Thyroxine methyl ester

Primary or secondary aliphatic amines in aqueous or methanolic solution may replace the ammonia, for these do not form explosive iodo derivatives.468,469 This method can be recommended for preparative purposes and has proved very valuable in the preparation of thyroxine from 3,5-diiodo-thyronine in 20% aqueous ethylamine (KI3), of thyroxine methyl ester from 3,5-diiodothyronine methyl ester in 1 2 butylamine-methanol (I2)4 9 and of 3,5-diiodotyrosine in 20% aqueous ethylamine (Nal3),470 as well as in iodination... 

A 3-maleimidobenzoyl derivative of L-thyroxine methyl ester has also been coupled to jS-D-galactosidase and used in an enzyme immunoassay of L-thyroxine. The procedures for the conjugation of rabbit immunoglobulin G and Fab antibodies with 3-D-galactosidase using AA -2-phenylene-dimaleimide have been improved by altering the reaction conditions. ... 

Serum thyroxine has been precisely measured by selected ion monitoring as its methyl ester-N,0-bis(tri-fiuoroacetyl) [119, 120] and methyl ester-KO-bis(hepta-fluorobutyryl) derivatives [121] in connection with the application of isotope dilution GC-MS as a reference method to control the results obtained from less specific immunoassay methods. The fragment ions monitored are in the higher mass range of around 800 amu, with little interference. 

A NOVEL CHEMILUMINESCENT IMMUNOASSAY OF TOTAL THYROXINE USING THE ACRIDINIUM ESTER 2 ,6,-DIMETHYL-4 -(N-SUCCINIMIDYLOXYCARBONYL) PHENYL-10-METHYL-ACRIDINIUM -9-CARBOXYLATE METHOSULFATE AS LABEL... 

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