Selective hydrogenation of nitroaromatics to N-arylhydroxylamines in a micropacked bed reactor with passivated catalyst.

In this contribution, a protocol was established for the selective catalytic hydrogenation of nitroarenes to the corresponding N-arylhydroxylamines. The reduction of 1-(4-chlorophenyl)-3-((2-nitrobenzyl)oxy)-1H-pyrazole, an intermediate in the synthesis of the antifungal reagent pyraclostrobin that includes carbon-chlorine bonds, benzyl groups, carbon-carbon double bonds and other structures that are easily reduced, was chosen as the model reaction for catalyst evaluation and condition optimization. Extensive passivant evaluation showed that RANEY®-nickel treated with ammonia/DMSO (1 : 10, v/v) afforded the optimal result, especially with a particle size of 400-500 mesh. To combine the modified catalyst with continuous-flow reaction technology, the reaction was conducted at room temperature, rendering the desired product with a conversion rate of 99.4% and a selectivity of 99.8%. The regeneration of catalytic activity was also studied, and an in-column strategy was developed by pumping the passivate liquid overnight. Finally, the generality of the method was explored, and 7 substrates were developed, most of which showed a good conversion rate and selectivity, indicating that the method has a certain degree of generality.

[Cloning, prokaryotic expression and polyclonal antibody preparation of HCCR: a new biomarker for hepatocellular carcinoma].

OBJECTIVES: To construct a prokaryotic plasmid expressing truncated human cervical cancer oncogene (HCCR-1(167-360)), to express and purify the recombinant protein, and to develop the polyclonal antibody against HCCR. METHODS: HCCR-1(167-360) was amplified by RT-PCR from HepG2 cells and cloned into vector pRSET-B, then expressed in E.coli BL21(DE3) pLysS, which was induced by IPTG. The recombinant protein was purified using Ni-NTA spin column and acrylamide gel electrophoresis. A polyclonal antibody was developed by immunizing BALB/c mice with the purified recombinant protein, and their sensitivity and specificity were tested using enzyme-linked immunosorbent assay, immunohistochemical staining and Western blot analysis. RESULTS: Recombinant plasmid expressing truncated HCCR-1167-360 was constructed. A protein of 2.70 x 10(4) was successfully expressed and purified. High titer polyclonal antibody with a high specificity was obtained by immunizing BALB/c mice with the purified recombinant protein. CONCLUSIONS: The truncated recombinant HCCR-1(167-360) developed in this study is highly purified and shows strong antigenecity; the polyclonal antibody against this HCCR protein was generated by regular immunization method, showing both high sensitivity and specificity. The protein and the antibody can be used for further clinical examination and research of HCCR.

Analysis of in vivo patterns of caspase 3 gene expression in primary hepatocellular carcinoma and its relationship to p21(WAF1) expression and hepatic apoptosis.

AIM:To detect the expression of caspase 3 gene in primary human hepatocellular carcinoma (HCC) and investigate its relationship top21(WAF1) gene expression and HCC apoptosis.METHODS:In situ hybridization was employed to determine caspase 3 and p21(WAF1) expression in HCC.In situ end-labeling was used to detect hepatocytic apoptosis in HCC.RESULTS:Twenty-one of 39 (53.8%) cases of HCC were found to express caspase 3 transcripts, while 46.2% of HCC failed to express caspase 3.Non-cancerous adjacent liver tissues showed more positive caspase 3(87.5%, 7/8) as compared with HCC (p < 0.05). The expression of caspase 3 is correlated with HCC differentiation, 72.2% (13/18) of moderately to highly differentiated HCC showed caspase 3 transcripts positive, while only 38.1% of poorly differentiated HCC harbored caspase 3 transcripts (italic>p < 0.05). No relationship was found between caspase 3 expression and tumor size or grade or metastasis, although 62.5% (5/8) of HCC with metastasis were caspase 3 positive and a little higher than that with no metastasis (51.6%, p> 0.05). Expression of caspase 3 alone did not affect the apoptosis index (AI) of HCC. The AI was 7.12 in caspase 3 positive tumors (n = 21), while in caspase 3-negative cases (n = 18) 6.59 (italic>p > 0.05). Expression of caspase 3 clearly segregated with p21(WAF1) positive tumors as compared with p21(WAF1) negative cases (16 of 23, 69.6% versus 5 of 16, 31.3%) with statistical significance (p = 0.017).In the cases with positive caspase 3 and negative p21(WAF1), the AI was found slightly higher, but with no statistical significance, than that with expres-sion of p21(WAF1) and caspase 3 (7.21 vs 6.98 , p>0.05).CONCLUSION:Loss of caspase 3 expression may contribute to HCC carcinogenesis, although the expression of caspase 3 does not correlate well with cell apoptosis in HCC.p21(WAF1) may be merely one of the inhibitors which can reduce caspase 3 mediated cell apoptosis in HCCs.