Use of Derivative Spectrophotometry for the In Vitro Determination of Allopurinol and Uric Acid Mixtures

Abstract

Allopurinol and uric acid are successfully assayed either in laboratory made mixtures or in urine using derivative spectrophotometry. The former is determined through first - derivative signal (¹ D) measurement at 284 nm, and the latter through second - derivative signal (²D) measurement at 293 nm. The colinearity of these values versus concentration of both compounds in the range 0.2–1.2 mg% permits their determination with high accuracy and good reproducibility. The method is recommended to monitor the allopurinol therapy in treatment of chronic gouty patients.     

Solid-State Synthesis of 1,3-Selenazoles Employing CuPy2Cl2 as a Lewis Acid Catalyst

1,3-Selenazoles were Synthesized from 3-bromo acetyl coumarin and selenourea in the presence of CuPy₂Cl₂ under solvent-free conditions at ambient temperature. The pure products were identified by spectral data.     

Practical and Efficient Method for α-Sialylation with an Azide Sialyl Donor Using a Microreactor

Efficient α-sialylation with a C5 azide sialyl donor was investigated under microfluidic conditions using a microreactor composed of a Comet X-01 micromixer and a tube reactor. Precise temperature control realized excellent α-selectivity, and Siaα(2,6)Gal, Siaα(2,3)Gal, and Siaα(2,9)Sia disaccharides were obtained in moderate to good yields.     

New D-π-A-conjugated organic sensitizers based on α-pyranylidene donors for dye-sensitized solar cells

A series of new push-pull organic dyes incorporating a cyanoacrylic acid group as electron acceptor unit and α-chalcogenopyranylidene group (X = S; O) as electron donor unit has been synthesized, characterized and used as sensitizer for dye-sensitized solar cells (DSSCs). For the first time, α-pyranylidene and thiopyranylidene groups, have been evaluated in DSSC. To obtain the thermodynamic values of the solar cell, an investigation of their electrochemical (CV) and optical properties (UV–vis absorption spectroscopy) is also reported.     

Convenient Preparation of Di- and Tri-Ethynylbenzenes by Cleavage of 2-Hydroxy-2-methylbut-3-yn-4-ylbenzenes with Water Miscible Reagents

2-Hydroxy-2-methylbut-3-yn-4-ylbenzenes, readily available from bromobenzenes, are efficiently cleaved by the water-miscible reagents sodium 2-propoxide in 2-propanol, or potassium hydroxide in dioxan, which facilitates isolation of volatile ethynylbenzenes.     

NMR Studies of the Regio and Stereoselectivity of 1,3-Dipolar Cycloaddition of Diazomethane to α,β-Unsaturated Spiroketals from Artemisia Species

In the presence of pyridine, naturally occurring acetylenic spiroketals isolated from Chinese Artemisia species underwent regio and stereoselectively 1,3-dipolar cycloaddition reactions with diazomethane. The structures of the adducts and the regio and stereoselectivity were established mainly by 1D and 2D NMR techniques. This is the first report concerning the 1,3-dipolar cycloaddition reaction of diazomethane to α,β-unsaturated ketals which is of utility in the structure modification of some organic compounds.     

Fe-Al-α,α′-联吡啶络合催化聚合马来酸酐与环氧氯丙烷研究

研究了马来酸酐与环氧氯丙烷交替共聚，及Ｆｅ（ａｃａｃ）３ Ａｌ（ｉ Ｂｕ）３ α，α’ 联吡啶络合物（ａｃａｃ＝ 乙酰丙酮） 催化马来酸酐（ＭＡ） 和环氧氯丙烷交替共聚的特征，并用红外光谱，核磁共振谱研究了共聚物的结构。动力学研究表明共聚反应与单体浓度和催化剂浓度均呈一级关系。     

Novel one-pot Cu-nanoparticles-catalyzed Mannich reaction

Recyclable heterogeneous Cu-nanoparticles efficiently catalyzed the one-pot three-component Mannich reaction of ketones, aromatic aldehydes and amines in methanol. This method provides a novel and improved method for obtaining β-amino carbonyl compounds in terms of good yield with little catalyst loading.