Hydrazine-Aldehyde Reagent Pairs

Glass slide containing Biotin-modified slide via 

The hydrazine-aldehyde reaction has been used intracellularly to deliver non-toxic drug components, which when linked to form a hydrazone bond in situ, become cytotoxic (Rideout, 1986, 1994 Rideout et al., 1990). This same approach has been used to generate enzyme inhibitors in vivo, wherein the hydrazine and aldehyde precursors are not active, but when coupled together within cells to form a hydrazone linkage, become active site binders (Rotenberg etal, 1991). 

The hydrazinium nicotinate group on these reagents commonly is protected against reaction with the active ester by the addition of acetone to form the acetone hydrazone derivative. This hydrazone protective group is readily reversible at neutral or mildly acidic pH and will immediately exchange with a benzaldehyde on the corresponding chemoselective partner to form a stable hydrazone linkage. 

The aromatic nature of the SFB and SANH reactants create a hydrazone structure with unique absorptivity for monitoring the course of the ligation process. The aromatic hydra-zone bond has a maximal absorbance at 354nm and a molar extinction coefficient equal to 

Solulink pairs used to modify macromolecuie pairs separately 

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