Separation and determination of purpurea glycosides in Digitalis purpurea leaves by micro-HPLC

A micro high-performance liquid chromatographic (micro-HPLC) method was developed for the determination of purpurea glycoside A, purpurea glycoside B, and glucogitaloxin in Digitalis purpurea leaves. The extract of dry leaf powder was applied to a Sep-Pak silica cartridge followed by preparative thin-layer chromatography prior to micro-HPLC analysis. The analysis was performed on an ODS micro column, using acetonitrile-methanol-water (21:20:45) and ultraviolet detection (220 nm). The amounts of purpurea glycoside A, purpurea glycoside B, and glucogitaloxin per 100 mg of dry leaf powder were estimated to be 52.6, 50.7, and 108.6 μg, respectively.     

Determination of trans-resveratrol in wine by micro-HPLC with fluorescence detection

A new method for the quantitative determination of trans-resveratrol in wine has been optimized and validated. The method is based on the direct injection of 500 nL of wine in an HPLC system fitted with an RP microcolumn of 10 cm x 0.32 mm and spectrofluorometric detection. The linear dynamic range of the method covers the normal range of occurrence of the analyte in wines and extends for two orders of magnitude with r(2)= 0.9994. Twenty-three wines have been analyzed with the proposed method, finding concentrations in the range reported by other authors.     

Micro high-performance liquid chromatographic determination of cardiac glycosides in beta-methyldigoxin and digoxin tablets

A micro high-performance liquid chromatographic (micro-HPLC) method has been developed for the assay of beta-methyldigoxin and digoxin tablets. Quantitation of cardiac glycosides in tablets was carried out by the incorporation of dexamethasone as an internal standard. The procedure consisted of disintegration of tablets, extraction with acetone-ethanol (9:1) and injection for micro-HPLC on an ODS micro column, using acetonitrile-water (28:72) for beta-methyldigoxin tablets and methanol-water (1:1) for digoxin tablets; the effluent was monitored by UV detection at 220 nm. The average values of the contents in beta-methyldigoxin and digoxin tablets were 99.6 and 100.2% of the labelled amounts, respectively. The proposed method is sufficiently precise and sensitive to examine the content uniformity of tablets.     

Determination of digitoxin in pharmaceutical oral dosages by automatic discrete-sample analysis

An automatic procedure for determination of digitoxin in pharmaceutical oral dosages is described. The procedure is based on the fluorimetric determination of digitoxin in hydrochloric acid media in the presence of hydrogen peroxide. Operational conditions and analytical setup are detailed. Results for repeatability, linearity, and tablet analysis are given. The procedure can be used for analysis of sets of up to 30 tablets at the rate of 17 readings per hour. Contents as low as 0.1 mg of digitoxin can be determined.     

Determination of the position of the glucose bond in some cardiac glycosides

Conclusions 1. The possibility of determining the position of attachment of glucose in some diglycosides by their capacity for forming isopropylidene derivatives has been shown.2. It has been established that in the cardiac glycosides erychordin, convalloside, convallatoxoloside, and hellebrin, the glucose is attached to C₄ of the D-gulomethylose and L-rhamnose.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 4, pp. 267–269, 1969     

Analysis of 5-methyl-deoxycytidine in DNA by micro-HPLC

Summary A method for the quantitative analysis of 5-methyl-deoxycytidine (5dmC) in DNA based on enzymatic hydrolysis to nucleosides, separation by Micro-HPLC and quantification with external calibration has been developed. The method was applied to DNA from calf thymus, drosophila and yeast; the fully sequenced DNA from the Phage X174 has been used to establish the accuracy of the procedure. The detection limit is 0.4 pmol 5dmC absolute; the content of modified nucleoside in DNA of drosophila and yeast was shown to be lower than the current detection limit, which means that less than one methylated cytosine per 14000 (12000 resp.) unmodified nucleobases are to be found in the genomes.

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Bestimmung von 5-Methyl-desoxycytidin in DNA mit Mikro-HPLC

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Dedicated to Prof. Dr. W. Fresenius on the occasion of his 75th birthday     

高效液相色谱法测定顺铂注射液中顺铂的含量

顺铂含量的测定方法有灼烧重量法[1]、高效液相色谱法[2,3]、络合滴定法[4]。顺铂注射液作为新剂型,其主含量顺铂的分析方法一直为省级标准,采用SnCl2显色法[5],该法所测值是二价铂化合物的总含量,对顺铂无选择性。文献上也有采用高效液相色谱法[6]的报道,但该法存在着:1.杂质峰与主峰分离度不够(Rs<1.5);2.方法重现性较差;3.对柱效要求高的缺点,其主要原因是所选色谱系统不理想。为此,本研究以高效液相色谱法测定顺铂注射液中顺铂的含量,取得了满意的结果。1　实验部分1.1　仪器和试剂SHIMADZULC 10A系统,双LC 10AD高压泵,DGU…     

Simultaneous analysis of cardiac glycosides in blood and urine by thermoresponsive LC-MS-MS

A new thermoresponsive polymer separation column was applied to simultaneous analysis of four cardiac glycosides (CGs) being widely used for the treatment of arrhythmias and heart failure in human blood and urine. This column is composed of an N-isopropylacrylamide polymer, the surface of which undergoes a reversible alteration from hydrophilic to hydrophobic by changing temperature. The chromatographic separation and retention times can be easily be controlled by adjusting the column temperature. As the column temperature was changed from 50 to 10 °C over 8 min, five CGs, including deslanoside, digoxin, methyldigoxin, digitoxin, and digitoxigenin (internal standard) were better resolved. Using these LC conditions, we analyzed four CGs in human whole blood and urine simultaneously by liquid chromatography-tandem mass spectrometry (LC-MS-MS). Validation data as functions of recovery rates, linearity, accuracy, and precision were carefully tested; all were generally satisfactory. The detection limits for the four CGs in both matrices were 0.2–0.3 ng/mL. The method was applied to analysis of methyldigoxin and its main metabolite digoxin in whole blood and urine samples obtained from a deceased person in actual autopsy case. To our knowledge, this is the first report describing an LC-MS-MS method using a thermoresponsive column for analysis of drug(s). The inclusion of the thermoresponsive column in an LC-MS-MS technique seems to extend the possibility for simultaneous analysis of compounds of different properties, such as hydrophobic precursors and their hydrophilic metabolites in biological samples within limited analysis times.     

Liquid chromatography of cardiac glycosides

Summary LC was used for the separation of several cardiac glycosides with water-alcohol eluents on a silanised silica column. The influence of temperature and composition of the eluent on the retention time, the retention volumes of the glycosides, the selectivity and the capacity factor of the column were studied. Higher temperature and a higher ethanol content in the eluent reduce the retention time, the selectivity and the capacity factor but the efficiency of the column increases. The best separation of six glycosides studied was obtained at 50°C, the ethanol content in the eluent being about 30%.     

Thermal tranformation of cardiac glycosides

The thermal transformations of cardiac glycosides in neutral alcoholic solutions have been investigated. The kinetics of their acidless hydrolysis at 100 and 142°C and the activation energy of the process have been studied. The possibility has been shown of the stepwise hydrolysis of natural trisdigitoxosides with the production of difficulty available mono- and bisdigitoxosides. The following were used as the objects of investigation: convallatoxin, glucostrophanthidin, cheirotoxin, desglucocheirotoxin, erycordin, erysimin, erysimoside, digitoxin, and cymarin.All-Union Scientific-Research Institute of Drug Chemistry and Technology, Kharkov. Kharkov State Pharmaceutical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 62–64, January–February, 1991.     

HPLC法测定苦参碱葡萄糖注射液中苦参碱的含量

苦参碱是一种生物碱 ,是豆科植物苦参的主要有效成分之一 ,其药理作用在临床表现显著 ,具有抗病原微生物、抗肿瘤、抗炎症、抗过敏、平喘等作用[1 ] 。近年来对苦参碱的测定方法有薄层扫描法、气相色谱法、高效电泳法、高效液相色谱法等[2 ] ,但有关苦参碱葡萄糖注射液中的苦参碱含量分析未见报道。本文采用高效液相色谱法建立了苦参碱葡萄糖注射液中苦参碱含量测定方法 ,避免了葡萄糖分解 ,可作为该制剂的质量控制方法之一。1　实验部分1 1　仪器与试剂高效液相色谱仪 (Ａｇｉｌｅｎｔ 1 1 0 0液相色谱系统 ,包括紫外检测器、四元梯度泵、…     

Determination of chlorthalidone and clonidine hydrochloride in tablets by HPLC

A rapid, reversed-phase high performance liquid chromatographic method is described for the determination of chlorthalidone and clonidine hydrochloride combinations in tablets. Individual tablets or composite samples were sonicated in water, diluted with methanol, and filtered prior to chromatographing. Chlorthalidone, formulated at 15 mg/tablet, was chromatographed on octadecylsilyl-bonded, 5 to 6-micrometers, spherical silica with 50% methanol in water mobile phase. Clonidine hydrochloride, formulated at 0.1 or 0.2 mg/tablet, was chromatographed on trimethylsilyl-bonded, 5 to 6-micrometers, spherical silica with 65% methanol in pH 7.9 phosphate buffer mobile phase. Both were determined with a spectrophotometric detector at 254 nm. Mean recoveries of the drugs from six synthetic tablet samples were 100.3% for chlorthalidone and 99.7% for clonidine hydrochloride (at 0.1 mg/tablet level) with coefficients of variation of 0.79 and 1.55%, respectively.     

偏最小二乘-近红外漫反射光谱法测定西米替丁药片

研究了应用偏最小二乘法(PLS)同近红外漫反射光谱法结合,对西米替丁片剂药品进行无损非破坏定量分析,建立了最佳的数学校正模型。讨论了波长间隔和主成分数对PLS定量预测能力的影响,预测了未知样品。     

Determination of impurities in validol tablets by gas-liquid chromatography

A procedure is developed for determining impurities in Validol tablets by gas-liquid chromatography (GLC). The reliability of the results obtained is confirmed by the analysis of model mixtures containing the active and all auxiliary substances of the tablets. The proposed procedure is introduced into the standardized documentation on the manufactured tablets. The presence of impurities in Validol tablets due to the technology of the synthesis of the Validol is inevitable. Therefore, the routine control of production is very important to ensure its quality.     

Conformations of the sugars found in cardiac glycosides

Conclusions On the basis of calculated and, for some of the compounds, experimentally determined figures, the most stable conformational formulas of all the monosaccharides present in cardiac glycosides have been determined. It has been shown that the majority of monosaccharides of the L-series are present in the 1-C form while the monosaccharides of the D-series are present in the C-1 form. It has also been established that the glycosidic centers in the cardenolides exhibit all types of conformational linkages: ee, ea, ae, and aa.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 4, pp. 260–267, 1969.