1. 1 Free radicals & antioxidant- OPCs 詹國鑫 96258007 97.11.17自然醫學專題研討

2. 2 A Periodic Table of the Elements http://en.wikipedia.org/wiki/Valence_(chemistry)

3. 3 Valence Electrons http://en.wikipedia.org/wiki/Valence_electrons

4. 4 In chemistry, free radicals are atoms, molecules or ions with unpaired electrons on a valence shell configuration. Valence Shell

5. 5 Valence Shell Electron Pair Repulsion The pairs of electrons may be bonding or nonbonding (also called lone pairs). Only valence electrons of the central atom influence the molecular shape in a meaningful way. VSEPR theory

6. 6 Octet Rule In simple terms, Molecules or ions tend to be more stable when the outermost electron shell of their constituent atoms contain eight electrons.

7. 7 These unpaired electrons are usually highly reactive, so radicals are likely to take part in chemical reactions. Free radicals

8. 8 The triphenylmethyl radical is a persistent radical and the first ever radical described in organic chemistry. --- by Moses Gomberg in 1900 at the University of Michigan http://en.wikipedia.org/wiki/Free_radicals

9. 9 http://en.wikipedia.org/wiki/Triphenylmethyl_radical Free radicals

10. 10 In chemistry, chain reactions involving free radicals can usually be divided into three distinct processes: initiation propagation termination Free radicals in chemical reactions

11. 11 Free radicals in chemical reactions.…..initiation..propagation...termination

12. 12 Free radicals in chemical reactions Long lived radicals can be placed into two categories ： Stability and Persistence

13. 13 Free radicals in chemical reactions Stable Radicals The prime example of a stable radical is molecular dioxygen O 2 ( O ＝ O ) The oxygen molecule is a stable diradical, best represented by O － O

14. 14 Free radicals in chemical reactions Spins The ground state of oxygen is an unreactive spin-unpaired (triplet) diradical, but an extremely reactive spin-paired (singlet) state is available.

15. 15 Free radicals in chemical reactions http://en.wikipedia.org/wiki/Singlet_oxygen tripletsinglet

16. 16 Free radicals in chemical reactions Stable Radicals Organic radicals can be long lived if they occur in a conjugated π system (π resonance stabilization ), such as the radical derived from α-tocopherol (vitamin E). 參 p.28

17. 17 Free radicals in chemical reactions http://en.wikipedia.org/wiki/Free_radicals

18. 18 Free radicals in chemical reactions β- carotene Conjugated πsystem

19. 19 Free radicals in chemical reactions Persistent Radicals Persistent radical compounds are those whose longevity is due to steric effect around the radical center and makes it physically difficult for the radical to react with another molecule.

20. 20 Free radicals in chemical reactions Persistent Radicals http://en.wikipedia.org/wiki/Triphenylmethyl_radical steric effect

21. 21 http://en.wikipedia.org/wiki/Triphenylmethyl_radical Free radicals in chemical reactions Persistent Radicals

22. 22 Radicals may also be formed by single electron oxidation or reduction of an atom or molecule. Redox reactions

23. 23 Redox reactions Redox (reduction-oxidation reaction) describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed.

24. 24 Redox reactions Reduction describes the gain of electrons by a molecule, atom or ion. Reduction is defined as a decrease in oxidation number.

25. 25 Redox reactions Oxidation describes the loss of electrons by a molecule, atom or ion. Oxidation is defined as an increase in oxidation number.

26. 26 Redox reactions In practice, the transfer of electrons will always cause a change in oxidation number.

27. 27 Redox reactions ascorbic acid dehydroascorbic acid (reduced form) (oxidized form) Vitamin C http://en.wikipedia.org/wiki/Ascorbic_acid

28. 28 Redox reactions Resonance effect 參 p.16

29. 29 Redox reactions in biology Vitamin C accumulates in mitochondria, where most of the free radicals are produced. Ascorbic acid protects the mitochondrial genome and membrane.

30. 30 Aromatic compounds are reduced to form free radicals that contain one more electron than their parent compounds. These anion free radicals reduce molecular oxygen to superoxide and regenerate the unchanged parent compound. Redox reactions in biology

31. 31 The net reaction is ： the oxidation of the aromatic compounds and the reduction of oxygen to form superoxide Redox reactions in biology

32. 32 Free radicals in biology The two most important oxygen-centered free radicals are superoxide and hydroxyl radical.

33. 33 Superoxide is biologically quite toxic and is deployed by the immune system to kill invading microorganisms, such as the intracellular killing of bacteria by neutrophile granulocytes. Free radicals in biology

34. 34 Free radicals in biology http://en.wikipedia.org/wiki/Neutrophile_granulocyte

35. 35 Free radicals in biology Superoxide radical Superoxide is also produced as a byproduct of mitochondrial respiration as well as several other enzymes.

36. 36 Free radicals in biology http://en.wikipedia.org/wiki/Electron_transfer_chain

37. 37 Free radicals in biology Superoxide radical Superoxide is the anion O 2 −. It is important as the product of the one-electron reduction of dioxygen. ex: O 2 ＋ e － → O 2 －

38. 38 Free radicals in biology Superoxide radical With one unpaired electron, the superoxide ion is a free radical. O 2 ＋ e － → O 2 － ex: O － O O － O

39. 39 Free radicals in biology Superoxide radical 2 O 2 − + 2 H + → O 2 + H 2 O 2 (disprotionation)

40. 40 Hydroxyl radical The hydroxyl radical, OH, is the neutral form of the hydroxide ion. Hydroxyl radicals are highly reactive and consequently short-lived. Free radicals in biology

41. 41 Hydroxyl radical Most hydroxyl radicals are produced from the decomposition of hydroperoxides. ex: R － O － O － R´…peroxides R － O － O － H …hydroperoxides Free radicals in biology

42. 42 Free radicals in biology Hydroxyl radical 2 H 2 O 2 → 2 H 2 O + O 2 (spontaneously) H 2 O 2 ＋ UV → 2 OH H 2 O 2 ＋ biocatalyst → 2 OH

43. 43 Free radicals in biology Hydroxyl radical H 2 O 2 → 2 OH H － O － O － H → 2 OH

44. 44 Free radicals in biology Hydroxyl radical It can damage virtually all types of macromolecules: carbohydrates, nucleic acids, lipids and amino acids.

45. 45 Free radicals in biology Oxidative stress is caused by an imbalance between the production of reactive oxygen and a biological system's ability to readily detoxify the reactive intermediates or easily repair the resulting damage.

46. 46 Free radicals in biology All forms of life maintain a reducing environment within their cells. This reducing environment is preserved by enzymes that maintain the reduced state through a constant input of metabolic energy.

47. 47 Free radicals in biology Disturbances in this normal redox state can cause toxic effects through the production of peroxides and free radicals that damage all components of the cell, including proteins, lipids, and DNA.

48. 48 Many forms of cancer are thought to be the result of reactions between free radicals and DNA. The only means to protect important cellular structures is the use of antioxidants. Free radicals in biology

49. 49 Antioxidants in biology Superoxide Dismutase (SOD) M (n+1)+ -SOD + O 2 − → M n+ -SOD + O 2 M n+ -SOD + O 2 − + 2H + → M (n+1)+ -SOD +H 2 O 2 Total: 2 O 2 − + 2 H + → O 2 + H 2 O 2 where M = Cu ; Mn ; Fe ; Ni

50. 50 Antioxidants in biology Catalase H 2 O 2 + Fe(III)-E → H 2 O + O=Fe(IV)-E(+) H 2 O 2 + O=Fe(IV)-E(+) → H 2 O + Fe(III)-E + O 2 Total: 2 H 2 O 2 → 2 H 2 O + O 2 Where E = enzyme (porphyrin) in heme.

51. 51 Antioxidants in biology http://en.wikipedia.org/wiki/Antioxidant Glutathione

52. 52 Antioxidants in biology Glutathione disulfide http://en.wikipedia.org/wiki/Glutathione_disulfide

53. 53 Oligomeric Proanthocyanidins Proanthocyanidin is also known as : procyanidin oligomeric proanthocyanidin, pycnogenol, leukocyanidin, leucoanthocyanin, is a class of flavanols.

54. 54 Oligomeric Proanthocyanidins One was discovered in 1936 by Professor and called Vitamin P, although this name did not gain official category status and has since fallen out of usage.

55. 55 Oligomeric Proanthocyanidins Proanthocyanidins are essentially polymer chains of flavonoids such as catechins.

56. 56 Flavonoids C 6 -C 3 -C 6

57. 57 http://en.wikipedia.org/wiki/Flavonoid Flavonoids

58. 58 Flavonoids

59. 59 Catechins Epicatechin, EC

60. 60 Catechins Epigallocatechin, EGC

61. 61 Catechins Epigallocatechin gallate, EGCG

62. 62 Procyanidins

63. 63 Oligomeric Proanthocyanidins

64. 64 運動訓練對人體體內自由基產生 及抗氧化酵素之影響 SED: 對照組, 原無運動習慣組 STT: 短期運動訓練組 LTT: 長期規律運動習慣組

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69. 69 Conclusion 研究結果發現對照組在運動後體內之超氧自由 基顯著比短期或長期運動訓練者高。 受試者接受短期運動訓練其體內會提高超氧化 歧化酶 (superoxide dismutase ； SOD) 、穀胱甘肽 過氧化酶 (glutathione peroxidase ； GPx) 、過氧 化氫酶 (catalase) 活性來清除體內瞬間大量產生 之自由基。 持續訓練一段時間後，體能狀況改善會提升體 內之產能效率，進而減少自由基的產生，以致 於抗氧化酵素系統活性調降。

70. 70 Conclusion 研究發現，短期運動訓練可提升抗氧化系統功 能，但長期訓練則是使體內產能效率提升，並 減少自由基之產生機率。 長期運動訓練組血漿中超氧自由基在運動前後 並無顯著差異，抗氧化酵素活性亦不會因運動 而改變其活性。 同時我們亦發現長期運動組超氧自由基之含量 顯著地比對照組及短期運動訓練者低。

71. 71 Conclusion 推測人體施以運動訓練後，訓練初期可能會先 提高 SOD 、 catalase 和 GPx 活性以清除體內瞬間 大量產生之自由基。 但若持續運動訓練一段時間後，體能狀況能改 善，進而提升體內之產能效率，減少自由基的 產生，以致於抗氧化酵素活性降低。 由此可知，運動習慣應是持續性和適度的運動， 運動不當或過度對人體是毫無助益或適得其反。

72. 72 Thanks for your attention