A novel tropylium-based coupling reagent has been developed to facilitate the synthesis of a series of esters, amides, lactones and peptides under mild reaction conditions. Remarkably, this reagent can be used in catalytic amounts in conjunction with a sacrificial reagent, offering a new and efficient method for nucleophilic coupling reactions of carboxylic acids.

The essential instrument settings are shown in Table 1. ‘Enzyme reagent was loaded as “2nd reagent,” and the modified color reagents A and B were “4th reagent” and “3rd reagent,” respectively. The instrument incubated sample and enzyme reagent for 4 mm in the inner chamber of the rotor. It then added 4-aminophenol to the inner chamber and sodium hydroxide to the outer chamber, mixed the content...

Triflic anhydride (Tf2O) is the reagent of choice for the introduction of the trifluoromethylsulfonyl (CF3SO2) group into a variety of organic substrates, and the resulting compounds often have a unique chemical reactivity [1]. A case in point is given by 3-trifloxypropene iminium triflates which are obtained by O-sulfonylation of enaminones with Tf2O [2, 3] and which are suited for transformat...

Catalytic enantioselective desymmetrization of meso-2-substituted glycerols has been developed to secure a novel synthetic route to chiral tertiary alcohols. The transformation has been realized by monobenzoylation using benzoyl chloride and triethylamine in the presence of the imine ligand (25)-CuCl2 complex in THF at ambient temperature. The desymmetrization turned out to be greatly dependent...

We present a method that allows simultaneous fusion and cloning of multiple PCR products in a rapid and efficient manner. The procedure is based on the use of PCR primers that contain a single deoxyuridine residue near their 5' end. Treatment of the PCR products with a commercial deoxyuridine-excision reagent generates long 3' overhangs designed to specifically complement each other. The combin...

A two-step method for assaying creatinine in serum and urine samples, suitable with automated analyzers, is reported. Reagent 1, for the first step, contains a blanking system [creatine amidinohydrolase (CRTase), urease, glutamate dehydrogenase, NADPH, and 2-oxoglutarate] and a NADPH-regenerating system [Mg(2+)-dependent isocitrate dehydrogenase (ICD), MgCl2, and excess isocitrate]. Reagent 2, ...

Vol.31, No. 3, 1985 sorption spectrometry (AA) gave the following results: for serum, RA-1000 = 1.09 + 0.918 AA (S = 0.59 mg/L, r = 0.98); for urine, RA-1000 = -6.92 + 1.05 .AA (S = 1.34 rng/L, r = 0.99). This convenient arrangement stablizes the alkaline reagent by eliminating the possibility of carbon dioxide being absorbed from the atmosphere. Carbon dioxide absorption not only reduces the p...

A dithiane derivative of BODIPY is synthesized. This new reagent could be used for the specific and instantaneous detection of Hg(2+) in physiological condition. This dithiane reagent reacts specifically with Hg(2+) to regenerate the parent BODIPY-aldehyde with consequential change in visually detectable optical responses and this provides the possibility of using this reagent as a colorimetric...

A nuclear antigen associated with cell proliferation (proliferating cell nuclear antigen [PCNA]) and blast transformation is recognized by autoantibodies in the sera of some patients with systemic lupus erythematosus. Using this autoantibody as a reagent, PCNA was purified 120-fold by ammonium sulfate fractionation, DEAE chromatography, and Sephadex G200 gel filtration. The antigenicity of PCNA...