藥學(xué)專業(yè)畢業(yè)論文外文翻譯--一些席夫堿配合物的合成及抗菌活性研究（英文）

1、J. Serb. Chem. Soc. 71 (7) 733–744 (2006) UDC 547.288+542.913:615.28 JSCS – 3467 Original scientific paperSynthesis and antibacterial activity of some Schiff base complexesR. NAIR1, A. SHAH2, S. BALUJA2 and S. CHANDA1*1D

2、epartment of Biosciences and 2Department of Chemistry, Saurashtra University, Rajkot 360 005, Gujarat, India (e-mail: sumitrachanda@yahoo.com)(Received 6 July, revised 9 November 2005)Abstract: Two Schiff bases were synt

3、hesized from raceacetophenone: 1) ADS1: 4-et- hyl-6-{(E)-1-[(3-nitrophenyl)imino]ethyl}benzene-1,3-diol and 2) ADS3: 4-eth- yl-6-{(E)-1-[(2-nitrophenyl)imino]ethyl}benzene-1,3-diol. Then their metal comple- xes were form

4、ed. The metals selected for the preparation of complexes were copper, nickel, iron and zinc. Hence, in total 8 metal complexes were synthesized and screened for antibacterial activity against some clinically important ba

5、cteria, such as Pseudomo- nas aeruginosa, Proteus vulgaris, Proteus mirabilis, Klebsiella pneumoniae and Staph- ylococcus aureus. The in vitro antibacterial activity was determined by the Agar Ditch technique using DMF (

6、polar) and 1,4-dioxane (non polar) as solvents. The Schiff bases showed greater activity than their metal complexes; the metal complexes showed differ- ential effects on the bacterial strains investigated and the solvent

7、 used, suggesting that the antibacterial activity is dependent on the molecular structure of the compound, the solvent used and the bacterial strain under consideration. The Schiff base ADS3 in the polar solvent DMF show

8、ed better antibacterial activity towards the investigated bacte- rial strains. Amongst the four metals, Zn showed the best antibacterial activity followed by Fe in 1,4-dioxane while Ni followed by Zn and Fe showed the be

9、st antibacterial ac- tivity in DMF. P. vulgaris was the most resistant bacteria.Keywords: Schiff base complexes, antibacterial activity, DMF, 1,4-dioxane.INTRODUCTIONTo overcome the alarming problem of microbial resistan

10、ce to antibiotics, the discovery of novel active compounds against new targets is a matter of urgency. Many of the crude drugs, which are sources of medicinal preparations, still origi- nate from wild-growing material. H

11、owever, plant-based drugs have shortened the life span of the source of material. There is a continuous search for more potent and cheaper raw materials to feed the industry. Compounds, which on dissolution do not give i

12、ons of which they are made but in- stead give complex ions are called co-ordination compounds. Co-ordination compo-733 doi: 10.2298/JSC0607733N* Author for correspondence.nolic –OH group. The metals selected for the prep

13、aration of the complexes were copper, nickel, iron and zinc. The synthesis of metal complexes was studied at different pH values. For different metals, the maximum yield was observed at different pH values. The pH of max

14、imum yield was selected for the synthesis of each complex. For each metal complex, different metal salt solutions were prepared. The solutions used for the synthesis of the copper, nickel, iron and zinc complexes were cu

15、pric chlo- ride, nickel chloride, ferrous ammonium sulphate and zinc chloride, respectively.Synthesis of copper complexes0.1 M solution of ligand and cupric chloride were prepared in 1,4-dioxane and distilled water, resp

16、ectively. Acetic acid and sodium acetate were added to the cupric chloride solution to maintain the pH (6.5–7.0). The ligand solution was added dropwise to the metal ion solution. A dark brown precipitate was obtained. T

17、he pH of solution was maintained by the buffer solution and the solution was refluxed for 4–5 h in a water bath. The precipitate was filtered and washed, first with 1,4-diox- ane and then with hot water to remove excess

18、ligand and metal ions, respectively. The precipitate was then dried.Synthesis of nickel complexes0.1 M solution of ligand and nickel chloride are prepared in 1,4-dioxane and distilled water, re- spectively. The ligand so

19、lution was added dropwise to the metal ion solution. The pH was main- tained between 10–10.5 by adding ammonium hydroxide. A yellowish orange precipitate was ob- tained on refluxing the solution on a water bath for 4–5 h

20、. The precipitate was filtered and washed with hot water and 1,4-dioxane to remove excess ligand and metal ions, respectively. The precipitate was then dried.Synthesis of iron complexes0.1 M ligand solution in 1,4-dioxan

21、e was added dropwise to a 0.1 M ferrous ammonium sul- phate solution in the presence of a buffer solution (ammonium hydroxide + acetic acid) to maintain the pH between 7–7.5. The solution was refluxed for 5–6 h. The form

22、ed yellowish brown precipitate was filtered, washed with hot water and 1,4-dioxane to remove excess ligand and metal ions, respec- tively. The precipitate was then dried.Synthesis of zinc complexes0.1 M ligand solution i

23、n 1,4-dioxane was added dropwise to a 0.1 M zinc chloride solution in presence of buffer solution and ammonium hydroxide to maintain the pH between 10–11. The solu- tion was refluxed for 4–5 h in a water bath. The formed

24、 brown precipitate was filtered, washed with hot water and 1,4-dioxane to remove excess ligand and metal ions, respectively. The precipitate was then dried.Antibacterial activityAntibacterial activity was determined by t

25、he Agar-ditch method.15 The investigated microor- ganisms were Pseudomonas aeruginosa, Proteus vulgaris, Proteus mirabilis, Klebsiella pneumo- niae and Staphylococcus aureus. The compounds were dissolved in one of the tw

26、o solvents (1,4-di- oxane or DMF) to obtain a final concentration 1 mg/0.1 ml. Aloop full of the given test strain was in- oculated in 25 ml of N-broth (nutrient broth) and incubated for 24 h in an incubator at 37 º

27、C in order to activate the bacterial strain. 28–30 ml of the nutrient agar media was added into a 100 mm diame- ter Petri-plate. Inoculation was done by the Pour-plate technique. 0.2 ml of the activated strain was inocul

28、ated into the media when it reached a temperature of 40–45 ºC. The complete procedure of the plate preparation was done in a laminar airflow to maintain strict sterile and aseptic condition. The medium was allowed t

29、o solidify. After solidification of the media, a well was made in the plates with the help of a cup-borer (0.85 cm), which was then filled with one of the test sample solutions. Con- trols were run (for each bacterial st