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Targeting redox vulnerability of cancer cells by pro-oxidants capable of generating reactive oxygen species (ROS) has surfaced as an important anticancer strategy. Due to the intrinsic narrow therapeutic window and other dangerous side effects of ROS generation, it is highly needed and challenging to develop pro-oxidative anticancer agents (PAAs) with high selectivity for generating ROS in cancer cells. Herein we report a hydrogen peroxide (H 2 O 2)-activated Cu(II) pro-ionophore strategy to develop naphthazarin (Nap) as such type of PAAs based on the H 2 O 2 -mediated conversion of boronate to free phenol. The boronate-protected Nap (PNap) can exploit increased levels of H 2 O 2 in HepG2 cells to in situ release Nap followed by its efflux via conjugation with reduced glutathione (GSH), allowing that the Nap-GSH adduct works as a Cu(II) ionophore to induce continuously GSH depletion via a reduction-dependent releasing of Cu(I) by GSH. This strategy endows PNap with the unprecedented ability to hit multi-redox characteristics (increased levels of H 2 O 2 , GSH and copper) of HepG2 cells, leading to ROS generation preferentially in HepG2 cells along with their selective death. Image 1 • A H 2 O 2 -activated Cu(II) pro-ionophore strategy was first used for developing pro-oxidative anticancer agent. • The protected naphthazarin (PNap) can be selectively activated by H 2 O 2 in HepG2 cells. • The strategy allows PNap with the ability to hit multi-redox characteristics of HepG2 cells. • PNap plus Cu(II) induced selective ROS generation in HepG2 cells. • Mechanisms by which PNap plus Cu(II) killed HepG2 cells selectively were described. [ABSTRACT FROM AUTHOR]

Developing concise theranostic prodrugs is highly desirable for personalized and precision cancer therapy. Herein we used the glutathione (GSH)-mediated conversion of 2,4-dinitrobenzenesulfonates to phenols to protect a catechol moiety and developed stable pro-catechol-type diphenylpolyenes as small molecule-based prooxidative anticancer theranostic prodrugs. These molecules were synthesized via a modular route allowing creation of various pro-catechol-type diphenylpolyenes. As a typical representative, PDHH demonstrated three unique advantages: (1) capable of exploiting increased levels of GSH in cancer cells to in situ release a catechol moiety followed by its in situ oxidation to o -quinone, leading to preferential redox imbalance (including generation of H 2 O 2 and depletion of GSH) and final selective killing of cancer cells over normal cells, and is also superior to 5-fluorouracil and doxorubicin, the widely used chemotherapy drugs, in terms of its ability to kill preferentially human colon cancer SW620 cells (IC 50 = 4.3 μM) over human normal liver L02 cells (IC 50 = 42.3 μM) with a favourable in vitro selectivity index of 9.8; (2) permitting a turn-on fluorescent monitoring for its release, targeting mitochondria and therapeutic efficacy without the need of introducing additional fluorophores after its activation by GSH in cancer cells; (3) efficiently targeting mitochondria without the need of introducing additional mitochondria-directed groups. Image 1 • Using the GSH-mediated conversion of DNBS to phenols to protect a catechol moiety. • Designing GSH-activated PDHH as a concise theranostic prodrug. • Monitoring for its release, targeting and therapeutic efficacy by a turn-on fluorescent. • Identifying PDHH as a potent prooxidative anticancer prodrug. • Identifying the diphenylpolyene skeletons as mitochondria-directed groups. [ABSTRACT FROM AUTHOR]

Four novel compounds were designed by 'tailoring' 3,3′-dihydroxyisorenieratene (a natural carotenoid) based on an isoprene unit retention truncation strategy. Among them, the smallest molecule 1 (2,3,6,2′,3′,6′-hexamethyl-4,4′-dihydroxy-trans-stilbene) was concisely synthesized in a one-pot Stille-Heck tandem sequence, and surfaced as a promising lead molecule in terms of its selective antiproliferative activity mediated by blocking the NCI-H460 cell cycle in G1 phase. Additionally, theoretical calculations and cell uptake experiments indicate that the unique polymethylation pattern of compound 1 significantly induces a conformational change shift out of planarity and increases its cell uptake and metabolic stability. The observation should be helpful to rationally design resveratrol-inspired antiproliferative agents. [ABSTRACT FROM AUTHOR]

The new and efficient catalyst system can be easily recovered and reused ten times without significant loss of activity. [ABSTRACT FROM AUTHOR]

Thioredoxin reductase (TrxR) is a pivotal antioxidant enzyme, but there remains a challenge for its fast imaging. This work describes the combination of a hydroxyl styrylpyridinium scaffold as the push-pull fluorophore with a carbonate-bridged 1,2-dithiolane unit as the reaction site to develop a fast mitochondrial TrxR2 probe, DSMP . It manifested a plethora of excellent properties including a rapid specific response (12 min), large Stokes shift (170 nm), ratiometric two-photon imaging, favorable binding with TrxR ( K m = 12.5 ± 0.2 μM), and the ability to cross the blood-brain barrier. With the aid of DSMP , we visualized the increased mitochondrial TrxR2 activity in cancer cells compared to normal cells. This offers the direct imaging evidence of the connection between the increased TrxR2 activity and the development of cancer. Additionally, the probe allowed the visualization of the loss in TrxR2 activity in a cellular Parkinson's disease model and, more importantly, in mouse brain tissues of a middle cerebral artery occlusion model for ischemic stroke.

Four novel compounds were designed by "tailoring" 3,3'-dihydroxyisorenieratene (a natural carotenoid) based on an isoprene unit retention truncation strategy. Among them, the smallest molecule 1 (2,3,6,2',3',6'-hexamethyl-4,4'-dihydroxy-trans-stilbene) was concisely synthesized in a one-pot Stille-Heck tandem sequence, and surfaced as a promising lead molecule in terms of its selective antiproliferative activity mediated by blocking the NCI-H460 cell cycle in G1 phase. Additionally, theoretical calculations and cell uptake experiments indicate that the unique polymethylation pattern of compound 1 significantly induces a conformational change shift out of planarity and increases its cell uptake and metabolic stability. The observation should be helpful to rationally design resveratrol-inspired antiproliferative agents., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)