As an antimalarial agent, artemisinin is well-known for its endoperoxide moiety, which is activated by the cellular iron.
Recent research efforts have focused on the development of the systems composed of two, separated or linked, molecular components, in which the photorelease occurs from the moiety that is indirectly activated by energy transfer from or electron transfer from/to the excited auxiliary chromophore (photosensitizer).
Platelets can sense other forms of danger, in particular those that are infectious in nature as they express numerous specialized (TLRs) and less specialized but highly functional receptors (FCR for Igs/antibodies and complement factor receptors). Platelets can be activated by infectious pathogen moieties and by immune complexes formed around infectious pathogens.
We have hypothesized that a hybrid ester prodrug (see Figure 1) containing the QM generating moiety that is selectively hydrolyzed and activated by oxidized protein hydrolase (OPH) will deplete intracellular GSH (see Figure 2) and promote oxidative stress induced apoptosis in cancer cells by a mechanism similar to that of NO-ASA, i.e., release of a QM depleting intermediate [ 23].
The principle of this kit is that the recombinant Factor C is activated by endotoxin binding, and the active moiety created then acts to cleave a synthetic substrate resulting in the generation of a fluorogenic compound.
This was used in combination with a benzoic acid mustard prodrug, CMDA, which is activated by cleavage of its glutamate moiety (Bagshawe et al, 1995; Napier et al, 2000).
Akt is recruited to the membrane by binding to phosphatidylinositol 3,4,5-phosphate moieties generated by PI3K, and, once recruited, it is activated by phosphorylation at Thr308 and Ser473.
UTX-12 consists of a p-nitro benzyl moiety, which is a latent hypoxia-selective leaving group activated by nitro reduction, directly linked to SNARF.
Twenty-three percent of prodrugs are activated by biotransformation, meaning there is no pro-moiety.
Because common fluorescent reagents for thiol labeling are typically activated by nucleophilic attack of the thiol on an electrophilic moiety of the probe reagent, we reasoned that H2S, which is a more potent nucleophile, could potentially react with and activate common thiol detection reagents.
