Copper-Catalyzed One-Pot Protocol for Reductive -Arylation of Nitroarenes with (Hetero)aryl Chlorides in Water.

A novel protocol for the Cu-catalyzed reductive -arylation of nitroarenes with (hetero)aryl chlorides in water has been realized. Combining -(9-carbazol-9-yl)-6-hydroxypicolinamide () with oxalohydrazide is vital to realize the method at 90 °C with a loading of 5 mol % of CuO/. Various nitroarenes and aryl chlorides have been successfully coupled in good to excellent isolated yields.

CuSO/-(9-carbazol-9-yl)picolinamide-Catalyzed C-O Coupling of (Hetero)Aryl Chlorides with Phenols on Water.

A Cu-catalyzed C-O coupling of (hetero)aryl chlorides with phenols at 120 °C on water was developed with a designed ligand, -(9-carbazol-9-yl)picolinamide (). This method features a good substrate scope (both electron-donating and electron-withdrawing), low catalyst/ligand loadings (down to 1 mol %), and excellent scalability and practicability.

Novel partially reversible NDM-1 inhibitors based on the naturally occurring houttuynin.

Discovering novel NDM-1 inhibitors is an urgent task for treatment of 'superbug' infectious diseases. In this study, we found that naturally occurring houttuynin and its sulfonate derivatives might be effective NDM-1 inhibitors with novel mechanism, i.e.

Room-Temperature CuI-Catalyzed -Arylation of Cyclopropylamine.

A general and efficient CuI/-carbazolyl-1-pyrrole-2-carbohydrazide catalyst system was developed for the -arylation of cyclopropylamine using aryl bromides at room temperature. Herein, 5 mol % CuI and 5 mol % of the ligand were used to synthesize -aryl cyclopropylamines in moderate to excellent yields. This protocol was scaled up to produce the desired product at gram levels and has been generalized for C-N coupling between aryl bromides and amines at room temperature.

GRGDS-functionalized chitosan nanoparticles as a potential intravenous hemostat for traumatic hemorrhage control in an animal model.

Hemostats, which are used for immediate intervention during internal hemorrhage in order to reduce resulting mortality and morbidity, are relatively rare. Here, we describe novel intravenous nanoparticles (CPG-NPs-2000) with chitosan succinate (CSS) as cores, polyethylene glycol (PEG-2000) as spacers and a glycine-arginine-glycine-aspartic acid-serine (GRGDS) peptide as targeted, active hemostatic motifs. CPG-NPs-2000 displayed significant hemostatic efficacy, compared to the saline control, CSS nanoparticles, and tranexamic acid in liver trauma rat models.

Magnetic resonance imaging tracking and assessing repair function of the bone marrow mesenchymal stem cells transplantation in a rat model of spinal cord injury.

The transplantation of bone marrow mesenchymal stem cells (BMSCs) to repair spinal cord injury (SCI) has become a promising therapy. However, there is still a lack of visual evidence directly implicating the transplanted cells as the source of the improvement of spinal cord function. In this study, BMSCs were labeled with NF-200 promoter and lipase-activated gadolinium-containing nanoparticles (Gd-DTPA-FA).

An arch-bridge-type fluorophore for bridging the gap between aggregation-caused quenching (ACQ) and aggregation-induced emission (AIE).

Solution and solid dual photoluminescence (PL) molecules fill the substantial gap between ACQ and AIE molecules to explore the mechanism of molecular luminescence in greater detail and to facilitate practical applications. A unique arch-bridge-like thiazolo[5,4-]thieno[3,2-]pyridine moiety is obtained as a stator after the rigidification of rotor 1 by intramolecular H-bonding of -OH or -NH to afford two classes of solid and solution dual PL molecules. As a typical example, is dual PL active.

Direct Arylation of Pyrroles via Indirect Electroreductive C-H Functionalization Using Perylene Bisimide as an Electron-Transfer Mediator.

The indirect electroreductive coupling of aryl halides and pyrroles was successfully conducted using a catalytic amount of perylene bisimide as a mediator in 1-ethyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)imide ([EMIM]NTf2)/DMSO.

Discovery of a phosphodiesterase 9A inhibitor as a potential hypoglycemic agent.

Phosphodiesterase 9 (PDE9) inhibitors have been studied as potential therapeutics for treatment of diabetes and Alzheimer's disease. Here we report a potent PDE9 inhibitor 3r that has an IC50 of 0.6 nM and >150-fold selectivity over other PDEs.

Dual specificity and novel structural folding of yeast phosphodiesterase-1 for hydrolysis of second messengers cyclic adenosine and guanosine 3',5'-monophosphate.

Cyclic nucleotide phosphodiesterases (PDEs) decompose second messengers cAMP and cGMP that play critical roles in many physiological processes. PDE1 of Saccharomyces cerevisiae has been subcloned and expressed in Escherichia coli. Recombinant yPDE1 has a KM of 110 μM and a kcat of 16.

Design, synthesis and biological evaluation of hydroxy- or methoxy-substituted 5-benzylidene(thio) barbiturates as novel tyrosinase inhibitors.

Here a new class of hydroxy- or methoxy-substituted 5-benzylidene(thio)barbiturates were designed, synthesized and their inhibitory effects on the diphenolase activity of mushroom tyrosinase were evaluated. The results showed that several compounds had more potent tyrosinase inhibitory activities than the widely used tyrosinase inhibitor kojic acid (IC50=18.25μM).

Design, synthesis and evaluation of N13-substituted evodiamine derivatives against human cancer cell lines.

Attempting to improve the anticancer activity and solubility of evodiamine in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) solutions, thirty-eight N13-substituted evodiamine derivatives were designed, synthesized and tested for antitumor activities against six kinds of human cancer cell lines, namely prostate cancer (DU-145 and PC-3), lung cancer (H460), breast cancer (MCF-7), colon cancer (HCT-5) and glioblastoma (SF-268). The solubility of these compounds in SGF and SIF solutions was evaluated, and apoptosis induced by 2-2, 2-3, 2-16 and 3-2 was determined. The results showed: (1) among all compounds examined, 2-16 showed the highest antitumor activity and a broader spectrum of activity, with IC50 values ranging from 1-2 µM; (2) their solubility was obviously improved; (3) 2-3, 2-16 and 3-2 had a significant impact inducing apoptosis in some cancer cell lines.

Specific lipase-responsive polymer-coated gadolinium nanoparticles for MR imaging of early acute pancreatitis.

Currently, available methods for diagnosis of acute pancreatitis (AP) are mainly dependent on serum enzyme analysis and imaging techniques that are too low in sensitivity and specificity to accurately and promptly diagnose AP. The lack of early diagnostic tools highlights the need to search for a highly effective and specific diagnostic method. In this study, we synthesized a conditionally activated, gadolinium-containing, nanoparticle-based MRI nanoprobe as a diagnostic tool for the early identification of AP.

Structure-based discovery of highly selective phosphodiesterase-9A inhibitors and implications for inhibitor design.

A new series of phosphodiesterase-9 (PDE9) inhibitors that contain a scaffold of 6-amino-pyrazolopyrimidinone have been discovered by a combination of structure-based design and computational docking. This procedure significantly saved the load of chemical synthesis and is an effective method for the discovery of inhibitors. The best compound 28 has an IC(50) of 21 nM and 3.

Biological and structural characterization of Trypanosoma cruzi phosphodiesterase C and Implications for design of parasite selective inhibitors.

Trypanosoma cruzi phosphodiesterase C (TcrPDEC) is a potential new drug target for the treatment of Chagas disease but has not been well studied. This study reports the enzymatic properties of various kinetoplastid PDECs and the crystal structures of the unliganded TcrPDEC1 catalytic domain and its complex with an inhibitor. Mutations of PDEC during the course of evolution led to inactivation of PDEC in Trypanosoma brucei/Trypanosoma evansi/Trypanosoma congolense, whereas the enzyme is active in all other kinetoplastids.

From the first selective non-peptide AT(2) receptor agonist to structurally related antagonists.

A para substitution pattern of the phenyl ring is a characteristic feature of the first reported selective AT(2) receptor agonist M024/C21 (1) and all the nonpeptidic AT(2) receptor agonists described so far. Two series of compounds structurally related to 1 but with a meta substitution pattern have now been synthesized and biologically evaluated for their affinity to the AT(1) and AT(2) receptors. A high AT(2)/AT(1) receptor selectivity was obtained with all 41 compounds synthesized, and the majority exhibited K(i) ranging from 2 to 100 nM.

Toward potent α-glucosidase inhibitors based on xanthones: a closer look into the structure-activity correlations.

A series of novel xanthone derivatives 6-16 having non-coplanar and flexible structures were synthesized as potent α-glucosidase inhibitors. Biological evaluation indicated that compounds 6-12 bearing one or two naphthol moieties exhibited up to 30-fold enhanced activities compared with their corresponding parent compounds 2-5, whereas compounds 13-16 bearing one dihydroxylnaphthalenyl group showed decreased activities compared with their corresponding analogs 6-9 having one naphthol group. Among them, compounds 7-8, 10-12 and 15 were more active than 1-deoxynojirimycin, a well-known inhibitor for α-glucosidase.

Pyrrolo[2,3-c]azepine derivatives: a new class of potent protein tyrosine phosphatase 1B inhibitors.

A series of pyrrolo[2,3-c]azepine derivatives was designed, synthesized, and evaluated as a new class of inhibitors against protein tyrosine phosphatase 1B (PTP1B) in vitro. The results demonstrated that compounds bearing a biphenyl moiety were proved to markedly influence the potency of these inhibitors. Particularly, compounds 29, 35 and 36 showed interesting inhibition with IC(50) value of 16.

Selective angiotensin II AT(2) receptor agonists with reduced CYP 450 inhibition.

Structural alterations to the benzylic position of the first drug-like selective angiotensin II AT(2) receptor agonist (1) have been performed, with the emphasis to reduce the CYP 450 inhibitory property of the initial structure. The imidazole moiety, responsible for the CYP 450 inhibitory effect in 1, was replaced with various heterocycles. In addition, the modes of attachment of the heterocycles, that is, carbon versus nitrogen attachment, and introduction of carbonyl functionalities to the benzylic position have been evaluated.

Synthesis and optical behaviors of 2-(9-phenanthrenyl)-, 2-(9-anthryl)-, and 2-(1-pyrenyl)-1-alkylimidazole homologues.

Eight 2-(9-phenanthrenyl)-, 2-(9-anthryl)- and 2-(1-pyrenyl)-1-alkyl-benzimidazole compounds, three 2-(9-anthryl)-1-alkylphenanthroimidazole compounds and five 4,5-diphenyl-1-alkyl-2-(9-anthryl)imidazole compounds were synthesized by alkylation reactions of the corresponding benzimidazole, phenanthroimidazole or imidazole compounds. 2-(10-Bromo-9-anthryl)-1-alkyl-benzimidazole compounds were prepared by bromination reaction of 2-(9-anthryl)-1-alkylbenzimidazole compounds. All the synthesized compounds were characterized by elemental analysis, (1)H NMR, (13)C NMR, MS or HRMS; their absorption coefficients (epsilon), maximum absorption lambda(amax), fluorescence emission maximum lambda(em), Stokes shifts and fluorescence quantum yields (Phi(F)) in ethyl acetate were determined; their fluorescent lifetimes (T(1) and T(2)) were measured in ethyl acetate and in solid state, respectively.

Synthesis and biological evaluation of helicid analogues as mushroom tyrosinase inhibitors.

A series of helicid analogues were synthesized and evaluated as tyrosinase inhibitors. The results demonstrated that some compounds had more potent inhibitory activities than arbutin (IC(50) 7.3 mM).

A class of potent tyrosinase inhibitors: alkylidenethiosemicarbazide compounds.

A series of alkylidenethiosemicarbazide compounds were synthesized and their inhibitory effects on the diphenolase activity of mushroom tyrosinase were evaluated. The results showed that most of the synthesized compounds exhibited significant inhibitory activities. Especially, compound 1f was found to be the most potent inhibitor with IC(50) value of 0.