Carbamic acid, N-(2-butyl-2,3-dihydro-1,3-dioxo-1H-benz[de]isoquinolin-6-yl)-, 1,2-dithiolan-4-yl ester

TRFS-green is a highly selective off−on fluorescent probe for imaging thioredoxin reductase (TrxR) in living cells. TRFS-green has the maximum absorbance at around 373 nm[1].

Research Areas >> Others

Signaling Pathways >> Others >> Others

TRFS-green itself emits at ∼480 nm when excited at 377 nm[1]. TRFS-green displays a green fluorescence off−on change induced by the TrxR-mediated disulfide cleavage and subsequent intramolecular cyclization to liberate the masked naphthalimide fluorophore[1]. The fluorescence signal of TRFS-green in living cells was inhibited by pretreating the cells with TrxR inhibitor in a dose-dependent manner, potentiating the development of living cell-based screening assay for identifying TrxR inhibitors[1]. After incubating the cells with TRFS-green (10 μM) for 4 h, the bright green fluorescence appears[1]. TRFS-green shows no response to GSH or Cys, the predominant thiols in cells, or the endogenous reducing agents, such as vitamin C and NADPH[1]. TRFS-green is the first fluorescent probe of TrxR with a green emission. However, the response rate of TRFS-green to the enzyme is slow, and it takes more than 2 h to reach the maximal fluorescence signal even using tris(2-carboxyethyl)phosphine (TCEP) as a reducing agent[2].

[1]. Liangwei Zhang, et al. Highly selective off-on fluorescent probe for imaging thioredoxin reductase in living cells. J Am Chem Soc. 2014 Jan 8;136(1):226-33.

[2]. Xinming Li, et al. A fast and specific fluorescent probe for thioredoxin reductase that works via disulphide bond cleavage. Nat Commun. 2019 Jun 21;10(1):2745.