Preclinical characterization of danatinib as a novel FLT3 inhibitor with excellent efficacy against resistant acute myeloid leukemia.

The therapeutic benefits of available FLT3 inhibitors for AML are limited by drug resistance, which is related to mutations, as well toxicity caused by off-target effects. In this study, we introduce a new small molecule FLT3 inhibitor called danatinib, which was designed to overcome the limitations of currently approved agents. Danatinib demonstrated greater potency and selectivity, resulting in cytotoxic activity specific to FLT3-ITD and/or FLT3-TKD mutated models.

Natural products as potential lead compounds to develop new antiviral drugs over the past decade.

Virus infection has been one of the main causes of human death since the ancient times. Even though more and more antiviral drugs have been approved in clinic, long-term use can easily lead to the emergence of drug resistance and side effects. Fortunately, there are many kinds of metabolites which were produced by plants, marine organisms and microorganisms in nature with rich structural skeletons, and they are natural treasure house for people to find antiviral active substances.

Bufotenine and its derivatives: synthesis, analgesic effects identification and computational target prediction.

Natural product bufotenine (5) which could be isolated from Venenum Bufonis, has been widely used as a tool in central nervous system (CNS) studies. We present here its quaternary ammonium salt (6) which was synthesized with high yields using 5-benzyloxyindole as raw materials, and we firstly discover its analgesic effects in vivo. The analgesic evaluation showed that compounds 5 and 6 had stronger effects on the behavior of formalin induced pain in mice.

Design, synthesis and evaluation of 2-amino-imidazol-4-one derivatives as potent β-site amyloid precursor protein cleaving enzyme 1 (BACE-1) inhibitors.

Inhibition of β-site amyloid precursor protein cleaving enzyme 1 (BACE1) to prevent brain β-amyloid (Aβ) peptide's formation is a potential effective approach to treat Alzheimer's disease. In this report we described a structure-based optimization of a series of BACE1 inhibitors derived from an iminopyrimidinone scaffold W-41 (IC = 7.1 μM) by Wyeth, which had good selectivity and brain permeability but low activity.

Design, synthesis, and biological activity evaluation of BACE1 inhibitors with antioxidant activity.

The proteolytic enzyme β-secretase (BACE1) plays a central role in the synthesis of the pathogenic β-amyloid peptides (Aβ) in Alzheimer's disease (AD), antioxidants could attenuate the AD syndrome and prevent the disease progression. In this study, BACE1 inhibitors (D1-D18) with free radical-scavenging activities were synthesized by molecular hybridization of 2-aminopyridine with natural antioxidants. The biological activity evaluation showed that D1 had obvious inhibitory activity against BACE1, and strong antioxidant activity in 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS ) assay, which could be used as a lead compound for further study.

Synthesis and Biological Evaluation of Scutellarein Alkyl Derivatives as Preventing Neurodegenerative Agents with Improved Lipid Soluble Properties.

Background: Exogenous antioxidants are considered as a promising therapeutic approach to treat neurodegenerative diseases since they could prevent and/or minimize the neuronal damage by oxidation.

Objective: Three series of lipophilic compounds structurally based on scutellarein (2), which is one metabolite of scutellarin (1) in vivo, have been designed and synthesized.

Methods: Their antioxidant activity was evaluated by detecting the 2-thiobarbituric acid reactive substance (TBARS) produced in the ferrous salt/ascorbate-induced autoxidation of lipids, which were present in microsomal membranes of rat hepatocytes.

Protective effect of 6-O-methyl-scutellarein on repeated cerebral ischemia/reperfusion in rats.

Scutellarin (1) possesses protective effects against neuronal injury, while 6-O-methyl-scutellarein (3), as the main metabolite of scutellarin in vivo, has not been reported about its protective effects previously. The present study mainly investigated whether the neural injury caused by ischemia/reperfusion would be influenced by different doses of 6-O-methyl-scutellarein (3). The results of behavioral, neurological, and histological examinations indicated that 6-O-methyl-scutellarein (3) could improve neuronal injury, and exhibit significant difference among the various doses.

Synthesis and Bioactivity Characterization of Scutellarein Sulfonated Derivative.

Scutellarin () has been widely used to treat acute cerebral infarction in clinic, but poor aqueous solubility decreases its bioavailability. Interestingly, scutellarin () could be metabolized into scutellarein () in vivo. In this study, a sulfonic group was introduced at position C-8 of scutellarein () to enhance the aqueous solubility of the obtained derivative ().

Design, Synthesis, and Biological Evaluation of Scutellarein Derivatives Based on Scutellarin Metabolic Mechanism In Vivo.

Three series of scutellarein derivatives have been designed and synthesized based on metabolic mechanism of scutellarin (1) in vivo. Their thrombin inhibition activities were tested through the analyzation of prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), and fibrinogen (FIB). The antioxidant activities of these target products were assessed by 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) assay and the ability to protect PC12 cells against H2 O2 -induced cytotoxicity, and their solubilities were evaluated by ultraviolet (UV) spectrophotometer.

Synthesis of scutellarein derivatives to increase biological activity and water solubility.

In order to improve the biological activity and water solubility of scutellarin (1), some derivatives of its main metabolite (scutellarein) were designed and synthesized. All the compounds were tested for their thrombin inhibition activity through the analyzation of thrombin time (TT), activated partial thromboplastin time (APTT), prothrombin time (PT) and fibrinogen (FIB). Their antioxidant activities were assessed by measuring their scavenging capacities toward 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and the ability to protect PC12 cells against H2O2-induced cytotoxicity, their water solubility were also assessed by ultraviolet (UV) spectrophotometer.

A new and practical synthetic method for the synthesis of 6-O-methyl-scutellarein: one metabolite of scutellarin in vivo.

Scutellarin (1) has been used for the treatment of angina pectoris, cerebral infarction and coronary heart disease with a large market share in China. Pharmacokinetic studies on scutellarin showed that scutellarin (1) is readily converted into its metabolites in vivo. In this paper, a new and practical synthetic method for the synthesis of 6-O-methyl-scutellarein (3) (one metabolite of scutellarin in vivo) is reported.

[Comparison of activated carbon and ultrafiltration technique in the production process of huoxue tongluo injection].

Objective: To research the applicability of activated carbon and ultrafiltration technique in the production process of Huoxue Tongluo Injection.

Methods: The kinetic-turbidimetric method was used to determine the content of bacterial endotoxins in Huoxue Tongluo solution. Particle size change in Huoxue Tongluo solution was determined by nanometer particle size instrument before and after the use of different concentration activated carbon and different molecular weight ultrafiltration membrane.

[Effect on elimination of pyrogen and effectual components of Panax notoginseng saponins by ultrafiltration membranes of different cut-off molecular weight and different materials].

Objective: To study the elimination effect of bacterial endotoxins and the transmittance of Panax notoginseng saponins by ultrafiltration membranes of different cut-off molecular weight and different materials.

Methods: The kinetic-turbidimetric method was used to determine the content of bacterial endotoxins in Panax notoginseng saponins solution before and after using the ultrafiltration. The change of the contents of active components was examined by HPLC,using notoginsennoside R1, ginsennoside Rg1, ginsennoside Rb1 and ginsennoside Rd as the mark components.

[Evaluation on the analytical sensitivity of 31 HBsAg enzyme immunoassay kits].

Objective: To study the analytical sensitivity on 31 HBsAg enzyme immunoassy (EIA) test kits.

Methods: Thirty one HBsAg EIA kits produced by domestic or overseas manufactories and applied for approval during May 2007 to May 2008, were evaluated using the national reference panels. The hyperbolic curve of the log A value and log concentration for the national sensitivity standards was established.

[Evaluation of multiplex nucleic acid testing assays for screening of hepatitis B virus DNA in blood donation process].

Objective: To evaluate the multiplex nucleic acid testing (NAT) assays for HBV, HCV and HIV in detecting HBV DNA in plasma samples.

Methods: 534 plasma samples collected form several areas were detected with Abbott Architect i2000 HBsAg, ani-HBs, HBeAg, anti-HBe, anti-HBc and anti-HBc IgM diagnostic kits. HBV DNA levels of those samples were detected with Roche COBAS AmpliPrep/COBAS TaqMan HBV Test.

[Sensitivity and specificity of 4 domestic ELISA kits for detection of hepatitis B virus markers].

Objective: To compare and analyze the sensitivity, specificity of 4 domestic ELISA kits for detection of hepatitis B virus (HBV) markers (HBsAg, anti-HBs, HBeAg, anti-HBe, and anti-HBc).

Methods: Five hundred and ninety four serum samples collected from patients with chronic hepatitis B and abnormal blood donors were detected for HBV markers and by 4 domestic ELISA kits. Samples with conflicting results by different diagnostic kits were retested.

[Preparation of the national reference panel for hepatitis B surface antigen].

Objective: To establish the national quantity standard of hepatitis B surface antigen according to the world health organization' s standard material and prepare the national liner reference panel for hepatitis B surface antigen.

Methods: Sera from hepatitis B patients and health blood donors in different areas were collected and detected by domastic HBsAg kits, anti-HBs kits, HBeAg kits, anti-HBe kits, anti-HBc kits and anti-HCV, and then confirmed by the kits produced by Abbott, which was approved by WHO. One serum with high concentration of HBsAg was calibrated with the standard sample of WHO.

[Comparison of the kinesis of immune responses in mice vaccinated by different kinds of recombinant hepatitis B vaccines].

Objective: To evaluate the kinesis of cellular and humoral immune responses to different kinds of recombinant hepatitis B(rHB) vaccines in the immunized mice.

Methods: At serial time points, the levels of IFN-gamma and IL-2 secreted by spleens mononuclear cells (MNC) of the vaccinated mice were detected by enzyme-linked immunospot methods (ELISPOT) after stimulation in vitro with HBsAg MHC class I peptide S28-39 or HBsAg. The lymphocytotoxicity of the immunized mice were also detected (CTL) by a specific lysis assay and the levels of anti-HBs were measured by the Abbott IMX kit.

[Cellular immune responses of recombinant hepatitis B (rHB) vaccine and HBsAG derived from Hansenula polymorpha cells].

Objective: To study the kinetics of immune response in mice and human immunized with rHB vaccine or rHBsAg derived from yeast cells (Hansenula polymorpha).

Methods: With different doses,the level of IFN-gamma secreted by spleen mononuclear cells (MNC) including CD8+ T cells by MACs of mice were detected by enzyme-linked immunospot (ELISPOT) methods after stimulation in vitro with HBsAg MHC class I peptide S28-39, respectively. At serial time points, the immunized mice were detected for IFN-gamma by ELISPOT as above and for the lymphocytotoxicity test (CTL) by specific lysis assay.

[Primary evaluation of anti-HEV diagnostic reagent by experimental infection animal model with hepatitis E virus].

Objective: To evaluate anti-HEV diagnostic kits by experimental infecting rhesus monkeys with HEV.

Methods: Eight rhesus monkeys were infected with genotype 1 and 4 HEV separately. The alanine aminotransferase (ALT) level of all monkeys were detected before and after the process of infection.

[Role of mutations on the "hepatitis B virus 'a' determinant hotpoint" to the efficacy of hepatitis B vaccine].

Objective: To study how hepatitis B virus(HBV) 'a' determinant hotpoint mutations were influecing the hepatitis B vaccine efficacy.

Methods: Primers were designed in HBV conservative region, and the degenerate probes for detecting 16 'a' determinant hotpoint mutations were developed for gene chips. Sensitivity and specificity of the gene chips were evaluated by clone sequencing.

[Study on the kinesis of cellular immunity in adults vaccinated with recombinant hepatitis B vaccine].

Objective: To evaluate the kinesis of cellular immunity in adults who were vaccinated with yeast recombinant hepatitis B(rHB) vaccine and the correlation between cellular and humoral immune responses induced by the vaccine.

Methods: Eight adults were vaccinated with rHB vaccine according to 0, 1,2 month schedule. The peripheral blood mononuclear cells(PBMCs) were collected at the 3, 8, 21, 34 and 65 days after the first dose.

[Studies on the status of immune memory after completion of hepatitis B vaccination].

Objective: To study the immune memory in vaccinees after the completion of a full schedule hepatitis B immunization.

Methods: One thousand and two hundred one infants born in 1987 -1989 were immunized with 3 doses of plasma derived hepatitis B vaccine, while 2484 newborn babies during 1996-1999 were injected with 3 doses of the yeast recombinant hepatitis B vaccine. All of the infants under observation were tested for HBsAg, anti-HBs and anti-HBc, in 2005.

[Establishment and preliminary application of a gene chip for detection of hepatitis B virus "a" determinant hotpoint mutation].

Objective: To develop a gene chip for rapid detection of the "a" determinant hotpoint mutation of hepatitis B virus (HBV).

Methods: Primers were designed in the HBV conservative region, and probes for detecting 126A, 126S, 144A, 145R, 145E, 144A+145R, and 144A+145E mutants were developed for that gene chip. PCR amplification and gene chip technology were optimized.