Fluorogenic/fluorescent probes derivative from sulfoxanthene, and use thereof

A method for detecting an enzyme activity of a microorganisms selected from the group consisting of nitroreductase, azoreductase, peptidase, glycosidase, esterase and myeloperoxidase activities, comprising the following steps:

• a) providing a reaction medium comprising at least one fluorogenic substrate of formula (I) or (II):
• wherein qu. is a fluorescence quencher group selected from the group consisting of:
• —NO2;
• —N═N—R1;
• R1 being any organic group that does not obscure the corresponding azo bond;
• —NHCO-Pept.;
• Pept. being a peptide residue or any organic group that does not obscure the corresponding amide bond;
• —O-Glyc.;
• Glyc. being an oligoglycoside residue that does not obscure the corresponding glycosidic bond;
• —O—C(O)—R2;
• —O—P(O)(OR2)(OR2′) and —O—S(O)2—R2;
• R2 and R2′ being independently a hydrogen atom or any organic group that does not obscure the corresponding ester bond;
• and
• Ra, Rb, Rc, Rd and Re being independently a hydrogen atom or any organic group that does not obscure the corresponding arylether bond;
• in accordance with the enzyme activity to detect,
• b) inoculating the reaction medium with a biological sample to be tested,
• c) incubating inoculated medium, and
• d) detecting whether there is an appearance or increase of an orange, far-red or near infra-red fluorescence.

A method for detecting an enzymatic activity of a microorganism selected from the group consisting of nitroreductase, azoreductase, peptidase, glycosidase, esterase and myeloperoxidase activities, the method comprising:

• detecting formation of a fluorescent reporter molecule of formula I′ or II′ as a result of a fluorogenic substrate of formula I or II being subjected to the enzymatic activity of the microorganism:
• wherein qu. is a fluorescence quencher group selected from the group consisting of:
• —NO2;
• —N═N—R1;
• R1 being any organic group that does not obscure the corresponding azo bond;
• —NHCO-Pept.;
• Pept. being a peptide residue or any organic group that does not obscure the corresponding amide bond;
• —O-Glyc.;
• Glyc. being an oligoglycoside residue that does not obscure the corresponding glycosidic bond;
• —O—C(O)—R2;
• —O—P(O)(OR2)(OR2′) and —O—S(O)2—R2;
• R2 and R2′ being independently a hydrogen atom or any organic group that does not obscure the corresponding ester bond;
• and
• Ra, Rb, Rc, Rd and Re being independently a hydrogen atom or any organic group that does not obscure the corresponding arylether bond.