Copper-Catalyzed Regioselective Coupling of Tosylhydrazones and 2-Pyridones: A Strategy for the Production of N-Alkylated Compounds.

The highly regioselective N-alkylation reaction of 2-pyridones was achieved through hydrazone chemistry, especially for substrates with bulky secondary alkyl groups. Described herein is a copper-catalyzed coupling reaction of pyridone derivatives with tosylhydrazones.

Development of a sensitive prognostic scoring system for the evaluation of severity of acute-on-chronic hepatitis B liver failure: a retrospective cohort study.

PURPOSE: The purpose of the current study was to establish an objective, simple, and sensitive prognostic scoring system for estimating the severity of acute-on-chronic liver failure in hepatitis B (ACLFB). METHODS: A novel prognostic scoring system was calculated from six clinical indices including total bilirubin (TB), prothrombin activity (PTA), creatinine (Cr), hepatic encephalopathy (HE), infections, and the depth of ascites from 726 patients with ACLFB. Indices were scored from 1 to 4 according to their severity. Groups of the same patients were scored with three-indices (TB, PTA and Cr), four-indices (TB, PTA, Cr and HE), five-indices (TB, PTA, Cr, HE and the depth of ascites) or six-indices (TB, PTA, Cr, HE, the depth of ascites, and infections). The differences in the sensitivity and specificity of four scoring systems were analyzed. RESULTS: The demarcation points of the three-, four-, five- and six-indices scoring systems were 4.62, 6.12, 7.88 and 9.57, respectively. The analysis of the areas under the receiver operating characteristic (ROC) curve indicated that the four-, five- and six-indices scoring systems were more exact, and objective than the three-indices prognostic scoring system. In the six-indices scoring system, the survival rates of patients with scores from 2 to 6 was 98.31% (233/237), and the mortality rate of patients with scores of 16 and above was 100.00% (140/140), while the mortality rates were 8.33% (3/36) and 96.43% (27/28) for those with scores from 7 to 15, respectively. CONCLUSION: A six-indices scoring system is an objective, pertinent, and sensitive system, and may be useful for the prognostic evaluation of ACLFB.

[Protective effects of Genistein on human renal tubular epithelial cells damage of microwave radiation].

OBJECTIVE: To observe the effects of microwave irradiation on human proximal renal tubular epithelial cells (HKC) and protec-tive effects of genistein. METHODS: HKC cells were divided into control group, microwave irradiation group and genistein group(n=6) re-spectively. The genistein group cells were pre-incubated with 30µmol/L genistein in DMEM for 2 hours. After irradiation for 24 hours, the concentrations of lactate dehydrogenase(LDH) and ß-N-acetyl glucosaminidase(NAG) in culture solution were measured to evaluate cell injury. Cells were curetted to measure the levels of malondialdehyde (MDA) and superoxide dismutase (SOD). Cell apoptosis and necrosis were de-tected with Hoechst 33258 stain. RESULTS: Compared with the control group, the NAG activity of the microwave irradiation group was signifi-cantly increased(P < 0.01), and NAG activity of genistein pre-incubated group was significantly decreased(P < 0.01). The levels of LDH in microwave irradiation group were also increased significantly (P < 0.01 vs control group). LDH levels could be decreased obviously (P < 0.01 vs microwave irradiation group) after genistein pre-incubate. Hoechst 33258 fluorescent staining revealed that the nucleus crimpled, cres-cent liked and chromatin condensed, even nucleus disintegrated. Our research showed that microwave irradiation could lead to large amount of cell apoptosis and necrosis, and genistein pre-treatment could reduce the ratio of apoptosis and necrosis than that in microwave irradiation group (P < 0.01). The concentration of MDA in microwave irradiation group was higher than that in control group (P < 0.01). At the same time, the activity of SOD was significantly reduced (P < 0.01). Pre-incubated with genistein could not decrease the MDA levels, but could increase the activities of SOD (P < 0.01 vs microwave irradiation group). CONCLUSIONS: microwave irradiation can induce human proximal renal tubular epithelial cells injury. The protective effects of genistein may partly correlated with decreasing oxidative stress damage and cell apoptosis in HKC cells.

Visible-light-initiated difluoromethylation of arene diazonium tetrafluoroborates.

A mild and efficient method for the radical addition of α-aryl-ß,ß-difluoroenol silyl with arene diazonium tetrafluoroborates at room temperature has been disclosed, which involves an innate radical long chain cycle, so only a small amount (0.05 mol%) of photocatalyst and a short light exposure time are required as radical initiators. A proposed mechanism for the transformation is also illustrated based on the results of control experiments and quantum calculations. A variety of α-aryl-α,α-difluoroketones were formed in moderate to high yields, and can be easily further transformed into various difluoromethylarenes under basic conditions.

Oxidative trifluoromethylation and fluoroolefination of unactivated olefins.

Fluorine-containing organic compounds are gaining increasing importance in medicinal chemistry. Described herein is a mild and efficient method for the radical addition of olefins with TMSCF3 and TMSCF2R (R = COOEt or CF3) to deliver various α-trifluoromethylated ketones and α-fluoroolefinated ketones.