Patent ID: 7695930

Claim:
A method for at least one of the detection, identification and quantification of microorganisms expressing at least one peptidase activity, comprising incorporating a chromogenic enzymatic substrate corresponding to formula (I) below, within a reaction medium: in which R 1 and R 2 form, with the phenyl ring to which they are attached, a naphthalene ring of formula: or an optionally substituted coumarin ring of formula: or R 1 and R 2 each independently represent a hydrogen atom, a C 1 -C 6 alkyl group, a halogen atom, a —C(O)OR′ group, a C(O)NR′R″ group, an —SO 3 H group or a sulfonamide group, R 3 and R 4 form, with the phenyl ring to which they are attached, an optionally substituted naphthalene ring of formula: or R 3 and R 4 each independently represent a hydrogen atom, a halogen atom, a —C(O)OR′ group, a C(O)NR′R″ group, an —SO 3 H group or a sulfonamide group, it being understood that: (i) R 1 and R 2 and/or R 3 and R 4 form, with the phenyl ring to which they are attached, an optionally substituted naphthalene or coumarin ring as defined above, and (ii) when R 1 and R 2 form, with the phenyl ring to which they are attached, an optionally substituted coumarin ring, R 3 and R 4 do not form, with the phenyl ring to which they are attached, an optionally substituted naphthalene ring, R 5 and R 6 each independently represent a hydrogen atom, a halogen atom, a —C(O)OR′ group, a C(O)NR′R″ group, or a C 1 -C 6 alkyl group, it being understood that R 6 represents a halogen atom when R 1 and R 2 and R 3 and R 4 each form, with the phenyl ring to which they are attached, a naphthalene ring, R 7 and R 8 each independently represent a hydrogen atom, a C 1 -C 6 alkyl group, an aralkyl group, an aryl group, a carboxyalkyl group, a carboxyl group or a sulfonic acid group, or R 7 and R 8 , together with the two carbon atoms to which they are attached, form a C 4 -C 6 ring, R 9 represents a hydrogen atom, a bromine atom, a chlorine atom, a benzoyl group, a —CO 2 H group or an —SO 3 H group, it being understood that, when R 9 is different from a hydrogen atom, then R 5 is a hydrogen atom, R′ represents a hydrogen atom or a C 1 -C 6 alkyl group, R″ represents a hydrogen atom or a C 1 -C 6 alkyl group, or R′ and R″, together with the nitrogen atom to which they are attached, form a heterocyclic ring containing one or more hetero atoms, A represents at least one amino acid, and X represents a blocking agent or is not present.