Assay method and compounds
AssigneeBurroughs Wellcome Co.
InventorsRichard J. Miller, Kwen-Jen Chang, Pedro Cuatrecasas
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Abstract
The present invention provides an assay method for opioid activity comprising the steps of: (a) incubating together an opiate receptor material, a radio-iodinated structural analogue of leucine-enkephalin or methionine-enkephalin, and a liquid sample; (b) measuring the percentage inhibition of the binding of the radio-iodinated compound to the opiate receptor material; and (c) determining the opioid activity of the liquid sample using the percentage inhibition measurement. Also provided are a test kit of value in the performance of such assays, and novel compounds of use in such assays together with methods for their preparation.
Claims10
A compound of formula (I):
- H--X.sup.1 --X.sup.2 --X.sup.3 --X.sup.4 --(X.sup.5).sub.m --(X.sup.6).sub.n --OH (I)
- wherein
- X.sup.1 is selected from L-tyrosyl and N-alkyl-L-tyrosyl (wherein the alkyl has 1 to 4 carbon atoms) substituted in the phenol moiety at the 2-position or at both the 2- and 6-positions (with respect to the hydroxy group) with an iodine radioisotope;
- X.sup.2 is selected from glycyl and D-alanyl;
- X.sup.3 is selected from glycyl and L-alanyl;
- X.sup.4 is selected from L-phenylalanyl and L-4-chlorophenylalanyl;
- X.sup.5 is selected from L-leucyl, D-leucyl,, L-methionyl, D-methionyl, L-valyl, D-valyl, L-norleucyl, D-norleucyl, L-threonyl and D-threonyl;
- X.sup.6 is L-threonyl;
- and m and n are each selected from O and I, provided that when they are both O then X.sup.2 is D-alanyl;
- together with their salts, esters, amides and N-alkylamides wherein the alkyl has 1 to 4 carbon atoms.
A compound selected from
- H.X.sup.1.D--Ala.Gly.Phe.Leu.OH
- H.X.sup.1.D--Ala.Gly.Phe.Met.OH
- H.X.sup.1.D--Ala.Gly.Phe.D--Leu.OH
- together with their salts, wherein X.sup.1 is L-tyrosyl substituted in the phenol moiety at the 2-position or at both the 2- and 6-positions (with respect to the hydroxy group) with an iodine radioisotope.
H.Tyr(3-.sup.125 I).D--Ala.Gly.Phe.Leu.OH and salts thereof.
H.Tyr(3-.sup.125 I).D--Ala.Gly.Phe.Met.OH and salts thereof.
H.Tyr(3-.sup.125 I).D--Ala.Gly.Phe.D--Leu.OH and salts thereof.
Dependencies are inferred from the claim text.