Chun Hu

Interaction study of two diterpenes, cryptotanshinone and dihydrotanshinone, to human acetylcholinesterase and butyrylcholinesterase by molecular docking and kinetic analysis.

Alzhemiers disease (AD) is a common form of dementia in the ageing population which is characterized by depositions of amyloids and a cholinergic neurotransmission deficit in the brain. Current therapeutic intervention for AD is primarily based on the inhibition of brain acetylcholinesterase (AChE) to restore the brain acetylcholine level. Cryptotanshinone (CT) and dihydrotanshinone (DT) were diterpenoids extracted from Salvia miltiorrhiza Bge. having anti-cholinesterase activity. Here we characterized the inhibition property of these two diterpenoids towards human AChE and butyrylcholinesterase (BChE). Both CT and DT were found to be mixed non-competitive inhibitors for human AChE and an uncompetitive inhibitor for human BChE. The docking analyses of CT and DT into the active sites of both cholinesterases indicate that they interact with the allosteric site inside the active-site gorge mainly by hydrophobic interactions.

Synthesis and biological evaluation of 3,6-diaryl-7H-thiazolo[3,2-b] [1,2,4]triazin-7-one derivatives as acetylcholinesterase inhibitors

Acetylcholinesterase (AChE) inhibitors played an important role in developing a cure for Alzheimer’ s disease. In order to study on the influence of modifications at different groups and side chains on the AChE inhibitory ability and the active sites of 7H-thiazolo[3,2-b][1,2,4]triazin-7-one derivatives, fourteen 3,6-diaryl-7H-thiazolo[3,2-b][1,2,4]triazin-7-one derivatives were designed and synthesized. The study of AChE inhibitory activity was carried out using the Ellman colorimetric assay with huperzine-A as the positive control drug. Most of the target compounds exhibited more than 50% inhibition at 10 μM. Some target compounds showed strong inhibition against AChE. The molecular fields analysis and preliminary structureactivity relationships are discussed.

6-acetyl-5H-thiazolo[3,2-a]pyrimidine derivatives as the novel acetylcholinesterase inhibitors: design, synthesis, and biological activity.

Acetylcholinesterase inhibitors are the most frequently prescribed anti-Alzheimers drugs. A series of 6-acetyl- 5H-thiazolo[3,2-a]pyrimidine derivatives as the novel acetylcholinesterase inhibitors were designed based on virtual screening methods. The target compounds which are not reported in the literature were synthesized with Biginelli reaction and Hantzsch-type condensation of dihydropyrimidines with substituted phenacyl chlorides, and were characterized with elemental analysis, IR, MS, 1H-NMR and 13C-NMR. The biological evaluation against human acetylcholinesterase in vitro showed most of the target compounds exhibited varying inhibition at 10 µM using the Ellman method. The results provide a starting point for the development of novel drugs to treat Alzheimers disease, and a foundation in search for improved acetylcholinesterase inhibitors with the novel scaffolds. The preliminary structure-activity relationships were the 2-hydroxyethoxy group at the phenyl ring at C4 position of the parent nucleus played significant roles in the AChE inhibitory activity of the target compounds.

Synthesis and antitumor activities of a new series of 4,5-dihydro-1 H -thiochromeno[4,3- d ]pyrimidine derivatives

A new series of 4,5-dihydro-1H-thiochromeno[4,3-d]pyrimidine derivatives have been designed and synthesized. The antitumor activities of the target compounds have been evaluated in vitro against two human cancer cell lines including A549 (human alveolar adenocarcinoma cell) and H460 (human lung cancer) by MTT assay. Most of the target compounds exhibited significant antitumor activities against A549 and H460 cancer cell lines. The most potent compound 4-(benzo[d][1,3]dioxol-5-yl)-8,9-difluoro-2-(4-methylpiperazin-1-yl)-4,5-dihydro-1H-thiochromeno[4,3-d]pyrimidine (CH05) (IC50 = 0.44 μM, 3.07 μM) was 2.0 and 8.4 times more active than gefitinib (IC50 = 0.89 μM, 16.81 μM) against A549 and H460 cell lines, respectively.

Identification of influenza polymerase inhibitors targeting C-terminal domain of PA through surface plasmon resonance screening.

Currently, many strains of influenza A virus have developed resistance against anti-influenza drugs, and it is essential to find new chemicals to combat this virus. The influenza polymerase with three proteins, PA, PB1 and PB2, is a crucial component of the viral ribonucleoprotein (RNP) complex. Here, we report the identification of a hit compound 221 by surface plasmon resonance (SPR) direct binding screening on the C-terminal of PA (PAC). Compound 221 can subdue influenza RNP activities and attenuate influenza virus replication. Its analogs were subsequently investigated and twelve of them could attenuate RNP activities. One of the analogs, compound 312, impeded influenza A virus replication in Madin-Darby canine kidney cells with IC50 of 27.0 ± 16.8 μM. In vitro interaction assays showed that compound 312 bound directly to PAC with Kd of about 40 μM. Overall, the identification of novel PAC-targeting compounds provides new ground for drug design against influenza virus in the future.

Discovery of 4,5-Dihydro-1H-thieno[2′,3′:2,3]thiepino [4,5-c]pyrazole-3-carboxamide Derivatives as the Potential Epidermal Growth Factor Receptors for Tyrosine Kinase Inhibitors

The epidermal growth factor receptors (EGFRs), in which overexpression (known as upregulation) or overactivity have been associated with a number of cancers, has become an attractive molecular target for the treatment of selective cancers. We report here the design and synthesis of a novel series of 4,5-dihydro-1H-thieno [2′,3′:2,3]thiepino[4,5-c]pyrazole-3-carboxamide derivatives and the screening for their inhibitory activity on the EGFR high-expressing human A549 cell line using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). A Docking simulation was performed to fit compound 6g and gifitinib into the EGFR to determine the probable binding models, and the binding sites and modes conformation of 6g and gifitinib were exactly similar, the two compounds were stabilized by hydrogen bond interactions with MET769. Combining with the biological activity evaluation, compound 6g demonstrated the most potent inhibitory activity (IC50 = 9.68 ± 1.95 μmol·L–1 for A549). Conclusively, 4,5-dihydro-1H-thieno[2′,3′:2,3]thiepino[4,5-c]pyrazole-3-carboxamide derivatives as the EGFR tyrosine kinase inhibitors were discovered, and could be used as potential lead compounds against cancer cells.

Synthesis, β -catenin Translocation Capability and ALP Activation Activity of 7H-thiazolo[3,2-b]-1,2,4-triazin-7-one Derivatives

BACKGROUND Osteoporosis (OP) is a common bone disease, most often diagnosed in post-menopausal women. The majority of OP treatments are focused on manipulation of the patients hormone levels, therefore, they are associated with significant adverse effects. OBJECTIVE The study aimed to design, synthesize and evaluate the β-catenin translocation capability and the alkaline phosphatase (ALP) activation activity of 7H-thiazolo[3,2-b]-1,2,4-triazin-7-one derivatives. METHOD The styrene derivatives were synthesized as raw materials, followed by oxidation and condensation reactions, in which 6-aryl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one derivatives (1) were obtained. The 3,6-diaryl-7H-thiazolo[3,2-b]-1,2,4-triazin-7-ones (2) were obtained by a condensation reaction of compound 1 with substituted phenacyl chlorides in acetic acid. The target compounds 3,6-diaryl-7H-thiazolo[3,2-b]-1,2,4-triazin-7-ones (3a-3c) were prepared by compound 2 with substituted alkyl chloride by Williamson reaction. As to 6-benzyl-3-aryl-7H-thiazolo[3,2- b]-1,2,4-triazin-7-one derivatives as the target compounds, the benzaldehyde and acetylglycine used as raw materials, followed by Erlenmeyer-Plochl reaction, condensation reaction, hydrolysis reaction, condensation reaction, 6-benzyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one derivatives were obtained, and were converted to the target compounds 6-benzyl-3-(hydroxylaryl)-7Hthiazolo[ 3,2-b]-1,2,4-triazin-7-one derivatives (5a-5d) using reaction with substituted α-phenacyl chlorides. Finally, Williamson reaction were used to yield 6-benzyl-3-aryl-7H-thiazolo[3,2-b]- 1,2,4-triazin-7-ones as target compounds (6a-6e). The β-catenin translocation capability and the ALP activation activity were tested, and the glycogen synthase kinase-3 (GSK-3) inhibition was simulated by molecular docking. RESULTS Fourteen 7H-thiazolo[3,2-b]-1,2,4-triazin-7-one derivatives were synthesized and characterized by mass spectra, proton NMR and infrared spectra, the β-catenin translocation capability and the ALP activation activities of the target compounds were tested and calculated. The EC50 value of the ALP activation activity of 6-(4-chlorobenzyl)-3-{4-[(2-dimethylamino)-2- oxoethoxy]phenyl}-7H-thiazolo[3,2-b]-1,2,4-triazin-7-one (6b) was 11.283 µM. The molecular docking results have showed that the target compounds would be GSK-3 inhibitors. CONCLUSION Based on the results of the biological activity test, the target compounds have exhibited the β-catenin translocation capability and the ALP activation activity.