Rapid fluorescence tagging of glycans and other biomolecules with enhanced MS signals

A compound selected from one of the following structures:

• wherein
• m=0-9;
• n=0-9;
• X═C or N;
• R1 is S═C═N—,
• R2 is independently selected from methylene, substituted nitrogen, oxygen, carbonyl, amide, ester, sulfur, sulfoxide, or sulfone;
• R3 and R4 are independently selected from —H, alkyl, alkyl amino, alkylsulfonic acid, alkyl phosphonic acid, wherein R3 or R4 is alkylamino, alkyl phosphonic acid, or alkylsulfonic acid, and
• wherein R3 and R4 together with the nitrogen to which they are attached may form an optionally substituted 5- to 8-membered saturated or partially unsaturated ring;
• and
• R5 is independently selected from —H, —C1-C8 alkyl, —C1-C8 cycloalkyl, halo, dialkylamino, CH2-dialkylamino, aminocarbonyl, alkoxycarbonyl, or alkoxy.

A compound selected from one of the following structures:

• or a salt or solvate thereof, wherein
• X═C or N;
• R1 is independently selected from O═C═N—,
• R2 is independently selected from —H, —C1-C8 alkyl, —C1-C8 cycloalkyl, halo, dialkylamino, CH2-dialkylamino, aminocarbonyl, alkoxycarbonyl, or alkoxy, but not Cl or O═C═N—;
• and
• R3 and R4 together with the nitrogen to which they are attached form an optionally substituted 5- to 8-membered saturated or partially unsaturated ring, but not when R1 is O═C═N—.

A compound of the following structure:

• wherein
• X═C or N;
• R1 is independently selected from O═C═N—,
• R2 is independently selected from —H, —C1-C8 alkyl, —C1-C8 cycloalkyl, halo, dialkylamino, CH2-dialkylamino, aminocarbonyl, alkoxycarbonyl, or alkoxy, but not Cl or O═C═N—;
• and
• R3 and R4 together with the nitrogen to which they are attached form an optionally substituted 5- to 8-membered saturated or partially unsaturated ring, but not when R1 is O═C═N—.