Evaluation of a new measurement method of indoxyl sulfate in hemodialysis patients.

Indoxyl sulfate (IS) is related to the development of cardiovascular disease and total mortality in dialysis patients. High-performance liquid chromatography (HPLC) is the conventional measurement approach. However, the HPLC method is difficult to perform in real time. Recently, the IS Assay Kit "NIPRO", which enables the measuring of total IS by the enzyme method, was developed. This new reagent allows the easy and quick measurement of many samples using the automatic biochemical analyzer. Moreover, it was reported that it demonstrated satisfactory analytical performance. If this enzyme method is useful for measuring IS in hemodialysis, we can expect that the mechanism in which the IS effects adversely on a body as uremic toxins will be clarified. However, the enzyme method is more easily influenced by other coexisting substances. In this study, we have assessed on how the uremic toxins and anticoagulation effect on this new reagent and evaluate whether it can be put into practice effectively for hemodialysis patients. For the enzyme method, accuracy, simultaneous repeatability, linearity, limit of detection, influence of coexisting materials, and correlation with the HPLC method were examined. Accuracy and simultaneous repeatability were satisfactory, and linearity was good. The limit of detection was acceptable, and there was no influence of coexisting materials. With regard to the correlation, the regression equation was y = 0.947X + 7.987 and the correlation coefficient (r) was 0.972. This new reagent showed sufficient fundamental performance and had a good correlation with the conventional HPLC method for assessing the plasma of dialysis patients.

Zinc-Catalyzed Synthesis of Acylsilanes Using Carboxylic Acids and a Silylborane in the Presence of Pivalic Anhydride.

Zinc-catalyzed synthesis of acylsilanes using carboxylic acids and a silylborane has been achieved in the presence of pivalic anhydride. Various carboxylic acids were converted to the corresponding acylsilanes. The in situ formation of mixed anhydrides was essential in the present reaction.

Palladium-catalyzed formal arylacylation of allenes employing acid chlorides and arylboronic acids.

Palladium-catalyzed formal arylacylation of allenes using acid chlorides and arylboronic acids has been achieved. The reaction afforded the corresponding α,ß-unsaturated ketones regio- and stereoselectively.

Palladium-catalyzed formal hydroacylation of allenes employing acid chlorides and hydrosilanes.

The palladium-catalyzed formal hydroacylation of allenes employing acid chlorides and hydrosilanes has been achieved. The reactions proceed with commercially available Pd(OAc)2 as a catalyst and HSi(iPr)3 as a reducing reagent, giving the corresponding α,ß-unsaturated ketones regio- and stereoselectively.