Photolabeling of human serum albumin by 4-azido-2-([14C]-methylamino) trifluorobenzonitrile. A high-efficiency, long wavelength photolabel

Chemistry of Bifunctional Photoprobes

“…The NH inserted product 3 was isolated using hexane, ethyl acetate, and methanol taken in the ratio 9 : 1 : 1, respectively, as an eluent. 19 …”

“…Again, photochemical reaction was monitored by 19 F NMR until the 19 F NMR signals assigned to the photoprobe disappeared. The reaction mixture was diluted with water, extracted into chloroform, dried using MgSO 4 , and the NH insertion product was separated from other photoproducts by flash chromatography as described above.…”

“…The reaction mixture was diluted with water, extracted into chloroform, dried using MgSO 4 , and the NH insertion product was separated from other photoproducts by flash chromatography as described above. 19 14 …”

“…Positions which can be modified without significantly decreasing the inhibitor binding can be subsequently derivatized with bifunctional chelating agents to carry radiometals or photoaffinity probes. The modifications described here, carried out with derivatives of perfluoroarylazides, extend the potential for covalent incorporation of heterobifunctional radioimaging agents, developed in our laboratory (15)(16)(17)(18)(19)(20), to lisinopril. The same modification procedure can be used for preparation of photoaffinity labeling probes which are useful for mapping the binding sites of enzymes and receptors (21 ).…”

“…The 31 P NMR chemical shifts are reported with respect to 85% H 3 PO 4 as an external standard and positive shifts lie downfield from the standard. 19 F NMR chemical shifts are reported with respect to CFCl 3 as an external standard. Infrared spectra were recorded as KBr pellets on a Nicolet 20DXB FT-IR spectrophotometer.…”