Rhodamine dyes and conjugates
The present invention relates generally to novel rhodamine dyes which upon conjugation with another molecule form single isomeric conjugation products. These novel rhodamine dyes contain only one single functional group on the rhodomine molecule for conjugation so that their conjugation products are single isomeric conjugation products.
1. A composition comprising a rhodamine dye or a salt thereof with the general structure of
wherein the rhodamine dye has a single functional group wherein the R1, R2, R3, R4 and R5 groups are independently selected as follows:
R5 is independently,
R4 is independently H,
R3 is independently H,
and R1 is H, and R2 is independently H or
wherein the Ar on the substituent is an aryl group, the R6 and/or R7 on the substituents form a spacer which contains a single functional group on either R6 or R7 suitable for conjugating with another molecule.
2. The composition of claim 1 wherein R1, R2, R3 and R4 are H, and R5 is —SO 2 NR 6 R 7 .
3. The composition of claim 1 wherein the other molecule is a macromolecule.
4. The composition of claim 3 wherein the macromolecule is selected from the group consisting of polymers, proteins, polysaccharides, polysaccharide derivatives, lipids and nucleic acids.
5. The composition of claim 4 wherein the protein is an antibody.
6. The composition of claim 4 wherein the nucleic acid is a DNA or an RNA.
7. The composition of claim 1 wherein the salt is selected from the group consisting of trifluoroacetate, chloride, hydrochloride, hydrobromide, hydroiodide, nitrate, sulfate, bisulfate, phosphate, acid phosphate, isonicotinate, acetate, lactate, salicylate, citrate, tartrate, pantothenate, bitartrate, ascorbate, succinate, maleate, gentisinate, fumarate, gluconate, glucuronate, saccharate, fortmate, benzoate, glutamate, methanesulfonate, ethanesulfonate, benzensulfonate and p-toluenesulfonate.
8. The composition of claim 1 wherein the salt is trifluoroacetate or chloride.
9. The composition of claim 1 wherein the salt is a pharmaceutically acceptable salt.
10. The composition of claim 1 wherein the spacer is selected from the group consisting of hydrogen, alkyl, aryl, amide, alkyl sulfonamide, alkyl ether and alkyl amide.
11. The composition of claim 10 wherein the alkyl groups have a carbon chain length of 1 to 20.
12. The composition of claim 1 wherein R1 and R2 are connected to form a cyclic structure.
13. The composition of claim 12 wherein the cyclic structure is
14. The composition of claim 1 undergoing a re-arrangement to form an isomer having the structure of
15. The composition of claim 14 wherein the rhodamine dye is a salt.
16. The composition of claim 15 wherein the salt is dichloride.
17. The composition of claim 14 wherein the rhodamine dye is capable of conjugating with another molecule via the amino functional group to form a single isomeric conjugation product.