Naofumi Sato

Synthesis and properties of new luminescent 10-carboxymethylacridinium derivatives

Abstract A novel method was developed to synthesize acridinium esters having a binding functional group at N-10. An acridine ester having steric hindrance is synthesized quickly, with excellent yields, using dimethylaminopyridine as a catalyst. Alkylation of the N-10 on the acridine ring proceeds using the trifluoromethanesulfonic acid ester under mild conditions. Deprotection of the benzyl ester using acid thus enables simple, high-yield synthesis for acridinium compounds with a binding functional group at N-10.

Competitive chemiluminescent immunoassay for estradiol using an N-functionalized acridinium ester.

We have compared three competitive chemiluminescent immunoassays (CLIA) for estradiol (E2) using an N-functionalized acridinium ester (AE). The assays were a standard competitive assay using immobilized antibody and directly labeled antigen (type A), an immobilized antibody and indirectly labeled antigen (type B), and an immobilized antigen and labeled antibody (type C). In an antibody-immobilized system, the assay using both AE- and E2-labeled thyroglobulin as a tracer (type B) was more sensitive than that using AE directly coupled with E2 (type A). Subsequently, a comparison of the antibody-immobilized system (type B) and an antigen-immobilized system (type C) showed that the latter was slightly more sensitive than the former. The sensitivity of the CLIA (type C) was similar or superior to commercially available CLIA or radioimmunoassays for E2. Thus, the N-functionalized AE proved to be a useful labeling reagent for a competitive CLIA with high sensitivity.

Synthesis and diuretic activity of 2,3-dihydro-4(1H)-quinolinone 4-oxime-O-sulfonic acid derivatives

Abstract The diuretic activity of 6-chloro-2,3-dihydro-1-propionyl-4(1H)-quinolinone 4-oxime 1 (M12285) was previously shown to derive from a 6-chloro-2,3-dihydro-1-propionyl-4(1H)-quinolinone 4-oxime-O-sulfonic acid salt as a rat metabolite. Thus, in the present study, the potassium salt 2 (M17000) was synthesized to unambiguously establish the structure as well as the stereochemistry of the oxime. The structural features of compounds 1 and 2 were compared with those of conventional diuretics by electrostatic potential maps. Using compound 2 as a lead compound, various quinolinone oxime sulfonic acid derivatives were synthesized and the diuretic activity for elucidation of the structure-activity relationships examined. Among the compounds synthesized, 7-chloro-2,3-dihydro-1-(2-methylbenzoyl)-4(1H)-quinolinone 4-oxime-O-sulfonic acid potassium salt 3 (M17055) showed a particularly high activity.

Chemiluminescent derivatization of adenyl compounds with glyoxal derivatives in the presence of heteropoly acids and its application to the simple and sensitive determination of DNA

A chemiluminescence (CL) determination of adenyl compounds is described. CL derivatization of adenyl compounds with methylglyoxal dimethyl acetal was performed in the presence of tungstosilicic acid and propan-2-ol. CL from adenyl compounds was produced by hydrogen peroxide and L-cysteine ethyl ester in DMF and water. The proposed method is highly sensitive and specific to compounds containing adenine. Adenine was determined in the range 1.0 x 10(-3)-5.0 x 10(-8) M with the detection limit of 3.0 x 10(-8) M (150 fmol per assay). The method was applied to the determination of DNA and detection limits of a few nanograms of DNA achieved.