Cyclometalated Gold(III)‐Hydride Complexes Exhibit Visible Light‐Induced Thiol Reactivity and Act as Potent Photo‐Activated Anti‐Cancer Agents

2020 ◽  
Vol 132 (27) ◽  
pp. 11139-11145
Author(s):  
Hejiang Luo ◽  
Bei Cao ◽  
Albert S. C. Chan ◽  
Raymond Wai‐Yin Sun ◽  
Taotao Zou
2020 ◽  
Vol 59 (27) ◽  
pp. 11046-11052 ◽  
Author(s):  
Hejiang Luo ◽  
Bei Cao ◽  
Albert S. C. Chan ◽  
Raymond Wai‐Yin Sun ◽  
Taotao Zou

2017 ◽  
Vol 93 ◽  
pp. 78-89 ◽  
Author(s):  
Faisal Mehmood ◽  
Javed Iqbal ◽  
Tariq Jan ◽  
Asma Gul ◽  
Qaisar Mansoor ◽  
...  

2019 ◽  
Vol 20 (6) ◽  
pp. 1464 ◽  
Author(s):  
Jochen Rutz ◽  
Sebastian Maxeiner ◽  
Eva Juengel ◽  
August Bernd ◽  
Stefan Kippenberger ◽  
...  

The anti-cancer properties of curcumin in vitro have been documented. However, its clinical use is limited due to rapid metabolization. Since irradiation of curcumin has been found to increase its anti-cancer effect on several tumor types, this investigation was designed to determine whether irradiation with visible light may enhance the anti-tumor effects of low-dosed curcumin on renal cell carcinoma (RCC) cell growth and proliferation. A498, Caki1, and KTCTL-26 cells were incubated with curcumin (0.1–0.4 µg/mL) and irradiated with 1.65 J/cm2 visible light for 5 min. Controls were exposed to curcumin or light alone or remained untreated. Curcumin plus light, but not curcumin or light exposure alone altered growth, proliferation, and apoptosis of all three RCC tumor cell lines. Cells were arrested in the G0/G1 phase of the cell cycle. Phosphorylated (p) CDK1 and pCDK2, along with their counter-receptors Cyclin B and A decreased, whereas p27 increased. Akt-mTOR-signaling was suppressed, the pro-apoptotic protein Bcl-2 became elevated, and the anti-apoptotic protein Bax diminished. H3 acetylation was elevated when cells were treated with curcumin plus light, pointing to an epigenetic mechanism. The present findings substantiate the potential of combining low curcumin concentrations and light as a new therapeutic concept to increase the efficacy of curcumin in RCC.


2021 ◽  
Author(s):  
Lena Kersting ◽  
Leah Kuhn ◽  
Maksim Anokhin ◽  
Florian Schuster ◽  
Cécile Häberli ◽  
...  

An efficient metal-free visible light-driven two-step domino reaction towards new bioactive tetrahydroisoquinoline-butenolide hybrid compounds was developed for the first time. Combination of fluorescein as photosensitizer and thiourea as an additive was found to be the most effective way to promote an aerobic amine oxidation/vinylogous Mannich domino reaction sequence with yields up to 97% for a broad substrate scope. While fluorescein without thiourea additive gave product in 84% yield, it was even observed that thiourea in absence of fluorescein is also able to promote formation of product with good yield of 75%, which is explained by a potential role of thiourea as an electron-transfer mediator in light-induced amine oxidation. Both experimental and computational evidence supported the crucial role of singlet oxygen in the developed C–H functionalization reaction. In addition, in vitro studies of tetrahydroisoquinoline-butenolide hybrid compounds demonstrated their high antischistosomal and anti-cancer activities.


2017 ◽  
Vol 12 (6) ◽  
pp. 1934578X1701200
Author(s):  
Steven Abood ◽  
Steven Eichelbaum ◽  
Sushmita Mustafi ◽  
Maria-Luisa Veisaga ◽  
Luis A. López ◽  
...  

Dehydroleucodine, a sesquiterpene lactone, belongs to the terpenoid class of secondary metabolites. Dehydroleucodine and other Artemisia-derived phytochemicals evolved numerous biodefenses that were first co-opted for human pharmacological use by traditional cultures in the Middle East, Asia, Europe and the Americas. Later, these phytochemicals were modified through the use of medicinal chemical techniques to increase their potency. All sesquiterpene lactones contain an α-methylene-γ-lactone group, which confers thiol reactivity, which is responsible, in part, for their therapeutic effects. A wide range of therapeutic uses of sequiterpene lactones has been found, including anti-adipogenic, cytoprotective, anti-microbial, anti-viral, anti-fungal, anti-malarial and, anti-migraine effects. Dehydroleucodine significantly inhibits differentiation of murine preadipocytes and also significantly decreases the accumulation of lipid content by a dramatic down regulation of adipogenic-specific transcriptional factors PPARγ and C-EBPα. Dehydroleucodine also inhibits secretion of matrix metalloprotease-2 (MMP-2), which is a known protease involved in migration and invasion of B16 cells. In addition to these anti-adipogenic and anti-cancer effects, dehydroleucodine effectively neutralizes several bacterial species, including Bacillus cereus, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Helicobacter pylori, methicillin resistant Staphylococcus aueus (MRSA) and S. epidermis (MRSE). The compound also inhibits the growth and secretion of several toxins of Pseudomonas aeruginosa, possesses gastro-protective qualities and possesses anti-parasitic properties against Trypanosoma cruzi, responsible for Chagas disease. Other sesquiterpene lactones, such as parthenolide, costunolide, and helanin, also possess significant therapeutic utility.


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