Patent ID: 7459284

Claim:
A chemiluminescent substrate of a hydrolytic enzyme, said substrate having the structure wherein P is PO 3 B or a sugar moiety, wherein B is a divalent cation selected from the group consisting of Ca and Mg or two monovalent cations selected from the group consisting of Na, H and K; M is oxygen; R 1 is an alkyl, alkenyl, alkynyl or aralkyl containing 0 to 20 heteroatoms; R 2a , R 2b , R 2c , R 2d , R 3a , R 3b , R 3c and R 3d can be the same or different and are selected from the group consisting of hydrogen, methyl, methoxy, halide and cyano (—CN); R 5 , R 7 , R 16 and R 17 can be the same or different and are selected from the group consisting of hydrogen, halides and —R, where R is an alkyl group having 1 to 6 carbon atoms; and A − is a counter ion for the electroneutrality of the quaternary nitrogen of the acridinium compound, said A − not being present if said R 1 substituent contains a strongly ionizable group that can form an anion and pair with the quaternary ammonium cationic moiety.