Oligosaccharide-protein conjugates
Provided herein are conjugates comprising a protein and an oligosaccharide of one of Formulae I-VI. Also provided herein are pharmaceutical compositions comprising such conjugates. Further provided herein are methods of treating a lysosomal storage disorder in a mammal by administration of an oligosaccharide-glycoprotein conjugate.
1. A method of preparing a compound having the Formula VII:
wherein:
R 1 is chosen from hydrogen, hydroxyl, optionally substituted lower alkyl, phosphate, sulfate, —OR 7 , a protecting group, and a saccharide;
R 2 , R 3 , R 4 , and R 5 are each independently chosen from hydrogen, sulfate, hydroxyl, —OR 8 , a protecting group and a saccharide;
R 6 is an alkoxycarbonyl;
R 7 and R 8 are each independently chosen from acetyl and optionally substituted lower alkyl; and
n is an integer from 2 to 4; comprising:
a) treating a compound having the Formula VIII:
wherein:
R 1 through R 5 are as defined above; and
R 9 and R 10 are chosen from hydrogen and hydroxyl, such that when one of R 9 and R 10 is hydroxyl, the other is hydrogen; with a compound having the Formula R 11 R 12 (Sn═O) to form a compound having the Formula IX:
wherein:
R 1 through R 5 are as defined above; and
R 11 and R 12 are each independently chosen from unsubstituted alkyl, or R 11 and R 12 , taken together, are chosen from unsubstituted alkylene; and
b) treating the compound of Formula IX, optionally in the presence of a metal fluoride, with a compound having the Formula R 6 —(CH 2 ) n -L,
wherein:
R 6 and n are as defined above; and
L is a halogen; to form the compound of Formula VII.
2. The method of claim 1 , wherein the compound of Formula R 6 —(CH 2 ) n -L is methyl 4-bromobutyrate.
3. The method of claim 2 , wherein the compound of Formula VIII is selected from optionally protected mannose, rhamnose, idose, talose and altrose.
4. The method of claim 3 , wherein the compound of Formula VIII is optionally protected mannose.
5. The method of claim 1 , wherein the metal fluoride is selected from cesium fluoride, sodium fluoride, calcium fluoride, magnesium fluoride, lithium fluoride, and potassium fluoride.
6. The method of claim 1 , wherein step b further comprises reacting the compound of Formula IX in the presence of a tetraalkylammonium halide.
7. The method of claim 6 , wherein the tetraalkylammonium halide is tetrabutylammonium iodide.
8. The method of claim 1 , wherein R 11 and R 12 are each butyl, R 11 and R 12 are each hexyl, or R 11 and R 12 , taken together, form hexamethylene.
9. The method of claim 1 , wherein the compound of Formula VIII is optionally protected mannose, and the compound of Formula R 6 —(CH 2 ) n -L is methyl 4-bromobutyrate.
10. The method of claim 9 , wherein the compound of Formula VIII is selected from 3,4,6-tri-O-benzyl-α-D-mannose and 3-O-allyl-6-O-trityl-α-D-mannose.
11. The method of claim 10 , wherein the compound of Formula VIII is and 3-O-allyl-6-O-trityl-α-D-mannose.
12. The method of claim 11 , further comprising treating the compound of Formula VII with at least one optionally protected monosaccharide to form an oligosaccharide.
13. The method of claim 12 , wherein the oligosaccharide is a hexasaccharide.
14. The method of claim 13 , wherein the hexasaccharide is
15. The method of claim 14 , further comprising attaching an aminoxy linker to the hexasaccharide through the methylbutyrate.