Lysosomal Targeted Cyclometallic Iridium(Ⅲ) Salicylaldehyde-Coumarin Schiff Base Complexes and Anticancer Application

Studies of Anticancer Activities In Vitro and In Vivo for Butyltin(IV)-Iridium(III) Imidazole-Phenanthroline Complexes with Aggregation-Induced Emission Properties

Organotin(IV) and iridium(III) complexes have shown good application potential in the field of anticancer; however, the aggregation-caused quenching (ACQ) effect induced by high concentration or dose has limited the research on their targeting and anticancer mechanism. Then, a series of aggregation-induced emission (AIE)-activated butyltin(IV)-iridium(III) imidazole-phenanthroline complexes were prepared in this study. Complexes exhibited significant fluorescence improvement in the aggregated state because of the restricted intramolecular rotation (RIR), accompanied by an absolute fluorescence quantum yield of up to 29.2% (IrSn9). Complexes demonstrated potential in vitro antiproliferative and antimigration activity against A549 cells, following a lysosomal-mitochondrial apoptotic pathway. Nude mouse models further confirmed that complexes had favorable in vivo antitumor and antimigration activity in comparison to cisplatin. Therefore, butyltin(IV)-iridium(III) imidazole-phenanthroline complexes possess the potential as potential substitutes for platinum-based drugs.

Insights into the antineoplastic activity and mechanisms of action of coumarin-coordinated 8-hydroxyquinoline ruthenium(II/III) compounds

Ruthenium(II/III) coordination compounds have gained widespread attention as chemotherapy drugs, photosensitizers, and photodynamic therapy reagents. Herein, a family of 11 novel coumarin-coordinated 8-hydroxyquinoline ruthenium(II/III) compounds, i.e., [RuII2(μ2-Cl)2(QL1a)2(DMSO)4] (YNU-4a = Yulin Normal University-4a), [RuII2(μ2-Cl)2(QL1b)2(DMSO)4] (YNU-4b), [RuII2(μ2-Cl)2(QL1c)2(DMSO)4] (YNU-4c), [RuII2(μ2-Cl)2(QL1d)2(DMSO)4]⋅2CH3OH (YNU-4d), [RuII(QL1e)2(DMSO)2] (YNU-4e), [RuIII(QL1e)2(QL3a)] (YNU-4f), [RuIII(QL1e)2(QL3b)] (YNU-4g), [RuIII(QL1e)2(QL3c)] (YNU-4h), [RuIICl2(H-QL3a)2(DMSO)2] (YNU-4i), [RuIICl2(H-QL3b)2(DMSO)2] (YNU-4j), and [RuIICl2(H-QL3c)2(DMSO)2] (YNU-4k), featuring the coligands 5,7-diiodo-8-hydroxyquinoline (H-QL1a), 5,7-dichloro-8-quinolinol (H-QL1b), 5-chloro-7-iodo-8-hydroxyquinolin (H-QL1c), 5,7-dibromo-8-hydroxyquinoline (H-QL1d), and 5,7-dichloro-8-hydroxy-2-methylquinoline (H-QL1e) and the main ligands 6,7-dichloro-3-pyridin-2-yl-chromen-2-one (H-QL3a), 6-bromo-3-pyridin-2-yl-chromen-2-one (H-QL3b), and 6-chloro-3-pyridin-2-yl-chromen-2-one (H-QL3c), respectively. The structure of compounds YNU-4a-YNU-4k was fully confirmed by conducting various spectroscopic analyses. The anticancer activity of YNU-4a-YNU-4k was evaluated in cisplatin-resistant A549/DDP lung cancer cells (LC549) versus normal embryonic kidney (HEK293) cells. Notably, compound YNU-4f bearing QL1e and QL3a ligands showed a more pronounced antiproliferative effect against LC549 cells (IC50 = 1.75 ± 0.09 μM) with high intrinsic selectivity toward LC549 cancer cells than YNU-4a-YNU-4e, H-QL1a-H-QL1e, cisplatin (PDD), YNU-4g-YNU-4k, and H-QL3a-H-QL3c. Additionally, a colocalization assay analysis of YNU-4e and YNU-4f showed that these two ruthenium(II/III) compounds were subcellularly accumulated in the mitochondria and other regions of the cytoplasm, where they induce mitophagy, adenosine triphosphate (ATP) reduction, mitochondrial respiratory chain complex I/IV(RC1/RC4) inhibition, and mitochondrial dysfunction. Accordingly, compounds YNU-4a-YNU-4k can be regarded as mitophagy inductors for the eradication of cisplatin-resistant LC549 cancer cells.

Synthesis and Characterization of Slow-Release Chitosan Oligosaccharide Pyridine Schiff Base Copper Complexes with Antifungal Activity

Herein, a series of chitosan oligosaccharide copper complexes modified with pyridine groups (CPSx-Cu complexes) were successfully prepared via the Schiff base reaction and ion complexation reaction for slow-release fungicide. The structures of the synthesized derivatives were characterized via Fourier transform infrared spectroscopy and 1H and 13C nuclear magnetic resonance spectroscopy, and the unit configuration of the complexes was calculated using Gaussian software. The slow-release performance experiment demonstrated that the cumulative copper ion release rate of CPSx-Cu complexes was dependent on the type of substituents on the pyridine ring. Furthermore, the in vitro and in vivo antifungal activities of the CPSx-Cu complexes were investigated. At a concentration of 0.4 mg/mL, CPSx-Cu complexes completely inhibited the growth of Pythium vexans and Phytophthora capsici. Results indicated that CPSx-Cu complexes with slow-release ability exhibited better antifungal activity than thiodiazole-copper and copper sulfate basic. This study confirmed that combining chitosan oligosaccharide with bioactive pyridine groups and copper ions is an effective approach to further developing slow-release copper fungicides, providing new possibilities for the application of copper fungicides in green agriculture. This study lays the foundation for further studies on biogreen copper fungicides.

Targeted liposomes encapsulated iridium(III) compound greatly enhance anticancer efficacy and induce cell death via ferroptosis on HepG2 cells

In this study, ligands 2-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline (PIP), 2-(2-nitrophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline (NPIP), 2-(2-nitronaphthalen-1-yl)-1H-imidazo[4,5-f][1,10]phenanthroline (NNIP) and their iridium(III) metal compounds [Ir(ppy)2(PIP)](PF6) (ppy = 2-phenylpyridine, 1a), [Ir(ppy)2(NPIP)](PF6) (1b), [Ir(ppy)2(NNIP)](PF6) (1c) were designed and synthesized. The anti-cancer activities of 1a, 1b and 1c on BEL-7402, HepG2, SK-Hep1 and non-cancer LO2 were detected using MTT method. 1a shows moderate, 1b and 1c display low or no anti-cancer activities. To elevate the anti-cancer effectiveness, encapsulating the compounds 1a, 1b and 1c into the ordinary or targeted liposomes to produce 1alip, 1blip, 1clip, or targeted 1aTlip, 1bTlip and 1cTlip. The IC50 values of 1alip, 1blip, 1clip, 1aTlip, 1bTlip and 1cTlip against HepG2 cells are 7.9 ± 0.1, 8.6 ± 0.2, 16.9 ± 0.5, 5.9 ± 0.2, 7.3 ± 0.1 and 9.7 ± 0.7 μM, respectively. Specifically, the anti-tumor activity assays in vivo found that the inhibitory rates are 23.24 % for 1a, 61.27 % for 1alip, 76.06 % for 1aTlip. It is obvious that the targeted liposomes entrapped iridium(III) compound greatly enhance anti-cancer efficacy. Additionally, 1alip, 1blip and 1clip or targeted 1aTlip, 1bTlip and 1cTlip can effectively restrain the cell colony and proliferation in the G0/G1 period. 1alip, 1blip, 1clip, 1aTlip, 1bTlip and 1cTlip can increase reactive oxygen species (ROS) concentration, arouse a decline in the mitochondrial membrane potential and promote Ca2+ release. RNA-sequence was applied to examine the signaling pathways. Taken together, the liposomes or targeted liposomes encapsulated compounds trigger cell death by way of apoptosis, autophagy, ferroptosis, disruption of mitochondrial function and PI3K/AKT/mTOR signaling pathways.