Photoaffinity reagents synthesis

Aryl azides which were introduced as photoaffinity reagents by Fleet et al. (1969) are now the most commonly used photoactivatable reagents. By early 1976 there were almost one hundred examples of their use (Bayley and Knowles, 1977) and today it would be impracticable to list a complete bibliography. The ease of synthesis of aryl azides, and not their other desirable properties, is probably responsible for their great popularity. 

Photoaffinity reagents of low molecular weight can be made by total synthesis or by attaching photoactivatable groups to preexisting ligands. For macromolecules, such as polypeptides, only the latter strategy is feasible. 

Soundararajan, N., Liu, S.H., Soundararajan, S., and Platz, M.S. (1993) Synthesis and binding of new polyfluoninated aryl azides to a-chymotrypsin. New reagents for photoaffinity labeling. Bioconjugate Chem. 4, 256-261. 

Photochemical, heterobifunctional reagents for crosslinking and for the synthesis of photoaffinity labels... 

A stereoselective synthesis of aminoalkyl-substituted P-lactams (41) has been developed, the key step of which is [2+2] cycloaddition of imines to ketenes generated photochemically from diazoketones (42), which are derived from protected a-amino acids. A number of steroidal diazoketones related to progesterone have been synthesized as potential photoaffinity labelling reagents for the mineralocorticoid receptor. ... 

Interest continues to be shown in the photodecomposition of diazonium salts,and aryldiazonium tetrafluoroborates have been recommended as potential photoaffinity labelling reagents for proteins.The key step in a recent synthesis of pyrazofurin involves the photodecomposition of the diazopyrazole (158) to give the hydroxypyrazole (159). ° 2-Azahypoxanthine (160) is the major... 

Reagents. Modified and unmodified antibiotics employed in reported affinity labeling studies are listed in Table IV. " The synthesis of additional derivatives of chloramphenicol of potential use in photoaffinity labeling has been described. Interestingly, the list includes two unmodified antibiotics chloramphenicol and puromycin. These two as well as reagents e and i react with the ribosome photolytically. 

A review on chemical reagents in photoaffinity labelling has reviewed die role of diazirino- ( azi- ) sugar derivatives. Disodium 3 -azibutyl a-D-mannopyranoside 6-phosphate and tetrasodium 2-azi-l,10-bis-(a-D-mannopyranosyloxy 6-phos-phate)-decane have been synthesis as photoaffinity probes for binding to mannose-6-phosphate receptors. ... 

M. Dias, R. Momet, M. Laloue, Synthesis, azido-tetrazole equihbrium studies and biological activity of l-(2-azido-6-chloropyrid-4-yl)-3-phenylimea, a photoaffinity labeling reagent for cytokinin-binding proteins, Bioorg. Med Chem., 1995, 5,361-366. 

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