Oligosaccharide analytical standards

1. A compound having the formula:

or a salt thereof, wherein

R MG2 is H or has the structure:

wherein R 5 is N 3 or NR 5a R 5b , wherein R 5a and R 5b are the same or different, and are H or Z—X 5 wherein Z is null, C═O, or SO 2 , and X 5 is C 1-4 alkyl, O—C 1-4 alkyl, C 1-4 haloalkyl, 0-C 1-4 haloalkyl, C 1-4 alkylaryl, O—C 1-4 alkylaryl, aryl, or O-aryl; or R 5a and R 5b can together form a ring; or R 5 is a radical having the formula:

wherein one or both of R 5c or R 5d constitute a conjugated payload;

R MG3 is H or has the structure:

wherein R 11 is N 3 , or NR 11a R 11b , wherein R 11a and R 11b are the same or different, and are H or Z—X 11 wherein Z is null, C═O, or SO 2 , and X 11 is C 1-4 alkyl, O—C 1-4 alkyl, C 1-4 haloalkyl, O—C 1-4 haloalkyl, C 1-4 alkylaryl, O—C 1-4 alkylaryl, aryl, O-aryl; or R 11a and R 11b can together form a ring; or R 11 can be a radical having the formula:

wherein one or both of R 11c or R 11d constitute a conjugated payload;

R MG4 is H or has the structure:

wherein R 9 is N 3 , or NR 9a R 9b , wherein R 9a and R 9b are the same or different, and are H or Z—X 9 wherein Z is null, C═O, or SO 2 , and X 9 is C 1-4 alkyl, O—C 1-4 alkyl, C 1-4 haloalkyl, O—C 1-4 haloalkyl, C 1-4 alkylaryl, O—C 1-4 alkylaryl, aryl, O-aryl; or R 9a and R 9b can together form a ring; or R 9 can be a radical having the formula:

wherein one or both of R 9c or R 9d constitute a conjugated payload;

R MG5 is H or has the structure:

wherein R 10 is N 3 or NR 10a R 10b , wherein R 10a and R 10b are the same or different, and are H or Z—X 10 wherein Z is null, C═O, or SO 2 , and X 10 is C 1-4 alkyl, O—C 1-4 alkyl, C 1-4 haloalkyl, O—C 1-4 haloalkyl, C 1-4 alkylaryl, O—C 1-4 alkylaryl, aryl, or O-aryl; or R 10a and R 10b can together form a ring; or R 10 can be a radical having the formula:

wherein one or both of R 10c or R 10d constitute a conjugated payload;

R 12 is hydrogen or a residue having the formula:

wherein R 13 is hydrogen or a residue having the formula:

wherein R 13b is selected from H and a conjugated cargo moiety, and R 13a is selected from OH and a conjugated cargo moiety;

R 14 is hydrogen or a residue having the formula:

wherein R 14b is selected from H and a conjugated cargo moiety, and R 14a is selected from OH and a conjugated cargo moiety;

R 1 is OH, or a residue having the formula:

R oz is H, C 1-4 alkyl, aryl, CF 3 , or CCl 3 ,

n is 1 or 0;

R fa is H or a fucose residue having the structure:

R 2 is OR c , NR 2n OR c , or NR 2n R c ; and R 3 is OR c or R c ;

wherein:

R 2n is H or C 1-4 alkyl;

R c is X p H, X p C 1-8 alkyl, X p C 1-8 alkylaryl, X p aryl, X p fluorescent marker, or an amino acid residue having the formula:

wherein R aa1 and R aa2 are selected from H, protecting group and additional amino acid residues;

R 3 is X p C 1-8 alkyl, X p C 1-8 alkylaryl, or X p aryl;

wherein X p is null or (CH 2 CH 2 O) z , wherein z is 1-500;

R 4 is N 3 , or NR 4a R 4b ,

wherein:

R 4a and R 4b are the same or different, and are H or Z—X 4 wherein Z is null, C═O, or SO 2 , and X 4 is C 1-4 alkyl, O—C 1-4 alkyl, C 1-4 haloalkyl, O—C 1-4 haloalkyl, C 1-4 alkylaryl, O—C 1-4 alkylaryl, aryl, or O-aryl; or R 4a and R 4b can together form a ring; or R 4 is a radical having the formula:

wherein one or both of R 4c or R 4d constitute a conjugated payload.

2. The compound according to claim 1 , wherein R 1 is a residue having the formula:

R c is an amino acid residue having the formula:

and

R aa1 and R aa2 are independently selected from H and Z a —X a wherein Z a is null, C═O, SO 2 , and X a can be C 1-4 alkyl, O—C 1-4 alkyl, C 1-4 haloalkyl, O—C 1-4 haloalkyl, C 1-4 alkylaryl, O—C 1-4 alkylaryl, aryl, or O-aryl.

3. The compound according to claim 2 , wherein R aa1 is Cbz (carboxybenzyl ether), and R aa2 is H.

4. The compound according to claim 1 , wherein R 1 has formula:

5. The compound according to claim 1 , wherein R 1 is a residue having the formula:

6. The compound according to claim 5 , wherein R 1 is a residue having the formula:

 wherein R c has the formula —(CH 2 ) nc R im , wherein nc is an integer from 1-8, and R im is —NH 2 , —SH, —OH, —COOH, —N 3 , C≡CH, a Michael acceptor, SO 3 , OSO 3 , or a biotin residue having the formula:

wherein X bt is selected from null, O, NH, or S.

7. The compound according to claim 5 , wherein R c is selected from coumarins, rhodamines, fluoresceins, cyanines, eosins, and erythrosins.

8. The compound according to claim 5 , wherein R c is a C 1-8 alkylaryl or aryl.

9. The compound according to claim 5 , wherein R c is a group having the formula:

wherein np is from 0-50, ns is from 2-7, and ns′ is from 2-5.

10. The compound according to claim 1 , wherein R MG2 , R MG3 , R MG4 and R MG5 are each hydrogen.

11. The compound according to claim 1 , having the formula:

12. The compound according to claim 11 , wherein the R 5 bearing residue is isotopically enriched.

13. A method for preparing an oligosaccharide, comprising the steps of glycosylating an oligosaccharide of Formula (1):

R 1 is OH or a residue having the formula:

R oz is H, C 1-4 alkyl, aryl, CF 3 , or CCl 3 ,

n is 1 or 0;

R fa is H or a fucose residue having the structure:

R 2 is OR c , NR 2n OR c , or NR 2n R c ; and R 3 is OR c or R c ;

wherein:

R 2 , is H or C 1-4 alkyl;

R c is X p H, X p C 1-8 alkyl, X p C 1-8 alkylaryl, X p aryl, X p fluorescent marker, or an amino acid residue having the formula:

wherein R aa1 and R aa2 are H, protecting group or additional amino acid residues;

R 3 is X p C 1-8 alkyl, X p C 1-8 alkylaryl, or X p aryl;

wherein X p is null or —(CH 2 CH 2 O) z —, wherein z is 1-500;

with a modified GlcNAc donor of Formula (2):

wherein R a is CX 3 , CHX 2 , CH 2 X, CH 3 , or OBn, wherein X is in each case independently selected from F, Cl, Br, and I,

in the presence of MGAT1, to give an oligosaccharide having the Formula (3):

wherein R 4 is NHC(O)R a .

14. The method according to claim 13 , further comprising converting R 4 to NH 2 or N 3 .

15. The method according to claim 14 , comprising the steps of glycosylating the oligosaccharide of Formula (3) with a modified GlcNAc donor of formula (2d):

wherein R a is CX 3 , CHX 2 , CH 2 X, CH 3 , or OBn, wherein X is in each case independently selected from F, Cl, Br, and I,

in the presence of MGAT, to give an oligosaccharide having the Formula (4):

wherein R 5 is NHC(O)R a and R 4 and R 5 are not the same.

16. The method according to claim 15 , comprising converting R 5 to NH 2 or N 3 .

17. The method according to claim 15 , wherein the modified GlcNAc donor of Formula (2d) is 13 C enriched.

18. A compound having the formula:

or a salt thereof,

wherein n is 1 or 0;

R a is N 3 , or NR 4a R 4b ,

wherein R 4a and R 4b are independently selected from H or Z—X 4 ,

wherein Z is null, C═O, or SO 2 , and X 4 is C 1-4 alkyl, O—C 1-4 alkyl, C 1-4 haloalkyl, O—C 1-4 haloalkyl, C 1-4 alkylaryl, O—C 1-4 alkylaryl, aryl, or O-aryl; or

R 4a and R 4b can together form a ring; or

R a is a radical having the formula:

wherein one or both of R 4c or R 4d constitute a conjugated payload;

R b is N 3 , or NR 4a R 4b ,

wherein R 4a and R 4b are independently selected from H or Z—X 4 ,

wherein Z is null, C═O, or SO 2 , and X 4 is C 1-4 alkyl, O—C 1-4 alkyl, C 1-4 haloalkyl, O—C 1-4 haloalkyl, C 1-4 alkylaryl, O—C 1-4 alkylaryl, aryl, or O-aryl; or

R 4a and R 4b can together form a ring; or R b is a radical having the formula:

wherein one or both of R 4c or R 4d constitute a conjugated payload;

provided that R a and R b are not both NHC(O)CH 3 ;

R is an asparagine;

R 1a is hydrogen or α-(L)-fucose, and

R 3 , R 2 , and R g1 are independently selected from hydrogen or additional carbohydrate.