Yu-Shun Yang

Synthesis, biological evaluation, and molecular docking studies of 1,3,4-oxadiazole derivatives possessing 1,4-benzodioxan moiety as potential anticancer agents.

In present study, a series of new 1,3,4-oxadiazole derivatives containing 1,4-benzodioxan moiety (6a-6s) as potential telomerase inhibitors were synthesized. The bioassay tests demonstrated that compounds 6k, 6l, 6m, 6n and 6s exhibited broad-spectrum antitumor activity with IC(50) concentration range from 7.21 μM to 25.87 μM against the four cancer cell lines, HEPG2, HELA, SW1116 and BGC823. Moreover, all the title compounds were assayed for telomerase inhibition using the TRAP-PCR-ELISA assay. The results showed compound 6k possessed the most potent telomerase activity (IC(50)=1.27 ± 0.05 μM). Docking simulation was performed to position compound 6k into the active site of telomerase (3DU6) to determine the probable binding model.

Template-confined growth and structural characterization of amorphous carbon nanotubes

Porous anodic aluminum oxide templates with different channel structures have been synthesized and used to grow carbon nanotubes (CNTs) through the pyrolysis of ethylene at 700 °C. Aligned CNT arrays, Y-branched as well as novel dendriform CNTs have been obtained and well characterized by scanning electron microscopy and high-resolution transmission electron microscopy. The amorphous structure, irregular and quasi-hemispherical ends as well as the branched junction have been revealed in detail. The disordered structure of the carbon nanotubes was assigned to the lattice mismatch between alumina and carbon species. A growth mechanism mainly based on the space-limited and self-catalytic functions of template channels has been proposed accordingly.

Synthesis, biological evaluation and molecular docking studies of 1,3,4-thiadiazole derivatives containing 1,4-benzodioxan as potential antitumor agents

A series of 1,3,4-thiadiazole derivatives containing 1,4-benzodioxan (2a-2s) have been synthesized to screen for FAK inhibitory activity. Compound 2p showed the most potent biological activity against HEPG2 cancer cell line (EC(50)=10.28 μg/mL for HEPG2 and EC(50)=10.79 μM for FAK), which was comparable to the positive control. Docking simulation was performed to position compound 2p into the FAK structure active site to determine the probable binding model. The results of antiproliferative and Western-blot assay demonstrated that compound 2p possessed good antiproliferative activity against HEPG2 cancer cell line. Therefore, compound 2p with potent FAK inhibitory activity may be a potential anticancer agent against HEPG2 cancer cell.

High-yield production of quasi-aligned carbon nanotubes by catalytic decomposition of benzene

High-yield production of quasi-aligned carbon nanotube (CNT) bundles is presented. Benzene was used as the precursor for this catalytic process at a moderate temperature of 650°C over γ-Al2O3-supported Fe–Ni alloy catalysts with different mole ratios. The maximum yield of high-quality CNTs per hour is even greater than 350% for the optimized catalyst. The products were characterized by thermal gravimetry/differential scanning calorimetry and high-resolution transmission electron microscopy. The results indicated that the products are well graphitized with tube diameters of about 20 nm. Three typical morphologies of the end parts of the CNTs were identified as the open end capped with an Fe–Ni catalyst, the open end without catalyst and the closed end, respectively. A hexagonal carbon-cluster-based growth for this synthesis is suggested.

Design, modification and 3D QSAR studies of novel naphthalin-containing pyrazoline derivatives with/without thiourea skeleton as anticancer agents.

Two series of novel naphthalin-containing pyrazoline derivatives C1-C14 and D1-D14 have been synthesized and evaluated for their EGFR/HER-2 inhibitory and anti-proliferation activities. Compound D14 displayed the most potent activity against EGFR and A549 cell line (IC(50)=0.05 μM and GI(50)=0.11 μM), being comparable with the positive control Erlotinib (IC(50)=0.03 μM and GI(50)=0.03 μM) and more potent than our previous compounds C0-A (IC(50)=5.31 μM and GI(50)=33.47 μM) and C0-B (IC(50)=0.09 μM and GI(50)=0.34 μM). Meanwhile, compound C14 displayed the most potent activity against HER-2 and MCF-7 cell line (IC(50)=0.88 μM and GI(50)=0.35 μM), being a little less potent than Erlotinib (IC(50)=0.16 μM and GI(50)=0.08 μM) but far more potent than C0-A (IC(50)=6.58 μM and GI(50)=27.62 μM) and C0-B (IC(50)=2.77 μM and GI(50)=3.79 μM). The docking simulation was performed to analyze the probable binding models and the QSAR models were built for reasonable design of EGFR/HER-2 inhibitors at present and in future. The structural modification of introducing naphthalin moiety reinforced the combination of our compounds and the receptor, resulting in progress of bioactivity. Moreover, the replacement of thiourea skeleton by using benzene ring resulted in the slight diversity of the two series towards specific targets.

Synthesis, molecular docking and evaluation of thiazolyl-pyrazoline derivatives containing benzodioxole as potential anticancer agents

A series of novel thiazolyl-pyrazoline derivatives containing benzodioxole (C1-C20) have been designed and synthesized. Among of the synthesized compounds, 2-(5-(benzo[d][1,3]dioxol-5-yl)-3-(4-bromophenyl)-4,5-dihydro-1H-pyrazol-1-yl)-4-(4-bromophenyl)thiazole (C6) displayed the most potent inhibitory activity for HER-2 (IC(50) = 0.18 μM for HER-2). Antiproliferative assay results indicated that compound C6 owned high antiproliferative activity against MCF-7 and B16-F10 in vitro, with IC(50) value of 0.09 and 0.12 μM, respectively, being comparable with the positive control Erlotinib. Docking simulation was further performed to determine the probable binding model. Based on the preliminary results, compound C6 with potent inhibitory activity in tumor growth would be a potential anticancer agent.

Design, synthesis and antibacterial activities of vanillic acylhydrazone derivatives as potential β-ketoacyl-acyl carrier protein synthase III (FabH) inhibitors.

Fatty acid biosynthesis is essential for bacterial survival. FabH, β-ketoacyl-acyl carrier protein (ACP) synthase III, is a particularly attractive target, since it is central to the initiation of fatty acid biosynthesis and is highly conserved among Gram-positive and Gram-negative bacteria. A series of acylhydrazone derivatives were synthesized and developed as potent inhibitors of FabH. This inhibitor class demonstrates strong broad-spectrum antibacterial activity. Compounds with potent antibacterial activities were tested for their Escherichia coli FabH inhibitory activity. Especially, compound E9 showed the most potent antibacterial activity with MIC values of 0.39-1.56 μg/mL against the tested bacterial strains and exhibited the most potent E. coli FabH inhibitory activity with IC(50) of 2.5 μM. Docking simulation was performed to position compound E9 into the E. coli FabH active site to determine the probable binding conformation.

Design, synthesis and antibacterial activities of 5-(pyrazin-2-yl)-4H-1,2,4-triazole-3-thiol derivatives containing Schiff base formation as FabH inhibitory.

A series of novel schiff base derivatives (H(1)-H(20)) containing pyrazine and triazole moiety have been designed and synthesized, and their biological activities were also evaluated as potential inhibitors of β-ketoacyl-acyl carrier protein synthase III (FabH). These compounds were assayed for antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis and Bacillus amyloliquefaciens and selected compounds among them were tested for their Escherichia coli FabH inhibitory activity. Based on the biological data, compound H(17) showed the most potent antibacterial activity with MIC values of 0.39-1.56μg/mL against the tested bacterial strains and exhibited the most potent E. coli FabH inhibitory activity with IC50 of 5.2μM, being better than the positive control Kanamycin B with IC50 of 6.3μM. Furthermore, docking simulation was performed to position compound H(17) into the E. coli FabH active site to determine the probable binding conformation. This study indicated that compound H(17) has demonstrated significant E. coli FabH inhibitory activity as a potential antibacterial agent and provides valuable information for the design of E. coli FabH inhibitors.

Discovery and modification of sulfur-containing heterocyclic pyrazoline derivatives as potential novel class of β-ketoacyl-acyl carrier protein synthase III (FabH) inhibitors

A series of sulfur-containing heterocyclic pyrazoline derivatives (C1-C18; D1-D9) have been synthesized and purified (all are new except one) to be screened for FabH inhibitory activity. Compound C14 showed the most potent biological activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis (MIC values: 1.56-3.13 μg/mL), being comparable with the positive control, while D6 performed the best in the thiazolidinone series (MIC values: 3.13-6.25 μg/mL). They also demonstrated strong broad-spectrum antimicrobial activity. Compounds C14 and D6 exhibited the most potent E. coli FabH inhibitory activity with IC(50) of 4.6 and 8.4 μM, respectively, comparable with the positive control DDCP (IC(50)=2.8 μM). Docking simulation was performed to position compound C14 and D6 into the E. coli FabH structure active site to determine the probable binding model. The structurally modification of previous compounds and the attempt in innovative target have brought a positive progress.

Design, synthesis and biological evaluation of heterocyclic azoles derivatives containing pyrazine moiety as potential telomerase inhibitors

Three series of novel heterocyclic azoles derivatives containing pyrazine (5a-5k, 8a-8k and 11a-11k) have been designed, synthesized, structurally determined, and their biological activities were evaluated as potential telomerase inhibitors. Among the oxadiazole derivatives, compound 5c showed the most potent biological activity against SW1116 cancer cell line (IC(50)=2.46 μM against SW1116 and IC(50)=3.55 μM for telomerase). Compound 8h performed the best in the thiadiazole derivatives (IC(50)=0.78 μM against HEPG2 and IC(50)=1.24 μM for telomerase), which was comparable to the positive control. While compound 11f showed the most potent biological activity (IC(50)=4.12 μM against SW1116 and IC(50)=15.03 μM for telomerase) among the triazole derivatives. Docking simulation by positioning compounds 5c, 8h and 11f into the telomerase structure active site was performed to explore the possible binding model. The results of apoptosis demonstrated that compound 8h possessed good antitumor activity against HEPG2 cancer cell line. Therefore, compound 8h with potent inhibitory activity in tumor growth inhibition may be a potential antitumor agent against HEPG2 cancer cell. Therefore, the introduction of oxadiazole, thiadiazole and triazole structures reinforced the combination of our compounds and the receptor, resulting in progress of bioactivity.