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1.
南雄银杏叶中银杏黄酮含量的H PLC测定   总被引:12,自引:3,他引:9  
用高效液相色谱法测定在广东省南雄市不同采摘时间、不同树龄的银杏叶中总黄酮含量;采用Kromasil C18柱,流动相为V(甲醇):V(4g/L磷酸水溶液)=55:45体系,检测波长254nm,外标法定量;结果表明南雄银杏叶中总黄酮平均含量为0.55%(w,干叶计),每年6月为最佳摘叶时间。  相似文献   

2.
研究了银杏叶提取物中5种银杏内酯含量的方法。外标法宣反相Symmetry-C18柱,流动相为甲醇-水;示差折光检测器。线形范围为0.02~0.40g/L,r=0.9814~0.9934,方法的回收率和相对标准偏差分别在93.2%~97.4%和1.27%~2.68%(n=15)之间,5种银杏内酯的检测限在2.07~3.98mg/L之间。本法简便、准确、重现性好,适宜于生产和工艺研究的质量控制。  相似文献   

3.
GC-MS测定家犬血浆中银杏内酯A、B的含量   总被引:2,自引:0,他引:2  
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。  相似文献   

4.
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   总被引:4,自引:0,他引:4  
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%.  相似文献   

5.
银杏叶中银杏萜内酯的GC/MS分析研究   总被引:1,自引:0,他引:1  
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.  相似文献   

6.
银杏茶中有毒成分银杏酸的研究   总被引:3,自引:0,他引:3  
吴向阳  仰榴青  陈钧 《分析化学》2003,31(11):1407-1407
1 引  言银杏茶是采用银杏叶为原料精制而成的一种保健品 ,目前市场上销售的银杏茶已有上百种 ,其主要药用成分黄酮和内酯具有改善心脑血管循环、拮抗血小板活化因子和抗血栓等作用 ,可用于预防和治疗老年性痴呆和脑血栓等疾病。然而银杏叶中还含有一些有毒成分 ,研究发现其中的银杏酸具有致敏性、细胞毒性和免疫毒性等作用 ,是银杏叶提取物EGb和银杏茶中的主要毒性物质 ,其食用安全性已引起人们的高度重视。目前国际上公认的EGb质量标准规定银杏酸含量必须小于 5 μg/g。但是有关银杏酸分析方法公开报道较少 ,未见银杏茶中银杏酸检测…  相似文献   

7.
近红外光谱法同时测定银杏提取液中总黄酮和总内酯含量   总被引:12,自引:0,他引:12  
胡钢亮  吕秀阳  罗玲  徐铸德 《分析化学》2004,32(8):1061-1063
采用傅里叶变换近红外透射光谱和偏最小二乘法,对银杏提取液中总黄酮和总内酯的含量进行了定量测定。所建立的数学模型对校正集样本的银杏总黄酮和总内酯复相关系数(MR)分别为O.998和o.986;对预测集样本的银杏总黄酮和总内酯复相关系数分别为0.983和0.971,标准回收率分别为95.71%~103.3%和95.29%~104.6%,相对标准偏差(RSD)分别为2.44%和3.19%。结果表明,近红外光谱测定银杏提取液中总黄酮和总内酯含量具有快速、准确的优点,有望应用于银杏提取过程的中间控制和大批量产品的检测。  相似文献   

8.
简要介绍银杏叶提取物的化学成分--黄酮类化合物、萜内酯类、银杏糖类、其他活性物质的结构、药理作用和用途.  相似文献   

9.
陈学国  孔亮  盛亮洪  厉欣  邹汉法 《色谱》2005,23(1):46-51
 建立了全二维液相色谱串联质谱分离分析模式,将质脂体色谱柱和ODS反相色谱柱作为二维分析色谱柱,二者通过一个连有两个0.5 mL定量环的八通阀耦联。质脂体色谱柱上的馏分在反相色谱柱上分离后,直接进入紫外-检测器,然后经分流器分流后进入大气压电离质谱。将该体系用于银杏叶提取物的组成研究,共检测到至少41个组分,结合紫外-可见光谱和质谱信息,其中13个组分初步鉴定为银杏内酯B、银杏内酯C、白果内酯、槲皮素芸香糖苷、槲皮素、槲皮素-3-O-β-D-葡萄糖基(1-2)-α-L-鼠李糖苷、槲皮素-3-O-β-D-葡萄糖苷、异鼠李素、山柰酚-3-O-β-D-芸香糖基(1-2)-α-L-鼠李糖苷、异鼠李素-3-O-β-D-芸香糖苷、山柰酚-3-O-β-D-葡萄糖苷、山柰酚和山柰酚-3-O-β-D-芸香糖苷。  相似文献   

10.
采用热辅助下的在线甲基衍生化-气相色谱法测定银杏叶中的银杏酸。银杏叶样品与衍生化试剂四甲基氢氧化铵(TMAH, 25%甲醇溶液)同时进样,在300 ℃的进样口瞬间生成了银杏酸甲基衍生物,银杏叶中6种银杏酸得到很好的分离。在一定的质量浓度范围内银杏酸的线性关系良好,回归系数均大于0.9966,最低检出限范围为0.8~2.8 mg/kg。银杏叶中主要的烷基酚类物质为银杏酸C13∶0,C15∶1和C17∶1,它们的含量(用质量分数表示)分别为11.0%,36.7%和42.8%,3次平行测定的相对标准偏差(RSD)均小于3.4%(n=3)。银杏叶样品中总银杏酸的含量为4.0~10.9 mg/g。该方法无需繁琐费时的衍生化和纯化等前处理步骤,不失为银杏叶中银杏酸测定的一种快速、简便、准确的方法。  相似文献   

11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

16.
Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.  相似文献   

17.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

18.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

19.
20.
The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe2O3. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

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