Synthesis, Evaluation, and Mechanism Study of New Tepotinib Derivatives as Antiproliferative Agents.

Inspired by the potent inhibition activity of the c-Met (mesenchymal-epithelial transition factor) inhibitor Tepotinib, a series of new Tepotinib derivatives were synthesized and evaluated for their ability to act as antiproliferative agents to find the leading compounds with good activity and limited side effects. Among them, compound 31e exhibited potent antiproliferative activity (IC50 (50% inhibitory concentration) = 0.026 µΜ) against hepatic carcinoma 97H (human liver cancer cell) cells and, importantly, had very low inhibitory activity against normal cells. A mechanism study demonstrated that 31e induced G1 phase (First growth phase or G indicating gap) arrest, inhibited the phosphorylation of c-Met and its downstream signaling component, Akt (Protein Kinase B), and also inhibited the migration of hepatic carcinoma 97H cells.

A pH-responsive layered double hydroxide (LDH)-phthalocyanine nanohybrid for efficient photodynamic therapy.

A pH-responsive nanohybrid (LDH-ZnPcPS4 ), in which a highly hydrophilic zinc(II) phthalocyanine tetra-α-substituted with 4-sulfonatophenoxy groups (ZnPcPS4 ) is incorporated with a cationic layered double hydroxide (LDH) based on electrostatic interaction, has been specially designed and prepared through a facile co-precipitation approach. ZnPcPS4 is an excellent singlet-oxygen generator with strong absorption at the near-infrared region (692 nm) in cellular culture media, whereas the photoactivities of ZnPcPS4 were remarkably inhibited after incorporation with the LDH. The nanohybrid is essentially stable in aqueous media at pH 7.4; nevertheless, in slightly acidic media of pH 6.5 or 5.0, ZnPcPS4 can be efficiently released from the LDH matrix, thus leading to restoration of the photoactivities. The nanohybrid shows a high photocytotoxicity against HepG2 cells as a result of much more efficient cellular uptake and preferential accumulation in lysosomes, whereby the acidic environment leads to the release of ZnPcPS4 . The IC50 value of LDH-ZnPcPS4 is as low as 0.053 µM, which is 24-fold lower than that of ZnPcPS4 . This work provides a facile approach for the fabrication of photosensitizers with high photocytotoxicity, potential tumor selectivity, and rapid clearance character.

Highly positive-charged zinc(II) phthalocyanine as non-aggregated and efficient antifungal photosensitizer.

A new tetra-α-substituted zinc(II) phthalocyanine containing dodeca-amino groups (compound 4) and its quaternized analogue (compound 5) have been prepared and evaluated for their photoactivities against Candida albicans. Compared with the dodeca-amino phthalocyanine 4, the dodeca-cationic phthalocyanine 5 exhibits a higher photodynamic inactivation against C. albicans with an IC90 value down to 1.46 µM, which can be attributed to its non-aggregated nature in aqueous environments and more efficient cellular uptake. More interestingly, 5 shows a higher photodynamic inactivation on C. albicans due to its stronger affinity to C. albicans cells than mammalian cells. These results suggest that the highly positive-charged phthalocyanine 5 is a potential non-aggregated antifungal photosensitizer, which shows some selectivity toward the fungus.

Design, synthesis, and evaluation of indanone derivatives as acetylcholinesterase inhibitors and metal-chelating agents.

A series of novel indanone derivatives was designed, synthesised and evaluated as potential agents for Alzheimer's disease. Among them, compound 6a, with a piperidine group linked to indone by a two-carbon spacer, exhibited the most potent inhibitor activity, with an IC(50) of 0.0018 µM for AChE; the inhibitory activity of this compound was 14-fold more potent than that of donepezil. Furthermore, these compounds also exhibited good metal-chelating ability.

Dual ß2-adrenoceptor agonists-PDE4 inhibitors for the treatment of asthma and COPD.

We designed and synthesized a novel class of dual pharmacology bronchodilators targeting both ß(2)-adrenoceptor and PDE4 by applying a multivalent approach. The most potent dual pharmacology molecule, compound 29, possessed good inhibitory activity on PDE4B2 (IC(50)=0.278 µM, which was more potent than phthalazinone, IC(50)=0.520 µM) and possessed excellent relaxant effects on tracheal rings precontracted by histamine (pEC(50)=9.3).

A pH-responsive stellate mesoporous silica based nanophotosensitizer for in vivo cancer diagnosis and targeted photodynamic therapy.

Development of a photosensitizer that can achieve tumor specificity, improve therapeutic efficacy, and reduce side effects remains a challenge for photodynamic therapy (PDT). In this work, a pH-sensitive activatable nanophotosensitizer (SMSN-ZnPc1) has been elaborately designed, which could be readily prepared by using a functionalized zinc(ii) phthalocyanine (ZnPc) to conjugate with stellate mesoporous silica nanoparticles (SMSNs) through an acid-sensitive hydrazone bond. Meanwhile, a non-activatable analogue SMSN-ZnPc2 has also been prepared as a negative control. The fluorescence emission and singlet oxygen generation of the photosensitizer are essentially quenched in the intact nanophotosensitizer. However, these properties of SMSN-ZnPc1 can be restored greatly both in acidic solutions and at the cellular level. More importantly, after intravenous administration, SMSN-ZnPc1 can also be selectively activated at the tumor site and exhibit efficient tumor growth inhibition in S180 rat ascitic tumor-bearing KM mice with negligible systemic toxicity. It thus may serve as a promising nanoplatform for cancer diagnosis and targeted PDT.

A non-aggregated and tumour-associated macrophage-targeted photosensitiser for photodynamic therapy: a novel zinc(II) phthalocyanine containing octa-sulphonates.

A novel zinc(II) phthalocyanine bearing octa-sulphonates has been prepared, which is non-aggregated in water, highly photoactive and low dark-toxic. More interestingly, it exhibits specific affinity to macrophages via the scavenger receptor-A, and can selectively accumulate in tumour sites.

Pd-catalyzed [3+2] cycloaddition of ketoimines with alkynes via directed sp³ C-H bond activation.

The Pd(II)-catalyzed oxidative [3+2] cycloaddition of N-(2-pyridyl) ketoimines with internal alkynes has been developed. The transformation is tolerant of extensive substitution on halogen, alkene, alkyne, hydroxyl, aryl and acyl groups, and allows facile assembly of multisubstituted pyrroles.

Synthesis, supramolecular behavior, and in vitro photodynamic activities of novel zinc(II) phthalocyanines "side-strapped" with crown ether bridges.

Two new tetra- or di-α-substituted zinc(II) phthalocyanines 5 and 6 have been prepared through a "side-strapped" method. In the molecules, the adjacent benzene rings of the phthalocyanine core are linked at α-position through a triethylene glycol bridge to form a hybrid aza-/oxa-crown ether. The tetra-α-substituted phthalocyanine 5 shows an eclipsed self-assembly property in CH2Cl2 and the effect on the di-α-substituted analogue 6 is significantly weakened. Furthermore, the crown ethers of these compounds can selectively complex with Fe(3+) or Cu(2+) ion in DMF, leading to formation of J-aggregated nano-assemblies, which can be disaggregated in the presence of some organic or inorganic ligands, such as triethylamine, tetramethylethylenediamine, CH3COO(-), or OH(-). In addition, both compounds are efficient singlet oxygen generators with the singlet oxygen quantum yields (Φ(Δ)) of 0.54-0.74 in DMF relative to unsubstituted zinc(II) phthalocyanine (Φ(Δ)=0.56). They exhibit photodynamic activities toward HepG2 human hepatocarcinoma cells, but the compound 6, which has more than 40-fold lower IC50 value (0.08 µM) compared to the analogue 5 (IC50=3.31 µM), shows remarkablely higher in vitro photocytotoxicity due to its significantly higher cellular uptake and singlet oxygen generation efficiency. The results suggest that these compounds can serve as promising multifunctional materials both in (opto)electronic field and photodynamic therapy.

Berberine ameliorates ß-amyloid pathology, gliosis, and cognitive impairment in an Alzheimer's disease transgenic mouse model.

The accumulation of ß-amyloid (Aß) peptide derived from abnormal processing of amyloid precursor protein (APP) is a common pathological hallmark of Alzheimer's disease (AD) brains. In this study, we evaluated the therapeutic effect of berberine (BBR) extracted from Coptis chinensis Franch, a Chinese medicinal herb, on the neuropathology and cognitive impairment in TgCRND8 mice, a well established transgenic mouse model of AD. Two-month-old TgCRND8 mice received a low (25 mg/kg per day) or a high dose of BBR (100 mg/kg per day) by oral gavage until 6 months old. BBR treatment significantly ameliorated learning deficits, long-term spatial memory retention, as well as plaque load compared with vehicle control treatment. In addition, enzyme-linked immunosorbent assay (ELISA) measurement showed that there was a profound reduction in levels of detergent-soluble and -insoluble ß-amyloid in brain homogenates of BBR-treated mice. Glycogen synthase kinase (GSK)3, a major kinase involved in APP and tau phosphorylation, was significantly inhibited by BBR treatment. We also found that BBR significantly decreased the levels of C-terminal fragments of APP and the hyperphosphorylation of APP and tau via the Akt/glycogen synthase kinase 3 signaling pathway in N2a mouse neuroblastoma cells stably expressing human Swedish mutant APP695 (N2a-SwedAPP). Our results suggest that BBR provides neuroprotective effects in TgCRND8 mice through regulating APP processing and that further investigation of the BBR for therapeutic use in treating AD is warranted.

Synthesis, biological evaluation of 9-N-substituted berberine derivatives as multi-functional agents of antioxidant, inhibitors of acetylcholinesterase, butyrylcholinesterase and amyloid-ß aggregation.

A series of 9-N-substituted berberine derivatives were synthesized and biologically evaluated as antioxidant and inhibitors of acetylcholinesterase (AChE), butyrylcholinesterase and amyloid-ß aggregation. Most of these compounds exhibited very good antioxidant activities, inhibitive activities of AChE and amyloid-ß aggregation. Among them, compound 8d, (o-methylphenethyl)amino linked at the 9-position of berberine, was found to be a good antioxidant (with 4.05 µM of Trolox equivalents), potent inhibitor of AChE (an IC(50) value of 0.027 µM), and high active inhibitor of amyloid-ß aggregation (an IC(50) value of 2.73 µM).