烟酰胺腺嘌呤二核苷酸类CD38抑制剂的合成及生物活性评价

分别以1,3,5-三苯甲酰基-α-D-核糖、3,5-二苯甲酰基-2-脱氧-2,2-二氟戊呋喃糖-1-酮和D-木糖为原料, 经由烟酰胺核苷及烟酰胺核苷酸中间体, 合成了系列糖环经氟原子取代的烟酰胺腺嘌呤二核苷酸(NAD)类CD38抑制剂. 基于对CD38的水解抑制能力的考察, 评价了所合成氟代NAD类似物的活性. 结果表明, 糖环上氟原子取代的数目和位置对抑制剂活性的影响十分明显, 烟酰胺核苷的端基构型对活性的影响较大. 2个化合物均显示出非常好的CD38抑制活性, 其中化合物2a的抑制活性高出阳性对照物阿糖型氟代烟酰胺腺嘌呤二核苷酸2个数量级.     

反相高效液相色谱法测定狼把草中的木犀草素

胜反相高效液相色谱法分离并测定了狼把草中的木犀草素，建立了该中药中木犀草素分离，测定的色谱方法。     

反相高效液相色谱法测定狼把草中的木犀草素

用反相高效液相色谱法分离并测定了狼把草中的木犀草素，建立了该中药中木犀草素分离、测定的色谱方法。色谱条件：ＯＤＳ柱，甲醇－水－乙酸（７０：３０：０．４Ｖ／Ｖ）为流动相，紫外检测波长２５４ｎｍ。为扩大中药及植物中木犀草素药物资源的开发提供了简便、灵敏、准确的测定方法     

Nicotinamide Adenine Dinucleotides Arrest Photoreduction of Class II DNA Photolyases in FADH˙ State

All light‐sensitive members of the photolyase/cryptochrome family rely on FAD as catalytic cofactor. Its activity is regulated by photoreduction, a light‐triggered electron transfer process from a conserved tryptophan triad to the flavin. The stability of the reduced flavin depends on available external electron donors and oxygen. In this study, we show for the class II photolyase of Methanosarcina mazei , Mm CPDII , that it utilizes physiologically relevant redox cofactors NADH and NADPH for the formation of the semiquinoid FAD in a light‐dependent reaction. Using redox‐inert variants Mm CPDII /W388F and Mm CPDII /W360F, we demonstrate that photoreduction by NADH and NADPH requires the class II ‐specific tryptophan cascade of Mm CPDII . Finally, we confirmed that mutations in the tryptophan cascade can be introduced without any substantial structural disturbances by analyzing crystal structures of Mm CPDII /W388F, Mm CPDII /W360F and Mm CPDII /Y345F.     

甲氧苄氨嘧啶纯度的反相高效液相色谱分析

本工作建立了抗菌药物甲氧苄氨嘧啶中少量杂质的反相高效液相色谱分析方法。方法操作简便，分析快。同时考察了有机改进剂对该药物分离的影响。     

High Performance Liquid Chromatographic Analysis of Rifampin and Related Impurities in Pharmaceutical Formulations

Abstract

High pressure liquid chromatography was employed for the assay of rifampin in capsules. A reverse phase RP-2 column and a mobile phase of 48% methanol, 5% tetrahydrofuran and 47% 0.05 M ammonium formate (pH 7.3) were used with detection at 254 nm. Rifampin was separated from all its major degradation products and quantitated.     

High-Performance Liquid Chromatographic Study of Topiramate and Its Impurities

A new patented route for the synthesis and analysis of Topiramate has been developed. In order to determine the impurities in the active pharmaceutical ingredient, three HPLC methods: an isocratic elution method with RI detection, a gradient elution method with diode-array detection, an ion-chromatographic method with inverse UV and/or RI detection and an HPLC-MS method were applied. Inverse RI proved to be a very powerful and sensitive technique. It is demonstrated that MS detection can replace both RI and UV detection, only one method being required for non ionic impurities. The methods were validated according to the ICH Q2A and Q2B guidelines. The full set of validation criteria laid out by the international guidelines were satisfied. With these new validated methods, the pharmaceutical analysis requirements were met; the methods can be successfully applied for product evaluation and stability testing.

     

丙烯酰胺中痕量杂质色谱分析

In this work traces of acrolein,acrylonitril,acetonitrile and cyanoethanol in 30%aqueous solution of acry-lamide has been analyzed by gas chromatography.The analysis was performed on a T-programmed quartz capilfary column XE-60 with the dimension of 50m×0. 25mm i.d.     

马铃薯体内腺嘌呤代谢物的薄层色谱法

马铃薯体内腺嘌呤代谢物的薄层色谱法乌云,李秉真,田瑞华,索兰弟,刘梦云（内蒙古农牧学院中心实验室农学系呼和浩特０１００１８）１前言在研究马铃薯块茎的形成和细胞分裂素的变化的相互关系时,除发现有玉米素、玉米素核苷外〔１〕,还发现有６－氨基嘌呤、腺嘌呤核...     

水溶性维生素制剂的反相离子对色谱分析

考察了反相离子对试剂Ｂ系列（Ｂ５～Ｂ８）对水溶性维生素分离的色谱行为，确定了用国产庚烷磺酸钠作离子对试剂、（甲醇）＝０．２９的水溶液为流动相的最佳色谱条件，在１６ｍｉｎ内达到对六种混合水溶性维生素（烟酸、烟酰胺、Ｖ—Ｂ１、Ｖ—Ｂ２、Ｖ—Ｂ６、叶酸）的一次性良好分离，并用所选定条件测定了多维胶囊、复合维生素Ｂ的含量。该方法线性良好，精密度较高．     

丙烯腈中微量杂质的毛细管色谱法分析

提出了一种分析丙烯腈中微量杂质的大孔径ＯＶ－１０１和ＯＶ－１７ＳＣＯＴ串联柱及毛细管进样系统。结果表明串联柱具有寿命长和分离效率高的特点,定量分析误差小于４％。     

Revrsed Phase High Performance Liquid Chromatographic Analysis of Triphenylphosphine in a Reaction Mixture

Abstract

An isocratic reversed phase high performance liquid chromatographic method is described for monitoring concentrations of triphenylphosphine (TPP) and other compounds involved in an oxygen-transfer reaction catalyzed by a molybdenum complex. Using an inexpensive octadecylsilane column and a mobile phase consisting of aqueous acetonitrile, good separations and linear chromatographic responses were achieved for solutions of TPP, pyridine and each of their oxides in the mobile phase with concentrations in the range of 0.0012 – 0.12 grams/100 mL. No evidence for TPP precipitation was observed during the analysis of supersaturated solutions containing TPP at concentrations as high as 0.27 grams/100 mL. Chromatograms of more concentrated TPP solutions exhibited a second peak corresponding in retention time to TPP-oxide. Contrary to the interpretation of a similar effect in a previous study, evidence is presented indicating that this second peak is not the result of decomposition of TPP to its oxide, but rather is caused by precipitation of TPP particles which coincidentally pass through the chromatographic system at the same rate as TPP-oxide.

Thus in this interpretation, the correspondence of the retention time of the early eluting peak in the chromatograms of solutions containing high concentrations of TPP with that of the oxide of TPP is coincidental, and does not indicate the decomposition of TPP during its HPLC analysis. This is consistent with the data presented here and in earlier studies.     

Reversed Phase High - Performance Liquid Chromatographic Analysis of Tricyclic Antidepressants in Plasma

Abstract

A reversed phase HPLC procedure is described for measuring the plasma concentration of four commonly used tricyclic anti-depressants (TCA): amitriptyline, desipramine, imipramine and nortriptyline in the range of 25 to 800ng per ml. The procedure involves rapid extraction, and HPLC analysis using a μBondapak C-18 column at 50°C, and a 254nm detector. Coefficients of variation are less than 5% for within run, and 7% for day-to-day experiments. Detection limits are: desipramine -0.5ng, nortriptyline or imipramine -0.6ng, and amitriptyline -0.7ng. Propoxyphene interferes with amitriptyline while chlorpromazine interferes with clomipramine. The procedure is easily adapted for clinical drug monitoring of TCA.     

合成2,6-叔丁基对甲酚的气相色谱分析

本文介绍了对甲酚与混合C4以杂多酸为催化剂合成2.6 二叔丁基对甲酚(BHT)的气相色谱分析。此方法使用Φ3×3m不锈钢填充柱,内装涂有10%SE 30的白色硅烷化101担体,FID检测器,已知物对照法及色质联用定性。该方法测定了样品中12种化合物,以扣除溶剂的面积归一法定量。     

Improved Isocratic Mobile Phases for the Reverse Phase Ion-Pair Chromatographic Analysis of Drugs of Forensic Interest

Abstract

Most drug exhibits of forensic interest can be analyzed by reverse phase ion-pair chromatography using a Microbondapak-C-18 column with two isocratic mobile phases. These systems employing methanesulfonic acid represent a great improvement in resolution and speed over the author's original methodology.     

Liquid Chromatographic Analysis of Pentobarbital

Abstract

A method is described for a one step acetonitrile precipitation of serum or plasma and subsequent analysis of pentobarbital by reverse phase HPLC. The results of using two internal standards, N,N-Diethyl-m-toluamide and 5-(p-Methylphenyl)-5-phenylhydantoin are compared. Internal standard is added to serum (as little as 25 μL) and vortex-mixed with acetonitrile followed by centrifugation. An aliquote of the supernatant is analyzed on a C18 reverse phase column eluted with metanol/0.05 M (NH₄)₂HPO₄, pH 8/water (55/20/25, v/v/v). The effluent is monitored at 220 nm.     

Analysis of 2-Acetylaminofluorene in Laboratory Animal Chow by Reverse Phase Liquid Chromatography

Abstract

A high speed liquid chromatographic procedure for analysis of 2-acetylaminofluorene (2-AAF) in laboratory animal chow is presented. The procedure is rapid and uncomplicated and provides accurate and precise analysis. The reverse phase liquid chromatography allows minimal clean-up of extracts with good column stability and high sample thru-put. Linearity and minimum detectable limit are discussed.     

Cyclodextrin Bonded Phase for Liquid Chromatographic Separation and Analysis of Some Oral Contraceptives

Abstract

A specific and sensitive analytical HPLC procedure was described for quantitative determination of ethinylestradiol and norethisterone acetate (Anovlar 1) and ethinylestradiol and norgestrel (Primovlar) in tablet formulation. These steroids were extracted from the tablets with methanol. The steroids were then determined with high performance liquid Chromatograph-Cyclobond 1 column using mobile phase phosphate buffer pH 7.0: methanol (60:40), flow rate 0.5 ml min^?1 and the detection was effected spectrophotometrically at 280 nm, using variable wavelength UV detector.

There was > 99.3% recovery from synthetic mixtures and the coefficient of variation was < 2.0% for the formulations investigated. The method is highly quantitative and reproducible.     

Preparation and Evaluation of Arylazide-Substituted Pyridine Adenine Dinucleotides for Photoaffinity Labeling Experiments

Two pyridine-modified NAD'analogs, 3–(3-azido benzo-yl) pyridine adenine dinucleotide 1 and N -(3-azido-5-car-boxyl) phenyl nicotinamide adenine dinucleotide 2 have been prepared and evaluated for photoaffinity labeling experiments. The syntheses were accomplished via a mammalian NADase-catalyzed base exchange reaction. The new NAD⁺ analogs retained the carbonyl or carhox-amido functional group at the 3 position of the pyridine ring. The analog 1 is the first pyridine-modified azido derivative of NAD⁺ that has shown coenzyme activity in a stereospecific hydride transfer reaction catalyzed by a dehydrogenase. Both NAD⁺ analogs have shown potential for the study of active sites of NAD⁺-utilizing enzymes.     

Analysis of Temocillin and Impurities by Reversed Phase Liquid Chromatography: Development and Validation of the Method

A robust, specific, precise and sensitive high-performance liquid chromatographic method has been described for purity control of temocillin. Chromatographic separation was achieved using a Symmetry C₁₈ (150 × 4.6 mm, 5 µm) column kept at 30 °C. The mobile phase consisted of a gradient mixture of mobile phases A (5 g/L solution of Na₂HPO₄·2H₂O, pH 7) and B (ACN-MeOH-H₂O, 50:10:40 v/v/v) pumped at a flow rate of 1.0 mL/min. UV detection was performed at 235 nm. The developed method was validated according to the ICH guidelines for its robustness, selectivity, sensitivity, precision and linearity. An experimental design was applied for the robustness study. Linearity was assessed both at impurity level in the range from LOQ to 10 % and assay level from 25 % to 150 % (0.6 mg/mL = 100 %). It is the first liquid chromatographic method described for the separation of temocillin and its potential impurities. It was possible to identify four degradation products from the forced degradation studies. The degradants do not interfere with the main peak and other known impurities showing that the method is specific and stability-indicating.