Tannous R,
Shelef O,
Gutkin S,
David M,
Leirikh T,
Ge L,
Jaber Q,
Zhou Q,
Ma P,
Fridman M,
Spitz U,
Houk KN,
*,
Shabat D.
*
University of California, Los Angeles, USA and Tel-Aviv University, Israel
Spirostrain-Accelerated Chemiexcitation of Dioxetanes Yields Unprecedented Detection
Sensitivity in Chemiluminescence Bioassays.
ACS Cent. Sci. 2024;
10: 28-42
DOI:
10.1021/acscentsci.3c01141
Key words
chemical biology - chemiluminescence - dioxetanes - oxetanes - cyclobutanes - spirocycles
Significance
The design of chemical probes to track biological processes in cellular assays is
a critical research area with the speed of detection and sensitivity of such molecules
is key to accurately tracking enzymatic activity. Chemiluminescence is a phenomenon
that involves light produced from a chemical reaction and can be sub-divided into
‘stable glow-type’ that produces a stable long light emission profile with low intensity
and ‘fast flash-type’, which occurs rapidly with a high intensity signal. The current
report describes the synthesis and evaluation of a series of substituted phenoxy-1,2-dioxetanes
as chemiluminescent luminophores with the incorporation of a spiro-cyclobutyl substituent
shown to significantly accelerate chemiexcitation with an exponential increase in
both the detection time and sensitivity.
Comment
The chemiexcitation of these probes occurs through electron transfer from the phenoxide
to the dioxetane leading to both O–O and C–C cleavage that generates the excited benzoate
that emits visible light. The adamantly-phenoxy-1,2-dioxetane (9) is established as the benchmark for chemiluminescent cell imaging with the EWG incorporated
at the ortho position to prevent water-mediated quenching and increase light-emission intensity
(D. Shabat and co-workers ACS Cent. Sci.
2017, 3, 349). Spiro-strain-release was shown to accelerate the chemiexcitation rate (see
6, 12) with the cyclobutyl-based motif (6) utilized in a cellular assay for the detection of the enzyme β-gal and shown to
be 125-fold more sensitive than 9.
