1. Synthesis of 9-fluorenylmethoxycarbonyl amino acid tert-butyl ester
Academic Journal of Second Military Medical University 2010;28(1):101-102
Objective: To search for a new method for synthesis of 9 fluorenylmethoxycarbonyl amino acid tert-butyl ester. Methods: Glycine, L-Proline, and L-Phenylanaline were separately allowed to react with 9-fluorenylnmthylchloroformate to obtain the corresponding 9-fluorenylmethoxycarbonyl amino acids. With 4-(dimethylamine) pyridine (DMAP) used as catalyst, the 9-fluorenylmethoxycarbonyl amino acids were allowed to react with Tert butyl dicarbonate for the corresponding 9-fluorenylmethoxycarbonyl amino acid tert-butyl esters. Results: Three 9-fluorenylmethoxycarbonyI amino acid tert-butyl esters were successfully synthesized by this method and their structures were confirmed by 1 H NMR. Conclusion: Ours is a simple method with mild condition and high yielding rate for synthesis of 9-fluorenylmethoxycarbonyl amino acid tert-butyl esters.
6.Research Advance on Marinomonas
Li WEI ; Jun-Chu ZHOU ; You-Guo LI ;
Microbiology 1992;0(01):-
In this mini review,some research advance on Marinomonas from domestic and overseas was briefly summarized,mainly including of its classification、ecological distribution、functional genes and bioactive molecules.Furthermore,some suggestion and perspectives for further studies on Marinomonas were also proposed.
7.Effects of estrogen and androgen on lens oxidative damage after ovariectomy in rat
Ying-xia, YIN ; Xiu-jun, SONG ; Jin-ling, LIU ; Zhong-you, ZHOU
Chinese Journal of Experimental Ophthalmology 2011;29(2):151-154
Background Epidemiological investigation in human has been conclusive. In postmenopausal women,the incidence of cataract is higher than men at the same age. In addition,hormone replacement therapy may protect against the development of cataract. However,this role of androgen is not clear. Objective This study was to explore the effects of estrogen and androgen on anti-oxidative ability of lens after ovariectomy. Methods Fifty-six three-month-old clean female Wistar rats were randomly divided into normal control group,sham operation group, castration group,estrogen eyedrops group;estrogen injection group;androgen eyedrops group;androgen injection group and 8 rats for each. Ovariectomy was performed in the rats of castration group and gonadal hormone application group, and estradiol benzoate solution or testosterone propionate solution were utilized topically or systemly in 5 months after ovariectomy for 6 weeks respectively. Only abdominal cut was curried out in sham operation group. The lenses of rats were examined weekly under the slit lamp. The serum estrogen and androgen levels of rats were detected before,after operation and 6 weeks following the administration of gonadal hormone. The contents of superoxide dismutase( SOD) , glutathione( GSH) ,malondialdehyde( MDA) and water-soluble protein ( WSP) in rat lens homogenate were detected at the end of the experiment. Utilization of animals complied with the Regulation for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission. Results No opacity of lenses was found during the experiment duration in various groups. The serum estradiol levels of rats in sham group were insignificantly different from normal groups in various time points( P>0. 05). The evident decline of serum estradiol was detected in the rats of castration group and gonadal hormone application groups compared with sham group in 5 months after operation( all P<0. 01). However,at the sixth weeks after the system use of estradiol or testosterone,the serum estradiol levels were significantly higher than the castration group and topical application groups of gonadal hormone(P<0. 01). The contents of SOD,GSH and WSP in lenses were considerably increased,but the MDA level in lenses was decreased after system use of estrogen ( P<0. 01). The activity of SOD and GSH were lower after system use of testosterone in comparison with castration rats ( P < 0. 05 ). Conclusion Estrogen can protect lens against oxidation damage. However, androgen, to a certain extent, may contribute to the development of oxidative damage in OVX female rats.
9.Genotypes of Plasmid-mediated AmpC Beta-lactamases in Klebsiella pneumoniae
Jing-Hong PENG ; Zi-Yong SUN ; You-Li ZHOU ; Jun LV ;
Chinese Journal of Nosocomiology 2006;0(09):-
OBJECTIVE To investigate the genotypes of plasmid-mediated AmpC beta-lactamases carried in Klebsiella pneumoniae,to provide reasonable use of antibacterial agents and to reduce the spread of these drug resistant genes.METHODS Two hundred and eighteen strains of K.pneumoniae were performed in Tongji Hospital in Wuhan.Plasmid-mediated AmpC beta-lactamases-producing strains were screened by improved three-dimensional method and identified by multiplex PCR.DNA sequencing method was used to confirm these drug resistant strains.The MIC of 15 kinds of antibacterial agents against the clinical isolates was detected by double agar dilution method.RESULTS Thirteen strains of K.pneumoniae were detected by improved three-dimensional method.The detection rates were 5.96%.There were seven of thirteen positive strains of K.pneumoniae through improved three-dimensional method harboring DHA-1 type plasmid-mediated AmpC beta-lactamase by multiplex PCR and confirmed by DNA sequencing.Plasmid-mediated AmpC beta-lactamase producers revealed a highly drug resistance to cephalosporins,monobactams,beta-lactam/beta-lactamase inhibitor combinations,aminoglycosides and fluoroquinolones.Only imipenem was susceptible to all of these detected strains.CONCLUSIONS DHA-1 plasmid-mediated AmpC beta-lactamase is detected in K.pneumoniae strains from Tongji Hospital.The detection rate is 3.2%.The pAmpC-producing strains reveal multi-drug resistance.Only imipenem is susceptible to them.
10.Identification of a Marine Bacterium Strain and Characterization of a Novel Functional Gene Cluster Involved in Melanin Biosynthesis
Li WEI ; Jia-Wei FANG ; Jun-Chu ZHOU ; You-Guo LI ;
Microbiology 1992;0(06):-
A marine bacterium MWYL1,originally isolated from the roots of Spartina anglica growing in a salt marsh near seaside,was identified as a member of the genus of Marinomonas via morphology characterization、physiological test and 16S rDNA sequencing and Blast analysis.The strain was short,rod,gram-negative,grew aerobically and optimally at 28℃.The analysis of 16S rDNA sequence suggests that the sequence similarity values are 97% and 95% with Marinomonas pontica and Marinomonas dokdonensis,respectively.One fosmid clone producing melanin was directly isolated by plating from the genomic library of Marinomonas MWYL1.The novel functional gene cluster involved in melanin biosynthesis was screened after subcloning and sequencing of the 14kb insert in pUC18,further more,the putative functional genes was preminary analyzed using bioinformatics.