Steroid derivatives and their use in radioimmunoassays
AssigneeE. R. Squibb & Sons, Inc.
InventorsJack Bernstein, Ravi K. Varma, B. Richard Vogt, Frank L. Weisenborn
Life of this patent
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Abstract
Radiolabeled steroid derivatives having the formula ##STR1## wherein St is a des-hydroxy steroid moiety of (i) a hydroxy steroid intended for radioimmunoassay or (ii) a hydroxy containing derivative of a steroid intended for radioimmunoassay, said derivative having a strong affinity for the antibodies of the steroid intended for radioimmunoassay; R is hydrogen or alkyl of 1 to 3 carbon atoms; n is 0, 1, 2, 3 or 4 and the asterisk (*) indicates tagging with a radioisotope, are useful as tracers in radioimmunoassays.
Claims20
A steroid having the formula ##STR9## wherein R is hydrogen or an alkyl group of 1 to 3 carbon atoms;
- n is 0, 1, 2, 3 or 4;
- and St is a des-hydroxy steroid moiety of (i) a hydroxy steroid intended for radioimmunoassay or (ii) a hydroxy containing derivative of a steroid intended for radioimmunoassay, said derivative having a strong affinity for the antibodies of the steroid intended for radioimmunoassay.
The steroid in accordance with claim 1, 21-[4-carboxy-3-(4-hydroxyphenyl)-1-oxobutoxy]-11.beta.,18-epoxy-18-hydrox ypregn-4-ene-3,20-dione.
The steroid in accordance with claim 1, 21-[4-carboxy-3-(4-hydroxyphenyl)-1-oxobutoxy]-11.beta.,17-dihydroxypregn- 4-ene-3,20-dione.
A steroid having the formula ##STR10## wherein R is hydrogen or alkyl having 1 to 3 carbon atoms;
- n is 0, 1, 2, 3 or 4;
- the asterisk (*) indicates labeling with iodine-125 or iodine-131;
- and St is a des-hydroxy steroid moiety of (i) a hydroxy steroid intended for radioimmunoassay or (ii) a hydroxy containing derivative of a steroid intended for radioimmunoassay, said derivative having a strong affinity for the antibodies of the steroid intended for radioimmunoassay.
A process for preparing a steroid derivative which can be readily labeled with a radioisotope and used as a tracer is a radioimmunoassay which comprises:
- (a) reacting a hydroxy steroid intended for radioimmunoassay or a hydroxy containing derivative of a steroid intended for radioimmunoassay, said derivative having a strong affinity for the antibodies of the steroid intended for radioimmunoassay, with a compound having the formula ##STR11## wherein R is hydrogen or an alkyl group having 1 to 3 carbon atoms;
- R.sub.1 is an alkanoyl group having 2 to 6 carbon atoms and n is 0, 1, 2, 3 or 4;
- and (b) saponifying the resultant steroid.
Dependencies are inferred from the claim text.