茶多酚及其氧化产物清除不同体系产生的活性氧自由基的分光光度法研究.doc

17 42 0 0 0 4 FINE CHEMICALSVol. 17, No. 4Apr. 2 0 0 0., ( , . 430070): O2.- .OH: O2.- , ( 8.3 167 ug.mL) 96.6% 92.1%2.D.OH, ( 5 800 ug.mL) 83.4%88. 5%, SOD , O2.- , 66.5%, 47.6%, 45.3%SOD , : ; ; ; : Q503 . . : A. . : 1003- 5214( 2000) 04- 0241- 04. . , , 1 : O2.- .OHH2O2 , , , , , , , ChengHsing YEN Gow.chin, CHEN Hui.yin 2 , 3 , .2B(TFM.2B) (TFD) ( EGCG) 4 , 5 , O2.- .OH SOD , 1. . 1. 1 . , ; : w( EGCG) > 85% , , 45 5 h , SOD : , 1. 2 . 1. 2. 1 . O2.-Beaucharp 6 pH 7.8 0.05mol.L , 3.3 ! 10- 6mol.L , 0.01 mol.L , 4. 6 ! 10- 5 mol.L(NBT) , 25 , 4000 lx 30 min, . : 1999- 09- 19560 nm1. 2. 2 . 2.D.( DR) .OH 7 0.4 mL 50 mmol.L pH 7.5 KH2PO4 -KOH , , 0.1 mL 1.04 mmol.LEDTA , 0.1 mL 10 mmol.L H2O2 , 0.1 mL60 mmol.L DR ( ) , 0.1 mL 2mmol.L Vc,1 mL, 37 1 h 1 mL w ( HCl) = 25% , 1 mL w (TBA) = 1% 15 min, , 532 nm ( 3 mL ) 1. 2. 3 . O2.- 8 20 mL 9 mL pH8.2 Tris- HCl , 25 20 min, 40 .L 25 ( 45 mmol.L10 mmol.LHC1 ) , 1 cm , 9mL Tris- HCl , 25 30 s A 420 , 0.06.min3 min , ( DTT) Vc, , 5 min A 420 , A02. . 3. 1 . O2.- O2.- , O2.- NBT, 560 nm A, O2.- , O2.- , A1 , A -A1 , O2.- ( S ) =A - A1A! 100%. . , , O2.- , 8.3 67 .g.mL , , , O2.- 96.6%92.1% , 11. O2.-. . . .( .g.mL) .% .%. . . . 8. 3 56. 93 52. 7516. 6 68. 44 57. 1424. 9 74. 84 64. 8333. 3 81. 24 75. 9167. 0 92. 11 91. 97100. 0 91. 55 96. 90133. 0 83. 80 93. 35167. 0 83. 52 89. 884. 2 . DR .OH 5. .D.OH :Fe3+ - EDTA+ Fe2+ - EDTA+ ( 1)Fe2+ - EDTA+ H2O2 OH- + .OH+ Fe3+ - EDTA ( 2).OH+ ( DR) fragments.TBA+ MDA ( 3)2TBA+ MDA chromogen ( 4)A 0 , .OH,(MDA) , A1 , A2 , :S =A 0 - ( A1 - A 2 )A0! 100%. . 22. 2.D.OH. . .( .g.mL) .% .%. . . . . 5 38. 5 27. 610 49. 1 50. 920 66. 7 58. 950 71. 7 83. 1100 74. 9 83. 4200 88. 5 76. 8500 77. 9 62. 4600 63. 6 53. 1800 68. 5 43. 92 , 5 800 .g.mL .OH, , , , , , 83.4%, 88.5% . 242 . . FINE CHEMICAL. S. . . . . . . . . . . . . 17.6. 3 . SOD, 3 min, A0 , , O2.- , , Tris- HCl ( SOD, ) , A s , As# , :( S) =A0 - ( A s - As#)A 0! 100%. . , SOD 47. 6% , 3 3. .( .g.mL)S.%V.VSOD= 1.1 V.VSOD= 1.1. . 10 51. 6 52. 150 44. 9 48. 8 66. 5 66. 5100 40. 6 49. 6 57. 9 77. 4200 56. 7 63. 3500 45. 3 48. 0 56. 3 64. 91000 45. 1 47. 6 58. 3 58. 73 , , ,SOD ; SOD , 7. 4 . , , , , , , , , , , , , , , , O2.- , ,SODO2.- , ,8. . , O2.- , , , O2.- H2O2 .OH,.OH, , , , , DNA 9 , O2.- .OH O2.- 96.9%92.1% , DR .OH, 83.4% 88.5%, , SOD , , , : 1 . , . J . , 1993, 19(1) : 25. 2 . YEN Gow.chin, CHEN Hui.yin.Antioxidant activity of various teaextract s in relation to their antimut agenicity J . J Agric Food Chem,1997, 45: 30- 34. 3 . , . , . J . , 1994, 6( 4) : 20- 23. 4 . . . J . , 1998,29(9) : 636- 638. 5 . , . , . J . , 1997, 18( 1) : 10- 11. 6 . Beauchamp C, Fridovich irwin. Superoxide dismutase: improvedassays and an assay applicable to acrylamide gels J . Anal Biochem,1971, 44: 276- 287. 7 . Barry Halliwell, Gut teridge John M C , Aruoma O I. The deoxyribose4 , :. 243 .method: a simple % Test.Tube& assay for determination of rate constantsfor reactions of hydroxyl radicals J . Analytical Biochemistry, 1987,( 165) : 215- 219. 8 . , . J . , 1995, 22(1) : 84- 86. 9 . Davis conf erences. Oxygen radicals and human disease C . Ann IntMed. 1987. 107- 526.: ( 1973- ) , , , Investigation with Spectrophotomeric Method on the Radical ScavengingEffect of Tea Polyphenol and its OxidantLI Chun.mei, XIE Bi.jun( Dep artment of Food Science and Technology , Huazhong Agriculture University , Wuhan 430070, China)Abstract:The radical scavenging effects of tea polyphenol ( TP) and its oxidant were investigated with spectrophotomericmethod in different systems.The result showed that, both tea polyphenol and its oxidant had strong scavenging effects to bothhydroxyl radical and superoxide radical generated by different systems. In the deoxyribose system, in the test concentrationrange from 8.3 .g.mL to 167 .g.mL, the maximum scavenging rate of TP and its oxidant to superoxide radical were 96.6%and 92.1% respectively. In the flavins system the maximum scavenging rate of TP and its oxidant to hydroxyl radical were83.4% and 88.5% respect ively in the test concentration range from 5 .g.mL to 800 .g.mL. In the pyrogallol autoxidationsystem, the maximum inhibition rate of TP oxidant, crude SOD and TP were 66.5%, 47.6% and 45.3% respectively, andboth TP and its oxidant have building action to crude SOD, but the effect of TP oxidant was stronger than TP.Key words: tea polyphenol; oxidant; radical system; spectrophotomeric method( 227 )Study of Hydrogenation of Ethyl Benzoate Catalyzed by Silica.supportedCarboxymethyl Cellulose.platinum ComplexJIN Feng.you( Department of Chemistry , Suihua Normal , Suihua 152061, China)Abstract: A natural polymer catalyst , silica.supported carboxymethyl cellulose.platinum complex ( abbreviated as Si.CMC.Pt) has been synthesized and found to catalyze the hydrogenation of ethyl benzoate to ethyl cyclohexaneccorboxylatein about 100% yield at 60- 70 and 0. 1 MPa hydrogen pressure. The catalyst is stable and could be reused forse