Luciferin derivatives from bicyclic reactants and aminothiol derivatives and methods of use thereof

A method for detection of endogenous H2O2 and caspase 8 activity in a test subject, the method comprising:

• a) contacting the test subject with:
• i) a compound of Formula (Ia):
• wherein:
• Q1 is a heteroatom functional group selected from —O— and —NRQ1—;
• RQ1 is selected from hydrogen, alkyl, and substituted alkyl;
• PGIV is an aryl or heteroaryl boronic acid-containing protecting group for the heteroatom functional group;
• R1 is selected from hydrogen, halogen, hydroxyl, alkyl, substituted alkyl, alkoxy, amino, and substituted amino;
• and
• PGI is an optional protecting group for the cyano group;
• and
• ii) a compound of Formula VIa:
• wherein
• PGII is a protecting group for an amino group;
• PGII forms a masked amino group in which the masked amino group is a carbamate or an amide;
• PGIII is a protecting group for a thiol group;
• PGV is hydrogen or a protecting group for a carboxyl group;
• and
• L is C1-2 alkylene, C1-2 alkenylene, or C1-2 alkynylene;
• and
• b) monitoring the test subject for luminescence, wherein luminescence indicates the presence of endogenous H2O2 and caspase 8 activity.

A method for detection of endogenous H2O2 and caspase 8 activity in a test subject, the method comprising:

• a) contacting the test subject with:
• i) a compound of Formula (Ia):
• wherein:
• Q1 is a heteroatom functional group selected from —O— and —NRQ1—;
• RQ1 is selected from hydrogen, alkyl, and substituted alkyl;
• PGIV is an aryl or heteroaryl boronic acid-containing protecting group for the heteroatom functional group;
• R1 is selected from hydrogen, halogen, hydroxyl, alkyl, substituted alkyl, alkoxy, amino, and substituted amino;
• and
• PGI is a protecting group for the cyano group;
• and
• ii) a compound of Formula VIa:
• wherein
• PGII is a protecting group for an amino group;
• PGII forms a masked amino group in which the masked amino group is a carbamate or an amide;
• PGIII is hydrogen or a protecting group for a thiol group;
• PGV is hydrogen or a protecting group for a carboxyl group;
• and
• L is C1-2 alkylene, C1-2 alkenylene, or C1-2 alkynylene;
• and
• b) monitoring the test subject for luminescence, wherein luminescence indicates the presence of endogenous H2O2 and caspase 8 activity.