Radio-iodinated tyrosine derivs. of oestradiol oxime cpds. - useful as reagents for radioimmunoassay of oestradiol

摘要

Oestradiol derivs. of formula (I) are new. (where R = tyrosine residue, tyrosine 1-6 C alkyl ester residue, radioiodinated tyrosine residue, or radioiodinated tyrosine 1-6 C alkyl residue). Cpds. (I) in which R is a radioiodinated tyrosine or tyrosine alkyl ester residue are useful as reagents for the radioimmunoassay of oestradiol; in a highly specific manner, they form complexes with oestradiol antibodies. Other cpds. (I) are useful as intermediates for the radio-iodinated cpds. A procedure for carrying out a radio-immunoassay with the new cpds. is described in the specification. Specific cpds. (I) include that in which R is a tyrosine methyl ester residue. In an example, this is prepd. by reacting 6-(carboxymthoxyimino)-oestradiol with isobutyl chlorocarbonate in dioxan in the presence of tributylamine and reacting the resulting mixed anhydride with L-tyrosine methyl ester. Reaction of the product with Na125I in the presence of chloramine T and hydrolysis with NAOH gives (I) in which R is a 125I-tyrosine residue.