Ginkgo is briefly summarised.     

Mass spectrometry analysis of terpene lactones in Ginkgo biloba

Terpene lactones are a family of compounds with unique chemical structures, first recognised in an extract of Ginkgo biloba. The discovery of terpene lactone derivatives has recently been reported in more and more plant extracts and even food products. In this study, mass spectrometric characteristics of the standard terpene lactones in Ginkgo biloba were comprehensively studied using both an ion trap and a quadrupole time-of-flight (QTOF) mass spectrometer. The mass spectral fragmentation data from both techniques was compared to obtain the mass spectrometric fragmentation pathways of the terpene lactones with high confidence. The data obtained will facilitate the analysis and identification of terpene lactones in future plant research via the fragmentation knowledge reported here.     

Chemical analysis of Ginkgo biloba leaves and extracts

The chemical analysis and quality control of Ginkgo leaves and extracts is reviewed. Important constituents present in the medicinally used leaves are the terpene trilactones, i.e., ginkgolides A, B, C, J and bilobalide, many flavonol glycosides, biflavones, proanthocyanidins, alkylphenols, simple phenolic acids, 6-hydroxykynurenic acid, 4-O-methylpyridoxine and polyprenols. In the commercially important Ginkgo extracts some of these compound classes are no longer present. Many publications deal with the analysis of the unique terpene trilactones. They can be extracted with aqueous acetone or aqueous methanol but also supercritical fluid extraction is possible. Still somewhat problematic is their sample clean-up. Various procedures, not all of them validated, employing partitioning or SPE have been proposed. Some further development in this area can be foreseen. Separation and detection can be routinely carried out by HPLC with RI, ELSD or MS, or with GC-FID after silylation. TLC is another possibility. No quantitative procedure for flavonol glycosides has been published so far due their difficult separation and commercial unavailability. Fingerprint analysis by gradient RP-HPLC is possible. After acidic hydrolysis to the aglycones quercetin, kaempferol and isorhamnetin and separation by HPLC, quantitation is straightforward and yields by recalculation an estimation of the original total flavonol glycoside content. For biflavones, simple phenols, 6-hydroxykynurenic acid, 4-O-methylpyridoxine and polyprenols analytical procedures have been published but not all assays are yet ideal. Lately a there is a lot of interest in the analysis of the undesired alkylphenols and a few validated procedures have been published. The analysis of Ginkgo proanthocyanidins is still in its infancy and no reliable assays exist.     

Determination of active components of Ginkgo biloba in human urine by capillary high-performance liquid chromatography/mass spectrometry with on-line column-switching purification

Ginkgo biloba is one of the most popular herbal nutritional supplements, with terpene lactones and flavonoids being the two major active components. An on-line purification high-performance liquid chromatography/mass spectrometry (HPLC/MS) method was successfully developed for the quantitative determination of flavonoids and terpene lactones excreted in human urine after ingesting the herbal supplement. Satisfactory separation was obtained using a C18 capillary column made in-house with sample clean-up and pre-concentration achieved using a C18 pre-column with column switching. High selectivity and limits of detection of 1-18 ng/mL were achieved using a selected ion monitoring (SIM) scan in negative ion mode; the on-line solid-phase extraction (SPE) recovery of the active components in Ginkgo biloba determined in this study was greater than 75%.